An overview of and issues with sky radiometer technology and SKYNET

Autor: Vijay K. Soni, Masahiro Momoi, Boossarasiri Thana, Monica Campanelli, Akihiro Yamazaki, Nas Urt Tugjsurn, Natalia Kouremeti, Govindan Pandithurai, Sujung Go, Huizheng Che, Kazuma Aoki, Tomoaki Nishizawa, Hitoshi Irie, Sang Woo Kim, Makiko Hashimoto, Teruyuki Nakajima, Rei Kudo, Akiko Higurashi, Claire L. Ryder, Franco Marenco, Stelios Kazadzis, Pradeep Khatri, Akihiro Uchiyama, Victor Estellés, Dong Liu, Shantikumar S. Ningombam, Jhoon Kim
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Atmospheric Measurement Techniques, Vol 13, Pp 4195-4218 (2020)
Nakajima, T. Campanelli, M. Che, Huizheng Estellés Leal, Víctor Irie, Hitoshi Kim, Sang-Woo Kim, Jhoon Liu, Dong Nishizawa, Tomoaki Pandithurai, Govindan Soni, V. Kumar Thana, Boossarasiri Tugjsurn, Nas-Urt Aoki, Kazuma Go, Sujung Hashimoto, Makiko Higurashi, Akiko Kazadzis, Stelios Khatri, P. Kouremeti, Natalia Kudo, Rei Marenco, Franco Momoi, Masahiro Ningombam, Shantikumar S. Ryder, Claire Uchiyama, A. Yamazaki, Akihiro 2020 An overview of and issues with sky radiometer technology and SKYNET Atmospheric Measurement Techniques 13 8 4195 4218
Atmospheric measurement techniques
13 (2020): 4195–4218. doi:10.5194/amt-13-4195-2020
info:cnr-pdr/source/autori:Nakajima, Teruyuki; Campanelli, Monica; Che, Huizheng; Estellés, Victor; Irie, Hitoshi; Kim, Sang Woo; Kim, Jhoon; Liu, Dong; Nishizawa, Tomoaki; Pandithurai, Govindan; Kumar Soni, Vijay; Thana, Boossarasiri; Tugjsurn, Nas Urt; Aoki, Kazuma; Go, Sujung; Hashimoto, Makiko; Higurashi, Akiko; Kazadzis, Stelios; Khatri, Pradeep; Kouremeti, Natalia; Kudo, Rei; Marenco, Franco; Momoi, Masahiro; Ningombam, Shantikumar S.; Ryder, Claire L.; Uchiyama, Akihiro; Yamazaki, Akihiro/titolo:An overview of and issues with sky radiometer technology and SKYNET/doi:10.5194%2Famt-13-4195-2020/rivista:Atmospheric measurement techniques (Print)/anno:2020/pagina_da:4195/pagina_a:4218/intervallo_pagine:4195–4218/volume:13
RODERIC. Repositorio Institucional de la Universitat de Valéncia
instname
RODERIC: Repositorio Institucional de la Universitat de Valéncia
ISSN: 1867-8548
1867-1381
DOI: 10.5194/amt-13-4195-2020
Popis: This paper is an overview of the progress in sky radiometer technology and the development of the network called SKYNET. It is found that the technology has produced useful on-site calibration methods, retrieval algorithms, and data analyses from sky radiometer observations of aerosol, cloud, water vapor, and ozone. A formula was proposed for estimating the accuracy of the sky radiometer calibration constant F0 using the improved Langley (IL) method, which was found to be a good approximation to observed monthly mean uncertainty in F0, around 0.5 % to 2.4 % at the Tokyo and Rome sites and smaller values of around 0.3 % to 0.5 % at the mountain sites at Mt. Saraswati and Davos. A new cross IL (XIL) method was also developed to correct an underestimation by the IL method in cases with large aerosol retrieval errors. The root-mean-square difference (RMSD) in aerosol optical thickness (AOT) comparisons with other networks took values of less than 0.02 for λ≥500 nm and a larger value of about 0.03 for shorter wavelengths in city areas and smaller values of less than 0.01 in mountain comparisons. Accuracies of single-scattering albedo (SSA) and size distribution retrievals are affected by the propagation of errors in measurement, calibrations for direct solar and diffuse sky radiation, ground albedo, cloud screening, and the version of the analysis software called the Skyrad pack. SSA values from SKYNET were up to 0.07 larger than those from AERONET, and the major error sources were identified as an underestimation of solid viewing angle (SVA) and cloud contamination. Correction of these known error factors reduced the SSA difference to less than 0.03. Retrievals of other atmospheric constituents by the sky radiometer were also reviewed. Retrieval accuracies were found to be about 0.2 cm for precipitable water vapor amount and 13 DU (Dobson Unit) for column ozone amount. Retrieved cloud optical properties still showed large deviations from validation data, suggesting a need to study the causes of the differences. It is important that these recent studies on improvements presented in the present paper are introduced into the existing operational systems and future systems of the International SKYNET Data Center.
Databáze: OpenAIRE
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