Emissions from energy and other anthropogenic activities have been altering the chemical composition of the atmosphere, both regionally and globally. Such modifications are linked not only to environmental degradation and human health problems but also with changes in the most sensitive parts of the physical climate system namely, clouds and aerosols. The Intergovernmental Panel on Climate Change (IPCC) is making progress toward its next major report, the Fifth Assessment Report (AR5), which will be released in 2013 and 2014. As part of the IPCC assessment process, it has repeatedly been concluded that innovative measurement technologies are needed to provide both input and comparison data for models used to assess the impacts of e.g. energy emissions on the physical and chemical composition of aerosols with particular attention to their subsequent influence on cloud radiative properties. The technologies that are needed are required to have much high accuracy and time stability than has been available to the research community.
When the last IPCC report was published in 2007, there was a lack of data to adequately represent some of the more climate sensitive regions, namely the Arctic and tropics. The Arctic, in particular, continues to be one of the most difficult places on Earth for year-round scientific observations and research, due to a combination both of remoteness and the difficulty of observing under very cold conditions. One of the major recommendations of an Arctic Research Consortium of the U.S. (ARCUS), 1997 report, Logistics Recommendations for an Improved U.S. Arctic Research Capability (www.arcus.org-logistics-index.html
), was to increase use of robotic aircraft to meet the growing need for environmental observing in the Arctic. Partly in response to this recommendation, the DOE Atmospheric Radiation Measurement (ARM) program (http:--www.arm.gov-) increased its emphasis on arctic observations. In the meantime since the release of the 1997 report, there has been an increasing climate change signal in the Arctic; and models have been dramatically underpredicting the rate of change. The DOE Climate and Environmental Sciences Division identified in its recently released strategic plan to emphasize greater attention to Arctic (and tropical) atmospheric sciences, by investing in the development of science and predictability of the climate system, where more sophisticated measurement methods as well as computational and analysis technologies underpin the development. More advanced measurement capabilities for aerosol absorption and scattering, cloud properties, turbulence, and remote sensing are high priority needs of the atmospheric sciences, particularly when such technologies are deployable on small Unmanned Aerial Vehicles (UAVs).
Grant applications that respond to this Atmospheric Measurement Technology topic must propose Phase I bench tests of critical technologies. (Critical technologies refers to components, materials, equipment, or processes that overcome significant limitations to current capabilities.) In addition, grant applications should (1) describe the purpose and benefits of any proposed teaming arrangements with government laboratories or universities, and (2) support claims of commercial potential for proposed technologies (e.g., endorsements from relevant industrial sectors, market analysis, or identification of potential spin-offs). Grant applications proposing only computer modeling without physical testing will be considered non-responsive.
- c: Measurements of the Chemical Composition of Atmospheric Aerosols
Description: Enhanced measurement methods are needed for the real-time characterization of the bulk and the size-resolved chemical composition of ambient aerosols, particularly carbonaceous aerosols. Such improved measurements would be used to facilitate the identification of the origin of aerosols, (i.e., primary versus secondary and fossil fuel versus biogenic). Also, improved measurements are needed to help elucidate how aerosol particles are processed in the atmosphere by chemical reactions and by clouds, and how their hygroscopic properties change as they age. This information is important because relatively little is known about organic and absorbing particles that are abundant in many locations in the atmosphere. In particular, there is a need for instruments capable of real-time measurements of the composition of these particles at the molecular level. Although recent advances have led to the development of new instruments, such as particle mass spectrometers and single particle analyzers, existing instruments still have important limitations in their ability to quantify black carbon vs. organic carbon, provide speciation of refractory and volatile organic compounds, and calibrate both organic and inorganic components. Furthermore, instruments that otherwise would be suitable for ground-based operation often have limitations (size, weight, power, stability, etc.) that restrict their application for in situ measurements, where critical atmospheric processes actually occur (e.g., in or near clouds using aircraft or balloons).
In order to better understand the chemical composition of atmospheric aerosols, grant applications are sought to develop improved instruments, or entirely new measurement methods, that provide: (1) speciation of individual organics, including those containing oxygen, nitrogen, and sulfur; (2) identification of elemental carbon and other carbonaceous material, so that the makeup of the absorbing fraction is known; (3) identification of source markers, such as isotopic abundances in aerosols; and (4) the ability to probe the chemical composition of aerosol surfaces.
In order to address the deficiencies associated with current techniques, proposed approaches should seek to provide: (1) quantifiable results over a wide range of compounds, which is a deficiency of laser ablation aerosol mass spectrometer methods; (2) measurements over a range of volatility so that dust, carbon, and salt are detectable, which is a deficiency of thermal decomposition aerosol mass spectrometers; and (3) measurements with high time resolution, which is a deficiency of filter techniques. Proposed approaches that can measure aerosol chemical composition from airborne platforms would be of particular interest