Journal of Geophysical Research: Atmospheres RESEARCH ARTICLE Understanding the Dominant Sources and Tracks of Moisture 10.1029/2017JD027652 for Summer Rainfall in the Southwest United States Key Points: Srijita Jana1,2 , Balaji Rajagopalan1,2 , Michael A. Alexander3 , and Andrea J. Ray3 • The leading source of moisture varies depending on the part of the region 1Department of Civil, Environmental and Architectural Engineering, University of Colorado Boulder, Boulder, CO, USA, • Land is an important source of 2 3 moisture during the summer season Cooperative Institute of Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA, NOAA • Large-scale circulation features are Earth System Research Laboratory, Boulder, CO, USA consistent with major pathways of moisture Abstract We investigated the moisture sources and tracks that enable summer rainfall over the four-state Supporting Information: southwestern U.S. region of Arizona, New Mexico, Colorado, and Utah by employing a high-resolution • Supporting Information S1 Lagrangian particle tracking model. Six locations were selected—Cedar City (Utah), Grand Junction • Table S1 (Colorado), Eastonville (Colorado), Laveen (Arizona), Redrock (New Mexico), and Melrose (New Mexico) • Table S2 —together, they represent six spatial regions of summer precipitation for the Southwest. Moisture tracks – Correspondence to: were generated for all the rainy days at these stations for the historical period 1979 2013. Tracks were S. Jana and B. Rajagopalan, generated for a 3-day period ending with the day of rainfall, which were then used to identify the
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