Near-term Plans: Climate Variability and Change

Okhotsk Ice Climate projections by coupled atmosphere-ocean global circulation models suggest significant environmental changes will occur in the Arctic during the next 80 years. Given the large potential impacts, and the significant uncertainty in the model projections, the U.S. Department of the Interior is developing a long-term permafrost monitoring network on Federal lands in northern Alaska; this network contributes to the Global Terrestrial Network for Permafrost and the Global Climate Observing System. Analysis of data acquired thus far by the monitoring network suggests that permafrost temperatures on the western half of the Arctic Coastal Plain in Alaska may have warmed several degrees Celsius between 1980 and 2005.

This activity will address Goals 1 and 4 and Questions 4.3 and 4.5 of the CCSP Strategic Plan.

Yukon River Basin: An Arctic Benchmark.

A developing consortium of U.S. and Canadian Federal, state, and provincial agencies, university scientists, and tribal organizations is initiating a major campaign to understand and predict climate-induced changes to the air, water, land, and biota within the Yukon River Basin (YRB). The consortium will implement a prototype environmental monitoring and research strategy that links air, water, soil, and forest information to understand changes in carbon and energy budgets across the Arctic, boreal, and Arctic Ocean systems. This collaborative scientific campaign, using the YRB and adjacent coastal ocean as a representative landscape unit, will provide a benchmark for tracking and understanding changes occurring throughout the Arctic and subarctic region.

This activity will address Goals 1, 2, and 4 and Questions 4.3, 4.4, 6.4, and 7.1 of the CCSP Strategic Plan.

Field Experiment to Improve Understanding of Southeast Pacific Climate Processes.

Islands The Variability of the American Monsoon System (VAMOS) Ocean-Cloud-Atmosphere-Land Study - Regional Experiment (VOCALS-REx) is planned for October and November 2008. This international field experiment is designed to better understand physical and chemical processes central to the climate system of the Southeast Pacific (SEP) region. The climate system of the SEP involves tightly coupled, but poorly understood, interactions among the ocean, atmosphere, and land. VOCALS-REx will focus on interactions among clouds, aerosols, marine boundary layer processes, upper ocean dynamics and thermodynamics, coastal currents and upwelling, large-scale subsidence, and regional diurnal circulations to the west of the Andes mountain range (see Figure 3). Multidisciplinary intensive observational data sets will be obtained during VOCALS-REx from several platforms including aircraft, research vessels, and a surface land site. An intensive observational period will take place during October and November, when the extent of stratocumulus over the SEP is at its greatest, the southeast trade winds are at their strongest, and the coupling between the upper ocean and the lower atmosphere is at its tightest.

This activity will address Goals 1 and 2 and Questions 3.1 and 4.2 of the CCSP Strategic Plan.

Figure 3: The Southeast Pacific Climate System. Schematic view of the coupled ocean-atmosphere-land system in the vicinity of the southeast Pacific. The interactions among clouds, aerosols, coastal upwelling and currents, upper ocean dynamics, and regional circulations influenced by the Andes are poorly understood and not well modeled, and yet these interactions over the southeast Pacific affect regional and global climate. Surface winds, faced with the Andes barrier, flow parallel to the coast and bring deep, nutrient-rich waters to the surface. These cold waters, aided by an air mass made stable in part by effects of the Andes, help support the largest and most persistent subtropical sheet of stratus and stratocumulus clouds on the planet. This cloud deck, affected by aerosols from both natural and human sources, helps in turn to maintain cool ocean waters beneath. A field campaign, VOCALS, is planned in 2008 to obtain measurements to better understand this complex system and to provide a basis for model improvements. Credit: R. Wood, University of Washington.

Constructing a Satellite-Era Reanalysis of the Coupled Ocean-Atmosphere System.

A national capacity for integrated Earth system analysis is being developed that extends beyond current attempts to map individual components of the Earth system separately. Achieving this capability requires parallel advancements in coupled Earth system modeling, and considerable progress is being made in this latter arena, particularly with the adoption by the research and operational forecasting communities of a common Earth system modeling framework. A coupled ocean-atmosphere model is currently in operational use, and during 2008 this model will serve as the basis for beginning the first attempt to create a reanalysis of the coupled ocean-atmosphere system dating back to the start of the satellite era (1979) through 2007. Development of a coupled ocean-atmosphere analysis capability will also support intensified efforts to improve the monitoring and understanding of changes in the ocean thermohaline circulation.

This activity will address Goals 1 and 3 and Questions 4.2, 4.4, and 4.5 of the CCSP Strategic Plan.

Creating a Historical Reanalysis of the Atmosphere of the 20th Century.

ElNino Recent research has shown the feasibility of using modern data assimilation techniques together with observations of sea-level pressure to produce, for the first time, a global analysis of tropospheric weather patterns at 6-hour temporal resolution that extends over the entire 20th century. Production of this historical reanalysis will be initiated in 2008, with the goal of at least doubling the length of current reanalysis records, which now extend back only until 1948. This historical reanalysis will enable researchers to address such questions as the range of natural variability of high-impact events like floods, droughts, hurricanes, and extratropical cyclones, and how ENSO and other climate modes alter these events. A century-long reanalysis will also help to clarify the origins of climate variations that produced major societal impacts and profoundly influenced policies, including the 1930s "Dust Bowl" drought and the prolonged cool, very wet period in the western United States early in the 20th century that led to over-allocation of Colorado River water through the 1922 Colorado Compact.

This activity will address Goals 1 and 3 and Questions 4.2, 4.4, and 4.5 of the CCSP Strategic Plan.

Drought in Coupled Models Project.

A new, multi-agency activity will support research into the physical and dynamical mechanisms of drought and the mechanisms through which drought may change as climate changes. Relevant issues include the role of the seasonal cycle in drought, the impacts of drought on water supplies, and the distinction between drought as a transient phenomena and drying produced by long-term changes in a region's water balance. A broad range of model simulations will be analyzed and evaluated in this effort, including multi-model simulations of 20th-century climate, model projections of future climate, paleoclimate simulations of the last glacial maximum, and seasonal model prediction data sets. The objective is to increase community-wide diagnostic research into the physical mechanisms of drought and to evaluate drought simulations by current models. This effort will lead to more robust evaluations of model projections of drought risk and severity, and to a better quantification of the uncertainty in such projections.

This activity will address Goals 1 and 3 and Questions 4.1, 4.2, 4.4, and 5.1 of the CCSP Strategic Plan.

For budget details, see: Climate Change Science Program. FY 2008 Scientific Research Budget by USGCRP Research Element

For long term plans, see Climate Variability and Change chapter of the Strategic Plan posted on web site of US Climate Change Science Program

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