Browsing by Author "Hall, C. M."
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Item Open Access First results of the refurbished SOUSY radar: Tropopause altitude climatology at 78°N, 16°E, 2008(American Geophysical Union, 2009-10) Hall, C. M.; Röttger, J.; Kuyeng, K.; Sigernes, F.; Claes, S.; Chau Chong Shing, Jorge LuisThe second generation SOUSY MST radar at 78°N, 16°E on Svalbard has recently completed its inaugural year of combined troposphere and mesosphere observations. Here, troposphere observations have been processed using a robust detection algorithm designed for obtaining tropopause climatology by automatic data processing, and the resulting monthly statistics have been compared with corresponding surface air temperatures. As our main objective, we describe the new radar system, present the tropopause detection method, and validate the results using radiosonde and surface temperature data. The tropopause height depends on the temperature of the underlying atmosphere but is also influenced by downward control from the stratosphere. We find that the climatological tropopause height is correlated with the surface temperature but with the former lagging the latter by approximately 1 month.Item Open Access Polar mesospheric summer echoes at 78°N, 16°E, 2008: First results of the refurbished sounding system (SOUSY) Svalbard radar(American Geophysical Union, 2009-06-06) Hall, C. M.; Röttger, J.; Kuyeng, K.; Tsutsumi, M.; Dyrland, M.; Chau Chong Shing, Jorge LuisThis paper examines in detail the electrical coupling between the high-, middle-, and low-latitude ionospheres during January 17–19, 1984, using interplanetary and high-latitude magnetic field data together with F region plasma drift measurements from the EISCAT, Sondre Stromfjord, Millstone Hill, Saint-Santin, Arecibo, and Jicamarca incoherent scatter radars. We study the penetration of both the zonal and meridional electric field components of high-latitude origin into the low-latitude and the equatorial ionospheres. In the dusk sector, a large perturbation of the zonal equatorial electric field was observed in the absence of similar changes at low and middle latitudes in the same longitudinal sector. The observations in the postmidnight sector are used to compare the longitudinal variation of the zonal perturbation electric field with predictions made from global convection models. Our results show that the meridional electric field perturbations are considerably more attenuated with decreasing latitude than the zonal fluctuations. As a result, we conclude that variations in the meridional electric field at low latitudes are largely due to dynamo effects. These observations are used to show that the global convection models reproduce a number of characteristics of low-latitude and equatorial electric fields associated with changes in the polar cap potential drop. In addition, we highlight several areas where there is still substantial disagreement between the electric field data and the theoretical results.Item Open Access Tropopause altitude and PMSE detection at 78°N, 16°E, 2008: first results of the refurbished SOUSY Svalbard Radar (SSR2)(Instituto Geofísico del Perú, 2009) Hall, C. M.; Röttger, J.; Kuyeng, K.; Sigernes, F.; Claes, S.; Chau Chong Shing, Jorge LuisPresentado en MST12 - 12th Workshop on Technical and Scientific Aspects of MST Radars, London, Ontario, Canada, 17-23 May 2009.