气候变化领域集成服务门户(CCPortal): Accurate 3-D radiative transfer simulation of spectral solar irradiance during the total solar eclipse of 21 August 2017

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DOI	10.5194/acp-20-1961-2020
	Accurate 3-D radiative transfer simulation of spectral solar irradiance during the total solar eclipse of 21 August 2017
	Ockenfu P.; Emde C.; Mayer B.; Bernhard G.
发表日期	2020
ISSN	1680-7316
起始页码	1961
结束页码	1976
卷号	20 期号:4
英文摘要	We calculate the variation of spectral solar irradiance in the umbral shadow of the total solar eclipse of 21 August 2017 and compare it to observations. Starting from the Sun's and Moon's positions, we derive a realistic profile of the lunar shadow at the top of the atmosphere, including the effect of solar limb darkening. Subsequently, the Monte Carlo model MYSTIC (Monte Carlo code for the physically correct Tracing of photons In Cloudy atmospheres) is used to simulate the transfer of solar radiation through the Earth's atmosphere. Among the effects taken into account are the atmospheric state (pressure, temperature), concentrations of major gas constituents and the curvature of the Earth, as well as the reflectance and elevation of the surrounding area. We apply the model to the total solar eclipse on 21 August 2017 at a position located in Oregon, USA, where irradiance observations were performed for wavelengths between 306 and 1020 nm. The influence of the surface reflectance, the ozone profile, the mountains surrounding the observer and aerosol is investigated. An increased sensitivity during totality is found for the reflectance, aerosol and topography, compared to non-eclipse conditions. During the eclipse, the irradiance at the surface not only depends on the total ozone column (TOC) but also on the vertical ozone distribution, which in general complicates derivations of the TOC from spectral surface irradiance. The findings are related to an analysis of the prevailing photon path and its difference compared to non-eclipse conditions. Using the most realistic estimate for each parameter, the model is compared to the irradiance observations. During totality, the relative difference between model and observations is less than 10%in the spectral range from 400 to 1020 nm. Slightly larger deviations occur in the ultraviolet range below 400 and at 665 nm. © 2020 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	accuracy assessment; computer simulation; irradiance; Monte Carlo analysis; numerical model; radiative transfer; solar eclipse; solar radiation; spectral analysis; three-dimensional modeling
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/141535
作者单位	Meteorological Institute, Ludwig Maximilian University, Theresienstr. 37, Munich, 80333, Germany; Biospherical Instruments Inc, San Diego, CA 92110, United States
推荐引用方式 GB/T 7714	Ockenfu P.,Emde C.,Mayer B.,et al. Accurate 3-D radiative transfer simulation of spectral solar irradiance during the total solar eclipse of 21 August 2017[J],2020,20(4).
APA	Ockenfu P.,Emde C.,Mayer B.,&Bernhard G..(2020).Accurate 3-D radiative transfer simulation of spectral solar irradiance during the total solar eclipse of 21 August 2017.Atmospheric Chemistry and Physics,20(4).
MLA	Ockenfu P.,et al."Accurate 3-D radiative transfer simulation of spectral solar irradiance during the total solar eclipse of 21 August 2017".Atmospheric Chemistry and Physics 20.4(2020).