Water Resources Research Act Program

Details for Project ID 2007AK64B

Increasing coverage of Alaska within the global network of isotopes in precipitation

Institute: Alaska
Year Established: 2007 Start Date: 2007-03-01 End Date: 2008-02-28
Total Federal Funds: $23,237 Total Non-Federal Funds: $11,038

Principal Investigators: Matthew Wooller

Project Summary: The stable oxygen and hydrogen isotopic compositions of water are widely used as tracers to study the global hydrological cycle. The heavy isotope content of precipitated water and snow varies widely and predictably across the globe, providing a label that is incorporated in climate archives (e.g., ice cores and lake sediments) and picked up as biosignatures by animals and plants when local water is consumed. The patterns of precipitated isotopes are a product of global and local meteorology processes. As a result, these isotopes serve as ideal hydrological tracers and have been applied to study past climate, paleohydrology, wildlife migration, archeology and forensics. Realizing the potential for application of water stable isotopes in a number of scientific disciplines, the World Meteorological Organization (WMO) and International Atomic Energy Agency (IAEA) established the Global Network for Isotopes in Precipitation (GNIP) in the early 1960s. This worldwide network of precipitation-monitoring stations persists and continues to evolve today. However, the GNIP data measurements are distributed very unevenly in space. Currently Alaska, with only three data points (Anchorage, Barrow, and Nome), is one of the most sparsely represented states in the USA. It is necessary to increase Alaskas spatial resolution within GNIP. Optimal geographic areas to include and to examine short-term climate changes are localities representing boundaries between climate zones, where ecosystems are very sensitive to changes in air mass transportation, precipitation and evaporation. Southwest Alaska, extending from central Alaska to coasts of Bristol Bay, is an ideal region to investigate past and current environmental change. The region is located at the edge of the Aleutian low-pressure cell in the winter and the North Pacific subtropical high-pressure cell in the summer. The area is also characterized by a transitional climate condition between maritime and continental climate zones. We have established a collaborative link with the National Weather Service at King Salmon in southwest Alaska. Since August 1st 2006 the staff at the King Salmon station have agreed to collect a minimum of at least one precipitation event for each day of precipitation for an entire year (August 1st 2007). These samples are sent to us to archive for stable isotope analysis. This proposal requests funds to analyze the stable hydrogen and oxygen isotope composition of these samples. These data will subsequently be examined relative to the comprehensive data (e.g., precipitation amount, air temperature, air pressure, and cloudiness) generated by the King Salmon weather station. These data will also be forwarded to GNIP for inclusion in the global database, increasing the number of locations represented within Alaska. These analyses will contribute to an enhanced understanding of climate changes in southwest Alaska using stable oxygen isotope analysis of precipitation, and they will allow a better understanding of the air mass movement and hydrology in the region.