Welcome to the ASP website archive  

This page is an archive of articles from the Atmospheric Science Program website. Dates in square brackets denote the date that the item originally appeared on the ASP website.

The Department of Energy's Atmospheric Science Program has as its long-term goal developing comprehensive understanding of the atmospheric processes that control the transport, transformation, and fate of energy related trace chemicals and particulate matter. The current focus of the program is aerosol radiative forcing of climate: aerosol formation and evolution and aerosol properties that affect direct and indirect influences on climate and climate change. [2004-11-12]

ASP-VOCALS PLANNING AND PREPARATIONS [2008-08-06]

Planning and preparations are well underway for the forthcoming ASP field project, ASP-VOCALS, the ASP component of the international interagency VOCALS project. [VOCALS is the acronym for VAMOS Ocean-Atmosphere-Land Study, where VAMOS is the acronym for the parent program Variability of the American Monsoon Systems]. ASP research will focus on aerosol chemical and microphysical properties with special reference to their ability to serve as cloud condensation nuclei (CCN). The project will be conducted under the auspices of NSF off the coast of Chile in October 2008. Equipment has been installed on the G-1 and test flights conducted. Planned measurements and flight plans for specific objectives of this field project are outlined here.

The study will examine how aerosol chemical and microphysical properties, and the ability of aerosol particles to act as CCN, differ between remote marine air-masses and marine air-masses that have been influenced to varying degrees by anthropogenic aerosols, and on how these differences in aerosol properties influence the microphysical properties of the clouds that form in these different environments. The study area is impacted to varying degree by aerosols from smelting operations.

The project will be conducted with the DOE G-1 research aircraft off the west coast of Chile in a climatologically important, but poorly understood region of the globe where extensive areas of marine clouds are prevalent (coverage ~70% during the month of October). This region is the location of one of the largest and most persistent subtropical stratocumulus cloud decks in the world. It is formed because the Andes Mountains provide a sharp barrier to the generally westerly zonal flow in the region resulting in strong winds parallel to the coasts of Chile and Peru. This causes an intense upwelling of deep water to the surface causing the sea surface temperature (SST) to be low. The low SST, in combination with warm dry air aloft, results in the formation of a persistent layer of marine stratocumulus clouds. This cloud layer helps maintain the cool SST resulting in tight couplings between the upper ocean and the atmosphere.

The data collected during this study will allow examination of the relationship between aerosol composition, size, and CCN activity; between CCN loading and activity and cloud droplet microphysics; between cloud droplet microphysics and cloud radiative properties (first indirect effect studies); and between cloud droplet microphysics and the formation of drizzle (second indirect aerosol effects studies). The data will also be used to examine the validity of recently developed parameterizations of cloud microphysical processes and properties designed for use in GCMs, and to develop the physical insight needed to develop more complete and sophisticated parameterizations of these quantities.

Other major participants in the VOCALS study will include the NSF C-130 aircraft; and the NOAA R/V Ronald H Brown (RHB). The C-130 will provide detailed in-situ measurements of cloud microphysics, gas and aerosol physicochemical properties, lower tropospheric structure, and MBL turbulence, in addition to passive and active cloud and precipitation remote sensing measurements. A major focus will be on Lagrangian experiments designed to document the lifecycle of open cell cloud structures. The RHB will provide atmospheric, oceanographic and air-sea exchange datasets. Atmospheric measurements will include in-situ surface meteorology, rawinsonde profiles, and gas/aerosol physicochemical properties. Remote sensing measurements of cloud and precipitation will be made from the RHB using active millimeter and centimeter radars, a ceilometer, and a passive microwave radiometer.

Several other platforms will provide additional important datasets especially at the land ocean boundary. A comprehensive near-coastal sampling strategy will include atmospheric thermodynamic and dynamic measurements with a Chilean Air Force Twin Otter), a Chilean research vessel, an elevated land site on the Chilean coastal range to measure cloud and aerosol microphysical properties, and enhanced meteorological observations at sites along the Chilean seaboard. A group of Peruvian researchers are proposing a set of enhanced atmospheric measurements and an oceanographic/atmospheric coastal cruise with the Peruvian research vessel.

Flight Plans. The basic flight strategy consists of the following legs:

1. Below-cloud leg(s) to measure aerosol composition, size distribution, CCN spectra, vertical velocities and their variability.

2. Multiple altitude in-cloud legs to measure measure cloud microphysical properties and their variability both with respect to location and altitude.

3. Above-cloud leg to characterize chemical and microphysical properties of above cloud air.

The following are flight plans that have been prepared to examine specific objectives in ASP-VOCALS.

Basic Flight Plan. Objective is to obtain statistically meaningful data on properties of clouds and the conditions under which they were formed by by flying ~100 km legs below-, in- and above-cloud. Flights can be made at any location consistent with the range and endurance of the aircraft.

Gradient Flight Plan. Objective is to characterize gradient in CCN and cloud microphysical properties that has been inferred from satellite measurements. Such flight plans may be profitably coupled with flights of the other aircraft to enhance the extent of change in properties being sampled.

Overpass of the Ron Brown. For G-1 Flight to be useful, Ron Brown must be within 200 nautical miles of Arica. This allows 1 hr transit, 2 hrs sampling above the Ron Brown, and 1 hr transit back to Arica.

Pockets of Open Cells (POC) Flight Plan. POC flights will occur primarily in collaboration with the C-130, which will locate cells and conduct initial sampling. POC's must be within ~200 nautical miles of Arica for useful sampling to be conducted.

Smelter Plumes Flight Plan. Under appropriate flow conditions, characterize in- and out-of plume cloud properties. Vertical profiles to obtain information on entrainment. Deploy aircraft so as to implement Lagrangian sampling of the smelter plume. Could involve as many as 4 aircraft.

Joint Flights. Objective of these flights is to link remote sensing measurements of cloud properties by the C-130 to in-situ cloud properties measured by the G-1. Especially useful are flights that combine remote sensing of cloud properties with in-situ measurements. Of interest are C-130 cloud radar, and radiation fields measurements. Such flights are planned to be conducted towards the end of the C-130 flights within about 200 nautical miles of the coast. Shown above is an example for the G-1 and the C-130. Joint flights with other aircraft are highly desirable. Similar flight plans could be conducted with the Twin Otter and the British Aerospace 146.

Aerosol layer. Objective is to determine whether aerosol layer observed just above cloud-top during MASE off the coast of California is also seen in off the Chilean coast in VOCALS. Sampling would focus on the interface between cloud-top and the free troposphere


For further information. An overview of the project is available in a white paper "ASP Participation in the Fall 2008 VOCALS Study". A set of viewgraphs showing flight plans and instrument complement is available at http://www.asp.bnl.gov/ASP-VOCALSflightplans.pdf

The lead scientist on this field project is Pete Daum.

BOSTON COLLEGE - AERODYNE SOOT PROJECT 2 CONCLUDED [2008-08-06]

The three-week (July 7 to 26, 2008) Boston College/Aerodyne Soot Project 2 has been completed. The Project utilized the Boston College laboratory flame apparatus and aerosol conditioning and characterization equipment which is a well-tested soot aerosol generation system for producing and modifying soot particles over a wide range of sizes, shapes, and coatings. A pre-mixed flat flame burner operating at controlled, premixed fuel-to-air ratios, produced stable and reproducible concentrations of soot particles with known morphologies and chemical compositions. Particles were fully characterized as a function of particle mass, shape, chemistry, and optical properties.

Highlights from the study will include:

Particle shape determination as a function of fuel-to-air ratio and collapse observed due to coatings

Characterization of several new instruments currently under development

Characterization of the physical and chemical properties of various types of black carbon particles (including incandescence, fullerene content, surface-bound PAH, etc.)

Mass specific absorption measurements as a function of fuel-to-air ratio and carbon particle type

Optical absorption enhancement measurements as a function of coatings

Wavelength-dependent measurements of absorption, scattering, and extinction as a function of fuel-to-air ratio, particle coating, and relative humidity


Altogether 19 instruments participated in the studies; 9 mass-based, 8 optically-based and 2 filter samples. Twenty-six people representing 12 institutions participated in the project. Experiments were conducted six days a week beginning typically at 9 a.m. and often continuing past midnight.

In the course of the three weeks, 318 runs were performed covering a matrix that systematically tested instruments' performance over a range of relevant parameters. Opportunity was provided for each instrument to sample soot particles as a function of the following measured (directly or indirectly) and controlled parameters: particle mobility size (in the range 30 to 300 nm), particle number concentration, particle shape (dynamic shape factor and fractal dimension), particle chemistry and density (changed via coatings), black carbon mass, and relative humidity in the range 5 to 90%. In selected runs, particles were coated with a measured thickness (few nm to ~150 nm) of sulfuric acid or dioctyl sebacate (DOS). In addition to flame-generated soot, black carbon (BC) particles were also obtained by atomizing fullerene soot, glassy carbon spheres, oxidized flame soot, Regal black toner, and Aquadag paint.

A brief report describing the project is available here. Further information on this project is available from Tim Onasch.

Initial results from CHAPS [2007-10-09]

Initial results are coming in from the ASP CHAPS (Cumulus Humilis Aerosol Processing Study) field project, which was conducted in the vicinity of Oklahoma City, OK, June 4-25, 2007. The project was conducted in close coordination with the Cloud and Land Surface Interaction Campaign (CLASIC) project conducted by the DOE Atmospheric Radiation Measurement (ARM) Program. The principal objective of CHAPS was to examine the influence of anthropogenic aerosols from a mid-size urban area on the microphysics of cumuliform clouds, and the effects of these clouds on urban aerosols that pass through fields of fair weather cumulus.

The DOE Gulfstream-1 Research Aircraft made in-situ measurements of particle and gas-phase composition and aerosol and cloud microphysics (12 research flights; 33 hours of flight time). Key instruments included time-of-flight aerosol mass spectrometer (AMS) and proton transfer mass spectrometer. A counterflow virtual impactor (CVI) allowed sampling of cloud droplets and examination of the composition of the residual dried particles. Coordination of G-1 flights with overpasses of the CALIPSO satellite permits use of in-situ measurements to assess the satellite aerosol and cloud retrievals.

The AMS was successfully applied for the first time to determine the composition of cloud-droplet residuals, as sampled with the CVI. A very short integration time of 3 seconds was employed; this short integration time is essential to be compatible with the dimensions of cumulus clouds given the G-1 speed of 100 m s^-1. The AMS could be applied either to clear-air aerosol or to cloud-droplet residuals, permitting examination of differences in composition. (L. M. Alexander, Y.-N. Lee).

The NASA Langley B200 King Air collected 66 flight hours of data over 20 science flights during CHAPS. Primary instruments on the King Air included the High Spectral Resolution Lidar (HSRL), the Langley Airborne A-band Spectrometer (LAABS), and digital camera. Portions of at least B200 eight flights were coordinated with the G-1 flights so that the HSRL and G-1 measurements were coincident and colocated. Figure 1 shows an example of a flight on June 24 around the northern part of the Oklahoma City region and shows how the HSRL measurements provide vertical context for the G-1 measurements. Note the increase in AOT northeast of OKC suggesting the possible location of the OKC plume. The B200 flights were also designed to provide aerosol and cloud data for use by investigators from the DOE ARM CLASIC campaign, which was conducted simultaneously with CHAPS. Twelve of the B200 flights included segments over the DOE ARM SGP CRF, and four B200 flights were coordinated with the CIRPAS Twin Otter aircraft deployed during CLASIC. The combination of HSRL measurements and digital camera images, along with the in situ data collected by the G-1 and CIRPAS Twin Otter aircraft, provide a unique dataset to examine the variability of aerosols near clouds.

Eight of the B200 flights were also coordinated with overpasses of the CALIPSO and CloudSat satellites in order to acquire HSRL data for validation of the CALIOP lidar. The G-1 and CLASIC aircraft were also coordinated with the CALIPSO overpasses on some of these validation flights; the in situ measurements will be used to provide a detailed characterization of aerosol and cloud properties to assess the satellite aerosol and cloud retrievals. Preliminary HSRL data and images for all the CHAPS/CLASIC flights are available to the CHAPS/CLASIC investigators via the ARM IOP archive.

Other participating aircraft included the CIRPAS Twin Otter (Center for Interdisciplinary Remotely Piloted Aircraft Studies) and a Cessna aircraft that makes systematic measurements of aerosol light scattering and absorption above the ARM (DOE Atmospheric Radiation Measurement Program) site at the Southern Great Plains (SGP) site in north central Oklahoma.

Meteorological and aerosol measurements were also made at a surface site just north of Oklahoma City.

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Some key initial results from CHAPS are as follows:

* AMS measurements (L. M. Alexander, Y.-N. Lee) include the following:

o Composition of clear-air aerosol immediately downwind of Oklahoma City was dominated by organics and sulfate. Nitrate concentrations were very low, at or below limit of detection, with nitrate to sulfate mass ratio less than 5%.

o Ammonium in clear-air aerosol in some instances was less than required for complete neutralization of sulfate. The low ammonium to sulfate ratio is consistent with the very low aerosol nitrate concentrations in cloud-free air.

o Composition of cloud-droplet residuals, like the clear air-aerosol, was dominated by organics and sulfate, but cloud-droplet residuals contained significant nitrate (nitrate to sulfate mass ratio up to 25%). The most likely pathway for incorporating nitrate into cloud droplets is dissolution of gaseous HNO3. The ratio of ammonium to sulfate in cloud residuals was similar to that in cloud-free air.

o Organic to sulfate ratios in cloud droplet residuals were lower than in aerosol particles in nearby cloud-free air, demonstrating that the pre-cloud aerosols were externally mixed in the near-source region examined in this study and suggesting selective activation of sulfate-dominated particles relative to organic-dominated.

- Concentrations of isoprene and several related species greatly exceeded values that would be expected from biogenic sources. As concentrations of other biogenic compounds were much lower, these observations suggest a previously unrecognized anthropogenic source of isoprene that may serve as a precursor of secondary aerosol formation. (L. M. Alexander)

- Aerosol optical thickness as determined by HSRL commonly exhibited considerable (>20%) small scale (~30 km) variability in the Oklahoma City and SGP regions (R. A. Ferrare).

- Determination of heights of planetary boundary layer and entrainment zone by remote sensing with the HSRL lidar (R. A. Ferrare, C. A. Hostetler)

- Ambient aerosol extinction (550 nm) derived from in situ measurements on the on G-1, CIRPAS Twin Otter, and ARM IAP Cessna aircraft agreed closely (10%) with values obtained by remote sensing with the HSRL (E. Andrews, J. A. Ogren).

- Aerosol size distributions by measured by three different instruments using different physical principles (optical, mobility) showed remarkable agreement especially for diameter above 200 nm (J. Olfert).

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The following papers were presented at the Fall 2007 meeting of the American Geophysical Union, Session A38: Cloud Effects on Aerosols.

- Alexander, L.M., Newburn, M., Hubbe, J., Berg, L., Berkowitz C.M., Springston, S.R., Senum, G.I. Lee, Y-N., Andrews, E., Measurement of the VOC Environment from an Aircraft Platform during an Aerosol-Cloud Interaction Study Near Oklahoma City

- Andrews, E., Lee, Y-N., Alexander, L., Ogren, J.A., Hubbe, J.M., Aerosol optical and chemical properties within and without clouds during an airborne field campaign in central Oklahoma

- Berkowitz, C. M., Berg, L.K., Ogren, J.A, Hostetler, C.A., Ferrare, R., Hubbe, J., An Overview of the Cumulus Humilis Aerosol Processing Study

- Lee, Y.-N., Alexander, L., Newburn, M., Jayne, J., Hubbe, J., Springston, S., Senum, G., Andrews, E., Ogren, J., Kleinman, L., Daum, P., Berg, L. and Berkowitz, C. M., Aerosol Chemical Composition and its Effects on Cloud-Aerosol Interactions during the 2007 CHAPS Experiment

- Nussbaum, N., Dubey, M.K., Mazzoleni, C., Gramann, J., Feingold, G., Schmidt, S., Hubbe, J., Springston, S., Arnott, P., McCubbin, I., Alexander, L., Seinfeld, J. and Berkowitz, C., Aerosol Optical Properties during GoMACCS and CLASIC: Evidence of Cloud Processing and Scavenging

- Obland, M.D., Cook, A.L., Ferrare, R.A., Hair, J.W., Harper, D.B., Hostetler, C.A., Rogers, R.R., Initial High Spectral Resolution Lidar Results From the Cumulus Humilis Aerosol Processing Study (CHAPS) and Cloud and Land Surface Interaction Campaign (CLASIC)

CHAPS Project Underway [2007-06-11]

The ASP field project CHAPS - Cumulus Humilis Aerosol Processing Study is now underway. This study is principally examining interactions of freshly emitted aerosols from Oklahoma City with fair weather cumulus clouds.

Click for daily updates from the project.

The CHAPS project is being carried out in conjunction with the CLASIC (Cloud and Land Surface Interaction Campaign) being conducted by the DOE Atmospheric Radiation Measurement Program.

ASP SCIENCE TEAM MEETING - FEBRUARY 25-27, 2008

The Annual Science Team Meeting of the Atmospheric Science Program (ASP) took place February 25 - 27, 2008, in Annapolis, Maryland. Approximately 80 ASP Science Team investigators attended along with other interested scientists and representatives of other agencies. The meeting program is available.

Much of the meeting was devoted to presentations by returning ASP investigators. New investigators introduced their intended work and how it fits in with other ASP activities.

A key component of the meeting was planning for future field projects. This included discussion of ASP participation in the forthcoming VOCALS project (VAMOS Ocean-Cloud-Atmospheric-Land Study) to be conducted in conjunction with NSF off the coast of Chile in October 2008 and prospective future field projects for the 2009-2010 time period and beyond. Discussions at this meeting helped to define these projects, which will allow identification of resource requirements.

Additionally, on the Wednesday afternoon there was a CHAPS data workshop at which participants reviewed first-look results and discussed plans for future analysis and publications.

Viewgraphs of platform presentations and posters presented at the meeting are available for downloading here.

Announcement of Funding Opportunity [2007-03-20]

NOTE: This funding opportunity is closed; this announcement is retained for reference only.

An announcement of funding opportunity for the Department of Energy's Atmospheric Science Program has been posted on the DOE grants and contracts web site.

The URL for the announcement is: http://www.science.doe.gov/grants/FAPN07-26.html

The URL for a pdf with more detailed information about the announcement and application procedure is: https://e-center.doe.gov/iips/faopor.nsf/UNID/8AAD315C4D281558852572A4005198BA/$file/FOA_Notice_07-26.pdf

The URL for the grants and contracts web site is: http://www.science.doe.gov/grants/

The following are excerpts from the announcement, but of course reference should be made to the announcement itself.

Atmospheric Science Program

The Office of Biological and Environmental Research of the Office of Science (SC), U.S. Department of Energy, hereby announces its interest in receiving applications for research grants in experimental and theoretical studies of aerosol radiative forcing of climate in conjunction with the Atmospheric Science Program in the Climate Change Research Division as part of the U.S. Climate Change Science Program.

Background

Understanding the role of aerosols in climate forcing is a critical factor in climate change research, as well as an essential element in advancing the state of the art in climate modeling. Aerosol forcing appears to be the same order of magnitude as the forcing from greenhouse gases, but far more uncertain. Aerosol forcing has two major components, direct and indirect. Direct effects of aerosols are the influence of the aerosols on the Earth's radiation balance due to the scattering and absorption of radiation by particles in clear (cloud-free) air. Indirect effects of aerosols include their influence on the radiation balance and hydrology through their impact on cloud microphysical properties (first indirect effect) and amount (second indirect effect). There is also a semi-direct effect, in which the heating by aerosol particles due to absorption of solar radiation decreases cloud amount.

Applications focused on the following functional categories are encouraged:

(1) focused laboratory studies
(2) field studies
(3) fundamental theoretical and process modeling
(4) the development of new aerosol measurement instruments and methods.

These categories are not mutually exclusive; in fact, projects in one category should generally have applicability to program activities in the other categories.

PREAPPLICATIONS

Potential applicants are required to submit a preapplication, referencing Program Notice DE-PS02-07ER07-26 for receipt by DOE by 4:30 p.m., Eastern Time, May 1, 2007.

Preapplications should be sent to Dr. Ashley D. Williamson, ASP Program Manager, via E-mail to: ashley.williamson@science.doe.gov .

Please include "Preapplication - ASP Program Notice" in the E-mail subject field.

All preapplications will be reviewed relative to the scope and research needs of the ASP Program. A response to each preapplication, discussing the potential program relevance of research for a formal application, generally will be communicated within 15 days of receipt. Applicants who have not received a response regarding the status of their preapplication within a reasonable time are responsible for contacting the program to confirm this status. Applicants should allow sufficient time so that the formal application deadline of June 18, 2007 is met.

A preapplication should consist of two or three pages of narrative describing the research objectives, methods of accomplishment, estimate of level of funding to be requested, and references. The preapplication should identify, on the cover sheet, the title of the project, the institution or organization, principal investigator name, telephone number, fax number, and e-mail address, and the names and affiliations of any proposed team members.

SC's preapplication policy can be found on SC's Grants and Contracts Web Site at: http://www.science.doe.gov/grants/preapp.html .

Please contact Dr. Ashley D. Williamson for any questions related to this announcement. Applicants should allow sufficient time so that the formal application deadline is met.

APPLICATION DUE DATE: June 18, 2007, 8:00 pm, Eastern Time

Applications must be submitted using Grants.gov, the Funding Opportunity Announcement can be found using the CFDA Number, 81.049 or the Funding Opportunity Announcement number, DE-PS02-07ER07-26. Applicants must follow the instructions and use the forms provided on Grants.gov.

ELIGIBLE APPLICANTS

All types of entities are eligible to apply except National Laboratories and Federally Funded Research and Development Center (FFRDC) Contractors as described in section 501(c)(4) of the Internal Revenue Code of 1986 that engaged in lobbying activities after December 31, 1995.

Federal agencies interested in applying should follow instructions at this website http://www.sc.doe.gov/grants/fed_prop.html

FOR FURTHER INFORMATION CONTACT:

For further information regarding this notice,

Contact: Dr. Ashley D. Williamson, ASP Program Manager
Telephone: 301-903-3120
Fax: 301-903-8519
E-mail: ashley.williamson@science.doe.gov

FY 2007 ASP Science Team Meeting

The FY 2007 ASP Science Team Meeting was held at the NOAA Laboratory in Boulder, Colorado, October 25-27, 2006. The meeting was attended by some 80 registered participants as well as a number of NOAA scientists. Thanks to NOAA for hosting our meeting and to the NOAA scientists who participated.

The meeting started off with a presentation by Joost de Gouw of NOAA on Emission Sources and Formation of Particulate Organic Matter. There were sessions dealing with the recently conducted MASE (MArine Stratus Experiment) and MAX-TEX (Megacity Aerosol eXperiment - TEXas) projects. As findings from the MAX-MEX (Megacity Aerosol eXperiment - MEXico City) project a had been fully discussed at the MILAGRO Science Meeting earlier in the week, in which many ASP investigators participated, there was no session on MAX-MEX. However there were a number of poster presentations on MAX-MEX.

Other sessions dealt with the forthcoming (Summer 2007) CHAPS (Cumulus Humilis Aerosol Processing Study) project and with prospective ASP field projects for 2008 and beyond. Numerous investigators gave short platform presentations of the highlights of their research. More detailed discussions took place during the break-out meetings of the several topical working groups, and these sessions were summarized by the working group leaders.

A highlight of the meeting was the poster presentations -- some 44 of them -- presenting the newest findings from virtually all of the investigators.

Click to go to the Meeting Program. This page gives links to the viewgraphs of the platform presentations and to copies of the posters. [2006-12-26]

ASP participation in TEXAQS II (August - September 2006)

ASP had a substantial presence in TEXAQS II.

Under support from the Texas Environmental Research Consortium (TERC) Carl Berkowitz (Carl.Berkowitz@pnl.gov) and colleagues (PNNL) together with investigators from Texas A & M University and Washington State University measured hydrocarbons, NO_y, CO, and O₃ at three sites in the Houston triangle.

Also participating were investigators from Los Alamos National Laboratory, led by Manvendra Dubey (dubey@lanl.gov). These investigators deployed a photoacoustic instrument to measure the optical properties of aerosols containing black carbon as well as CO₂ and CO on the CIRPAS Twin Otter as a part of the GoMACCS (Gulf of Mexico Atmospheric Composition and Climate Study) campaign in Houston led by Graham Feingold of NOAA.

The NASA Langley group contributed to TEXAQS II/GoMACCS with the King Air, flying the same combination of instruments as in MILAGRO, the primary instrument being the High Spectral Resolution Lidar.

Further information on these activities including viewgraphs is available on the ASP MAX-TEX web page. [2006-12-26]

Revised CHAPS White Paper on line

A greatly expanded description of the Summer 2007 ASP Field Campaign Cumulus Humilis Aerosol Processing Study (CHAPS) is now accessible from the CHAPS web page.

The primary goal of this campaign is to characterize and contrast freshly emitted aerosols above, within and below fields of cumulus humilis (or fair-weather cumulus, FWC) and to use these observations to address how below-cloud and above-cloud aerosol optical and cloud nucleating properties differ downwind of a mid-size city relative to similar aerosols in air less affected by emissions. The observations from this campaign will also be used to aid in the development and evaluation of parameterizations of the transformation and transport of these aerosols by FWC for use in regional-scale and Global Climate Models. This final product has the potential to reduce the uncertainties associated with the treatment of aerosols by these models.

Supporting the in situ observations to be made by the DOE Gulfstream-1 (G-1) aircraft will be profiles of aerosol backscatter and extinction in the vicinity of these clouds to be made with a High Spectral Resolution Lidar (HSRL) onboard the NASA Langley Research Center's King Air Be-200.

Measurements will also be made of the composition of aerosols inside and outside of the urban plume in order to characterize both activated and interstitial aerosols. In view of the transient nature and the small spatial scale of the individual FWC, this study will look at the aerosol properties in aggregate, rather then data from individual transects through a cloud. Surface measurements will be used to continuously characterize aerosol and chemical features within the boundary layer.

Discussions with the science team of the Cloud and Land Surface Interaction Campaign (CLASIC) project of the DOE ARM Program have identified overlap between the science questions posed for the CLASIC Intensive Operation Period (IOP) and the proposed ASP campaign suggesting collaboration would benefit both teams. [2006-05-26]

ASP MAX-MEX and JOINT MILAGRO field projects concluded

The MILAGRO (Megacity Initiative: Local and Global Research Observations) 2006 field study and the ASP MAX-MEX component of that study are concluded as of the end of March.

After a rocky start to the project, operations in Mexico went very well, with several coordinated flights among the several aircraft having taken place. ASP investigators are now at home with much good data to analyze. If you haven't visited the Field reports page, you are invited to take a look. This page has links to quick-look graphics of PRELIMINARY data.

The official opening ceremony of MILAGRO was held on March 2, 2006, at the Universidad Autonomous Nacional de Mexico (UNAM) main campus at the newly opened Universum - Science Museum in Mexico City, D.F. For an account of that ceremony, which involved officials and scientists from U.S. and Mexican institutions and government agencies, click here (pdf file).

A detailed article about the project "Mexico City a Living Laboratory for Smog Study" appeared in the March 31 Los Angeles Times. Another article "Air pollution mega-project merits mega-response" appeared in the March 12 English online edition of El Universal.

NOTE OF APPRECIATION TO ASP MAX-MEX PARTICIPANTS [2006-04-21]

To MAX-MEX Participants

From Rick Petty, Acting Program Manager, Atmospheric Science Program

At the close of the field portion of the Megacity Aerosol eXperiment in MEXico City (MAX-MEX Project) I would like to express my appreciation and that of the Department of Energy to all who participated in this important study. I recognize that many difficulties had to be faced in the field, but I understand that most of these were surmounted through extra efforts on your part, so I especially wish to thank all those whose dedication and perseverance led to the success of the field portion of MAX-MEX and the MILAGRO collaboration.

I have been advised that you have obtained a multitude of good data from both the aircraft and the ground-based sites. The multiple aircraft operations went well. I am especially pleased with the joint flights between the NASA King Air with its downlooking Lidar and the G-1, as this will provide both a useful context for interpreting the measurements made on the G-1 and in-situ measurements for interpreting the Lidar data. This is an important step forward. I also understand that there were several successful flights that will permit examination of the evolution of aerosol microphysical properties and composition of aerosols in the Mexico City plume, one of our prime objectives.

By all reports there was outstandingly good interaction with our partners in the larger MILAGRO study, both other US agencies and our Mexican colleagues on the ground. This collaboration and combined data set will be of great use for our ASP modeling efforts as well as the global climate modeling community world-wide.

As we enter the analysis phase of the project I look forward to seeing the fruits of your field efforts reported in scientific papers and at national meetings of scientific societies, as well as serving as the basis for model-based representation of the phenomena that you studied in the field. Please advise me if there is anything I can do to assist you in your continued efforts.

Again, congratulations on a job well done.

Sincerely,

Rick Petty

MASE data available

Most of the data from the MASE (MArine Stratus Experiment) field campaign (July 2005) have been posted on the ASP Data Archive website. These data are also available to ASP investigators as a CD ROM. Interested investigators should contact Stephen Springston (srs@bnl.gov). [2006-07-11]

MASE Project Concluded. For an account of the MASE (MArine Stratus Experiment) conducted in the vicinity of Point Reyes, CA, in July, 2005, click here. [2005-08-31]

MASE Project. The ASP MASE (MArine Stratus Experiment) field project was conducted in the vicinity of Point Reyes, CA, just north of San Francisco, throughout the month of July, 2005. The project examined the influences of anthropogenic aerosols on marine stratus clouds so that the relevant processes can be more accurately represented in climate models.

The primary measurement platform was the DOE G-1 Research aircraft, which was outfitted for this study with numerous state-of-the-art instruments for characterization of aerosol properties. The project made extensive use of the DOE Atmospheric Radiation Measurement (ARM) program's ARM Mobile Facility (AMF) with its array of in-situ and remote-sensing instruments, supplemented by specialized measurements made by instrumentation provided by ASP investigators and others. Another key measurement platform was the Twin Otter research aircraft operated by the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) at the Naval Postgraduate School and instrumented by researchers from the California Institute of Technology and ASP investigators.

For additional information regarding the rationale for the study, objectives and deliverables, collaborations, and operations see the MASE Project Overview. For links to data, photos of operations, and other information click on the MASE Experiment Home Page. [2005-08-31]

Olfert wins Friedlander Award [2007-10-09]

ASP investigator Jason Olfert, who is working with Jay Wang at Brookhaven on the Fast Integrated Mobility Spectrometer was awarded the Sheldon K. Friedlander Award at the September 2007 meeting of the American Association for Aerosol Research. This award recognizes an outstanding dissertation by an individual who has earned a doctoral degree in a field of aerosol science and technology in the prior three years. Olfert's thesis (University of Cambridge, 2006), "On New Methods of Ultra-Fine Particle Mass Classification," described a new instrument called the Couette Centrifugal Particle Mass Analyzer. This instrument, in conjunction with particle size data, can be used to accurately determine effective particle densities, fractal dimensions, and dynamic shape factors.

ARM Indirect and Semi-Direct Aerosol Campaign

Attention is called to a series of intensive cloud and aerosol observations conducted at the ARM North Slope of Alaska (NSA) locale for three weeks in April 2008. This period was chosen because it is during the International Polar Year when many ancillary observing systems were collecting data that are synergistic for interpreting the Indirect and Semi-Direct Aerosol Campaign (ISDAC) data. The study included aircraft measurements of temperature, humidity, total particle number, aerosol size distribution, aerosol hygroscopicity, cloud condensation nuclei concentration, ice nuclei concentration, optical scattering and absorption, updraft velocity, cloud liquid water and ice contents, cloud droplet and crystal size distributions, cloud particle shape, and cloud extinction.

Lead scientist for ISDAC was Steve Ghan, who is an investigator in both ASP and ARM. ASP investigators wishing further information about ISDAC are invited to contact Steve. Further information is available at http://science.arm.gov/isdac/. [2008-06-30]

ASP FY 2006 Science Team Meeting Held October 31- November 1, 2005 [2005-11-11]

The FY-2006 ASP Science Team meeting took place October 31 - November 1, 2005 in Alexandria VA. In addition to ASP investigators and members of the Adjunct Science Team an invitation to attend was extended to members of the broader atmospheric science research community, a number of whom attended, including members of the ASP adjunct science team and investigators supported under the NIGEC program. Click here for a pdf file of the meeting attendees. (Please advise of any errors).

Here only a brief overview of the meeting is given. A more detailed report of the meeting will be presented shortly.

Click here for the meeting agenda. This agenda contains links to viewgraphs of the presentations at the meeting.

A slate of outstanding experts in climate modeling presented their views on the requirements of these large-scale models regarding aerosol processes and on how the research in ASP and ASP deliverables can be made most useful to the modeling community.

The agenda also included ten talks denoted "ASP Science Highlights", in which ASP investigators presented their recent results and findings. Three of these talks (plus two brief post-deadline presentations) reported exciting first results from the recent (July 2005) MASE (MArine Stratus Experiment) field study.

Topical working groups met to discuss how they can meet the needs of the climate modeling community, to refine deliverables, to identify common needs and strategies, and to conduct other working group business. Brief reports of these working group meetings are also available from the meeting agenda web page. [2005-11-09]

Davidovits and Worsnop AAAS Fellows [2005-11-11]

Paul Davidovits and Doug Worsnop elected fellows of the AAAS. Science Team members Paul Davidovits of Boston College and Doug Worsnop of Aerodyne, Inc., have been elected fellows of the American Association for the Advancement of Science. Fellowship in the AAAS is quite an honor. Paul's citation reads in part "For groundbreaking studies in the chemistry of gas-liquid interactions at aerosol surfaces." Doug's award cites: "major advances in atmospheric heterogeneous chemical kinetics and the measurement of atmospheric aerosol particle composition and microphysics, including the development of the aerosol mass spectrometer." Much of the work that led to both these awards was supported by the Atmospheric Science Program. Congratulations, Paul and Doug! [2005-11-11]

FY 2005 Science Team Meeting [2005-03-25]

The first annual science team meeting of the reconfigured Atmospheric Science Program took place January 25-27 in Charleston, South Carolina. A key component of the meeting was a series of ten-minute presentations by each principal investigator. The purpose of these presentations was to convey to the rest of the Program participants the objectives of the individual projects (what the investigator intends to do), the approach (how he or she intends to do it), the requirements of the project (what is required from others--other science projects and program infrastructure) and the products (what it is intended to provide to others; who would use, or even better, rely on, what will be produced in the project).

A second key component of the meeting was planning for future field projects. Several descriptions of potential field projects have been posted. This meeting helped to refine the technical requirements for these projects, necessary for identification of the resource requirements (including fiscal) of these projects. [2005-02-12]

Agenda. To download a copy of the final meeting agenda click here.

Meeting Presentations. To download individual electronic presentations from the meeting click here.

Attendees. To download a list of registered attendees click here.

Featured Article

Chief Scientist's Report of the Science Team Meeting [2005-02-12]

The first Science Team Meeting of the newly reconfigured Atmospheric Science Program was held in Charleston SC January 25-27. The venue, which was suggested by Peter Lunn, ASP Program Director, was conducive to good scientific discussion. Thanks especially to Lenny Newman for being responsible for the arrangements and to Barbara Roland for serving as meeting secretary.

The meeting consisted mainly of brief presentations by the ASP investigators of the work they intend to do in the Program followed by topical group discussions and planning discussions for field projects. Almost all of the presentations of the science team projects succeeded in conveying the essence of the work, what the project will deliver, and what the project will rely on from others--and did so within the specified ten-minute time slot, which made for a rather intense initial day and a half. Thank you to all the investigators and presenters for your efforts. There were some 60 attendees--science team principal investigators, potential members of the adjunct science team, project officers from DOE and other agencies, and several senior administrators from DOE National Labs. By most accounts the meeting went well, a good start to the Program.

The following report summarizes some key outcomes of the meeting.

Deliverables. Peter Lunn emphasized that all programs in DOE, and elsewhere in Washington, are being strongly encouraged to identify deliverables, and he thus stressed the importance of ASP preparing a list of deliverables that he can carry upward in DOE.

It was observed that the Climate Change Science Program (CCSP) is conducting an early assessment and synthesis of aerosols, and that it would be valuable for ASP to be proactive in conveying deliverables to this sort of activity.

Field Projects. Peter Lunn announced tentative decision on his part for ASP field programs, specifically the Marine Stratus off California, Summer 2005 Study, and the Mexico City, Late Winter or Early Spring 2006 Field Project, subject to concurrence on the part of the Science Team. Based on discussions at the meeting this decision was affirmed and ASP will conduct these two field projects. The lead scientists for the two projects are Pete Daum for MASE (MArine Stratus Experiment), Jeff Gaffney for MAX-Mex (Megacity Aerosol eXperiment -- Mexico City). Expanded descriptors are now available for MASE and MAX-Mex. The possible Houston, Summer 2006 Field Project remains on hold pending determination of whether sufficient funding will become available. Larry Kleinman will act as lead scientist to develop a plan for a possible Houston-2006 field project. A possible 2007 Field project examining the interactions of aerosols with cumuliform clouds from the boundary layer to the free troposphere was outlined by Carl Berkowitz. Science issues include the role of clouds in transport and in uptake and removal of aerosols in precipitation and influence of aerosols on clouds. A project descriptor is now available.

It was emphasized that the planning horizon for the 2005 and 2006 field projects is quite short.

Pete Daum indicated that planning for MASE is well in hand, especially as it is a fairly limited deployment. Investigators wishing to participate, especially in ground-based measurements, should contact Pete as soon as possible.

For MAX-Mex it is necessary that planning move into high gear as this is a major deployment with numerous logistical issues and the added difficulty of working in a non-US venue, with potential issues involving shipping, customs, and the like. It is noted that NSF has not made a decision whether to conduct MIRAGE. Proposals are in review with a programmatic decision to be made in May. The following working groups and chairs for this deployment were identified: Aircraft, Larry Kleinman; Modeling, Jerome Fast; Surface, Chris Doran with assist from Chuck Kolb; Logistics, Jeff Gaffney.

Working Groups. Several different working groups are being formed within ASP to facilitate communication among investigators. Working groups will be focused on specific research themes or topics, on a given field project (MASE and MAX-Mex), and as necessary on a particular theme within a given field project. Potential topical working groups and chairs are: New particle formation, Pete McMurry; Aerosol optical properties, Jim Barnard; Gas-particle interaction, Rahul Zaveri; and Cloud-aerosol interactions, Pete Daum.

Working groups and chairs for the MAX-Mex project are: Modeling, Jerome Fast; Logistics, Luisa Molina and Jeff Gaffney; Aircraft measurements, Larry Kleinman; Surface sites, Chris Doran; and Forecasting, Sasha Madronich and Jerome Fast.

Data plan and data policy. The previously posted draft data policy was discussed. Issues and concerns noted included data control (who can access the data; who can use the data, and when); credit (the person who generates the data should have the option of being a coauthor). Each field project should have a data plan. Non-participants should be informed that data will become available when posted into the archive. Based on these discussions a revised data policy will be formulated and posted.

Communications. It was decided that the primary vehicle for communication among program participants should be the web page. To facilitate awareness it was suggested that an email be sent out weekly or when necessary calling attention to additions to the web page.

Concerns. Peter Lunn remarked that ASP is "weakest on the fringes," the boundaries with entities responsible for characterizing emissions and with the radiation and climate modeling community. He observed that it is all right to have a fuzzy boundary, that some overlap is appropriate, but that we need to assure connectivity with these communities.

The short time horizon in getting ready to conduct the 2005 and 2006 field projects is a concern.

A continuing concern is sufficiency of funding to meet the needs of the program.

Unresolved matters. Peter Lunn noted the following unresolved matters: Membership of the Science Steering Committee, firming up the data policy, and preparation of a list of project deliverables. It is anticipated that these matters will be resolved in the near future.

- Steve Schwartz

Message from the Chief Scientist [2004-11-12].

Let me first extend my welcome to all of the scientist participants in the reconfigured DOE Atmospheric Science Program. As the ASP Program Director Peter Lunn has emphasized, there was an outstanding set of proposals and regrettably it was not possible to fund quite a few well reviewed proposals that would materially advance the science. As you know as well, it has been necessary to ask some of you to tighten your belts a bit and we appreciate your willingness to do so.

We have a big task in front of us, namely to narrow down the uncertainty in aerosol radiative forcing of climate change. You are all familiar with the IPCC bar chart, so let me use that as the basis of an analogy. The relative uncertainty associated with the estimate of greenhouse forcing by tropospheric ozone is much greater than that associated with that of the well mixed greenhouse gases. The reason for this is not in the physics of the forcing per incremental molecule, which is similar for both ozone and the well mixed GHGs, but in the question of how much ozone has increased over the industrial period. Tropospheric ozone is inherently more complicated than the well mixed GHGs: it is a secondary substance, it is quite nonuniformly distributed spatially and temporally, and the dependence of ozone loading as a function of secular time over the industrial period is not well known. So uncertainty in ozone forcing is rooted in questions of atmospheric chemistry.

In this context consider the uncertainty in aerosol forcing, which is much greater than forcings either of tropospheric ozone or well mixed GHGs, on both relative and absolute basis. Here also I would argue that the big source of uncertainty is not in the radiative forcing of a well specified aerosol (optical depth, single scatter albedo, asymmetry parameter) but rather in the incremental aerosol loading (relative to preindustrial) and specification of the pertinent aerosol properties, at least for the direct forcing. Thus for aerosols the uncertainty is rooted like it is for ozone in questions of atmospheric chemistry. However for aerosols the situation is all the more complicated because of the key role played by aerosol microphysics. We all know that it is insufficient just to specify mass loading; that knowledge of the size distribution and real and imaginary components of the index of refraction is essential. Also essential if we are to make progress in reducing the uncertainty in aerosol forcing is identification of the anthropogenic contribution to the aerosol and to aerosol forcing.

The situation is yet more complicated in determining aerosol indirect forcing. Here several mechanisms have been adduced, and it is possible, on the basis of model calculations that are consistent with current understanding, to infer a wide range of plausible magnitudes of such forcings. For the indirect effect as well, the forcing, the change in radiative flux components, is highly sensitive not just to the incremental aerosol, but also to the assumption of what the aerosol would have been in the absence of the anthropogenic perturbation, so knowledge just of the perturbation is insufficient. This indirect forcing is dependent as well on aspects of cloud microphysics that are not themselves fully understood.

This is the context in which we initiate the Atmospheric Science Program focus on radiative forcing by aerosols. And it is in this context that I wish to commend the program managers and administrative staff of the DOE Office of Biological and Environmental Research (OBER) for stepping up to this challenge by initiating this activity. I look forward to working with them in this program. I also wish to thank the subcommittee of DOE's Biological and Environmental Research Advisory Committee (BERAC), chaired by Gene Bierly, for their key role in conveying the importance of the aerosol radiative forcing issue to senior management in OBER. The report of that committee A Reconfigured Atmospheric Science Program (U.S. Department of Energy, Biological and Environmental Research, Advisory Committee, April 2004) played a key role in getting this Program started.

Let me also acknowledge at this time the superb effort by Peter Lunn over the past few months in bringing this program into existence. Once he got the green light from BERAC to proceed on this program he got the program announcement officially released in record time, arranged for reviews of some 150 proposals again in something like record time, and has done the paperwork to get the money out the door so that all of you can get to work. I would be remiss as well if I did not thank all the reviewers who likewise put in much time and effort in a timely way so that Peter could proceed with identification of the projects for immediate funding.

We will have more to say in the next weeks on how we intend to meet the requirements, but I am confident we have a superb team. But for now, welcome to the Program, and I look forward to working with you all.

- Steve Schwartz

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News & Notes

Peter Lunn Retires. Peter Lunn, DOE Program Manager for ASP for quite some years, retired from the Federal Service in June, 2005. Rick Petty, who has long been associated with the Program and most recently had responsibility for the Instrument Development and Laboratory Measurements components of the Program, has been designated as Acting Program Manager. [2005-06-21]

New Web Page Launched. If you are reading this, you have already discovered our new web page. We hope to make this page a place that you will visit regularly. This page will include features on ASP science, news and notes that may be of interest to ASP investigators, and links to the various program components. We hope this page will be of interest not just to ASP investigators but also to colleagues from other programs, program officers and managers in DOE and their counterparts in other agencies, and the broader scientific public. We invite ASP investigators to contribute items to this page.

We expect to use this page as a major vehicle of communication in the program, with frequent updates. We invite you to visit here often. [2004-11-12]

ARM Aerosol Working Group meeting. The ARM aerosol working group met in Boulder, Colorado, December 8-10, 2004. The agenda included discussion of the ARM-ACP Aerosol IOP, which took place at the ARM SGP site in May, 2003. A series of papers is planned for submission to a special section of JGR. For further information please contact Rich Ferrare. [2005-01-13]

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Science News

John Jayne and Doug Worsnop received the 2004 Benjamin Y.H. Liu Award from the American Association of Aerosol Research for development of the Aerosol Mass Spectrometer system. This work was funded in part by ASP. For further information click here. Congratulations John and Doug. [2005-01-13]

Summer 2004 Field Study. Scientists from the U.S. Department of Energy's (DOE) Argonne National Laboratory (ANL), Brookhaven National Laboratory (BNL), and Pacific Northwest National Laboratory (PNNL) took to the skies above Western Pennsylvania for four weeks in July and August, 2004 to sample the air for aerosol pollutants and evaluate their effects on Earth's climate. The research was part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) experiment, an effort by many separate institutions and government agencies to conduct a joint regional air quality and climate study of unprecedented scope. More [2004-11-12]

Research Highlights

Sea Salt Aerosol Production: Mechanisms, Methods, Measurements, and Models -- A Critical Review. Lewis E. R. and Schwartz S. E. Geophysical Monograph Series Vol. 152, (American Geophysical Union, Washington, 2004). Overview and publication information

Sea salt aerosol (SSA) particles influence climate and climate change by serving as condensation nuclei for cloud drop formation, by scattering solar radiation, and by influencing the nature and evolution of other aerosol constituents. Consequently it is important that SSA be accurately represented in chemical transport models and that these influences of SSA be accurately represented in climate models. Central to this is representing SSA production--specifically the size-dependent production flux of SSA particles as a function of controlling variables. SSA particles are formed primarily by the bursting of bubbles following wave breaking; large SSA particles are formed also by tearing of drops from wave crests. Both processes are highly dependent on wind speed. This review examines information pertinent to production of SSA particles and their subsequent behavior in the atmosphere--measurements of SSA concentration and production in the context of other components of the marine aerosol, the physico-chemical properties of SSA, including optical and cloud-nucleating properties, kinematics and dynamics of SSA particles, and dependence of these properties on relative humidity. SSA production is usefully distinguished as an interfacial flux or as an effective flux at a height of interest, typically 10 m. Nine independent methods of determining one or the other of these fluxes as a function of SSA particle size have been identified, and the data required to evaluate the pertinent flux according to these methods (from both laboratory experiments and field measurements) have been systematized and critically examined and compared. Key required data are sizes and numbers of drops produced per bubble burst, size-dependent drop production flux per whitecap area, whitecap coverage and behavior, and concentrations of SSA particles in the marine atmosphere. Best estimates are presented for the SSA production fluxes according to each of the methods, and the associated uncertainties quantified. Estimates of size-dependent SSA production flux at a given wind speed are uncertain to a factor of 5 for small SSA particles (radius at 80% relative humidity, r₈₀ 0.1 to 1 m) decreasing to 3 for medium SSA particles (r₈₀ 1 to ~25 m). Little credibility can be placed in current formulations for the size dependent production flux of large SSA particles (r₈₀ 25 m). These large uncertainties limit confidence that can be placed in representations of SSA in chemical transport models and in evaluations of its influences on climate and climate change. [2005-01-13]

Evidence that the spectral dependence of light absorption by aerosols is affected by organic carbon. T. W. Kirchstetter, T. Novakov, and P. V. Hobbs. J. Geophys. Res. 109, D21208, doi:10.1029/2004JD004999, 2004. Abstract and link to publication

This paper reports measurements of spectral extinction of carbonaceous aerosols collected on quartz filters at several locations dominated by vehicular emissions or alternatively by biomass burn aerosols. The wavelength dependence of attenuation is readily determined and expressed as a power law in wavelength , . Absorption by aerosols from vehicular emissions exhibited a wavelength dependence p approximately unity, consistent with a wavelength-independent imaginary component of index of refraction, whereas absorption by biomass-burn aerosols exhibited a much stronger wavelength dependence (that is, much stronger absorption in the UV and near UV than at longer wavelengths) although this power-law dependence was not strictly constant over the full wavelength range. The wavelength-dependent absorption was attributed to organic material present on the aerosol particles, as shown by extraction of the filter with acetone resulting in nearly complete removal of this absorption signal. For both the extractable organic carbon and the non-extractable black carbon it was possible to quantitatively relate absorption to the amount of carbon on the filter, determined as CO₂ by thermal oxidative desorption, albeit with some uncertainty associated with enhancement of absorption signal due to multiple passes of the illuminating radiation through the particles embedded on the quartz fiber filter, permitting determination of the imaginary component of the index of refraction. These measurements demonstrate the substantial contribution of organic materials to aerosol absorption and to the wavelength dependence of this absorption, both of which must be taken into account in determining the radiative influence of these aerosols. Quantitative determination of the wavelength-dependent absorption coefficient per amount of carbon provides a path forward to representing this absorption in climate models that include a representation of these two carbonaceous aerosol constituents. [2004-11-29]

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Presentations

Overview Presentations of ASP. Steve Schwartz presented an overview of ASP at the 2005 Gordon Research Conference on Atmospheric Chemistry to be held September 4-9 in Big Sky Montana. A copy of his poster presentation may be downloaded here. Steve also made a presentation on behalf of the DOE Climate Change Research Division to the participants in the 8th ACCESS Colloquium. This colloquium, whose acronym stands for Atmospheric Chemistry Colloquium for Emerging Senior Scientists, is held every alternate year in conjunction with the Atmospheric Chemistry Gordon Conference. Its participants include some 25 new (or almost) PhDs in atmospheric chemistry and related disciplines who are selected competitively from a national pool of applicants. The purpose of the colloquium is to familiarize these outstanding young scientists with each other, with active scientists in the discipline (through their participation in the Gordon Conference) and with the programs in the several national agencies responsible for conduct of research in atmospheric chemistry. A copy of the viewgraphs from this presentation may be downloaded here. [2005-08-31] Pete Daum, Brookhaven, presented results from the G-1 flights conducted during the summers of 2002 and 2004 at the November meeting of the Air Quality Research Subcommittee (AQRS) of the National Science and Technology Council in Washington on November 18, 2004. The purpose of these flights was to conduct a regional scale survey of aerosol chemical and microphysical to examine loading, composition, optical properties and geographic distribution of aerosols in the northeastern U.S. in the context of source locations and prevailing meteorology, and to conduct process level studies of aerosol formation and growth. Results of these measurements indicate that aerosol composition in the Northeast is dominated by sulfate and organic species. Studies of the evolution of aerosol composition in several power-plant plumes indicate that the growth of aerosol mass is consistent with oxidation of SO₂ by OH, with rates on the order of 2-3 %/h. Several of the major power plants studied during the 2004 intensive exhibited very low NO_x emissions consistent with control strategies that have been recently implemented to control regional O₃ concentrations during the summer. A powerpoint file of viewgraphs from this presentation may be downloaded here. [2004-11-04].

John Jayne, Aerodyne, presented preliminary findings from the summer 2002 and summer 2004 New England Air Quality Studies, focusing on measurements from the G-1 Aircraft platform, at the 2004 Annual Conference of the American Association for Aerosol Research, in Atlanta, October 4-8, 2004. Key findings included demonstration of sulfate plumes in New England originating from the Ohio Valley area in the 2002 study. Overflights above the NOAA Research Vessel Ron Brown 25 km east of the Massachusetts - New Hampshire coast under off shore flow conditions identified distinctly different plumes in which the size distribution of sulfate and the ratio of sulfate to SO₂ differed markedly with altitude, attributed to differences in plume age. Measurements in the 2004 study indicated high concentrations of sulfate resulting directly from emissions from coal-fired power plants in the Pennsylvania area. In rural areas of Pennsylvania the organic aerosol consisted mainly of highly oxidized secondary organic aerosol derived from biogenic sources. In contrast, in the New York - New Jersey area a measurable fraction of the organic aerosol was primary emitted hydrocarbon (consistent with a vehicle traffic source); this adds to the oxidized organic aerosol background. A powerpoint file of viewgraphs from this presentation may be downloaded here. [2004-11-12].

Steve Schwartz, ASP chief scientist, gave a presentation at the 14th Science Team Meeting of DOE's Atmospheric Radiation Measurement (ARM) Program in March 2004 highlighting some of the issues facing the new aerosol focus of ASP and pointing to the interfaces with ARM. A pdf file of the viewgraphs from that presentation may be downloaded here. [2004-11-12].

Megacity Respiration - Mexico City Example. C.E. Kolb. Aerosol Workshop on Climate Prediction Uncertainties, Santa Fe, NM, July 19-21, 2006. 6 M ppt file. [2006-08-14]

Multiwavelength Photoacoustic Measurements of Light Absorption and Scattering by Wood Smoke - Evidence for light absorption by organic carbon species in woodsmoke. Kristin Lewis, William P. Arnott, Stephanie Winter, Hans Moosmuller, Claudio Mazzoleni. Aerosol Workshop on Climate Prediction Uncertainties, Santa Fe, NM, July 19-21, 2006. 300K ppt file. [2006-08-14]

MAX-MEX Presentation to BERAC

Jeff Gaffney, ASP lead scientist for the MAX-MEX project, gave an overview presentation on MAX-MEX on July 10 to the BERAC (Biological and Environmental Research Advisory Committee of DOE). The viewgraphs of this presentation may be downloaded (10M pdf file) here.

BERAC oversees the research and operations of the DOE Office of Biological and Environmental Research, which includes the Climate Change Research Division in which ASP resides. The Committee meets twice a year, and at each meeting there is one science presentation, so it was a rare opportunity to showcase the work of ASP to this body. Thanks to all who contributed early results to this presentation, and thanks to Jeff for putting it all together and for an excellent presentation. [2006-07-11]

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Program News

ASP Science Steering Committee. On March 15, 2005, Peter Lunn, DOE Program Director for the Atmospheric Science Program announced the membership of the ASP Science Steering Committee, as follows:

In his letter to the newly named members of this committee Peter wrote as follows:

Thank you for agreeing to serve on the ASP Science Steering Committee (SSC). I am delighted to have you all as part of the program and for you to be playing this important role within the program.

We will endeavor to meet and coordinate as much as we can electronically, to minimize the burden. We anticipate that the duration of membership shall coincide with the funding cycle, i.e., the current cycle is FY 2005- FY 2007.

The purpose of the committee is simply to enhance the effectiveness of the program, by providing scientific insights and encouragement to the chief scientist and program manager.

While the specific roles and opportunities are by no means fixed, there are several areas where we believe you can help us a great deal.

1. By providing feedback on the list of program deliverables that Steve Schwartz and I are compiling at the moment. These deliverables need to be both measurable, accomplishable, and meaningful.

2. By identifying, proposing, evaluating, and recommending field campaigns that will advance the state of the science in the context of ASP and the national Climate Change Science Program. Although we are committed to the first two campaigns, Point Reyes and Mexico City, we welcome your counsel on these as well as prospective future campaigns,

3. By helping us establish and maintain connections to external communities, especially in the sense of the climate modeling community and the customers we should be serving.

4. By recommending the focus of our next ASP research announcement, through identifying gaps and priorities in the program. This is quite important to lay the groundwork for the next funding cycle.

Again, thank you. We very much appreciate your willingness to serve in this capacity, and we look forward to working more closely with all. [2005-03-22]


Report to BERAC. ASP Program Director Peter Lunn presented a report on the status of ASP to the semi-annual meeting of the DOE Biological and Environmental Research Advisory Committee, in April, 2005. A copy of his viewgraphs may be downloaded here. [2005-05-05]


ASP Science Team Membership. Peter Lunn, Program Manager for ASP has announced the Science Team projects to be supported in ASP based on the peer review and programmatic review of proposals and grant applications received in response to the DOE program announcement for the Atmospheric Science Program. Also announced were the infrastructure projects that will provide support for these activities, mainly in conjunction with the field measurements component of the program. More [2004-11-12]


Program News Archive

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Contacts

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