A case study of an elevated stratopause generated in the Whole Atmosphere Community Climate Model

Chandran, Amal; Collins, R. L.; García, Rolando R.; Marsh, Daniel R.

doi:10.1029/2010gl046566

Cited by 50 publications

(81 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Various modelling studies have shown eastward GW forcing anomalies at mesosphere and lower thermosphere (MLT) altitudes in relation to SSWs (e.g. Yamashita et al, 2010;Chandran et al, 2011Limpasuvan et al, 2012), a result that has been confirmed by radar observations of GW forcing at mesopause heights during the 2013 major SSW (de Wit et al, 2014b). Model studies have shown this departure away from climatological wintertime westward GW forcing to be associated with the weakening or reversal of the wintertime residual circulation and associated cooling of the mesosphere during…”

Section: Introductionmentioning

confidence: 80%

Coupling in the middle atmosphere related to the 2013 major sudden stratospheric warming

et al. 2015

View full text Add to dashboard Cite

Abstract. The previously reported observation of anomalous eastward gravity wave forcing at mesopause heights around the onset of the January 2013 major sudden stratospheric warming (SSW) over Trondheim, Norway (63 • N, 10 • E), is placed in a global perspective using Microwave Limb Sounder (MLS) temperature observations from the Aura satellite. It is shown that this anomalous forcing results in a clear cooling over Trondheim about 10 km below mesopause heights. Conversely, near the mesopause itself, where the gravity wave forcing was measured, observations with meteor radar, OH airglow and MLS show no distinct cooling. Polar cap zonal mean temperatures show a similar vertical profile. Longitudinal variability in the high northern-latitude mesosphere and lower thermosphere (MLT) is characterized by a quasi-stationary wave-1 structure, which reverses phase at altitudes below ∼ 0.1 hPa. This wave-1 develops prior to the SSW onset, and starts to propagate westward at the SSW onset. The latitudinal pole-to-pole temperature structure associated with the major SSW shows a warming (cooling) in the winter stratosphere (mesosphere) which extends to about 40 • N. In the stratosphere, a cooling extending over the equator and far into the summer hemisphere is observed, whereas in the mesosphere an equatorial warming is noted. In the Southern Hemisphere mesosphere, a warm anomaly overlaying a cold anomaly is present, which is shown to propagate downward in time. This observed structure is in accordance with the temperature perturbations predicted by the proposed interhemispheric coupling mechanism for cases of increased winter stratospheric planetary wave activity, of which major SSWs are an extreme case. These results provide observational evidence for the interhemispheric coupling mechanism, and for the wave-mean flow interaction believed to be responsible for the establishment of the anomalies in the summer hemisphere.

show abstract

Section: Introductionmentioning

confidence: 80%

Coupling in the middle atmosphere related to the 2013 major sudden stratospheric warming

et al. 2015

View full text Add to dashboard Cite

show abstract

“…A striking aspect of the unusual dynamics of those winters were shown in the observations of temperature (Manney et al 2005(Manney et al , 2008(Manney et al , 2009Orsolini et al 2010) and simulations of similar events by WACCM (Chandran et al 2011;Limpasuvan et al 2011). In those winters, the position of the stratopause, identified as the middle atmosphere temperature maximum, jumped from its average altitude range (45-55 km) to 75-85 km.…”

Section: Mlt Variations Due To Active Winter Dynamicsmentioning

confidence: 89%

Global Dynamics of the MLT

2012

View full text Add to dashboard Cite

The transition between the middle atmosphere and the thermosphere is known as the MLT region (for mesosphere and lower thermosphere). This area has some characteristics that set it apart from other regions of the atmosphere. Most notably, it is the altitude region with the lowest overall temperature and has the unique characteristic that the temperature is much lower in summer than in winter. The summer-to-winter-temperature gradient is the result of adiabatic cooling and warming associated with a vigorous circulation driven primarily by gravity waves. Tides and planetary waves also contribute to the circulation and to the large dynamical variability in the MLT. The past decade has seen much progress in describing and understanding the dynamics of the MLT and the interactions of dynamics with chemistry and radiation. This review describes recent observations and numerical modeling as they relate to understanding the dynamical processes that control the MLT and its variability. Results from the Whole Atmosphere Community Climate Model (WACCM), which is a comprehensive high-top general circulation model with interactive chemistry, are used to illustrate the dynamical processes. Selected observations from the Sounding the Atmosphere with Broadband Emission Radiometry (SABER) instrument are shown for comparison. WACCM simulations of MLT dynamics have some differences with observations. These differences and other questions and discrepancies described in recent papers point to a number of ongoing uncertainties about the MLT dynamical system.

show abstract

“…For example, model simulations show that the formation of the new stratopause is sensitive to nonorographic gravity wave drag (e.g., Chandran et al, 2011;Ren et al, 2011). Further, model simulations that explicitly resolve a considerable part of the gravity wave spectrum reveal that during PJO events the dissipation altitude of westward propagating gravity waves is higher after the SSW than before.…”

Section: Effects Of Gravity Waves During Sswsmentioning

confidence: 99%

Satellite observations of middle atmosphere gravity wave absolute momentum flux and of its vertical gradient during recent stratospheric warmings

Ern¹,

Trinh²,

Kaufmann³

et al. 2016

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Sudden stratospheric warmings (SSWs) are circulation anomalies in the polar region during winter. They mostly occur in the Northern Hemisphere and affect also surface weather and climate. Both planetary waves and gravity waves contribute to the onset and evolution of SSWs. While the role of planetary waves for SSW evolution has been recognized, the effect of gravity waves is still not fully understood, and has not been comprehensively analyzed based on global observations. In particular, information on the gravity wave driving of the background winds during SSWs is still missing.

show abstract

A case study of an elevated stratopause generated in the Whole Atmosphere Community Climate Model

Cited by 50 publications

References 17 publications

Coupling in the middle atmosphere related to the 2013 major sudden stratospheric warming

Coupling in the middle atmosphere related to the 2013 major sudden stratospheric warming

Global Dynamics of the MLT

Satellite observations of middle atmosphere gravity wave absolute momentum flux and of its vertical gradient during recent stratospheric warmings

Contact Info

Product

Resources

About