An Analysis Study of FORMOSAT-7/COSMIC-2 Radio Occultation Data in the Troposphere

Autor:	Hsiu Wen Li, Shen Cha Hsu, Jia Ping Cheng, Po-Hsiung Lin, Ching Yuang Huang, Shu Ya Chen, Cheng Yung Huang, Chian-Yi Liu
Rok vydání:	2021
Předmět:	COSMIC cancer database FORMOSAT-7/COSMIC-2 GNSS RO verification 010504 meteorology & atmospheric sciences Science 0211 other engineering and technologies 02 engineering and technology Collocation (remote sensing) Atmospheric sciences 01 natural sciences Occultation Standard deviation law.invention Troposphere law Radiosonde General Earth and Planetary Sciences Environmental science Radio occultation Dropsonde 021101 geological & geomatics engineering 0105 earth and related environmental sciences
Zdroj:	Remote Sensing, Vol 13, Iss 717, p 717 (2021) Remote Sensing; Volume 13; Issue 4; Pages: 717
ISSN:	2072-4292
Popis:	This study investigates the Global Navigation Satellite System (GNSS) radio occultation (RO) data from FORMOSAT-7/COSMIC-2 (FS7/C2), which provides considerably more and deeper profiles at lower latitudes than those from the former FORMOSAT-3/COSMIC (FS3/C). The statistical analysis of six-month RO data shows that the rate of penetration depth below 1 km height within ±45° latitudes can reach 80% for FS7/C2, significantly higher than 40% for FS3/C. For verification, FS7/C2 RO data are compared with the observations from chartered missions that provided aircraft dropsondes and on-board radiosondes, with closer observation times and distances from the oceanic RO occultation over the South China Sea and near a typhoon circulation region. The collocated comparisons indicate that FS7/C2 RO data are reliable, with small deviations from the ground-truth observations. The RO profiles are compared with collocated radiosondes, RO data from other missions, global analyses of ERA5 and National Centers for Environmental Prediction (NCEP) final (FNL), and satellite retrievals of NOAA Unique Combined Atmospheric Processing System (NCAPS). The comparisons exhibit consistent vertical variations, showing absolute mean differences and standard deviations of temperature profiles less than 0.5 °C and 1.5 °C, respectively, and deviations of water vapor pressure within 2 hPa in the lower troposphere. From the latitudinal distributions of mean difference and standard deviation (STD), the intertropical convergence zone (ITCZ) is evidentially shown in the comparisons, especially for the NUCAPS, which shows a larger deviation in moisture when compared to FS7/C2 RO data. The sensitivity of data collocation in time departure and spatial distance among different datasets are presented in this study as well.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5e793671bb81f6690c2f0bb0fcc6c9d6 https://doi.org/10.3390/rs13040717 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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