US Fish and Wildlife Service Grant for Alaska Precipitation Trends Research

PURPOSE:

A detailed understanding of historical climatology is needed to assess how potential future changes in temperature and precipitation may impact fish and wildlife and their habitats in Alaska. Precipitation trends in Alaska are poorly understood, due to the high spatial variability as well as the difficulties in measuring precipitation. Understanding historic trends in precipitation will help inform downscaled climate models essential to land managers.

The purpose of this agreement is to provide support to TWS so that it can reconcile variability in Alaska�s precipitation data to better understand how climate may have changed in recent history and to help refine projections of potential future climate change. They will compile climate data from weather stations across Alaska, assess data for homogeneity, determine whether detected inhomogeneities in station-based precipitation data are associated with changes in station location or the manner in which it is operated, or are related to historical climate variability, evaluate actual trends in precipitation using two analytical methods over both short and long analytical periods, and characterize variability in the historical climate of Alaska�s Arctic and other critical habitats used by species migrating to the Arctic.

REASON FOR SINGLE SOURCE:

Unique Qualifications � The staff currently employed by the Wilderness Society are uniquely qualified to accomplish this project due to the following factors:
1) existing technical expertise, local knowledge, and familiarity with existing data sets;

2) specialized and demonstrated expertise in homogeneity assessment of the station and the gridded data and to the Man Kendall trend calculations on precipitation data sets. Prior experience includes assessment of homogeneity of temperature time series from several stations in Bulgaria using the methodology proposed for this research project, performance of non-parametric Man Kendall trend analysis of the same temperature data and of circulation frequency and persistence data for the European-North Atlantic domain.

3) performance of non-parametric Man-Kendall trend evaluation of a set of station temperature data from Colorado related to the preparation efforts for �Climate Change in Colorado: A synthesis to support water resources management and adaptation�.

4) performance of a trend-free pre-whitening procedure (which consisted of removing the AR(1) process from the data) in order to assess the significance and the size of the identified trend without the impacts of the inherent autocorrelation of the temperature series. This methodology will be an important part of the proposed trend evaluation strategy for the station and gridded precipitation data from Alaska.

5) performance of a detailed homogeneity analysis of gridded observed precipitation data sets for the Colorado River basin using the same set of four absolute homogeneity tests (Guentchev G., J. Barsugli, J. Eischeid, 2010. Homogeneity of gridded precipitation data sets for the Colorado River Basin, Journal of Applied Meteorology and Climatology, vol. 49, 2404-2415).

6) Completion of a doctoral dissertation on understanding precipitation bias in general circulation models using a number of gridded precipitation products and reanalyses, including products from the University of Delaware, the Global Precipitation Climatology Project, the Global Precipitation Climatology Centre, PRISM, the NCEP-NCAR, NCEP-DOE, and ECMWF reanlyses, as well as station-based precipitation from the U.S. Historical Climatology Network.

7) thorough involvement in other aspects of this project outside of, but related to, the scope of work detailed in this grant agreement, including a survey and partial compilation of the available weather stations in Alaska.