Development of the Geostationary Environment Monitoring Spectrometer (GEMS) NO2 Retrieval Algorithm and First-time Observations of Its Diurnal Characteristics over Asia
- Abstract
- In this present study, a near-real-time operational Nitrogen Dioxide (NO2) retrieval algorithm of the Geostationary Environment Monitoring Spectrometer (GEMS), which is the first Ultraviolet-Visible (UV-Vis) spectrometer in geostationary orbit, was developed. GEMS was successfully launched onboard Geostationary Korea Multi-Purpose Satellite 2B (GEO-KOMPSAT 2B) on February 18, 2020, and enables hourly monitoring of key air quality components over Asia during the daytime. To investigate sensitivities under various Signal-to-Noise Ratios (SNR), a comparison with the true NO2 Vertical Column Density (VCD) after retrieval under various SNR conditions was conducted. In addition, GEMS NO2 retrieval uncertainties caused by a polarization error were also investigated. In the GEMS NO2 near-real-time operational algorithm, NO2 Slant Column Density (SCD) is retrieved using Differential Optical Absorption Spectroscopy (DOAS) technique. Then NO2 SCD is converted to NO2 Vertical Column Density (VCD) by dividing NO2 SCD by NO2 Air Mass Factor (AMF), calculated by the pre-structured NO2 scattering weight Look-Up Table (LUT) calculated by VLIDORT Radiative Transfer Model (RTM) and NO2 vertical profile simulated by WRF-Chem and CAM-Chem Chemical Transport Model (CTM). In addition, multidimensional linear interpolation was used to determine the NO2 AMF from the pre-calculated NO2 scattering weight LUT.
Last part of this present study, the first results of GEMS total and troposphere NO2 VCDs were introduced. Hourly variations and spatial distributions of total and troposphere NO2 VCDs over Asia measured by GEMS observation are also presented in this present study. Finally, case studies of long-range transport of NO2 are presented and validation of GEMS observation data was conducted using the other LEO satellite observation and ground-based observation data.
- Issued Date
- 2022
- Awarded Date
- 2022. 8
- Type
- Dissertation
- Publisher
- 부경대학교
- Affiliation
- 부경대학교 대학원
- Department
- 대학원 지구환경시스템과학부공간정보시스템공학전공
- Advisor
- 이한림
- Table Of Contents
- CHAPTER Ⅰ. INTRODUCTION 1
1. Background 1
2. Literature review 5
3. Objective 12
CHAPTER Ⅱ. THEORETICAL BACKGROUND 16
1. NO2 SCD retrieval and NO2 VCD calculation method 16
1.1. Difference Optical Absorption Spectroscopy (DOAS) technique 16
1.2. Air mass factor 21
CHAPTER Ⅲ. DESCRIPTION OF THE GEOSTATIONARY ENVIRONMENT MONITORING SPECTROMETER (GEMS) 24
1. Geostationary Environment Monitoring Spectrometer 24
CHAPTER Ⅳ. GEMS NO2 RETRIEVAL ALGORITHM 28
1. GEMS NO2 retrieval algorithm 28
1.1. GEMS NO2 SCD retrieval 31
1.2. Air Mass Factor calculation 41
1.3. Stratosphere-Troposphere Separation (STS) 52
CHAPTER Ⅴ. FIRST RESULTS OF GEMS OBSERVATIONS (SPATIAL DISTRIBUTIONS AND HOURLY VARIATIONS OF TOTAL AND TROPOSPHERIC NO2 VCDS AT MANY ASIAN CITIES) AND NO2 TRANSPORTATION EVENT OBSERVATION 58
1. Evaluation of retrieved total and tropospheric NO2 VCDs from GEMS observation with other LEO satellite observation data 58
2. Evaluation of retrieved total and tropospheric NO2 VCDs from GEMS observation with ground-based Pandora and MAX-DOAS observation data 67
3. The first results of diurnal variation of total NO2 VCDs over the Asia based on space-borne observation 73
3.1. Spatiotemporal characteristics of total NO2 VCD 73
3.2. Spatial distribution of total NO2 VCDs at the cities of capital over the Asia 82
3.3. Spatial distribution of total NO2 VCDs at the major industrial cities and port regions over the Asia 96
3.4. Spatial distribution of total NO2 VCDs at the megacities over the Asia 107
4. The first results of diurnal variation of troposphere NO2 VCDs over the Asia based on space-borne observation 114
4.1. Spatial distribution of troposphere NO2 VCDs at the major cities over the Asia 114
4.2. Spatial distribution of tropospheric NO2 VCDs at the major industrial cities and port regions over the Asia 123
4.3. Spatial distribution of tropospheric NO2 VCDs at the megacities over the Asia 129
5. Case study of NO2 transportation event 135
6. Retrieved GEMS NO2 VCDs compared with a priori NO2 profile 141
CHAPTER Ⅵ. CONCLUSION 144
REFERENCE 148
APPENDIX: ACRONYMS 174
- Degree
- Doctor
- Appears in Collections:
- 대학원 > 지구환경시스템과학부-공간정보시스템공학전공
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