Department of Climate and Space Sciences and Engineering in the College of Engineering at the University of Michigan

Alumnus of the Year Lecture - Dr. Dan Cayan

Date: October 4, 2018
Time: 3:30 pm - 4:30 pm
Location: CSRB Auditorium, room 2246

Our guest for this year's CLaSP Alumnus of the Year Lecture will be Dr. Dan Cayan of Scripps Institution of Oceanography, University of California San Diego. Please join us! 

Title: "Climate change, water availability, and hydrologic extremes in the western U.S."

Abstract: In contrast to the midwestern U.S., much of the western United States, and especially California, has a pronounced seasonal precipitation regime, with the majority of precipitation falling between November through March. Interannual fluctuations in the Pacific storm activity that delivers precipitation to West Coast create challenges for humans, agriculture and natural systems. Climate changes will very likely amplify the challenges in managing and planning for secure water supplies and safety from water hazards in the western United States. A seasonal mountain snowpack has historically provided water supply for the region, although fluctuating precipitation and temperatures modulate the amount and characteristics of this natural supply, including rain/snow elevations and the timing and amount of snowmelt.  Significantly warmer winters and springs since the mid-1970’s have diminished western snow packs by approximately 10% over climatological norms from earlier decades.  This warming has resulted from a combination natural fluctuations but also by mounting levels of atmospheric greenhouse gases. Likely increases in anthropogenic climate changes over the next several decades would result in further warming and change important characteristics of precipitation. These changes would further diminish snow, increase rain, and alter seasonal runoff from mountain catchments.  Increased moisture loss to the atmosphere would reduce streamflows in western watersheds, and would likely exacerbate dry spells as summer soil moisture is depleted. Depleted spring snowpack, earlier melt and increased drying will exacerbate wildfire danger, which is already a chronic issue across western U.S. forests and shrublands. Conversely, the largest storms, often in the form of atmospheric rivers are projected to increase in intensity as global climate warms.  The largest storms supply a large fraction of the region’s water, and the presence or absence of these largest storms is an important driver of whether a given year is wet or dry.   Increased storm intensity would sometimes be hazardous, though-- Increased storm precipitation along with heightened freezing levels would cause greater flood volumes.

Upcoming Events

November 22nd
12:00 am - 11:59 pm
Thanksgiving - No Seminar
November 29th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Dr. Valentin Pillet
December 6th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Prof. Justin Kasper
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