The Roles of Clouds and their Accomplices in Modulating the Trajectory of the Arctic
The overarching objectives of the proposed effort are to identify and evaluate relationships between cloud properties, surface radiation fluxes, horizontal heat and moisture transport, large-scale circulation patterns, sea ice extent, and melt onset in past conditions when Arctic change was moderate, and in the future, which models project will be characterized by dramatic loss of permanent ice. Certain cloud-related interactions that were insignificant in the past may play more mid-latitude-like roles as the Arctic's ice disappears, such as exerting an overall cooling rather than warming influence. The proposed effort is aligned with the new directions of the ARCSS program, as it will improve our understanding of linkages among components of the Arctic system, build upon previous work and integrate existing data sets, address cross-cutting questions, investigate causes of spatial and temporal variability, and investigate relationships among components in a range of space and time scales. Data products are not expected from this study, thus a specific plan for data archival is not included. Intellectual merit: Existing data sets and reanalysis products will be combined with global climate model (GCM) simulations to identify and evaluate important factors affecting downwelling surface radiation fluxes, and how these influences vary: 1) in the past during large-scale and large-magnitude shifts in the climate system; 2) among model simulations of the past; 3) owing to local and remote variability; 4) seasonally; 5) and in model projections of future conditions. The expected outcome is a more complete understanding of processes and conditions affecting Arctic cloud properties, the ability of GCMs to simulate observed relationships among cloud properties and factors that influence them, which cloud-related parameters exert either enhancing or dampening effects on Arctic ice loss, and how those effects can be expected to evolve in the future as the Arctic system continues on its trajectory toward a new state. Broader Impacts: By its very nature, this project is interdisciplinary and cross-cutting. It focuses on relationships and interactions among various components of the climate system, both within and outside the Arctic, and how these relationships might change in the future. The relationships initially targeted encompass a variety of spatial and temporal scales. The broader impacts of the work, consequently, are naturally extensive across the scientific community. Graduate students at three universities will participate directly and/or indirectly in the project -- one explicitly at the University of Wisconsin -- and the methodology and results will provide new fodder for courses related to climate change. Ultimately the findings should contribute to better informing policy makers, which will benefit society as a whole. The Polar Science Center at the University of Washington has just completed its first annual Polar Science Weekend hosted by the pacific Science Center in Seattle. A combination of exhibits, demonstrations and lectures brought various aspects of polar research to approximately 5,000 participants, including K-12 classes and the general public. A module based on the roles of clouds in Arctic change will be developed for the events planned for 2008 and 2009.
