scholarly journals Atmospheric temperature change detection with GPS radio occultation 1995 to 2008

2009 ◽  
Vol 36 (18) ◽  
Author(s):  
A. K. Steiner ◽  
G. Kirchengast ◽  
B. C. Lackner ◽  
B. Pirscher ◽  
M. Borsche ◽  
...  
Keyword(s):  
Change Detection ◽  
Temperature Change ◽  
Radio Occultation ◽  
Atmospheric Temperature ◽  
Gps Radio Occultation

scholarly journals Correction to “Atmospheric temperature change detection with GPS radio occultation 1995 to 2008”

2010 ◽  
Vol 37 (3) ◽  
pp. n/a-n/a
Author(s):  
A. K. Steiner ◽  
G. Kirchengast ◽  
B. C. Lackner ◽  
B. Pirscher ◽  
M. Borsche ◽  
...  
Keyword(s):  
Change Detection ◽  
Temperature Change ◽  
Radio Occultation ◽  
Atmospheric Temperature ◽  
Gps Radio Occultation

Optimum prediction of atmospheric temperature using GPS radio occultation measurements

2017 ◽  
Vol 919 (1) ◽  
pp. 48-51
Author(s):  
N.H. Javadov ◽  
R.A. Eminov ◽  
N.Ya. Ismailov
Keyword(s):  
Radio Occultation ◽  
General Procedure ◽  
Atmospheric Temperature ◽  
Mean Value ◽  
Optimization Criterion ◽  
Temperature Measurements ◽  
Gps Radio Occultation ◽  
Applied Optimization ◽  
Quadratic Deviation ◽  
The Mean

The matters of optimum forecasting atmospheric temperature using GPS radio occultation measurements are considered. The analysis of the available data regarding to the comparison of temperature measurements using radio occultation method and radiosondes was made. As a result it was concluded that the mean value of those results’ difference and also the mean quadratic deviation of these difference increases in common by increase of the forecasting time. In order to prevent surplus loading of telemetry channels and broadcasting inaccurate forecast values via them the optimization of general procedure of radio occultation temperature measurements are carried out using fine functions method. For optimization the concurrent parameters, changing on antiphase order are determined. It is found out that utilization of fine function method taking into account the applied optimization criterion and some limitation conditions make it possible to optimize the whole procedure of forecasting atmospheric temperature using the GPS radio occultation measurements.

scholarly journals A method to improve the determination of wave perturbations close to the tropopause by using a digital filter

2011 ◽  
Vol 4 (9) ◽  
pp. 1777-1784 ◽  
Author(s):  
P. Alexander ◽  
A. de la Torre ◽  
P. Llamedo ◽  
R. Hierro ◽  
T. Schmidt ◽  
...  
Keyword(s):  
Digital Filter ◽  
Radio Occultation ◽  
Atmospheric Temperature ◽  
Lapse Rate ◽  
Gps Radio Occultation ◽  
Suggested Technique ◽  
Low Latitudes ◽  
Synthetic Temperature ◽  
First Time

Abstract. GPS radio occultation satellite data allowed to analyze in the last decade for the first time a large amount of atmospheric temperature profiles including both the troposphere and the stratosphere all over the globe. Wave amplitude enhancements have been systematically observed around tropopause levels, which are apparently due to artifacts generated by any digital filter used to isolate the wave components from these data. We present a new filtering method which can be equally applied to temperature or refractivity profiles. It was tested with synthetic temperature data based on NCEP reanalyes and observed wave climatologies and it was also statistically validated with GPS radio occultation profiles from the COSMIC mission. The suggested technique significantly reduces artificial enhancements around the tropopause, mainly at low latitudes, where a sharp lapse rate change usually exists. This represents an improvement in comparison to previous applications of standard filters. In addition it would allow the study of longer vertical wavelengths than previously done with other filtering procedures.

scholarly journals An investigation of atmospheric temperature profiles in the Australian region using collocated GPS radio occultation and radiosonde data

2011 ◽  
Vol 4 (10) ◽  
pp. 2087-2092 ◽  
Author(s):  
K. Zhang ◽  
E. Fu ◽  
D. Silcock ◽  
Y. Wang ◽  
Y. Kuleshov
Keyword(s):  
Standard Deviation ◽  
Radio Occultation ◽  
Atmospheric Temperature ◽  
Radiosonde Data ◽  
Data Sets ◽  
Temperature Profiles ◽  
Gps Radio Occultation ◽  
The One ◽  
Distinct Features ◽  
The Impact

Abstract. GPS radio occultation (RO) has been recognised as an alternative atmospheric upper air observation technique due to its distinct features and technological merits. The CHAllenging Minisatellite Payload (CHAMP) RO satellite and FORMOSAT-3/COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) RO constellation together have provided about ten years of high quality global coverage RO atmospheric profiles. This technique is best used for meteorological studies in the difficult-to-access areas such as deserts and oceans. To better understand and use RO data, effective quality assessment using independent radiosonde data and its associated collocation criteria used in tempo-spatial domain are important. This study compares GPS RO retrieved temperature profiles from both CHAMP (between May 2001 and October 2008) and FORMOSAT-3/COSMIC (between July 2006 and December 2009) with radiosonde data from 38 Australian radiosonde stations. The overall results show a good agreement between the two data sets. Different collocation criteria within 3 h and 300 km between the profile pairs have been applied and the impact of these different collocation criteria on the evaluation results is found statistically insignificantly. The CHAMP and FORMOSAT-3/COSMIC temperature profiles have been evaluated at 16 different pressure levels and the differences between GPS RO and radiosonde at different levels of the atmosphere have been studied. The result shows that the mean temperature difference between radiosonde and CHAMP is 0.39 °C (with a standard deviation of 1.20 °C) and the one between radiosonde and FORMOSAT-3/COSMIC is 0.37 °C (with a standard deviation of 1.24 °C). Different collocation criteria have been applied and insignificant differences were identified amongst the results.

scholarly journals The GPS radio occultation record – a novel dataset for atmospheric change detection

2009 ◽  
Vol 6 (9) ◽  
pp. 092024
Author(s):  
Andrea K Steiner ◽  
G Kirchengast ◽  
B C Lackner ◽  
G C Hegerl ◽  
B Pirscher ◽  
...  
Keyword(s):  
Change Detection ◽  
Radio Occultation ◽  
Gps Radio Occultation ◽  
Atmospheric Change

GPS radio occultation for climate monitoring and change detection

Radio Science ◽  
2011 ◽  
Vol 46 (6) ◽  
Author(s):  
A. K. Steiner ◽  
B. C. Lackner ◽  
F. Ladstädter ◽  
B. Scherllin-Pirscher ◽  
U. Foelsche ◽  
...  
Keyword(s):  
Change Detection ◽  
Radio Occultation ◽  
Gps Radio Occultation ◽  
Climate Monitoring

scholarly journals Global 3D Features of Error Variances of GPS Radio Occultation and Radiosonde Observations

2020 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Xu Xu ◽  
Xiaolei Zou
Keyword(s):  
Radio Occultation ◽  
Weather Prediction ◽  
Lower Troposphere ◽  
Error Variance ◽  
Specific Humidity ◽  
Temperature Error ◽  
Observation Error ◽  
Bending Angle ◽  
Gps Radio Occultation ◽  
Low Latitudes

Global Positioning System (GPS) radio occultation (RO) and radiosonde (RS) observations are two major types of observations assimilated in numerical weather prediction (NWP) systems. Observation error variances are required input that determines the weightings given to observations in data assimilation. This study estimates the error variances of global GPS RO refractivity and bending angle and RS temperature and humidity observations at 521 selected RS stations using the three-cornered hat method with additional ERA-Interim reanalysis and Global Forecast System forecast data available from 1 January 2016 to 31 August 2019. The global distributions, of both RO and RS observation error variances, are analyzed in terms of vertical and latitudinal variations. Error variances of RO refractivity and bending angle and RS specific humidity in the lower troposphere, such as at 850 hPa (3.5 km impact height for the bending angle), all increase with decreasing latitude. The error variances of RO refractivity and bending angle and RS specific humidity can reach about 30 N-unit2, 3 × 10−6 rad2, and 2 (g kg−1)2, respectively. There is also a good symmetry of the error variances of both RO refractivity and bending angle with respect to the equator between the Northern and Southern Hemispheres at all vertical levels. In this study, we provide the mean error variances of refractivity and bending angle in every 5°-latitude band between the equator and 60°N, as well as every interval of 10 hPa pressure or 0.2 km impact height. The RS temperature error variance distribution differs from those of refractivity, bending angle, and humidity, which, at low latitudes, are smaller (less than 1 K2) than those in the midlatitudes (more than 3 K2). In the midlatitudes, the RS temperature error variances in North America are larger than those in East Asia and Europe, which may arise from different radiosonde types among the above three regions.

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