Use of Environmental Isotopes to Determine the Predominant Sources of Moisture that Drives the Precipitation Events in North-East Iowa
Mohammad Z. Iqbal, Department of Earth Science, UNI

This study is an inquiry into the evaporation-precipitation processes in northeast Iowa. Oxygen and deuterium isotopes in rainwater will be analyzed (in delta-notation) to determine what fraction of the atmospheric moisture is derived from the local surface water bodies (streams, lakes, etc.) during precipitation events. Deuterium excess parameter, based on 18O/16O and 2H/1H ratios in rain, will be used to determine the importance of a distant vapor source (e.g., oceans) in sustaining the regional hydrologic cycle in the area. In addition, the linear correlation of the isotopic ratio values of rainwater with air temperature, humidity and precipitation amount will be verified to predict long-term weather shifts. The above environmental isotopes are excellent climate indicators, and when properly used, can signal any short term and long term shift in precipitation patterns in a region. This project could be a good contribution to the numerous regional climate models that are currently in progress.more