JNTP-DTC Sponsored Seminar - Gary Lackmann - North Carolina State University

Using the WRF Model to Investigate Climate Change Influence
on the Track and Intensity of Hurricane Sandy

Gary M. Lackmann
Department of Marine, Earth, and Atmospheric Sciences
North Carolina State University
Developmental Testbed Center, August 2014

Hurricane Sandy was associated with historic societal impacts when it made landfall
along the New Jersey shore in late October 2012. The event generated vigorous
discussions as to whether the severity, or perhaps occurrence, of the event was tied to
anthropogenic climate change. Two related questions are (i) whether the frequency of
this type of event is altered by anthropogenic climate change, and (ii) if the synoptic
pattern accompanying Hurricane Sandy had taken place 100 years ago (or 100 years in
the future), how would the track, intensity, and impacts have differed? Here, we
investigate question (ii) using a simplified approach that is designed to quantify the
storm-scale changes attributable to large-scale thermodynamic changes. First, hypotheses
are presented as to how and why we would expect climate change to alter Sandy’s track
and intensity. An ensemble of WRF model simulations, in conjunction with GCM derived
large-scale thermodynamic changes, is used to analyze changes between current, past, and future versions of Sandy.


The impact of climate change on the synoptic steering features suggests offsetting
processes. Warming and increased precipitation/condensational heating would strengthen
the downstream ridge to the north of Sandy, resulting in stronger westward motion.
Diabatic weakening of an upper-level trough to the south of Sandy would have the
opposite effect. Increased upper-level westerly flow would lead to more progressive
synoptic features, suggesting a more eastward track with warming. Numerical
experiments are required to determine which effect, if any, dominates. For this
presentation, I will explore some of the WRF features that enable skillful simulations of
the storm. Results indicate that climate warming to date had limited effect on the
observed Sandy, but that projected future warming would result in a significantly
stronger storm with a more northward landfall location. Research to date has not directly
addressed the question of climate-change influences on Sandy’s genesis or early track
evolution.


Date:     Monday, August 11, 2014
Time:     3:30pm
Place:    FL 2 Rm 1022


This seminar will be recorded and available via webcast at:
http://www.fin.ucar.edu/it/mms/fl-live.htm

About you
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Marybeth
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Zarlingo
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2751
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Marybeth
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Zarlingo
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Monday, August 11, 2014
End: 
Monday, August 11, 2014