Assimilation of MWHS-2/FY-3C 183 GHz Channels Using a Dynamic Emissivity Retrieval and Its Impacts on Precipitation Forecasts: A Southwest Vortex Case

Chen, Keyi; Fan, Jiao; Xian, Zhipeng

doi:10.1155/2021/6427620

Cited by 10 publications

(10 citation statements)

References 23 publications

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“…In the Met Office global model, MWHS-2 was found to reduce the 24 h forecast error significantly, by 0.6% [37]. With regional models, assimilating FY-3C/MWHS-2 observations under both clear-and all-sky conditions improved the forecasts of typhoons [38], Meiyu [39] and the Southwest Vortex [40]. Later, FY-3D was successfully launched in October 2017.…”

Section: Introductionmentioning

confidence: 99%

Impacts of the All-Sky Assimilation of FY-3C and FY-3D MWHS-2 Radiances on Analyses and Forecasts of Typhoon Hagupit

Chen

Xian

et al. 2023

Remote Sensing

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With the Microwave Humidity Sounder-2 (MWHS-2)/Fengyun (FY)-3D in operation, this is the first study to evaluate the impact of a joint assimilation of MWHS-2 radiances under all-sky conditions from both the FY-3C and FY-3D satellites on typhoon forecasting within regional areas. In this study, Typhoon Hagupit in 2020 was chosen to investigate the impacts of assimilating MWHS-2 radiances; the forecasting performances of the joint assimilation method were slightly better than the experiments assimilating MWHS-2 observations from FY-3C or FY-3D only, and the results of the latter two experiments were comparable, especially in terms of the landfall location of Hagupit. With additional assimilated cloud- and precipitation-affected MWHS-2 observations, improved typhoon track and intensity forecasts as well as forecasts of the precipitation caused by Hagupit were achieved due to the improved analyses of relative humidity, temperature and wind fields around Hagupit compared to the clear-sky assimilation experiments. In addition, the channel-selection scheme evidently affected the forecasting performance; that is, the radiances from the MWHS-2 118 GHz and 183 GHz channels provided opposite results in terms of the Hagupit track, and this finding needs further investigation in the future.

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Section: Introductionmentioning

confidence: 99%

Impacts of the All-Sky Assimilation of FY-3C and FY-3D MWHS-2 Radiances on Analyses and Forecasts of Typhoon Hagupit

Chen

Xian

et al. 2023

Remote Sensing

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“…Until now, the MWHS‐I and MWHS‐II have been operationally assimilated by the European Centre for Medium‐range Weather Forecasts (ECMWF; Bormann et al, 2021; Lawrence et al, 2018) and the UK Met Office (Carminati et al, 2021; Carminati & Migliorini, 2021). The impacts of these sensors on several data assimilation systems have been studied, including the Gridpoint Statistical Interpolation global analysis system (Jiang et al, 2020), the Weather Research and Forecasting data assimilation system (Chen, Fan, & Xian, 2021; Jiang et al, 2019; Mi et al, 2014; Su et al, 2013; Tang et al, 2018; Xian et al, 2019; Zhang et al, 2013), the Weather Research and Forecasting Hybrid‐3DVAR data assimilation system (Sun & Xu, 2021; Xu et al, 2016), the ensemble three‐dimensional variational assimilation method based on proper orthogonal decomposition (POD‐3DEnVar; Zhang, Liu, Liu, et al, 2019; Zhang, Lu, & Gu, 2019; Zhang, Lu, Hu, et al, 2019; Zhang, Zhang, Zhang, et al, 2019) and the Rapid‐refresh Multi‐scale Analysis and Prediction System‐Short Term (RMAPS‐ST) operational system (Liu et al, 2021). The special channels at 118 GHz on the MWHS‐II have some difficulties for operational assimilation, due to their complex sensitivity to both temperature and humidity (Bormann et al, 2021; Carminati et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

Assimilation of data from the MWHS‐II onboard the first early morning satellite FY‐3E into the CMA global 4D‐Var system

Xiao

Han

Zhang

et al. 2023

Meteorological Applications

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Radiance data from satellite microwave radiometers are becoming increasingly important in the assimilation of numerical prediction systems. FengYun-3E (FY-3E), which was launched in July 2021, as the first early morning orbital satellite among FY-3 polar-orbiting meteorological satellite series, can greatly enhance the atmospheric sounding capacity in three orbits compared with the two-orbit system that is distributed in morning or afternoon orbit. Focusing on MicroWave Humidity Sounder-2 (MWHS-II) onboard it, the schemes for thinning, quality control, bias correction and observational error calculation are developed. The scan-position-dependent biases are assessed in each channel and increasing biases near the edges of scanline are found in several temperature-sounding channels. The data quality is compared with four analogous instruments used in Global/Regional Assimilation and Prediction System-Global Forecast System (CMA_GFS), and the performance improvements are confirmed relative to the previous FY-3C/D MWHS-II. Three batch experiments were implemented in CMA_GFS with four-dimensional variational (4D-Var) system-assimilating only the humidity-sounding channels, the temperature-sounding channels and the combined channels-to reveal the impact of assimilation by different channel groupings. Analysis results conclude that FY-3E MWHS-II radiances are beneficial to the humidity and temperature analysis fields. These results emphasize the advantage of simultaneously assimilating the humidity/temperature-sounding channels, in which the former dominates the improvement above 700 hPa while the latter have a positive impact below 700 hPa. The forecast results also show that assimilating both the 183-and 118-GHz channels further improves the forecast skills, especially short-to medium-term forecasts in both hemispheres. FY-3E MWHS-II also improves the short-term prediction of heavy rain, which is always weakly predicted in global forecast systems. This study shows that a three polar orbits system that FY-3E began can produce marked effects in the numerical

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“…Yang et al (2011) proposed a forecast equation for SWV precipitation and emphasized different forecast focuses for various SWV types [13]. Chen et al (2021) enhanced the assimilation of dynamic emissivity data to improve 24-h predictions of initial fields and precipitation distribution [14].…”

Section: Introductionmentioning

confidence: 99%

Case Study on the Evolution and Precipitation Characteristics of Southwest Vortex in China: Insights from FY-4A and GPM Observations

Xiang,

Wang,

et al. 2023

Remote Sensing

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This research investigates Southwest Vortex (SWV) events in China’s Sichuan Basin using Fengyun-4A (FY-4A) and Global Precipitation Mission (GPM) observations. We selected representative cloud systems and precipitation cases, divided into developing, mature, and dissipating stages. Detailed analysis revealed critical characteristics of precipitation cloud systems at each stage. Our findings reveal that (1) during the SWV’s developing and mature stages, a high concentration of water particles and ice crystals stimulates precipitation. In contrast, the dissipating stage is marked by fewer mixed-phase and ice particles, reducing precipitation area and intensity. (2) Near-surface precipitation in all stages is predominantly liquid, with a bright band of around 5.5 km. At the same time, stratiform precipitation is dominant in each life stage. Stratiform precipitation remains dominant throughout the life stages of the SWV, with localized convective activity evident in the developing and mature stages. (3) Mature stage particles, characterized by a configuration of 1.0–1.2 mm Dm and 31–35 dBNW (dBNW = 10log10NW), contribute significantly to near-surface precipitation. The Cloud Top Height (CTH) serves as an indicator of convective intensity and assists in characterizing raindrop concentration. These findings considerably enhance routine observations, advance our understanding of SWV events, and propose a novel approach for conducting refined observational experiments.

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Assimilation of MWHS-2/FY-3C 183 GHz Channels Using a Dynamic Emissivity Retrieval and Its Impacts on Precipitation Forecasts: A Southwest Vortex Case

Cited by 10 publications

References 23 publications

Impacts of the All-Sky Assimilation of FY-3C and FY-3D MWHS-2 Radiances on Analyses and Forecasts of Typhoon Hagupit

Impacts of the All-Sky Assimilation of FY-3C and FY-3D MWHS-2 Radiances on Analyses and Forecasts of Typhoon Hagupit

Assimilation of data from the MWHS‐II onboard the first early morning satellite FY‐3E into the CMA global 4D‐Var system

Case Study on the Evolution and Precipitation Characteristics of Southwest Vortex in China: Insights from FY-4A and GPM Observations

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