Ocean Sciences

COMPASS (Combined OCE MPO ATM Seminar Series) FRIDAY

SPRING 2018

(11:00 in the Auditorium)

Jan 19: NO SEMINAR

Jan 26: NO SEMINAR (OCE Faculty Retreat)

Feb 02 (2:00 pm): Dr. Jie He (Princeton University / Georgia Tech)

"Quantifying Tropical Air-Sea Interactions"

It is well accepted that tropical atmospheric variability is largely regulated by variations in sea surface temperature (SST). On the other hand, the atmosphere is able to generate variability internally, which in turn influences the SST. As a result, the coupled climate system reflects a complex combination of oceanic and atmospheric forcing. This makes it challenging to understand either process directly from coupled air-sea relationships. For example, observations show a very weak correlation between convection and SST variability at high background SSTs. While this led some early studies to counterintuitively suggest that the SST forcing of convection might be weak in warm pool regions, the weak correlation could also result from a large atmospheric intrinsic variability. In this study, I will show that the uncoupled atmosphere-only simulations are a perfect stepping stone to understanding coupled air-sea relationships due to their ability to isolate SST forcing. Using these atmosphere-only simulations, I will discuss precipitation and evaporation sensitivity to tropical SST variability and will attempt to clarify some previous misunderstandings on this subject. I will finally present a linear framework derived from atmosphere-only simulations as an effective tool for the quantitative understanding of tropical air-sea relationships.

Feb 09: NO SEMINAR (Recruitment Day)

Feb 16: NO SEMINAR (Ocean Sciences Meeting)

Feb 23: Student Seminars

James Hlywiak (MPO): "Coupled 3d Numerical Simulations of the Effects of Ocean Salinity on TC Intensity"

Jeremy Klavans (MPO): "Estimating the Magnitude of the Lagged SST Response to the North Atlantic Oscillation"

Bosong Zhang (MPO): "Quasi-Biennial Oscillation - Madden-Julian Oscillation Connection"

Activities of the Madden-Julian Oscillation (MJO) in boreal winter has recently been found to be stronger in easterly phases of the stratospheric quasi-biennial oscillation (QBO) than its westerly phases. This QBO-MJO connection was investigated in this study using a method that identifies individual MJO events by tracking their eastward propagating signals in precipitation. Stronger MJO activities in QBO easterly phases are a consequence of more MJO days, not larger amplitudes of individual MJO events as previously thought. More MJO days come from more MJO events initiated over the Indian Ocean and their longer duration because of a weaker barrier effect of the Maritime Continent on MJO propagation. Zonal heterogeneity exists in the connection between QBO, MJO, and tropical total precipitation in general. This poses a challenge to our current understanding of the MJO dynamics, which has yet to fully include upper-tropospheric and stratospheric processes.

Mar 02: Kaycie Lanpher (OCE), Molly Martin (MAC), Mingming Shao (AMP)

Mar 09: Dr. Claire Paris (RSMAS)

Mar 16: NO SEMINAR (Spring Recess)

Mar 23: John Lodise, Joshua Wadler, Jianhao Zhang

Mar 30: Luna Hiron, Steven Simon, Rachel Sodowsky

Apr 06: Marybeth Arcodia, Xingchen Yang, Wei Zhang

Apr 13: Simge Bilgen, Yi Dai, Yu Gao, Matthew Grossi

Apr 20: Romain Chaput (OCE), Houraa Daher (OCE), Shannon Doherty (OCE)

Apr 27: Alessandro Cresci (OCE), Valeria Donets, Mampi Sarkar