scholarly journals Comparison of three retrievals of COSMIC GPS radio occultation results in the tropical upper troposphere and lower stratosphere

2017 ◽  
Vol 69 (1) ◽  
Author(s):  
Noersomadi ◽  
Toshitaka Tsuda
Keyword(s):  
Radio Occultation ◽  
Lower Stratosphere ◽  
Upper Troposphere ◽  
Gps Radio Occultation ◽  
Tropical Upper Troposphere

scholarly journals Evaluation of CMIP5 upper troposphere and lower stratosphere geopotential height with GPS radio occultation observations

2015 ◽  
Vol 120 (5) ◽  
pp. 1678-1689 ◽  
Author(s):  
Chi O. Ao ◽  
Jonathan H. Jiang ◽  
Anthony J. Mannucci ◽  
Hui Su ◽  
Olga Verkhoglyadova ◽  
...  
Keyword(s):  
Geopotential Height ◽  
Radio Occultation ◽  
Lower Stratosphere ◽  
Upper Troposphere ◽  
Gps Radio Occultation

scholarly journals Radio occultation bending angle anomalies during tropical cyclones

2011 ◽  
Vol 4 (6) ◽  
pp. 1053-1060 ◽  
Author(s):  
R. Biondi ◽  
T. Neubert ◽  
S. Syndergaard ◽  
J. K. Nielsen
Keyword(s):  
Radio Occultation ◽  
Lower Stratosphere ◽  
Time Window ◽  
Deep Convection ◽  
Atomic Clock ◽  
Space Station ◽  
Radiation Balance ◽  
Bending Angle ◽  
Upper Troposphere ◽  
Gps Radio Occultation

Abstract. The tropical deep convection affects the radiation balance of the atmosphere changing the water vapor mixing ratio and the temperature of the upper troposphere lower stratosphere. The aim of this work is to better understand these processes and to investigate if severe storms leave a significant signature in radio occultation profiles in the tropical tropopause layer. Using tropical cyclone best track database and data from different GPS radio occultation missions (COSMIC, GRACE, CHAMP, SACC and GPSMET), we selected 1194 profiles in a time window of 3 h and a space window of 300 km from the eye of the cyclone. We show that the bending angle anomaly of a GPS radio occultation signal is typically larger than the climatology in the upper troposphere and lower stratosphere and that a double tropopause during deep convection can easily be detected using this technique. Comparisons with co-located radiosondes, climatology of tropopause altitudes and GOES analyses are also shown to support the hypothesis that the bending angle anomaly can be used as an indicator of convective towers. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES) payload on the International Space Station.

scholarly journals Radio occultation bending angle anomalies during tropical cyclones

2011 ◽  
Vol 4 (1) ◽  
pp. 1371-1395 ◽  
Author(s):  
R. Biondi ◽  
T. Neubert ◽  
S. Syndergaard ◽  
J. Nielsen
Keyword(s):  
Radio Occultation ◽  
Lower Stratosphere ◽  
Time Window ◽  
Deep Convection ◽  
Atomic Clock ◽  
Space Station ◽  
Radiation Balance ◽  
Bending Angle ◽  
Upper Troposphere ◽  
Gps Radio Occultation

Abstract. The tropical deep convection affects the radiation balance of the atmosphere changing the water vapor mixing ratio and the temperature of the upper troposphere lower stratosphere. The aim of this work is to better understand these processes and to investigate if severe storms leave a significant signature in radio occultation profiles in the tropical tropopause layer. Using tropical cyclone best track database and data from different GPS radio occultation missions (COSMIC, GRACE, CHAMP, SACC and GPSMET), we selected 1194 profiles in a time window of 3 h and a space window of 300 km from the eye of the cyclone. We show that the bending angle anomaly of a GPS radio occultation signal is typically larger than the climatology in the upper troposphere and lower stratosphere and that a double tropopause during deep convection can easily be detected using this technique. Comparisons with co-located radiosondes, climatology of tropopause altitudes and GOES analyses are also shown to support the hypothesis that the bending angle anomaly can be used as an indicator of convective towers. The results are discussed in connection to the GPS radio occultation receiver which will be part of the Atomic Clock Ensemble in Space (ACES) payload on the International Space Station.

Intraseasonal temperature variability in the upper troposphere and lower stratosphere from the GPS radio occultation measurements

2012 ◽  
Vol 117 (D15) ◽  
pp. n/a-n/a ◽  
Author(s):  
Baijun Tian ◽  
Chi O. Ao ◽  
Duane E. Waliser ◽  
Eric J. Fetzer ◽  
Anthony J. Mannucci ◽  
...  
Keyword(s):  
Radio Occultation ◽  
Lower Stratosphere ◽  
Temperature Variability ◽  
Upper Troposphere ◽  
Gps Radio Occultation

scholarly journals GPS radio occultation with TerraSAR-X and TanDEM-X: sensitivity of lower troposphere sounding to the Open-Loop Doppler model

2014 ◽  
Vol 7 (12) ◽  
pp. 12719-12733 ◽  
Author(s):  
F. Zus ◽  
G. Beyerle ◽  
S. Heise ◽  
T. Schmidt ◽  
J. Wickert
Keyword(s):  
Radio Occultation ◽  
Weather Prediction ◽  
Lower Troposphere ◽  
Systematic Difference ◽  
Open Loop ◽  
Negative Bias ◽  
Upper Troposphere ◽  
Gps Radio Occultation ◽  
Global Positioning ◽  
Data Source

Abstract. The Global Positioning System (GPS) radio occultation (RO) technique provides valuable input for numerical weather prediction and is considered as a data source for climate related research. Numerous studies outline the high precision and accuracy of RO atmospheric soundings in the upper troposphere and lower stratosphere. In this altitude region (8–25 km) RO atmospheric soundings are considered to be free of any systematic error. In the tropical (30° S–30° N) Lower (<8 km) Troposphere (LT), this is not the case; systematic differences with respect to independent data sources exist and are still not completely understood. To date only little attention has been paid to the Open Loop (OL) Doppler model. Here we report on a RO experiment carried out on-board of the twin satellite configuration TerraSAR-X and TanDEM-X which possibly explains to some extent biases in the tropical LT. In two sessions we altered the OL Doppler model aboard TanDEM-X by not more than ±5 Hz with respect to TerraSAR-X and compare collocated atmospheric refractivity profiles. We find a systematic difference in the retrieved refractivity. The bias mainly stems from the tropical LT; there the bias reaches up to ±1%. Hence, we conclude that the negative bias (several Hz) of the OL Doppler model aboard TerraSAR-X introduces a negative bias (in addition to the negative bias which is primarily caused by critical refraction) in our retrieved refractivity in the tropical LT.

scholarly journals Modeling the transport of very short-lived substances into the tropical upper troposphere and lower stratosphere

2009 ◽  
Vol 9 (5) ◽  
pp. 18511-18543 ◽  
Author(s):  
J. Aschmann ◽  
B. M. Sinnhuber ◽  
E. L. Atlas ◽  
S. M. Schauffler
Keyword(s):  
Large Scale ◽  
Lower Stratosphere ◽  
Transport Model ◽  
Three Dimensional ◽  
Chemical Transport Model ◽  
Heating Rates ◽  
Model Calculations ◽  
Upper Troposphere ◽  
Mass Fluxes ◽  
Tropical Upper Troposphere

Abstract. The transport of very short-lived substances into the tropical upper troposphere and lower stratosphere is investigated by a three-dimensional chemical transport model using archived convective updraft mass fluxes (or detrainment rates) from the European Centre for Medium-Range Weather Forecast's ERA-Interim reanalysis. Large-scale vertical velocities are calculated from diabatic heating rates. With this approach we explicitly model the large scale subsidence in the tropical troposphere with convection taking place in fast and isolated updraft events. The model calculations agree generally well with observations of bromoform and methyl iodide from aircraft campaigns and with ozone and water vapor from sonde and satellite observations. Using a simplified treatment of dehydration and bromine product gas washout we give a range of 1.6 to 3 ppt for the contribution of bromoform to stratospheric bromine, assuming a uniform source in the boundary layer of 1 ppt. We show that the most effective region for VSLS transport into the stratosphere is the West Pacific, accounting for about 55% of the bromine from bromoform transported into the stratosphere under the supposition of a uniformly distributed source.

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