Atmospheric Composition
Near-Term (Fiscal Year 2008) Plans

Atmospheric Composition

Overview

Recent Accomplishments

Near-Term Plans

Archived News Postings [June 2000 - July 2005]

Related Sites

Calls for Proposals

CCSP / USGCRP Atmospheric Composition Working Group Members

For long term plans, see Atmospheric Composition Chapter of the Strategic Plan posted on web site of US Climate Change Science Program

Past Accomplishments:

Recent

Fiscal Year 2006

Fiscal Years 2004-2005

Fiscal Year 2003

Fiscal Year 2002

Fiscal Year 2001

Fiscal Year 2000

Climate Change Science Program.  FY 2008 Scientific Research Budget by USGCRP Research Element

HIGHLIGHTS OF PLANS FOR FY 2008

Tropical Composition, Clouds, and Climate Coupling.

CCSP researchers will begin their analysis of data from a FY 2007 field mission in Costa Rica to study how climate is linked to atmospheric composition and clouds in the tropical summer convective wet season. This successful Tropical Composition Cloud and Climate Coupling field mission involved three major aircraft (DC-8, ER-2, WB-57F) making over 20 research flights, using some 60 instruments, involving balloon launches from three locations, and engaging over 250 participants. Analyses will incorporate data from aircraft flights and ground measurements, as well as Aura satellite observations, to address scientific questions related to how clouds, aerosols, and trace gases influence radiative heating in the very active tropical atmosphere.

These activities will address Questions 3.1 and 3.2 of the CCSP Strategic Plan.

International Polar Year Research on Arctic Aerosols and their Connections to Clouds, Radiation, and Ice Melting.

The long-range transport of anthropogenic pollution from North America, Europe, and western Asia creates the aerosols associated with the so-called Arctic haze, a phenomenon that recurs every winter and spring. The direct and indirect climate impacts of the aerosols can be quite different in the Arctic compared to elsewhere, because high surface reflections from snow and ice mean that even weakly absorbing aerosol layers can heat the Earth/atmosphere system in the Arctic. As part of International Polar Year (IPY) research, CCSP scientists will conduct field missions to investigate Arctic aerosol/climate connections in this unique environment. Spring and summer measurements from satellites, aircraft, and the surface will be made in collaboration with the larger IPY study POLARCAT (Polar Study using Aircraft, Remote Sensing, Surface Measurements, and Models of Climate, Chemistry Aerosols, and Transport). Springtime observations will be made to assess the long-range transport of anthropogenic pollution to the Arctic and its contribution to Arctic Haze, ozone chemistry, and the possible connections between Arctic aerosols and the melting of polar ice. Summertime observations will be made to assess fire emissions from the boreal forests. Analyses of these measurements will ultimately improve the ability of current models to simulate the influence of anthropogenic pollution and boreal fires on the Arctic atmosphere and climate. In 2008, new aerosol measurements made on the North Slope of Alaska will be used to evaluate model simulations of clouds and aerosol influences in the Arctic.

This activity will address Questions 3.1 and 3.3 of the CCSP Strategic Plan.

Completion of CCSP Synthesis and Assessment Product 2.3.

CCSP researchers will finalize the second phase of CCSP Synthesis and Assessment Product 2.3, Aerosol Properties and their Impacts on Climate. The first phase of development of this product was to produce major scientific reviews on the following three topics: dependence of radiative forcing by tropospheric aerosols on aerosol composition in the north Atlantic, Pacific, and Indian Ocean regions; measurement-based understanding of aerosol radiative forcing from remote-sensing observations; and model intercomparison to quantify uncertainties associated with indirect aerosol forcing. The second-phase product will draw upon the scientific information gathered by the development of the Intergovernmental Panel on Climate Change Fourth Assessment Report and the National Research Council review, Radiative Forcing of Climate Change. Authors will draw from these community-wide assessments of climate change (and the aerosol- climate topic inclusively) in writing this synthesis and assessment product.

This activity will address Questions 3.1 and 3.2 of the CCSP Strategic Plan.

VOCALS Cloud/Aerosols Field Study.

Extensive and persistent layers of stratus clouds occur off the subtropical west coasts of Africa and of North and South America. These cloud decks have a significant impact on Earth's radiation budget. Aerosols, arising from natural processes and from human activity, have important influences on the brightness and persistence of these clouds. The Variability of the American Monsoon System (VAMOS) Ocean-Cloud-Atmosphere-Land Study (VOCALS) is planning a field campaign that will study the stratus deck off the Pacific coast of Chile and Peru, using in situ and remote aircraft observations, along with satellite and ship-based measurements. Natural and human sources of particles will be observed, as well as the roles these particles play in the determining the brightness and lifetimes of stratus clouds. The VOCALS field campaign is planned for October 2008; preliminary work to simulate the southeast Pacific stratus deck will begin earlier that year.

This activity will address Questions 3.1, 3.2, and 3.3 of the CCSP Strategic Plan.

The Ice in Clouds Experiment.

The Ice in Clouds Experiment (ICE) will take place in November 2007. The goal of this study is to improve understanding of ice nucleation in the atmosphere. This knowledge will improve the modeling of ice cloud formation, precipitation, and climate effects. The specific objective of ICE is to show that under given conditions, direct measurements of the thermodynamic and kinetic environments of clouds (temperature, humidity, wind) and specific measurable characteristics of the aerosol, including chemical composition, can be used to predict the number of tiny ice particles that are initially seeded by existing atmospheric particles. ICE will use airborne measurements of clouds along with coordinating ground measurements in mountainous locations such as the Front Range of Colorado and Wyoming. Close collaboration between theory, field, lab, and modeling studies will be emphasized.

This activity will address Questions 3.1 and 3.3 of the CCSP Strategic Plan.

Completion of CCSP Synthesis and Assessment Product 2.4.

In FY 2008, CCSP researchers will finalize CCSP Synthesis and Assessment Product 2.4, Trends in Emissions of Ozone-Depleting Substances, Ozone Layer Recovery, and Implications for Ultraviolet Radiation Exposure. This report will focus on updating trends in stratospheric ozone, ozone-depleting gases, and ultraviolet exposure, and on improving model evaluations of the sensitivity of the ozone layer to changes in tropospheric composition and climate, along with the implications for the United States. This information is key to ensuring that international agreements to phase out production of ozone-depleting substances are having the expected outcome: recovery of the protective ozone layer.

This activity will address Question 3.4 of the CCSP Strategic Plan.