Gravity waves above Andes detected from GPS radio occultation temperature profiles: Mountain forcing?

Torre, A. de la; Alexander, P.

doi:10.1029/2005gl022959

Cited by 45 publications

(51 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Including RO into reanalyses can reduce biases in the troposphere and stratosphere in both hemispheres (Poli et al, 2010). Several studies also used RO data to investigate dynamical features of the atmosphere such as waves (Randel and Wu, 2005;de la Torre and Alexander, 2005;Tsuda, 2014), the ENSO (ScherllinPirscher et al, 2012;Sun et al, 2014), tropopause characteristics (Schmidt et al, 2008;Rieckh et al, 2014;Peevey et al, 2014;Randel et al, 2003;Schmidt et al, 2005), and blocking .…”

Section: Radio Occultation Datamentioning

confidence: 99%

See 1 more Smart Citation

A global perspective on atmospheric blocking using GPS radio occultation – one decade of observations

Brunner

Steiner

2017

Atmos. Meas. Tech.

View full text Add to dashboard Cite

Abstract. Atmospheric blocking represents a weather pattern where a stationary high-pressure system weakens or reverses the climatological westerly flow at mid-latitudes for up to several weeks. It is closely connected to strong anomalies in key atmospheric variables such as geopotential height, temperature, and humidity. Here we provide, for the first time, a comprehensive, global perspective on atmospheric blocking and related impacts by using an observation-based data set from Global Positioning System (GPS) radio occultation (RO) from 2006 to 2016. The main blocking regions in both hemispheres and seasonal variations are found to be represented well in RO data. The effect of blocking on vertically resolved temperature and humidity anomalies in the troposphere and lower stratosphere is investigated for blocking regions in the Northern and Southern hemispheres, respectively. We find a statistically significant correlation of blocking with positive temperature anomalies, exceeding 3 K in the troposphere, and a reversal above the tropopause with negative temperature anomalies below −3 K in the lower stratosphere. Specific humidity is positively correlated with temperature throughout the troposphere with larger anomalies revealed in the Southern Hemisphere. At the eastern and equatorward side of the investigated blocking regions, a band of tropospheric cold anomalies reveals advection of cold air by anticyclonic motion around blocking highs, which is less distinct in the Southern Hemisphere due to stronger zonal flow. We find GPS RO to be a promising new data set for blocking research that gives insight into the vertical atmospheric structure, especially in light of the expected increase in data coverage that future missions will provide.

show abstract

Section: Radio Occultation Datamentioning

confidence: 99%

“…All three reanalyses assimilate RO data. ERA-Interim includes measurements from CHAMP, FORMOSAT-3/COSMIC, GRACE, MetOp, and TerraSAR-X (Poli et al, 2010;Dee et al, 2016); MERRA-2 additionally includes SAC-C (McCarty et al, 2016); and JRA-55 all the former plus C/NOFS (Kobayashi et al, 2015).…”

Section: Reanalysis Datamentioning

confidence: 99%

A global perspective on atmospheric blocking using GPS radio occultation – one decade of observations

Brunner

Steiner

2017

Atmos. Meas. Tech.

View full text Add to dashboard Cite

show abstract

“…Babu et al, 2008;Tsuda, 2014), Rayleigh lidars (Yamashita et al, 2009;Alexander et al, 2011), rockets , and radiosondes (Tsuda et al, 1991;Zhang et al, 2006). Satellite observations have revealed a global distribution of GW activity in the middle atmosphere (Wu and Waters, 1996;Tsuda et al, 2000;de la Torre and Alexander, 2005;Jiang et al, 2005). Numerical model experiments of the global circulation have showed the Published by Copernicus Publications on behalf of the European Geosciences Union.…”

Section: Introductionmentioning

confidence: 99%

Global distribution of vertical wavenumber spectra in the lower stratosphere observed using high-vertical-resolution temperature profiles from COSMIC GPS radio occultation

Noersomadi¹,

Tsuda

2016

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. We retrieved temperature (T ) profiles with a high vertical resolution using the full spectrum inversion (FSI) method from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) GPS radio occultation (GPS-RO) data from January 2007 to December 2009. We studied the characteristics of temperature perturbations in the stratosphere at 20-27 km altitude. This height range does not include a sharp jump in the background Brunt-Väisälä frequency squared (N 2 ) near the tropopause, and it was reasonably stable regardless of season and latitude. We analyzed the vertical wavenumber spectra of gravity waves (GWs) with vertical wavelengths ranging from 0.5 to 3.5 km, and we integrated the (total) potential energy E T p . Another integration of the spectra from 0.5 to 1.75 km was defined as E S p for short vertical wavelength GWs, which was not studied with the conventional geometrical optics (GO) retrievals. We also estimated the logarithmic spectral slope (p) for the saturated portion of spectra with a linear regression fitting from 0.5 to 1.75 km.Latitude and time variations in the spectral parameters were investigated in two longitudinal regions: (a) 90-150 • E, where the topography was more complicated, and (b) 170-230

show abstract

“…In order to obtain the vertical wavelengths and amplitudes we first removed any trend and mean in the temperature profiles to avoid artifacts at large wavelengths. To minimize leakage in the transformation, a Hanning truncation function was applied to the data (Brigham, 1973). The results are shown in Fig.…”

Section: Amplitude and Wavelength Distributionmentioning

confidence: 99%

A gravity waves study close to the Andes mountains in Patagonia and Antarctica with GPS radio occultation observations

et al. 2010

Self Cite

View full text Add to dashboard Cite

Abstract. We first study the seasonal and geographical behavior of gravity wave activity in the lower stratosphere over the southernmost Andes mountains and their prolongation in the Antarctic Peninsula by global positioning system (GPS) radio occultation (RO) temperature profiles, obtained between years 2002 and 2005 by the CHAllenging Minisatellite Payload (CHAMP) mission. The observed features complement observations in the same zone by other satellite passive remote sensing instruments, which are able to detect different height regions and other spectral intervals of the wave spectrum. Comparisons with previous GPS RO studies in smaller areas than the one covered in our analysis are also established. Significant seasonal variation of wave activity is observed in our work, in agreement with results from other instruments. The locations of significant cases indicate that topography is an important source. Some strong wave activity is also found over open ocean. Critical level filtering is shown to have an attenuation effect, implying that a large fraction of the observed activity can be considered to be an outcome of mountain waves. The studied region has a significant advantage as compared to other regions of our planet: it generates wavefronts nearly aligned with the North-South direction (almost parallel to the mountains), whereby this geometry favors the wave detection by the nearly meridional line of sight characterizing most of the GPS RO observations used. A distribution of the observed gravity waves in terms of amplitudes and wavelengths is also presented.

show abstract

Gravity waves above Andes detected from GPS radio occultation temperature profiles: Mountain forcing?

Cited by 45 publications

References 21 publications

A global perspective on atmospheric blocking using GPS radio occultation – one decade of observations

A global perspective on atmospheric blocking using GPS radio occultation – one decade of observations

Global distribution of vertical wavenumber spectra in the lower stratosphere observed using high-vertical-resolution temperature profiles from COSMIC GPS radio occultation

A gravity waves study close to the Andes mountains in Patagonia and Antarctica with GPS radio occultation observations

Contact Info

Product

Resources

About