Graduation Year

2024

Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts

Department

Chemistry

Second Department

Mathematics

Reader 1

Eric A. Kort and Claire Pettersen

Reader 2

Katie Purvis-Roberts

Reader 3

Anie Chaderjian

Terms of Use & License Information

Terms of Use for work posted in Scholarship@Claremont.

Rights Information

© 2024 Natalie J Burton

Abstract

Offshore oil and gas fields, a stationary and consistent source of atmospheric aerosol particles in the marine environment, offer a novel opportunity to study anthropogenic marine boundary layer cloud brightening and to determine the meteorological conditions necessary for this cloud enhancement to occur. In this project, we studied offshore oil and gas platforms in the Bay of Campeche in the southern Gulf of Mexico, a highly productive offshore petroleum extraction region. To determine seasonality of cloud enhancement, we classified daily cloud conditions in 2021 and 2022 with corrected reflectance satellite imagery from the National Aeronautics and Space Administration’s (NASA)'s Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and the National Oceanic and Atmospheric Administration’s (NOAA)'s Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging-Radiometer Suite (VIIRS). We then evaluated the meteorological conditions in this region to determine local atmospheric stability using the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) modeled product. In an effort to improve our method of classification, we used meteorological variables from 2021 to model what range of values correspond with each cloud condition. We then used this criteria to classify days in 2022. Cloud enhancement in 2022 was correctly identified 11\% to 79\% of the time using these models, with some meteorological variables tending towards over-classifying days as exhibiting cloud enhancement, while other variables tending towards over-classifying days as exhibiting no cloud enhancement or being obscured. To verify emission trajectories for case study days, we used the NOAA Air Resources Laboratory’s (ARL)'s Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. We found that marine boundary layer cloud brightening exhibited seasonal differences, with cloud enhancement being most frequent in the summer and least frequent in the spring. This correlated with a more stable boundary layer height, which allows for atmospheric aerosol particles to persist at cloud height. Additionally, the stability of the boundary layer in the summer is not anomalous when compared to the climatology of the region, which suggests that this is a regular phenomenon that may impact the local hydrological processes and radiative budget.

Download

This thesis is restricted to the Claremont Colleges current faculty, students, and staff.

Share

COinS