Lara Tobias-Tarsh
Pronouns: she/her
Research Mentor(s): Andrew Gronewold
Co-Presenter:
Research Mentor School/College/Department: School for Environment and Sustainability / SNRE
Presentation Date: April 20
Presentation Type: Poster
Session: Session 2 – 11am – 11:50am
Room: League Ballroom
Authors: Lara Tobias-Tarsh, Andrew Gronewold
Presenter: 45
Abstract
Precipitation patterns fluctuate naturally, however in the last decade these have become significantly more accented, likely under the influence of climate change. Significant flooding events have become more frequent across the globe, causing a host of socio-economic and environmental issues in the affected areas including in North America, with a marked increase in precipitation occurring alongside these events. The Great Lakes Basin is no exception to this trend, experiencing a marked increase in precipitation since 2012, with particularly extreme precipitation increases occurring in 2012 and 2014. This is currently unexplained, and is not evident in Global Climate Model (GCM) forecasts, indicating that climate change may also be impacting the effectiveness of historical analogues. Changes in extratropical cyclone tracks through the basin is a possible contributing factor: cyclones originating in areas with higher levels of atmospheric moisture such as in the Gulf of Mexico may bring higher precipitation rates, a directional shift in common cyclone tracks may change synoptic patterns that bring moisture into the basin, whilst increased extratropical cyclone frequency will likely increase the frequency of high precipitation events. This paper investigates the frequency, origin and track of all extratropical cyclones entering the Great Lakes Basin since 1979 using the ECMWF ERA-5 reanalysis, then examines observed precipitation in the basin associated with these extratropical cyclones. An increase in extratropical cyclones entering the basin is expected to be found from 2012 to 2020, likely correlated with an observed increase in precipitation. Anomalously high precipitation years are also analyzed. Finally these differences in cyclone track, origin and precipitation rates are compared to GCM forecasts as well as medium range global ensemble forecast models to determine areas in which these models fall short, allowing for suggestions of model improvement.
Engineering
