Employment of Multi-Source Satellite-Based Observations in Air Quality Modeling over Asia

This dissertation explored a series of satellite-based approaches to improving the reliability of Asia’s air quality simulations and contribute to methodological advances in this field. In Chapter 1, I sequentially constrained the inventoried estimates of East Asia’s nitrogen oxides (NOx) and primary particulate matter (PM) emissions to improve model accuracy in simulating aerosol optical depth (AOD), using nitrogen dioxide (NO2) columns and AOD data from the TROPOspheric Monitoring Instrument (TROPOMI), Advanced Himawari Imager (AHI), and Geostationary Ocean Color Imager (GOCI). While the model initially underestimated AOD by -50.73% in 2019, the emissions updates, with increases in NOx and primary PM emissions by 122.79% and 114.63%, reduced the negative bias to -33.84% and -19.60%, respectively. This suggested the effectiveness of constraining both the primary aerosols and secondary aerosol precursors in addressing the model bias. In Chapter 2, I evaluated the utility of the Geostationary Environment Monitoring Spectrometer’s (GEMS) tropospheric NO2 columns as top-down constraints to refine Asia’s NOx emissions inventory. Informed by 8 to 10 snapshots a day during the 2022 spring, I performed Bayesian inversion to hourly constrain the NOx emissions. This enabled the model to better capture the diurnal variation in NOx emissions, such as its morning rush hour peak, particularly when more retrievals were available each day, reducing the extent of model underestimation of surface NO2 concentrations from 17.38% to 5.58% in Korea and from 13.05% to 4.54% in China. In Chapter 3, I conducted source apportionment of East Asia’s nitrogen loadings during the 2022 winter-spring transition, leveraging the GEMS-informed estimates of NOx emissions. I quantified the local and transboundary contributions of NOx emissions to reactive nitrogen species (NOy) concentrations across East Asia. From January to May, local contributions steadily decreased from 32%-43% to 23%-30%, while transboundary contributions showed an increasing trend from 16%-33% to 27%-37%. Some regions maintained their consistent contributions to East Asia’s NOy loadings, whereas others showed noticeable fluctuations in the contributions as the months progressed. This shift was driven by synoptic settings, where wintertime northwesterly winds directed pollutants southeastward, while their weakening in spring led to more multidirectional transport patterns.

Name thesis:degree_name

Doctor of Philosophy

Discipline thesis:degree_discipline

Atmospheric Sciences

Grantor

University of Houston

Year dc:date.issued

2024

Author dc:creator

• Park, Jincheol

Advisor dc:contributor.advisor

• Choi, Yunsoo

Committee members dc:contributor.committeemember

• Jiang, Xun
• Baker, Barry
• Wang, Yuxuan

• Atmospheric Sciences

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10657/18293

OAI identifier oai:identifier

oai:uh-ir.tdl.org:10657/18293