Coupling Current, Waves, and Wind Stress Over the Gulf Stream
Environmental Engineering Graduate Seminar
Qi Shi, Postdoc Scholar, Great Lakes Research Center,
Michigan Technological University
The exchanges of momentum, heat, moisture, and gas across the air-sea interface play crucial roles in atmospheric and oceanic circulations on variety of spatial and temporal scales. Therefore, improved understanding and realistic simulations of air-sea fluxes are critical to advancing oceanic and atmospheric prediction capabilities. This study provides the first detailed analysis of oceanic and atmospheric responses to the current-stress, wave-stress, and wave-current-stress interaction around the Gulf Stream using a high-resolution three-way coupled regional modeling system. In general, our results highlight the substantial impact of coupling currents and/or waves with wind stress on the air-sea fluxes and upwelling/downwelling in the upper ocean over the Gulf Stream. In the wave-current-stress coupled experiment, wind stress increases by 15% over the Gulf Stream. Alternating positive and negative bands of changes of Ekman-related vertical velocity appear in response to the changes of wind stress curl along the Gulf Stream, with magnitudes exceeding 0.3 m/day (95th percentile). This small-scale feature is also revealed by four-year averages of 25-km scatterometer observations. The response of wind stress and its curl to the wave-current-stress coupling is not a linear combination of responses to the wave-stress coupling and the current-stress coupling. Therefore, both waves and currents, and their interactions should be included in coupled models. Considerable changes of latent heat flux in excess of 20 W/m2 and sensible heat flux in excess of 5 W/m2 are found over the Gulf Stream in all coupled experiments. Sensitivity test shows that SST-induced difference of air-sea humidity is the major contributor to the LHF change.
Qi Shi got her bachelor’s degree in Atmospheric Science from Nanjing University, China. She moved to the U.S. in the fall of 2010 for graduate school at the Florida State University. Qi received Master’s and Ph.D. degree in Meteorology in 2014 and 2017 respectively. Qi’s Ph.D. research focused on coupled atmosphere-ocean model development and validation. Qi joined the Great Lakes Research Center as a Postdoc Scholar this May.
Monday, October 22, 2018 at 3:00 pm to 4:00 pm
Great Lakes Research Center (GLRC), 202
1400 Townsend Drive, Houghton, MI 49931