Relationship between atmospheric circulation and winter precipitation δ18O in central New York State

Abstract

Oxygen isotope values of meteoric precipitation (δ18O) are strongly influenced by water vapor source and trajectory history, and can therefore be used as a tool for the reconstruction of atmospheric circulation. However, this approach requires an understanding of how differing patterns of atmospheric circulation influence precipitation δ18O. This study examines the relationship between atmospheric circulation and winter precipitation δ18O in central New York State. Circulation back trajectories, weather maps, and δ18O values for 132 precipitation samples were examined to determine the circulation type for each event. Lake-effect precipitation, which generated the lowest δ18O values, featured low pressure over New England and northwesterly flow over the Great Lakes. Events with the highest δ18O values were associated with low pressure north of New York and strong southerly flow within the warm sector. Less frequent were the Atlantic coastal and warm frontal overrunning events, both of which yielded relatively depleted precipitation. Copyright 2004 by the American Geophysical Union.