Vertical Wave Number Spectra of Ozone and Temperature Fluctuations in the Troposphere and Lower Stratosphere over Costa Rica (10 N, 83.4W) a Tropical Station

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.

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Vertical wave number spectra of wind fluctuations in the troposphere and lower stratosphere over Gadanki, a tropical station

Journal of Atmospheric and Solar-Terrestrial Physics ◽

10.1016/j.jastp.2004.08.003 ◽

2005 ◽

Vol 67 (3) ◽

pp. 251-258 ◽

Cited By ~ 3

Author(s):

Gopa Dutta ◽

B. Bapiraju ◽

T.S.P.L.N. Prasad ◽

P. Balasubrahmanyam ◽

H. Aleem Basha

Keyword(s):

Lower Stratosphere ◽

Wave Number ◽

Tropical Station

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Long Period Waves and Oscillations Over Costa Rica, a Tropical Station

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.d6483.049420 ◽

2020 ◽

Vol 9 (4) ◽

pp. 64-67

Keyword(s):

Costa Rica ◽

Lower Stratosphere ◽

Interannual Variations ◽

Mixing Ratio ◽

Long Period ◽

Tropopause Region ◽

Morlet Wavelet Transform ◽

Tropical Station ◽

Lower Period ◽

Prominent Peak

Seasonal, annual and interannual variations of Ozone Mixing Ratio (OMR) have been studied for 12 years, from balloonsondes and Ozonesondes that were launched over Costa Rica (10oN, 83.4oW), a tropical station, as part of Southern Hemisphere Additional Ozonesondes (SHADOZ) network. It was found that near tropopause region there exists prominent peak of OMR during July month for most of the years. Lomb-Scargle Periodogram (LSP) analysis has been applied for the years 2005-2017 to identify the wave activities and found that Quasi Biennial Oscillations (QBO) with period of 2-2.5 years and even higher period oscillations of 3-4 years are prominent in middle troposphere and lower stratosphere regions which could cause large annual variabilities of OMR fluctuations. Fluctuations of OMR were subjected to Morlet wavelet transform over a year, 2008, to study seasonal variabilities. The wavelet analysis confirm that Madden Julian Oscillations (MJO) with periods 49-60 days are prominent during summer near tropopuase and in lower stratosphere regions, while lower period equatorial Kelvin waves of 14-20 days periods dominate during winter and spring in troposphere region, which could be responsible for maximum seasonal variability.

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Effect of meteorology on the variability of ozone in the troposphere and lower stratosphere over a tropical station Thumba (8.5°N, 76.9°E)

Journal of Atmospheric and Solar-Terrestrial Physics ◽

10.1016/j.jastp.2021.105567 ◽

2021 ◽

Vol 215 ◽

pp. 105567

Author(s):

P.R. Satheesh Chandran ◽

S.V. Sunilkumar ◽

M. Muhsin ◽

Maria Emmanuel ◽

Geetha Ramkumar ◽

...

Keyword(s):

Lower Stratosphere ◽

Tropical Station

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Climatic variability of the mean flow and stationary planetary waves in the NCEP/NCAR reanalysis data

Annales Geophysicae ◽

10.5194/angeo-26-1233-2008 ◽

2008 ◽

Vol 26 (5) ◽

pp. 1233-1241 ◽

Cited By ~ 11

Author(s):

A. Yu. Kanukhina ◽

E. V. Suvorova ◽

L. A. Nechaeva ◽

E. K. Skrygina ◽

A. I. Pogoreltsev

Keyword(s):

Lower Stratosphere ◽

Climatic Variability ◽

Reanalysis Data ◽

Planetary Waves ◽

Lower Atmosphere ◽

Wave Number ◽

Mean Flow ◽

The Mean ◽

The 1960S ◽

Environmental Prediction

Abstract. NCEP/NCAR (National Center for Environmental Prediction – National Center for Atmospheric Research) data have been used to estimate the long-term variability of the mean flow, temperature, and Stationary Planetary Waves (SPW) in the troposphere and lower stratosphere. The results obtained show noticeable climatic variabilities in the intensity and position of the tropospheric jets that are caused by temperature changes in the lower atmosphere. As a result, we can expect that this variability of the mean flow will cause the changes in the SPW propagation conditions. The simulation of the SPW with zonal wave number m=1 (SPW1), performed with a linearized model using the mean flow distributions typical for the 1960s and for the beginning of 21st century, supports this assumption and shows that during the last 40 years the amplitude of the SPW1 in the stratosphere and mesosphere increased substantially. The analysis of the SPW amplitudes extracted from the geopotential height and zonal wind NCEP/NCAR data supports the results of simulation and shows that during the last years there exists an increase in the SPW1 activity in the lower stratosphere. These changes in the amplitudes are accompanied by increased interannual variability of the SPW1, as well. Analysis of the SPW2 activity shows that changes in its amplitude have a different sign in the northern winter hemisphere and at low latitudes in the southern summer hemisphere. The value of the SPW2 variability differs latitudinally and can be explained by nonlinear interference of the primary wave propagation from below and from secondary SPW2.

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

Atmospheric Measurement Techniques ◽

10.5194/amt-4-1627-2011 ◽

2011 ◽

Vol 4 (8) ◽

pp. 1627-1636 ◽

Cited By ~ 24

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.

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

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-4-2071-2011 ◽

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.

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On the Detection of Subphotospheric Convective Velocities and Temperature Fluctuations

International Astronomical Union Colloquium ◽

10.1017/s0252921100095737 ◽

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

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Intensive radiosonde observations of gravity waves in the lower atmosphere over Yichang (111°18´ E, 30°42´ N), China

Annales Geophysicae ◽

10.5194/angeo-26-2005-2008 ◽

2008 ◽

Vol 26 (7) ◽

pp. 2005-2018 ◽

Cited By ~ 9

Author(s):

◽

Keyword(s):

Energy Density ◽

Gravity Waves ◽

Lower Stratosphere ◽

Daily Basis ◽

Lower Atmosphere ◽

Wave Number ◽

Kinetic Energy Density ◽

Seasonal Differences ◽

Seasonal Characteristics ◽

The Mean

Abstract. The characteristics of dynamical and thermal structures and inertial gravity waves (GWs) in the troposphere and lower stratosphere (TLS) over Yichang (111°18´ E, 30°42´ N) were statistically studied by using the data from intensive radiosonde observations in August 2006 (summer month) and January 2007 (winter month) on an eight-times-daily basis. The background atmosphere structures observed in different months exhibit evident seasonal differences, and the zonal wind in winter has a prominent tropospheric jet with a maximum wind speed of about 60 ms−1 occurring at the height of 11.5 km. The statistical results of the inertial GWs in our two-month observations are generally consistent with previous observations in the mid-latitudes. In the summer month, the mean intrinsic frequency and vertical wavelength of the inertial GWs in the troposphere are still larger than those in the lower stratosphere with the absence of intensive tropospheric jets, suggesting that the Doppler shifting due to the tropospheric jets cannot completely account for the differences between the GWs in the troposphere and lower stratosphere. Compared with the observations in the summer month, some interesting seasonal characteristics of the GWs are revealed by the observations in the winter month: 1) more and stronger tropospheric GWs are observed in the winter month; 2) less and weaker GWs are observed in the lower stratosphere in winter; 3) the ratio of the mean GW kinetic energy density to potential energy density is smaller than 1 in winter, which contrasts to that in summer. Most of the seasonal differences can be explained by the intensive tropospheric jets in winter. In both the summer and winter months, the fitted spectral slopes of the vertical wave number spectra for GWs are generally smaller than the canonical spectral slope of −3. Correlation analyses suggest that the tropospheric jet induced wind shear is the dominant source for GWs in both the troposphere and lower stratosphere. Moreover, the tropospheric (lower stratospheric) GWs are found to be modulated by the quasi-7-day (10-day) PW, and the impacts of the diurnal tide on the GWs are relatively weak.

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The Role of Eddy-Eddy Interactions in Sudden Stratospheric Warming Formation

10.5194/wcd-2019-7 ◽

2019 ◽

Author(s):

Erik Anders Lindgren ◽

Aditi Sheshadri

Keyword(s):

General Circulation ◽

Lower Stratosphere ◽

Circulation Model ◽

Wave Number ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Wave Forcing ◽

Wave Numbers ◽

Tropospheric Heating ◽

Wave Flux

Abstract. The effects of eddy-eddy interactions on sudden stratospheric warming formation are investigated using an idealized atmospheric general circulation model, in which tropospheric heating perturbations of zonal wave numbers 1 and 2 are used to produce planetary scale wave activity. Eddy-eddy interactions are removed at different vertical extents of the atmosphere in order to examine the sensitivity of stratospheric circulation to local changes in eddy-eddy interactions. We show that the effects of eddy-eddy interactions on sudden warming formation, including sudden warming frequencies, are strongly dependent on the wave number of the tropospheric forcing and the vertical levels where eddy-eddy interactions are removed. Significant changes in sudden warming frequencies are evident when eddy-eddy interactions are removed even when the lower stratospheric wave forcing does not change, highlighting the fact that the upper stratosphere is not a passive recipient of wave forcing from below. We find that while eddy-eddy interactions are required in the troposphere and lower stratosphere to produce displacements when wave number 2 heating is used, both splits and displacements can be produced without eddy-eddy interactions in the troposphere and lower stratosphere when the model is forced by wave number 1 heating. We suggest that the relative strengths of wave numbers 1 and 2 vertical wave flux entering the stratosphere largely determine the split and displacement ratios when wave number 2 forcing is used, but not wave number 1.

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