[Eoas-seminar] Meteorology Masters Defense - Daneisha Blair - June 16, 3:30 - Zoom

[eoas-seminar at lists.fsu.edu]

Meteorology Seminar

Daneisha Blair

Master's Meteorology Candidate



Title:  Impact of surface roughness and surface temperature on the motion of surface oil spill in the gulf of mexico



Major Professor:  Dr. Mark Bourassa



Date: June 16, 2021                                    Time: 3:30 PM



Location: Zoom   https://fsu.zoom.us/j/96515048863  Meeting ID: 965 1504 8863



ABSTRACT



This study provides, to our knowledge, the first detailed analysis of how oil changes air-sea interaction in a two-way coupled model (COAWST), and how the modified surface stress and surface Ekman current change the transport of the oil. Our results highlight the substantial influences of oil-related changes in surface roughness, surface wind, surface and near surface temperature differences, atmospheric stability, and corresponding changes in surface stress and oil transport. These results are dependent on the effectiveness of our tuning of the modeled oil concentration on the surface. These considerations are examined in part by running twin coupled modeling simulations with and without the influences of oil. Subsequently, we compare the results by using a flux model with parameterizations selected to match those selected in COAWST adapted to either ignore or account for different atmospheric/oceanic processes in the calculation of surface stress. This approach investigates the effects of oil separately on atmospheric stability, surface wind, and surface roughness and how those conditions impact surface stress.

The model results find that surface stress changes due to oil-related damping of surface roughness are always negative in the absence of changes to model input parameters (i.e., wind speed and atmospheric stability). However, oil-related changes to 10 m wind speed appears to play a much dominant role than oil-related changes in roughness in the changes in stress. The wind speed changes due to reduced surface friction (which increase stress) and due to changes in stability (which increase or decrease stress). We find that oil-related changes in atmospheric stability plays a dominate role in the changes in stress. This finding indicates that the vast majority of the changes in modeled stress are due to the changes in modeled stability and wind. This finding is contrary to the assumption by an idealized study (Zheng et al. 2013) where the changes in scatterometer observed roughness were assumed to be entirely due to damping of the roughness by oil. Finally, the results indicate that the oil-related changes in surface roughness, surface wind, and atmospheric stability combine to result in changes of surface stress are not large enough to cause a major impact on the surface current and oil transport. Therefore, this study demonstrates that the consideration of oil-related temperature and oil-related surface roughness for modeling an oil spill motion is not important for forecasting the transport of oil.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.fsu.edu/pipermail/eoas-seminar/attachments/20210611/5ebe9e55/attachment.html>