scholarly journals Vertical Wave Number Spectrum of Temperature Fluctuations in the Stratosphere using GPS Occultation Data.

2002 ◽  
Vol 80 (4B) ◽  
pp. 925-938 ◽  
Author(s):  
Toshitaka TSUDA ◽  
Klemens HOCKE
Keyword(s):  
Temperature Fluctuations ◽  
Wave Number ◽  
Occultation Data ◽  
Gps Occultation

A Calibrated Tec Methord for Inversion of Ionospheric GPS Occultation Data

2006 ◽  
Vol 49 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Xiao-Cheng WU ◽  
Xiong HU ◽  
Xun-Xie ZHANG ◽  
Wickert JENS
Keyword(s):  
Occultation Data ◽  
Gps Occultation

scholarly journals Analysis of vertical wave number spectrum of atmospheric gravity waves in the stratosphere using COSMIC GPS radio occultation data

2011 ◽  
Vol 4 (8) ◽  
pp. 1627-1636 ◽  
Author(s):  
T. Tsuda ◽  
X. Lin ◽  
H. Hayashi ◽  
Keyword(s):  
Gravity Waves ◽  
Radio Occultation ◽  
Temperature Fluctuations ◽  
Ground Level ◽  
Wave Number ◽  
Radiosonde Data ◽  
Small Scale ◽  
Vertical Resolution ◽  
Full Spectrum ◽  
Gps Radio Occultation

Abstract. GPS radio occultation (RO) is characterized by high accuracy and excellent height resolution, which has great advantages in analyzing atmospheric structures including small-scale vertical fluctuations. The vertical resolution of the geometrical optics (GO) method in the stratosphere is about 1.5 km due to Fresnel radius limitations, but full spectrum inversion (FSI) can provide superior resolutions. We applied FSI to COSMIC GPS-RO profiles from ground level up to 30 km altitude, although basic retrieval at UCAR/CDAAC sets the sewing height from GO to FSI below the tropopause. We validated FSI temperature profiles with routine high-resolution radiosonde data in Malaysia and North America collected within 400 km and about 30 min of the GPS RO events. The average discrepancy at 10–30 km altitude was less than 0.5 K, and the bias was equivalent with the GO results. Using the FSI results, we analyzed the vertical wave number spectrum of normalized temperature fluctuations in the stratosphere at 20–30 km altitude, which exhibits good consistency with the model spectra of saturated gravity waves. We investigated the white noise floor that tends to appear at high wave numbers, and the substantial vertical resolution of the FSI method was estimated as about 100–200 m in the lower stratosphere. We also examined a criterion for the upper limit of the FSI profiles, beyond which bending angle perturbations due to system noises, etc., could exceed atmospheric excess phase fluctuations. We found that the FSI profiles can be used up to about 28 km in studies of temperature fluctuations with vertical wave lengths as short as 0.5 km.

scholarly journals Analysis of vertical wave number spectrum of atmospheric gravity waves in the stratosphere using COSMIC GPS radio occultation data

2011 ◽  
Vol 4 (2) ◽  
pp. 2071-2097
Author(s):  
T. Tsuda ◽  
X. Lin ◽  
H. Hayashi ◽  
Keyword(s):  
Gravity Waves ◽  
Radio Occultation ◽  
Temperature Fluctuations ◽  
Ground Level ◽  
Wave Number ◽  
Radiosonde Data ◽  
Small Scale ◽  
Vertical Resolution ◽  
Full Spectrum ◽  
Gps Radio Occultation

Abstract. GPS radio occultation (RO) is characterized by high accuracy and excellent height resolution, which has great advantages in analyzing atmospheric structures including small-scale vertical fluctuations. The vertical resolution of the geometrical optics (GO) method in the stratosphere is about 1.5 km due to Fresnel radius limitations, but full spectrum inversion (FSI) can provide superior resolutions. We applied FSI to COSMIC GPS-RO profiles from ground level up to 30 km altitude, although basic retrieval at UCAR/CDAAC sets the sewing height from GO to FSI below the tropopause. We validated FSI temperature profiles with routine high-resolution radiosonde data in Malaysia and North America collected within 400 km and about 30 min of the GPS RO events. The average discrepancy at 10–30 km altitude was less than 0.5 K, and the bias was equivalent with the GO results. Using the FSI results, we analyzed the vertical wave number spectrum of normalized temperature fluctuations in the stratosphere at 20–30 km altitude, which exhibits good consistency with the model spectra of saturated gravity waves. We investigated the white noise floor that tends to appear at high wave numbers, and the substantial vertical resolution of the FSI method was estimated as about 100–200 m in the lower stratosphere. We also examined a criterion for the upper limit of the FSI profiles, beyond which bending angle perturbations due to system noises, etc, could exceed atmospheric excess phase fluctuations. We found that the FSI profiles can be used up to about 28 km in studies of temperature fluctuations with vertical wave lengths as short as 0.5 km.

scholarly journals Spectral analysis of 10-m resolution temperature profiles from balloon soundings over Beijing

2006 ◽  
Vol 24 (7) ◽  
pp. 1801-1808 ◽  
Author(s):  
Y. Wu ◽  
J. Xu ◽  
W. Yuan ◽  
H. Chen ◽  
J. Bian
Keyword(s):  
Lower Stratosphere ◽  
Temperature Fluctuations ◽  
Wave Number ◽  
Temperature Profiles ◽  
Vertical Temperature ◽  
Spectral Character ◽  
Meteorological Observatory ◽  
Wave Numbers ◽  
Temperature Spectra ◽  
Spectrum Model

Abstract. Vertical temperature profiles with a height resolution of 10 m have been measured in the troposphere and lower stratosphere during March and April 2003 over the Beijing Meteorological Observatory. This resolution allows us to study temperature spectra up to higher wave numbers than many published papers. Our purposes in this study are to examine the spectral character of normalized temperature fluctuations in the 2.90–8.01 km (troposphere) and 14.65–19.76 km (lower stratosphere) altitude ranges and to compare them with model spectra. Vertical wave number spectra of six temperature profiles are presented. Results indicate that mean spectral slopes are about −1.9 in the troposphere and −2.2 in the lower stratosphere, which is believed to be the shallowest slopes ever measured by balloon-borne radiosonde soundings. Mean spectral amplitudes at m=1/(100 m) are about 17 times larger in the troposphere and 4 times larger in the lower stratosphere than the predicted saturated spectral amplitudes. These results show that the observed temperature spectra do not obey current gravity wave saturation models, the "universal" atmospheric spectrum model, or the wind-shifting model, in both slope and amplitude.

scholarly journals On the Detection of Subphotospheric Convective Velocities and Temperature Fluctuations

1983 ◽  
Vol 66 ◽  
pp. 401-410
Author(s):  
D. O. Gough ◽  
J. Toomre
Keyword(s):  
Large Scale ◽  
Temperature Fluctuations ◽  
Wave Number ◽  
Convective Velocity ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Wave Patterns ◽  
Large Scale Flow ◽  
Low Amplitude ◽  
High Degree

AbstractA procedure is outlined for estimating the influence of large-scale convective eddies on the wave patterns of five-minute oscillations of high degree. The method is applied to adiabatic oscillations, with frequency ω and wave number k, of a plane-parallel polytropic layer upon which is imposed a low-amplitude convective flow. The distortion to the k – ω relation has two constituents: one depends on the horizontal component of the convective velocity and has a sign which depends on the sign of ω/k; the other depends on temperature fluctuations and is independent of the sign of ω/k. The magnitude of the distortion is just at the limit of present observational sensitivity. Thus there is reasonable hope that it will be possible to reveal some aspects of the large-scale flow in the solar convection zone

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.

Generating climate benchmark atmospheric soundings using GPS occultation data

2006 ◽  
Author(s):  
Anthony J. Mannucci ◽  
Chi O. Ao ◽  
Thomas P. Yunck ◽  
Larry E. Young ◽  
George A. Hajj ◽  
...  
Keyword(s):  
Occultation Data ◽  
Gps Occultation

scholarly journals Radio Wave Propagation Phenomena from GPS Occultation Data Analysis

10.5772/55480 ◽  
2013 ◽  
Author(s):  
Alexey Pavelyev ◽  
Alexander Pavelyev ◽  
Stanislav Matyugov ◽  
Oleg Yakovlev ◽  
Yuei-An Liou ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Data Analysis ◽  
Radio Wave ◽  
Radio Wave Propagation ◽  
Occultation Data ◽  
Gps Occultation
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