# The impact of GPS ro data on the prediction of tropical cyclogenesis using a nonlocal observation operator: An initial assessment

7 引文 斯高帕斯（Scopus）

## 摘要

In this study, the impact of global positioning system (GPS) radio occultation (RO) data on the prediction of the genesis of 10 tropical cyclones over the western North Pacific Ocean is assessed. With the use of a nonlocal excess phase observation operator in cycling data assimilation, the probability of detection for tropical cyclogenesis is increased from 30% to 70% for the cases considered, all of which developed into typhoons. However, the probability of detection is only increased to 40% when a local observation operator is used, indicating that the observation operator can significantly influence the performance of RO data assimilation in capturing tropical cyclogenesis. A nonlocal excess phase operator, which considers the atmospheric horizontal gradients by integrating the refractivity along a ray path, gives superior performance over the local observation operator. Additional sensitivity experiments on 3 of the 10 typhoon cases show that the RO data in the vicinity of the incipient cyclones (within 500 km of the cyclone center) are most critical to successful cyclogenesis prediction. This reflects the fact that having good RO observations at the right time and place is critical for RO to have beneficial impacts on tropical cyclogenesis. Further analyses for Typhoon Nuri (2008) show that assimilation of RO data using the nonlocal operator leads to moistening of the lower and middle troposphere, organized convection, robust grid-scale vertical motions, and the development of midlevel relative vorticity, all of which are favorable for tropical cyclogenesis.

原文 ???core.languages.en_GB??? 2701-2717 17 Monthly Weather Review 148 7 https://doi.org/10.1175/MWR-D-19-0286.1 已出版 - 1 7月 2020

## 指紋

• ### 台灣區域大氣水文觀測與預報實驗-子計畫：GNSS掩星資料之全球同化模式應用對於台灣劇烈天氣之研究

Chen, S.

1/08/1831/07/19

研究計畫: Research