scholarly journals Interannual variations of stationary planetary wave activity in the northern winter troposphere and stratosphere and their relations to NAM and SST

2003 ◽  
Vol 108 (D24) ◽  
pp. n/a-n/a ◽  
Author(s):  
Wen Chen ◽  
Masaaki Takahashi ◽  
Hans-F. Graf
Keyword(s):  
Planetary Wave ◽  
Wave Activity ◽  
Interannual Variations ◽  
Northern Winter ◽  
Stationary Planetary Wave

Interannual variations of planetary wave activity from OH (6-2) observations at the Maimaga station

2020 ◽  
Author(s):  
Vera I. Sivtseva ◽  
Petr P. Ammosov ◽  
Galina A. Gavrilyeva ◽  
Igor I. Koltovskoi ◽  
Anastasia M. Ammosova
Keyword(s):  
Planetary Wave ◽  
Wave Activity ◽  
Interannual Variations

scholarly journals Arctic Stratosphere Circulation Changes in the 21st Century in Simulations of INM CM5

Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 25
Author(s):  
Pavel N. Vargin ◽  
Sergey V. Kostrykin ◽  
Evgeni M. Volodin ◽  
Alexander I. Pogoreltsev ◽  
Ke Wei
Keyword(s):  
21St Century ◽  
Planetary Wave ◽  
Climate Model ◽  
Meridional Circulation ◽  
Wave Activity ◽  
The Arctic ◽  
Wave Number ◽  
Coupled Climate Model ◽  
Sudden Stratospheric Warming ◽  
Stationary Planetary Wave

Simulations of Institute of Numerical Mathematics (INM) coupled climate model 5th version for the period from 2015 to 2100 under moderate (SSP2-4.5) and severe (SSP5-8.5) scenarios of greenhouse gases growth are analyzed to investigate changes of Arctic polar stratospheric vortex, planetary wave propagation, Sudden Stratospheric Warming frequency, Final Warming dates, and meridional circulation. Strengthening of wave activity propagation and a stationary planetary wave number 1 in the middle and upper stratosphere, acceleration of meridional circulation, an increase of winter mean polar stratospheric volume (Vpsc) and strengthening of Arctic stratosphere interannual variability after the middle of 21st century, especially under a severe scenario, were revealed. March monthly values of Vpsc in some winters could be about two times more than observed ones in the Arctic stratosphere in the spring of 2011 and 2020, which in turn could lead to large ozone layer destruction. Composite analysis shows that “warm” winters with the least winter mean Vpsc values are characterized by strengthening of wave activity propagation from the troposphere into the stratosphere in December but weaker propagation in January–February in comparison with winters having the largest Vpsc values.

Interdecadal Variations of the East Asian Winter Monsoon and Their Association with Quasi-Stationary Planetary Wave Activity

2009 ◽  
Vol 22 (18) ◽  
pp. 4860-4872 ◽  
Author(s):  
Lin Wang ◽  
Ronghui Huang ◽  
Lei Gu ◽  
Wen Chen ◽  
Lihua Kang
Keyword(s):  
Planetary Wave ◽  
East Asian Winter Monsoon ◽  
East Asian ◽  
Wave Activity ◽  
Winter Monsoon ◽  
Planetary Waves ◽  
Asian Winter Monsoon ◽  
Zonal Wavenumber ◽  
Propagation Of Waves ◽  
Stationary Planetary Wave

Abstract Interdecadal variations of the East Asian winter monsoon (EAWM) and their association with the quasi-stationary planetary wave activity are analyzed by using the 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis dataset and the National Centers for Environmental Prediction–National Center for Atmospheric Research reanalysis dataset. It is found that the EAWM experienced a significant weakening around the late 1980s; that is, the EAWM was strong during 1976–87 and became weak after 1988. This leads to an obvious increase in the wintertime surface air temperature as well as a decrease in the frequency of occurrence of cold waves over East Asia. The dynamical process through which the EAWM is weakened is investigated from the perspective of quasi-stationary planetary waves. It is found that both the propagation and amplitude of quasi-stationary planetary waves have experienced obvious interdecadal variations, which are well related to those of the EAWM. Compared to the period 1976–87, the horizontal propagation of quasi-stationary planetary waves after 1988 is enhanced along the low-latitude waveguide in the troposphere, and the upward propagation of waves into the stratosphere is reduced along the polar waveguide. This results in a weakened subtropical jet around 40°N due to the convergence of the Eliassen–Palm flux. The East Asian jet stream is then weakened, leading to the weakening of the EAWM since 1988. In addition, the amplitude of quasi-stationary planetary waves is significantly weakened around 45°N, which is related to the reduced upward propagation of waves from the lower boundary after 1988. This reduced amplitude may weaken both the Siberian high and the Aleutian low, reduce the pressure gradient in between, and then weaken the EAWM. Further analyses indicate that zonal wavenumber 2 plays the dominant role in this process.

scholarly journals Interannual Variations of the Stratosphere and Troposphere during Northern Winter as Simulated by WACCM

2008 ◽  
Vol 21 (10) ◽  
pp. 2326-2331 ◽  
Author(s):  
Masakazu Taguchi
Keyword(s):  
Correlation Analysis ◽  
Observational Studies ◽  
Planetary Wave ◽  
Climate Model ◽  
Southern Oscillation ◽  
Hadley Circulation ◽  
Sea Surface ◽  
Interannual Variations ◽  
Northern Winter ◽  
Tropical Troposphere

Abstract This study explores interannual variations (IAVs) of the stratosphere and troposphere during Northern Hemisphere (NH) winter using a 50-yr simulation of Sassi et al. with the Whole Atmosphere Community Climate Model (WACCM). The simulation is forced with observed sea surface temperature (SST) and sea ice distributions from 1950 to 1999. The focus herein is on tropical tropospheric variations correlated with NH stratospheric variations and El Niño–Southern Oscillation (ENSO). The discussed correlation analysis generally reproduces the following features as obtained in observational studies by Salby and Callaghan: an intensification of the Brewer–Dobson (BD) circulation driven by enhanced planetary wave (PW) drag in the NH stratosphere is accompanied by intensification of the Hadley circulation and anomalous warming of the tropical troposphere. It is further revealed that the tropical tropospheric warming is a reflection of the ENSO variability resulting from a positive correlation between the PW driving/BD circulation and ENSO, whereas the Hadley circulation does intensify with the BD circulation even when ENSO’s effects are removed.

Comparison of Key Characteristics of Remarkable SSW Events in the Southern and Northern Hemisphere

2021 ◽  
Author(s):  
Michal Kozubek ◽  
Peter Krizan
Keyword(s):  
Northern Hemisphere ◽  
Planetary Wave ◽  
Polar Vortex ◽  
Wave Number ◽  
Strong Activity ◽  
Key Characteristics ◽  
Zonal Wave Number ◽  
Show Difference ◽  
Temperature Enhancement ◽  
Stationary Planetary Wave

<p>An exceptionally strong sudden stratospheric warming (SSW) in the Southern Hemisphere (SH) during September 2019 was observed. Because SSW in the SH is very rare, comparison with the only recorded major SH SSW is done. According to World Meteorological Organization (WMO) definition, the SSW in 2019 has to be classified as minor. The cause of SSW in 2002 was very strong activity of stationary planetary wave with zonal wave-number (ZW) 2, which reached its maximum when the polar vortex split into two circulations with polar temperature enhancement by 30 K/week and it penetrated deeply to the lower stratosphere and upper troposphere. On the other hand, the minor SSW in 2019 involved an exceptionally strong wave-1 planetary wave and a large polar temperature enhancement by 50.8 K/week, but it affected mainly the middle and upper stratosphere. The strongest SSW in the Northern Hemisphere was observed in 2009. This study provides comparison of two strongest SSW in the SH and the strongest SSW in the NH to show difference between two hemispheres and possible impact to the lower or higher layers.</p>

scholarly journals Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM

2011 ◽  
Vol 11 (3) ◽  
pp. 9743-9767 ◽  
Author(s):  
M. M. Hurwitz ◽  
I.-S. Song ◽  
L. D. Oman ◽  
P. A. Newman ◽  
A. M. Molod ◽  
...  
Keyword(s):  
El Niño ◽  
Planetary Wave ◽  
Lower Stratosphere ◽  
El Nino ◽  
Warm Pool ◽  
Wave Activity ◽  
Central Pacific ◽  
Quasi Biennial Oscillation ◽  
South Central ◽  
The Antarctic

Abstract. A new formulation of the Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM), with an improved general circulation model and an internally generated quasi-biennial oscillation (QBO), is used to investigate the response of the Antarctic stratosphere to (1) warm pool El Niño (WPEN) events and (2) the sensitivity of this response to the phase of the QBO. Two 50-yr time-slice simulations are forced by repeating annual cycles of sea surface temperatures and sea ice concentrations composited from observed WPEN and neutral ENSO (ENSON) events. In these simulations, greenhouse gas and ozone-depleting substance concentrations represent the present-day climate. The modelled responses to WPEN, and to the phase of the QBO during WPEN, are compared with NASA's Modern Era Retrospective-Analysis for Research and Applications (MERRA) reanalysis. WPEN events enhance poleward planetary wave activity in the central South Pacific during austral spring, leading to relative warming of the Antarctic lower stratosphere in November/December. During the easterly phase of the QBO (QBO-E), the GEOS V2 CCM reproduces the observed 3–5 K warming of the polar region at 50 hPa, in the WPEN simulation relative to ENSON. In the recent past, the response to WPEN events was sensitive to the phase of the QBO: the enhancement in planetary wave driving and the lower stratospheric warming signal were mainly associated with WPEN events coincident with QBO-E. In the GEOS V2 CCM, however, the Antarctic response to WPEN events is insensitive to the phase of the QBO: the modelled response is always easterly QBO-like. OLR, streamfunction and Rossby wave energy diagnostics are used to show that the modelled QBO does not extend far enough into the lower stratosphere and upper troposphere to modulate convection and thus planetary wave activity in the south central Pacific.

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