Abstract ATM-9414381 Fritz, Sherilyn C. University of Minnesota This award supports the study of fossil diatom assemblages as paleohydrological/paleoclimatic indicators in Moon Lake,a closed- basin lake in the northern Great Plains. This study will attempt to reconstruct changes ineffective moisture (precipitation minus evapotranspiration. The historical relationship between diatom- inferred salinity and climate will be used to calculate a transfer function for effective moisture and hydrological drought (Palmer Hydrological Drought Index) which will then be extended to the entire post-glacial record. Climatic conditions will be assessed at century-scale resolution through the entire Holocene and at decadal-scale resolution during three periods: the last glaciation- deglaciation period, the early-Holocene forest/prairie transition, and past 2000 years. Paleoclimatic records from climatically sensitive agricultural regions such as the Great Plains, where little is known of past climate, and what is known is of a coarse resolution, will provide a valuable contribution to the understanding of climatic variability on local, regional, and global scales. Understanding drought characteristics through the analysis of long-term trends in the paleoclimatic record will provide valuable information for planning and managing water shortages that may accompany future drought events.
