Thermospheric dynamics at the South Pole

Abstract

A self‐aligning Fabry‐Perot spectrometer has been installed at Amundsen‐Scott Station, Antarctica (Geographic South Pole) and has been used to determine neutral upper thermosphere winds and temperatures, obtained from the measurement of the Doppler shift and Doppler width of the line profiles of the [OI] 15,867 K (630 nm) line emission, during the austral winter of 1989 (April 1989 to September 1989). These first ground‐based measurements of F‐region neutral dynamics at the South Pole, show a rich variety of dynamic phenomena and strong couplings with the ionospheric plasma. Data for two contrasting days in April 1989 are presented here. The data of April 23 UT illustrate the diurnal variations of winds and temperatures during geomagnetic quiet‐to‐moderate conditions, while the data of April 27 UT illustrate diurnal variations during geomagnetically disturbed periods. These data are compared with the average pattern obtained at a similar geomagnetic latitude and conditions, but in the Northern Hemisphere (Longyearbyen, Spitsbergen) and with predictions of the average dynamics in the South Pole region made by the NCAR thermosphere‐ionosphere general circulation model (TIGCM). The measured winds at the South Pole have a stronger prevailing westward component in its diurnal cycle than is either observed at Longyearbyen (in the Northern Hemisphere) or predicted at South Pole by the TIGCM.

Studies of thermospheric dynamics with a Fabry–Perot interferometer network: A review

“…5. The results obtained with such observatories have contributed to advances of our understanding of the mesospheric and thermospheric dynamics over the past three decades in various places including the equatorial, mid-latitude, and polar regions (Hernandez, 1979;Burnside et al, 1981;Meriwether, 1983;Killeen et al, 1986;Hernandez et al, 1990Hernandez et al, , 1992Conde and Smith, 1995;Rees et al, 1995;Killeen et al, 1995;Biondi et al, 1999;Aruliah and Griffin, 2001;Aruliah et al, 2005).…”

Energetics and Composition in the Thermosphere

“…FPIs have been used to deduce neutral temperatures in the upper atmosphere for many years [e.g., Killeen et al, 1995]. A limited number of these instruments are currently deployed in a widespread array of sites, ranging from Resolute in the Arctic [e.g., Wu et al, 2008] through the equatorial regions [e.g., Meriwether, 2006] to the Antarctic [e.g., Hernandez et al, 1990]. In recent years, an imaging FPI has been developed in Alaska [Conde and Smith, 1998] that has allowed both spatial and temporal information about temperature changes to be measured from the ground.…”

Long-term thermospheric neutral wind observations over the northern polar cap

“…There are reports on thermospheric wind observations at the South Pole, Antarctica, which is on edge of the polar cap (MLAT 75S) (Hernandez et al, 1990;Hernandez et al, 1991;Smith et al 1994). Hernandez and Roble (2003) reported storm time observations over both South Pole and Arrival Heights (77.81S,166.661E,MLAT 80S).…”