Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Yochanan Kushnir

Kushnir is collaborating with researchers of the NOAA/ESRL Physical Sciences Laboratory and CIRES as part of a broader research goal to characterize, understand and attribute the space-time properties of extreme hydrological events in the Western U.S. Intense and/or prolonged precipitation event or long breaks between them are a serious natural hazard that regularly inflicts property damage and loss, causes environmental degradation, and often also leads to loss of life. We are therefore motivated to characterize them, understand their cause and predict their occurrence. It is also important to determine how the probability of such events and their spatial pattern will change in the future. During his visit, Kushnir is joining the study of the organization of high intensity hydrological events in space. He is interested in characterizing their seasonal distribution and links to large-scale atmospheric circulation features and global sea surface temperature variations. Kushnir is using different accepted indices (metrics) of extremes that are determined in a similar manner from station observations, reanalyses, and climate models. Clusters of events are identified and related to sea surface temperature anomalies and large-scale atmospheric circulation patterns on time scales from the intraseasonal, to the interannual and to multi-year anomalies. Building such links enables understanding how extreme events are governed and form, verify that models used in climate predictions and projections can correctly simulate them and ultimately aid in developing applications that can assist decision makers in addressing the hazard posed by such events.