Global distribution of atmospheric waves in the equatorial upper troposphere and lower stratosphere: COSMIC observations of wave mean flow interactions

Abstract The feedback of mountain waves and low-level blocking on an idealized baroclinically unstable wave passing over an isolated ridge is examined through numerical simulation. Theoretical analysis implies that the volume-integrated perturbation momentum budget is dominated by mean-flow deceleration, the divergence of vertical fluxes of horizontal momentum, and the Coriolis force acting on the perturbation ageostrophic wind. These do indeed appear as the dominant balances in numerically computed budgets averaged over layers containing 1) wave breaking in the lower stratosphere, 2) flow blocking with wave breaking near the surface, and 3) a region of pronounced horizontally averaged mean-flow deceleration in the upper troposphere where there is no wave breaking. The local impact of wave breaking on the jet in the lower stratosphere is dramatic, with winds in the jet core reduced by almost 50% relative to the no-mountain case. Although it is the layer with the strongest average deceleration, the local patches of decelerated flow are weakest in the upper troposphere. The cross-mountain pressure drag over a 2-km-high ridge greatly exceeds the vertical momentum flux at mountain-top level because of low-level wave breaking, blocking, and lateral flow diversion. These pressure drags and the low-level momentum fluxes are significantly different from corresponding values computed for simulations with steady forcing matching the instantaneous conditions over the mountain in the evolving large-scale flow.

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Measurements of the upper troposphere and lower stratosphere during tropical cyclones using the GPS radio occultation technique

Advances in Space Research ◽

10.1016/j.asr.2010.05.031 ◽

2011 ◽

Vol 47 (2) ◽

pp. 348-355 ◽

Cited By ~ 7

Author(s):

Riccardo Biondi ◽

Torsten Neubert ◽

Stig Syndergaard ◽

Johannes Nielsen

Keyword(s):

Tropical Cyclones ◽

Radio Occultation ◽

Lower Stratosphere ◽

Upper Troposphere ◽

Gps Radio Occultation

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A Case Study of Mass Transport during the East-West Oscillation of the Asian Summer Monsoon Anticyclone

Advances in Meteorology ◽

10.1155/2017/5174025 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Jiali Luo ◽

Jiayao Song ◽

Hongying Tian ◽

Lei Liu ◽

Xinlei Liang

Keyword(s):

Lower Stratosphere ◽

Asian Summer Monsoon ◽

Chemical Transport ◽

Upward Motion ◽

High Concentration ◽

Upper Troposphere ◽

Asian Summer ◽

Mode Tm ◽

East West

We use ERA-Interim reanalysis, MLS observations, and a trajectory model to examine the chemical transport and tracers distribution in the Upper Troposphere and Lower Stratosphere (UTLS) associated with an east-west oscillation case of the anticyclone in 2016. The results show that the spatial distribution of water vapor (H2O) was more consistent with the location of the anticyclone than carbon monoxide (CO) at 100 hPa, and an independent relative high concentration center was only found in H2O field. At 215 hPa, although the anticyclone center also migrated from the Tibetan Mode (TM) to the Iranian Mode (IM), the relative high concentration centers of both tracers were always colocated with regions where upward motion was strong in the UTLS. When the anticyclone migrated from the TM, air within the anticyclone over Tibetan Plateau may transport both westward and eastward but was always within the UTLS. The relative high concentration of tropospheric tracers within the anticyclone in the IM was from the east and transported by the westward propagation of the anticyclone rather than being lifted from surface directly. Air within the relative high geopotential height centers over Western Pacific was partly from the main anticyclone and partly from lower levels.

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Atmospheric measurements of aerosol precursor gases in the upper troposphere and lower stratosphere

Journal of Aerosol Science ◽

10.1016/s0021-8502(97)85033-1 ◽

1997 ◽

Vol 28 ◽

pp. S65-S66 ◽

Cited By ~ 3

Author(s):

F. Arnold ◽

K.H. Wohlfrom ◽

J. Schneider ◽

M. Klemm ◽

T. Stilp ◽

...

Keyword(s):

Lower Stratosphere ◽

Atmospheric Measurements ◽

Upper Troposphere

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Eddy-mean flow interactions and vertical eddy energy redistribution associated with the standing meander in the Antarctic Circumpolar Current

10.1002/essoar.10506510.1 ◽

2021 ◽

Author(s):

Takuro Matsuta ◽

Yukio Masumoto

Keyword(s):

Antarctic Circumpolar Current ◽

Mean Flow ◽

Energy Redistribution ◽

Flow Interactions ◽

Circumpolar Current ◽

The Antarctic ◽

Vertical Eddy

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Aircraft measurements of gravity waves in the upper troposphere and lower stratosphere during the START08 field experiment

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-7667-2015 ◽

2015 ◽

Vol 15 (13) ◽

pp. 7667-7684 ◽

Cited By ~ 13

Author(s):

Fuqing Zhang ◽

Junhong Wei ◽

Meng Zhang ◽

K. P. Bowman ◽

L. L. Pan ◽

...

Keyword(s):

Power Law ◽

Gravity Waves ◽

Lower Stratosphere ◽

Potential Temperature ◽

Shear Instability ◽

Aircraft Measurements ◽

Upper Troposphere ◽

Airborne Measurements ◽

Wide Range

Abstract. This study analyzes in situ airborne measurements from the 2008 Stratosphere–Troposphere Analyses of Regional Transport (START08) experiment to characterize gravity waves in the extratropical upper troposphere and lower stratosphere (ExUTLS). The focus is on the second research flight (RF02), which took place on 21–22 April 2008. This was the first airborne mission dedicated to probing gravity waves associated with strong upper-tropospheric jet–front systems. Based on spectral and wavelet analyses of the in situ observations, along with a diagnosis of the polarization relationships, clear signals of mesoscale variations with wavelengths ~ 50–500 km are found in almost every segment of the 8 h flight, which took place mostly in the lower stratosphere. The aircraft sampled a wide range of background conditions including the region near the jet core, the jet exit and over the Rocky Mountains with clear evidence of vertically propagating gravity waves of along-track wavelength between 100 and 120 km. The power spectra of the horizontal velocity components and potential temperature for the scale approximately between ~ 8 and ~ 256 km display an approximate −5/3 power law in agreement with past studies on aircraft measurements, while the fluctuations roll over to a −3 power law for the scale approximately between ~ 0.5 and ~ 8 km (except when this part of the spectrum is activated, as recorded clearly by one of the flight segments). However, at least part of the high-frequency signals with sampled periods of ~ 20–~ 60 s and wavelengths of ~ 5–~ 15 km might be due to intrinsic observational errors in the aircraft measurements, even though the possibilities that these fluctuations may be due to other physical phenomena (e.g., nonlinear dynamics, shear instability and/or turbulence) cannot be completely ruled out.

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Wave-mean flow interactions in the upper atmosphere

Boundary-Layer Meteorology ◽

10.1007/bf02265242 ◽

1973 ◽

Vol 4 (1-4) ◽

pp. 327-343 ◽

Cited By ~ 48

Author(s):

Richard S. Lindzen

Keyword(s):

Upper Atmosphere ◽

Mean Flow ◽

Flow Interactions

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Effect of tropical cyclones on the Stratosphere-Troposphere Exchange observed using satellite observations over north Indian Ocean

10.5194/acp-2015-988 ◽

2016 ◽

Cited By ~ 3

Author(s):

M. Venkat Ratnam ◽

S. Ravindra Babu ◽

S. S. Das ◽

Ghouse Basha ◽

B. V. Krishnamurthy ◽

...

Keyword(s):

Water Vapor ◽

Indian Ocean ◽

Tropical Cyclones ◽

Lower Stratosphere ◽

North Indian Ocean ◽

Satellite Observations ◽

Upper Troposphere ◽

North West ◽

The North ◽

The Impact

Abstract. Tropical cyclones play an important role in modifying the tropopause structure and dynamics as well as stratosphere-troposphere exchange (STE) process in the Upper Troposphere and Lower Stratosphere (UTLS) region. In the present study, the impact of cyclones that occurred over the North Indian Ocean during 2007–2013 on the STE process is quantified using satellite observations. Tropopause characteristics during cyclones are obtained from the Global Positioning System (GPS) Radio Occultation (RO) measurements and ozone and water vapor concentrations in UTLS region are obtained from Aura-Microwave Limb Sounder (MLS) satellite observations. The effect of cyclones on the tropopause parameters is observed to be more prominent within 500 km from the centre of cyclone. In our earlier study we have observed decrease (increase) in the tropopause altitude (temperature) up to 0.6 km (3 K) and the convective outflow level increased up to 2 km. This change leads to a total increase in the tropical tropopause layer (TTL) thickness of 3 km within the 500 km from the centre of cyclone. Interestingly, an enhancement in the ozone mixing ratio in the upper troposphere is clearly noticed within 500 km from cyclone centre whereas the enhancement in the water vapor in the lower stratosphere is more significant on south-east side extending from 500–1000 km away from the cyclone centre. We estimated the cross-tropopause mass flux for different intensities of cyclones and found that the mean flux from stratosphere to troposphere for cyclonic stroms is 0.05 ± 0.29 × 10−3 kg m−2 and for very severe cyclonic stroms it is 0.5 ± 1.07 × 10−3 kg m−2. More downward flux is noticed in the north-west and south-west side of the cyclone centre. These results indicate that the cyclones have significant impact in effecting the tropopause structure, ozone and water vapour budget and consequentially the STE in the UTLS region.

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The Influence of Sea Surface Temperatures on the Northern Winter Stratosphere: Ensemble Simulations with the MAECHAM5 Model

Journal of Climate ◽

10.1175/jcli3826.1 ◽

2006 ◽

Vol 19 (16) ◽

pp. 3863-3881 ◽

Cited By ~ 292

Author(s):

E. Manzini ◽

M. A. Giorgetta ◽

M. Esch ◽

L. Kornblueh ◽

E. Roeckner

Keyword(s):

Lower Stratosphere ◽

Southern Oscillation ◽

Internal Variability ◽

Sea Surface ◽

Sea Surface Temperatures ◽

Mean Flow ◽

Enso Events ◽

Surface Temperatures ◽

Northern Winter ◽

Mean State

Abstract The role of interannual variations in sea surface temperatures (SSTs) on the Northern Hemisphere winter polar stratospheric circulation is addressed by means of an ensemble of nine simulations performed with the middle atmosphere configuration of the ECHAM5 model forced with observed SSTs during the 20-yr period from 1980 to 1999. Results are compared to the 40-yr ECMWF Re-Analysis (ERA-40). Three aspects have been considered: the influence of the interannual SST variations on the climatological mean state, the response to El Niño–Southern Oscillation (ENSO) events, and the influence on systematic temperature changes. The strongest influence of SST variations has been found for the warm ENSO events considered. Namely, it has been found that the large-scale pattern associated with the extratropical tropospheric response to the ENSO phenomenon during northern winter enhances the forcing and the vertical propagation into the stratosphere of the quasi-stationary planetary waves emerging from the troposphere. This enhanced planetary wave disturbance thereafter results in a polar warming of a few degrees in the lower stratosphere in late winter and early spring. Consequently, the polar vortex is weakened, and the warm ENSO influence clearly emerges also in the zonal-mean flow. In contrast, the cold ENSO events considered do not appear to have an influence distinguishable from that of internal variability. It is also not straightforward to deduce the influence of the SSTs on the climatological mean state from the simulations performed, because the simulated internal variability of the stratosphere is large, a realistic feature. Moreover, the results of the ensemble of simulations provide weak to negligible evidence for the possibility that SST variations during the two decades considered are substantially contributing to changes in the polar temperature in the winter lower stratosphere.

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