2.2 Improve understanding of the composition of the Arctic atmosphere – moisture, clouds, precipitation, aerosols, and gases—their net radiative effects and impact on Arctic climate.
Changes in chemistry, moisture, and atmospheric state drive radiative forcing through a complex set of processes and interactions (Morrison, et al. 2012; de Boer et al. 2012). Long-term, continuous measurements at the surface are necessary to monitor trends in atmospheric composition, but must be complemented by in situ aerial measurements to provide process-level understanding and to fill observational gaps over regions and domains (e.g., sea ice and open ocean) that are not accessible from fixed site locations. Information describing the vertical structure of atmospheric constituents is critical to determining how and when the different constituents interact and their radiative effects. Measurements to gain such information are achievable through manned and unmanned aircraft programs, ground-based observations, and satellites.
Performance elements from the Arctic research plan
2.2.1 Maintain and enhance support for fixed ground sites that contribute to long-term observations of Arctic atmospheric components using in situ and remote sensing measurements of atmospheric state parameters, gases, aerosols, and clouds. Improve uniformity in the suite of measurements and data products across sites to provide “network” information for increased physical understanding and representation of the Arctic climate system.
2.2.2 Continue support for and planning and analysis of past and potential future aircraft missions (e.g., NASA Atmospheric Tomography Mission—AToM—and air Pollution in the Arctic: Climate, Environment, and Societies—PACES24) that contribute observations of atmospheric composition and relevant processes such as transport, deposition, and radiation.
2.2.3 Improve vertical and regional characterization of atmospheric gases, aerosol, and cloud properties through the use of existing, long-term data sets, together with new measurements, in underrepresented Arctic regions. Develop a better understanding of the representative nature of fixed sites by describing the range of conditions that exist across the Arctic.
2.2.4 In collaboration with efforts described under the Permafrost Goal, support observation syntheses of atmospheric carbon to provide better process understanding of the relationships between warming and soil carbon release in the Arctic. Integrate atmospheric measurements with related observations and modeling of land surface and environmental parameters to advance this process understanding.