Regional response of the mesosphere–lower thermosphere dynamics over Scandinavia to solar proton events and geomagnetic storms in late October 2003

A superposed epoch study of the effects of solar wind stream interface events on the upper mesospheric and lower thermospheric temperature

“…Ozone itself is significant in the absorption of solar ultraviolet radiation and thus may affect the radiative balance, temperature and dynamics of the atmosphere. While our observations of the cooling effect below 95 km is similar to Pancheva et al (2007), it is however not fully consistent with the work of von Savigny et al (2007) A heating effect was also found below 100 km in the Southern hemisphere in a recent case study by Ogunjobi et al (2014) for a different type of storm-driven event known as magnetic cloud (MC). The apparent contradictory temperature responses demonstrate the complexity of the energy budget in the MLT region.…”

“…The superposed average temperature characteristics at 95 km correlates with the abrupt peaks seen during particle precipitation and absorption on SI arrival. Previous work by Pancheva et al (2007) also found a temperature decrease of about 25 K below 100 km associated with a geomagnetic storm in the Northern hemisphere. This implies that particle precipitation has perhaps affected the neutral chemistry of the MLT via ionisation.…”

“…Intuitively, particle precipitation is anticipated to enhance upper atmospheric temperature. Nonetheless, some previous works (for example, Banks, 1977;Offermann, 1985;Jackman et al, 2007;von Savigny et al, 2007;Pancheva et al, 2007) have shown a potential heating effect, an apparent cooling effect or no measurable temperature response to precipitating particles. The apparent inconsistency is probably due to some differences in the solar wind-magnetosphere coupling processes.…”

Responses of Lower Thermospheric Temperature to the 2013 St. Patrick's Day Geomagnetic Storm

“…Note that strong SPEs are usually associated with geomagnetic storms. By analyzing the temperature data derived from a meteor radar at Andenes (69°N), Pancheva et al (2007) found a significant cooling (~25 K) at~90 km during storms in late October 2003. By analyzing temperature data from the ALOMAR Na lidar (69°N) during the SPEs on January 2005, Nesse Tyssøy et al (2008) found that the mean temperature above 90 km was warmer than the monthly mean temperature and this warming could be due to particle precipitation and Joule heating.…”

“…By analyzing the nocturnal temperature data measured decrease are seen during the storm and extended downward below 100 km over a wide range of latitude • The peak of temperature change varied with latitudes and occurred about 0.5-1.5 days after the storm main phase, depending on height by a Fabry-Perot interferometer at 23°S, Fagundes et al (1996) found that the nighttime temperature in the mesosphere was unaffected by storms. By analyzing the temperature data derived from a meteor radar at Andenes (69°N), Pancheva et al (2007) found a significant cooling (~25 K) at~90 km during storms in late October 2003. Note that strong SPEs are usually associated with geomagnetic storms.…”