Additional Calendars
Calendar Views
Conferences and Meetings
Law School
Special Events

EAS PhD Proposal Defense by iury T. Simoes-Sousa

When: Monday, August 16, 2021
2:00 PM - 4:00 PM
Where: Online
Description: EAS PhD Thesis Proposal Defense Presentation
by iury T. Simoes-Sousa

Date: August 16, 2021
Time: 2:00 p.m.

Topic: On Three Sub-Grid Scale Processes and Their Influence on Larger Scales in the Ocean- Atmosphere System

Zoom Teleconference:

Meeting ID: 978 4577 9618
Passcode: 903478


Subgrid-scale physics relates to important small-scale physical processes that occur at length scales that cannot be appropriately resolved on a computational mesh. This physics is important to understand so that the implications of missing it are clear. In the context of climate models, these scales are usually smaller than 0.5° (~50 km), comprising part of the ocean and atmospheric mesoscale and the so-called submesoscale. Some of the effects of these features are parameterized in climate models to diminish the error related to not resolving them.

In this thesis, we will explore three of these processes and its impact on larger scales. While not necessarily proposing new parameterizations, our focus is mainly on understanding the processes involved, and estimating the possible effects of these smaller scales on the atmospheric and ocean climate predictions. These subgrid-scale physical processes are: The implications of ocean submesoscale dynamics on the ecosystem (Chapter 2), The impact of atmospheric cold pools on the air-sea interaction, and their size distribution (Chapter 3), and The impact of sub-grid processes on the wind-driven generation of near inertial waves (Chapter 4).

In Chapter 2, we compare a three-dimensional fine-scale simulation with a coarsened experiment in which eddy-driven restratification is parameterized. Our results highlight the importance of submesoscale on spring blooms, pointing out the biological implications of the submesoscale fluxes at the base of the mixed layer in climate models.

In Chapter 3, we explore satellite and data from three nearby moorings to investigate the role and size distribution of atmospheric cold pools in the North Bay of Bengal. Our analysis shows that the tropical cold pools mainly occur during Monsoons, are dry, and have an important influence on the evaporative latent heat and sensible heat fluxes at the air-sea boundary. We also present the first size distribution of cold pools in the tropical Indian ocean, showing that most cold pools are larger than 20 km, present a lognormal distribution from 30 to 60 km, and some are bigger than 80 km. Larger cold pools are more transient and weaker in intensity.

In Chapter 4, we step further in complexity, proposing an investigation of a combination of submesoscale and air-sea interaction impacts on the wind-driven generation of near-inertial internal waves (NIW). We pose a number of open questions related to generation of NIWs and a hierarchy of modeling approaches to make progress.

The main objective of this proposal is to characterize and understand these processes and describe the effects of these subgrid-scale features on larger scales, so that future models can better include such processes.

ADVISOR(S): Prof. Amit Tandon Department of Mechanical Engineering
(, 508-999-8357)

COMMITTEE MEMBERS: Prof. Samuel M. Kelly, Associate Professor, University of Minnesota Duluth
Prof. Daniel MacDonald, Department of Civil & Environmental Engineering
Prof. Geoffrey Cowles, SMAST/Fisheries Oceanography

NOTE: All EAS Students are ENCOURAGED to attend.
Contact: > See Description for contact information
Topical Areas: Alumni, General Public, SMAST, Students, Students, Graduate, Students, Undergraduate, Bioengineering, Civil and Environmental Engineering, College of Engineering, Computer and Information Science, Co-op Program, Electrical and Computer Engineering, Mechanical Engineering, Physics