EOL Seminar: Fingerprinting changes in hydrologic balance from cloud to regional scales

Friday, June 16, 2017 - 14:00 to 15:00
FL2-1022 Large Auditorium
Contact Name: 
Holger Voemel
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Fingerprinting changes in hydrologic balance from cloud to regional scales

Dr. Adriana Bailey of Dartmouth

As global temperatures rise, many of us will experience climate change through the water cycle—through intensification of precipitation, changing patterns of floods and droughts, loss of mountain glaciers and sea ice, and sea-level rise. The water cycle will also play a key role in determining the magnitude of these changes by modifying Earth’s temperature response to greenhouse-gas forcing. For these reasons, understanding the processes that regulate changes in humidity, cloudiness, and precipitation—both locally and globally—is critical. This presentation develops a novel framework for investigating variations in the hydrological cycle using the isotopic fingerprints of hydrogen and oxygen in water. These fingerprints allow one to distinguish air masses by their water cycle histories due to the fact that isotopically heavy water molecules preferentially condense while isotopically light molecules evaporate. When integrated across large geographic areas, such distinctions permit one to detect shifting regional moisture imbalances between precipitation and evaporation. Satellite data and model simulations suggest this application can provide a much-needed observational constraint for estimating intensification of the global hydrological cycle. Isotopic fingerprints can also be used to estimate the precipitation efficiency of individual storms. Multi-year measurements from the Mauna Loa Observatory demonstrate how this characterization helps elucidate the oft-entangled roles of large-scale dynamics and microphysics in modifying concentrations of aerosols and trace gases. Future plans to observe variations in the precipitation efficiency of dynamically similar weather systems will be discussed since such efforts constitute a key step toward identifying controls on subtropical cloudiness and reducing the large uncertainties associated with cloud-climate feedbacks in models.

Seminar will be webcast at: http://www.fin.ucar.edu/it/mms/fl-live.htm

Friday 16 June, 2017 2:00pm

3450 Mitchell Lane Boulder, CO

FL2-1022 Large Auditorium