대전 지역 UV-A 자외선 복사량을 이용한 GK-2A와 HIMAWARI 위성의 구름 광학 두께 비교
Comparison of Cloud Optical Thickness of GK-2A and HIMAWARI Satellites by Using UV-A Irradiance in Daejeon
1
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
Cloud optical thickness, also known as cloud optical depth, is an indicator that quantitatively shows the attenuation effect of solar radiance by clouds in the atmosphere and is calculated through statistical models or the radiative transfer model of each satellite using its observation data and ancillary data. Therefore, even for observations performed at the same location and time, the retrieved COT differ from satellite to satellite. Thus, this study aims to verify the retrieved COT of the GK-2A and HIMAWARI satellites, which are Korean and Japanese geostationary satellites, respectively, covering the Korean Peninsula. To verify the COT data, the method used by Qin et al. (2019) was used, where the COT was indirectly verified by calculating downward radiation using satellite-retrieved data such as COT, cloud phase, and cloud top pressure as parameters and comparing this with ground-observed radiation. In this study, a radiative transfer model, libRadtran 2.0.4, was used to calculate UV-A radiation and compare it with observed data in Daejeon as the true value for the cloud phase retrieved from each satellite. When comparing the COT from both satellites directly, the values from HIMAWARI tended to be larger than the data from GK-2A. A comparison of the UV-A radiation shows that the observed values are seemingly larger than the satellite results,indicating that both satellites may overestimate the cloud optical depth. Additionally, when both satellites were estimated to have the same cloud phase, HIMAWARI showed better parameters for RMSE and MAE, whereas GK-2A was better when GK-2A and HIMAWARI had different cloud phase estimates. By comparing the freezing level from the vertical profile and the cloud top height from each satellite, the actual cloud phase was estimated, which showed that GK-2A had better performance in estimating cloud phases.
Abstract
Cloud optical thickness, also known as cloud optical depth, is an indicator that quantitatively shows the attenuation effect of solar radiance by clouds in the atmosphere and is calculated through statistical models or the radiative transfer model of each satellite using its observation data and ancillary data. Therefore, even for observations performed at the same location and time, the retrieved COT differ from satellite to satellite. Thus, this study aims to verify the retrieved COT of the GK-2A and HIMAWARI satellites, which are Korean and Japanese geostationary satellites, respectively, covering the Korean Peninsula. To verify the COT data, the method used by Qin et al. (2019) was used, where the COT was indirectly verified by calculating downward radiation using satellite-retrieved data such as COT, cloud phase, and cloud top pressure as parameters and comparing this with ground-observed radiation. In this study, a radiative transfer model, libRadtran 2.0.4, was used to calculate UV-A radiation and compare it with observed data in Daejeon as the true value for the cloud phase retrieved from each satellite. When comparing the COT from both satellites directly, the values from HIMAWARI tended to be larger than the data from GK-2A. A comparison of the UV-A radiation shows that the observed values are seemingly larger than the satellite results,indicating that both satellites may overestimate the cloud optical depth. Additionally, when both satellites were estimated to have the same cloud phase, HIMAWARI showed better parameters for RMSE and MAE, whereas GK-2A was better when GK-2A and HIMAWARI had different cloud phase estimates. By comparing the freezing level from the vertical profile and the cloud top height from each satellite, the actual cloud phase was estimated, which showed that GK-2A had better performance in estimating cloud phases.
참고문헌 (12)
- Forster, P, "Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change", pp.923~1054 (2021), Cambridge University Press
- Qin, Y., "Classification and Optical Depth Retrieval Algorithm for the Advanced Himawari Imager", Frontiers in Envionmental Science, 7, pp.20~ (2019)[DOI]
- Turner, D. D., "Validating Mixed-Phase Cloud Optical Depth Retrieved From Infrared Observations With High Spectral Resolution Lidar", IEEE Geoscience and Remote Sensing Letters, 5(2), pp.285~288 (2008)[DOI]
- "GK-2A AMI Algorithm Theoretical Basis Document, Retrieval Algorithm of Daytime Cloud Optical Depth and Micro-physics (주간 구름광학두께 및 미세물리량 산출 알고리즘)" (2019)[URL]
- Nakajima, T. Y., "Wide-Area Determination of Cloud Microphysical Properties from NOAA AVHRR Measurements for FIRE and ASTEX Regions", Journal of the Atmospheric Sciences, 52(23), pp.4024~4059 (1995)[DOI]
- "LibRadtran" (2020)[URL]
- Emde, C., "The libRadtran Software Package for Radiative Transfer Calculations (Version 2.0.1)", Geoscientific Model Development, 9(5), pp.1647~1672 (2016)[DOI]
- Nina Črnivec, "Towards an improved treatment of cloud–radiation interaction in weather and climate models: exploring the potential of the Tripleclouds method for various cloud types using libRadtran 2.0.4", Geoscientific Model Development, 14(6), pp.3663~3682 (2021), Copernicus GmbH[DOI]
- "GK-2A AMI Algorithm Theoretical Basis Document, Cloud Top Products (운정산출물)" (2019)[URL]
- Letu, H., "High-resolution Retrieval of Cloud Microphysical Properties and Surface Solar Radiation using Himawari-8", AHI Next-generation Geostationary Satellite, 2020, pp.239, 111583~
- William B. Rossow, "Advances in Understanding Clouds from ISCCP", Bulletin of the American Meteorological Society, 80(11), pp.2261~2287 (1999), American Meteorological Society[DOI]
- Kotaro BESSHO, "An Introduction to Himawari-8", 9— Japan’s New-Generation Geostationary Meteorological Satellites, 2016, pp.94(2), 151~183[DOI]