Investigação da temperatura mesosférica sobre a Estação Antártica Comandante Ferraz por meio da técnica de aeroluminescência validada com dados de satélites

Abstract

This work has the objective of analyzing the temperature data of the Earth's upper mesosphere (85 to 95 km) using optical observations, employing the airglow technique, along with data from the SABER instrument on board the TIMED satellite. The data used in this work is composed of six (6) months of observation from the FotAntar-3 (Fot3) instrument in 2007, when there were data available from TIMED satellite (Mar-Mai; Jul-Sep), always in the night-time period, at the new moon phases. To compare and validate the temperatures obtained via Fot3 and SABER, data from the closest sounding profiles (SMP) to the observation site, the Comandante Ferraz Antarctic Station (EACF), located on King George Island (62.08°S, 58.39'W), South Shetland Islands, and nighttime mean soundings (SM) in a restricted area of 600 km radius, centered at EACF, aiming to evaluate the method that best fits the intercomparison of the Fot3 and SABER data, when both datasets were available simultaneously. Temperature measurements revealed that, in general, the temperature values obtained by Fot3 were lower than those retrieved from TIMED/SABER. However, a strong correlation (R = 0.74) was observed in March 2005 when using the SMP method, even though for the other months a weak correlation was identified between the data using this method. When we used the SM method, moderate correlations (R > 0.45) were observed for March, May, and September, while for the other months (April, July, and August) the correlations were very weak. Therefore, the FotAntar-3 instrument demonstrated reasonable performance when compared with the average temperatures obtained by the TIMED/SABER satellite in a large geographic area around the observation site, and in at least one of the months (March), the hourly average temperatures from FotAntar-3 were very close to those from SABER in both methods. In general, the results show that the method of average soundings (SM), within the pre-defined area, shows to be the best regarding the cross-correlation results. The results of this work will contribute to a better understanding of the thermal variability of the upper mesosphere and can give a basis for the use of different methods for comparing satellite data and ground-based data.