scholarly journals Global tropopause height trends estimated from GPS radio occultation data

2008 ◽  
Vol 35 (11) ◽  
Author(s):  
T. Schmidt ◽  
J. Wickert ◽  
G. Beyerle ◽  
S. Heise
Keyword(s):  
Radio Occultation ◽  
Tropopause Height ◽  
Gps Radio Occultation ◽  
Occultation Data ◽  
Radio Occultation Data

Backpropagation Processing of GPS Radio Occultation Data

2003 ◽  
pp. 415-422 ◽  
Author(s):  
Chi O. Ao ◽  
George A. Hajj ◽  
Thomas K. Meehan ◽  
Stephen S. Leroy ◽  
E. Robert Kursinski ◽  
...  
Keyword(s):  
Radio Occultation ◽  
Gps Radio Occultation ◽  
Occultation Data ◽  
Radio Occultation Data

scholarly journals GPS Radio Occultation Data Assimilation in the AREM Regional Numerical Weather Prediction Model for Flood Forecasts

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Wei Cheng ◽  
Youping Xu ◽  
Zhiwu Deng ◽  
Chunli Gu
Keyword(s):  
Data Assimilation ◽  
Radio Occultation ◽  
Weather Prediction ◽  
Radiosonde Data ◽  
Light Rain ◽  
Gps Radio Occultation ◽  
Study Results ◽  
Occultation Data ◽  
Radio Occultation Data

Based on the Backward Four-Dimensional Variational Data Assimilation (Backward-4DVar) system with the Advanced Regional Eta-coordinate Model (AREM), which is capable of assimilating radio occultation data, a heavy rainfall case study is performed using GPS radio occultation (GPS RO) data and routine GTS data on July 5, 2007. The case study results indicate that the use of radio occultation data after quality control can improve the quality of the analysis to be similar to that of the observations and, thus, have a positive effect when improving 24-hour rainfall forecasts. Batch tests for 119 days from May to August during the flood season in 2009 show that only the use of GPS RO data can make positive improvements in both 24-hour and 48-hour regional rainfall forecasts and obtain a better B score for 24-hour forecasts and better TS score for 48-hour forecasts. When using radio occultation refractivity data and conventional radiosonde data, the results indicate that radio occultation refractivity data can achieve a better performance for 48-hour forecasts of light rain and heavy rain.

Impact of GPS radio occultation data assimilation on regional weather predictions

GPS Solutions ◽  
2009 ◽  
Vol 14 (1) ◽  
pp. 35-49 ◽  
Author(s):  
Ching-Yuang Huang ◽  
Ying-Hwa Kuo ◽  
Shu-Ya Chen ◽  
Chuen-Tsyr Terng ◽  
Fang-Ching Chien ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Radio Occultation ◽  
Gps Radio Occultation ◽  
Occultation Data ◽  
Radio Occultation Data

scholarly journals Observation and a numerical study of gravity waves during tropical cyclone Ivan (2008)

2014 ◽  
Vol 14 (2) ◽  
pp. 641-658 ◽  
Author(s):  
F. Chane Ming ◽  
C. Ibrahim ◽  
C. Barthe ◽  
S. Jolivet ◽  
P. Keckhut ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Gravity Waves ◽  
Radio Occultation ◽  
Numerical Study ◽  
Wide Spectrum ◽  
Wave Number ◽  
Southwest Indian Ocean ◽  
Gps Radio Occultation ◽  
Occultation Data ◽  
Radio Occultation Data

Abstract. Gravity waves (GWs) with horizontal wavelengths of 32–2000 km are investigated during tropical cyclone (TC) Ivan (2008) in the southwest Indian Ocean in the upper troposphere (UT) and the lower stratosphere (LS) using observational data sets, radiosonde and GPS radio occultation data, ECMWF analyses and simulations of the French numerical model Meso-NH with vertical resolution < 150 m near the surface and 500 m in the UT/LS. Observations reveal dominant low-frequency GWs with short vertical wavelengths of 0.7–3 km, horizontal wavelengths of 80–400 km and periods of 4.6–13 h in the UT/LS. Continuous wavelet transform and image-processing tools highlight a wide spectrum of GWs with horizontal wavelengths of 40–1800 km, short vertical wavelengths of 0.6–3.3 km and periods of 20 min–2 days from modelling analyses. Both ECMWF and Meso-NH analyses are consistent with radiosonde and GPS radio occultation data, showing evidence of a dominant TC-related quasi-inertia GW propagating eastward east of TC Ivan with horizontal and vertical wavelengths of 400–800 km and 2–3 km respectively in the LS, more intense during TC intensification. In addition, the Meso-NH model produces a realistic, detailed description of TC dynamics, some high-frequency GWs near the TC eye, variability of the tropospheric and stratospheric background wind and TC rainband characteristics at different stages of TC Ivan. A wave number 1 vortex Rossby wave is suggested as a source of dominant inertia GW with horizontal wavelengths of 400–800 km, while shorter scale modes (100–200 km) located at northeast and southeast of the TC could be attributed to strong localized convection in spiral bands resulting from wave number 2 vortex Rossby waves. Meso-NH simulations also reveal GW-related clouds east of TC Ivan.

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