First results of warm mesospheric temperature over Gadanki (13.5°N, 79.2°E) during the sudden stratospheric warming of 2009

Sridharan, S.; Raghunath, K.; Sathishkumar, Solomon; Nath, Debashis

doi:10.1016/j.jastp.2010.06.003

Cited by 21 publications

(10 citation statements)

References 31 publications

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“…The WACCM simulations presented by that have been discussed above for the stratosphere, also showed a warming of the mid-latitude and equatorial mesosphere. In addition, an equatorial warming between 70 and 80 km in connection to the 2009 major SSW was observed over Gadanki (14 • N) using lidar observations (Sridharan et al, 2010). However, our observations contrast with the result presented by Shepherd et al (2007), who used WINDII, MLS (both aboard UARS), and SABER temperature satellite data to study the SSW effect on the mesospheric temperature field from 5-15 • N and observed an equatorial mesospheric cooling in relation to stratospheric warmings.…”

Section: Discussioncontrasting

confidence: 97%

“…This equatorial cooling in connection to SSWs has been observed to extend upward to the mesosphere by Shepherd et al (2007). In the equatorial upper mesosphere (between 70-80 km), Sridharan et al (2010) observed a warming of 10-15 K in relation to the 2009 major SSW. Using an SSW composite generated with the specified dynamics version of the Whole Atmosphere Community Climate Model (WACCM-SD), found a cooling equatorward of 40 • N below 60 km, and a warming above, which was seen to extend to the Southern Hemisphere low latitudes.…”

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 86%

“…Shepherd et al, 2007;Sridharan et al, 2010;Matthias et al, 2013;. To study the latitudinal extent of the temperature perturbations related to the 2013 major SSW in more detail, Fig.…”

Section: Pole-to-pole Middle Atmosphere Zonal Mean Temperature Anomalmentioning

confidence: 99%

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

et al. 2015

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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.

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Section: Discussioncontrasting

confidence: 97%

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 86%

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

et al. 2015

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“…At Tromsø (69.6°N, 19.2°E) in Norway, temperature at 90 km shows a strong cooling of more than 50 K from 16 January [ Kurihara et al ., ]. At low latitude, lidar observations of temperature at Gadanki (13.5°N, 79.2°E) in India show an enhancement in the nightly mean temperature by 10–15 K at 70–80 km [ Sridharan et al ., ]. In the midlatitude, the simultaneous wind and temperature observations document the direct impact of the major SSW on the dynamic and thermal circulation of the mesopause region [ Yuan et al ., ].…”

Section: Introductionmentioning

confidence: 99%

Coupling between mesosphere and ionosphere over Beijing through semidiurnal tides during the 2009 sudden stratospheric warming

et al. 2013

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Sudden stratospheric warming (SSW) in the winter of 2008/2009 is the strongest recorded SSW event. The enhancement in semidiurnal variation of ionospheric TEC (total electron content) with phase shift forward is shown during 22 to 27 January 2009, based on the TEC observations in Beijing (40.30°N, 116.19°E geographic, 39.73°N dip latitude). We focus on finding the reason for the TEC variation. Winds observed by an all‐sky meteor radar in the same observatory are used to study mesospheric variation. The semidiurnal solar tide in the mesosphere starts to increase before the SSW and maintains oscillation with period 16–20 days during the SSW. The semidiurnal lunar tides in TEC and wind start to increase on 17 and 15 January, respectively. Although the semidiurnal lunar tide in TEC over Beijing almost dies out on 1 February, that over equatorial ionospheric anomaly crest does not vanish until 15 February when lunar tide in wind tends to be very weak. The maximum of lunar tide in wind appears on 2 February at 96 km with amplitudes of 15 m/s and 21 m/s for zonal and meridional winds. The phase comparison shows that lunar tides in TEC and zonal wind reach their maxima at almost the same time, which is 2–4 h lag behind the meridional wind. The coupling between the mesosphere and ionosphere contributes to the semidiurnal variation of TEC through both solar and semidiurnal lunar tides. The enhancement in semidiurnal lunar tide is responsible for the TEC peak shift forward during the SSW.

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“…also reported low and mid-latitude winds during the SSW events of 1998-1999, 2003-2004, and 2005-2006 found differences in the behavior of MLT winds at Tirunelveli (8.7 • N, 77.8 • E) and Collm (52 • N, 15 • E) and attributed the differences to variability in local gravity wave activity during the SSW events. (Sridharan et al, 2010) and a change in the direction of mesospheric gravity wave propagation from westward to eastward (Nath et al, 2013) during the 2009 SSW. Butler and Polvani (2011) found that SSW events are nearly twice as frequent during El Niño-Southern Oscillation (ENSO) winters than during non-ENSO winters, while SSWs occur with equal probability during El Niño and La Niña winters.…”

mentioning

confidence: 98%

Stratospheric sudden warming effects on winds and temperature in the middle atmosphere at middle and low latitudes: a study using WACCM

Chandran

Collins

2014

Ann. Geophys.

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Abstract.A stratospheric sudden warming (SSW) is a dynamical phenomenon of the wintertime stratosphere caused by the interaction between planetary Rossby waves propagating from the troposphere and the stratospheric zonal-mean flow. While the effects of SSW events are seen predominantly in high latitudes, they can also produce significant changes in middle and low latitude temperature and winds. In this study we quantify the middle and low latitude effects of SSW events on temperature and zonal-mean winds using a composite of SSW events between 1988 and 2010 simulated with the specified dynamics version of the Whole Atmosphere Community Climate Model (WACCM). The temperature and wind responses seen in the tropics also extend into the low latitudes in the other hemisphere. There is variability in observed zonal-mean winds and temperature depending on the observing location within the displaced or split polar vortex and propagation direction of the planetary waves. The propagation of planetary waves show that they originate in mid-high latitudes and propagate upward and equatorward into the mid-latitude middle atmosphere where they produce westward forcing reaching peak values of ∼ 60-70 m s −1 day −1 . These propagation paths in the lower latitude stratosphere appear to depend on the phase of the quasibiennial oscillation (QBO). During the easterly phase of the QBO, waves originating at high latitudes propagate across the equator, while in the westerly phase of the QBO, the planetary waves break at ∼ 20-25 • N and there is no propagation across the equator. The propagation of planetary waves across the equator during the easterly phase of the QBO reduces the tropical upwelling and poleward flow in the upper stratosphere.

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First results of warm mesospheric temperature over Gadanki (13.5°N, 79.2°E) during the sudden stratospheric warming of 2009

Cited by 21 publications

References 31 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

Coupling between mesosphere and ionosphere over Beijing through semidiurnal tides during the 2009 sudden stratospheric warming

Stratospheric sudden warming effects on winds and temperature in the middle atmosphere at middle and low latitudes: a study using WACCM

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