Climate Hazards Group Seminar: Optimal Ranking Regime Analysis of U.S. Climate Variability: 1896-2012



10/16/2015 - 12:00pm to 10/17/2015 - 11:45am


Dr. Steven Mauget


The ability to predict seasonal climate, and to understand low frequency climate cycles that may rival or even dominate greenhouse warming effects over some areas of the U.S., requires a better understanding of low frequency climate mechanisms. However, understanding oceanic temperature cycles such as the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) and identifying the timing, geographic location, and seasonality of their effects over the continental U.S. requires that they first be correctly detected in observed data.  Here, multi-decadal cycles in U.S. precipitation and temperature variability during 1896-2012 are studied using a time series analysis method -­ the Optimal Ranking Regime method ­- that is particularly well suited to identifying low  frequency climate effects.  In precipitation data a multi-decadal regime of wetter Fall conditions east of the Rockies is evident after 1970. Although a warming trend similar to the hemispheric trend is evident over the areas of the western and northeastern U.S., eastern  temperature regimes in annual, winter, summer and fall temperatures are  more coincident with cool and warm phase periods of the AMO. Given evidence of the sudden onset of cold winter temperatures in the eastern U.S. during  1957-1958,  the cause and duration of  a period of cool temperatures occurring between the late 1950¹s and late 1980¹s - ­referred  to by  some as the 'Warm Hole' period - is discussed.


Dr. Mauget obtained his B.S. Physics  at U.C Santa Cruz (1986) and M.Sc. PhD in Atmospheric Science at U.C. Davis (1996).  Since 1997 he has been working at the USDA/ARS, Plant Stress and Water Conservation Lab. His most recent research project focuses on managing and modeling deficit irrigation and limited rainfall for crop production in semi-arid regions. Dr. Mauget has authored/coauthored numerous publications on topics related to climate variation and change and agriculture. His publications and research projects can be assessed at: