Eureka, 80° N, SKiYMET meteor radar temperatures compared with Aura MLS values

Abstract

The meteor trail echo decay rates are analysed on-site to provide daily temperatures near 90 km. In order to get temperatures from trail decay times, either knowledge of the pressure or the background temperature height gradient near 90 km is required (Hocking, 1999). Hocking et al. (2004) have developed an empirical 90 km temperature gradient model depending only on latitude and time of year, which is used in the SKiYMET on-site meteor temperature analysis. <br><br> Here we look at the sensitivity of the resulting temperature to the assumed gradient and compare it and the temperatures with daily AuraMLS averages near Eureka. Generally there is good agreement between radar and satellite for winter temperatures and their short-term variations. However there is a major difference in mid-summer both in the temperatures and the gradients. Increased turbulence in summer, which may overwhelm the ambipolar diffusion even at 90 km, is likely a major factor. <br><br> These differences are investigated by generating ambipolar-controlled decay times from satellite pressure and temperature data at a range of heights and comparing with radar measurements. Our study suggests it may be possible to use these data to estimate eddy diffusion coefficients at heights below 90 km. Finally the simple temperature analysis (using satellite pressures), and a standard meteor wind analysis are used to compare mean diurnal variations of temperature (<I>T</I>) with those of zonal wind (<I>U</I>) and meridional wind (<I>V</I>) in composite multi-year monthly intervals

New method of estimating temperatures near the mesopause region using meteor radar observations

“…From equation , the temperature at the meteor peak height can be estimated once the meteor decay time profiles are obtained from meteor radar observations. Several observational studies have been conducted to validate or improve this method via comparisons between temperatures derived from pressure models and airglow observations from the ground and satellites [ Hocking et al ., ; Singer et al ., ; Vineeth et al ., ; Hocking et al ., ; Kumar , ; Dyrland et al ., ; Kim et al ., ; Meek et al ., ].…”

Thermal and dynamical perturbations in the winter polar mesosphere‐lower thermosphere region associated with sudden stratospheric warmings under conditions of low solar activity

“…Meek et al . [] analyzed the temperature distribution measured by the Eureka MR (80°N). The Eureka and Svalbard MR (78°N) wind data were compared to the model prediction [ Manson et al ., ].…”

“…The occurrence of wind oscillations reversals in the MLT in relation to planetary wave activity and circulation disturbances was demonstrated by Hoffmann et al [2002] on the basis of radar wind observations at Andenes (69°N). Meek et al [2013] analyzed the temperature distribution measured by the Eureka MR (80°N). The Eureka and Svalbard MR (78°N) wind data were compared to the model prediction [Manson et al, 2011].…”

“…MLS measures temperature at high vertical resolution from the lower stratosphere to the lower thermosphere. The MLS observations have been used to compare and verify the MR temperature at high latitudes [Dyrland et al, 2010;Meek et al, 2013]. Iida et al [2014] used the MLS data to study the January 2009 major SSW.…”

Lidar temperature series in the middle atmosphere as a reference data set. Part B: Assessment of temperature observations from MLS/Aura and SABER/TIMED satellites

“…Other current measurement techniques for this region of the atmosphere include: 50 a) Rocketsondes were used during the early satellite era to make in situ measurements of the middle atmosphere but this technique has many well known limitations and requires large corrections and uncertainties in the upper mesosphere (Johnson and Gelman, 1985 data from an independent source (Meek et al, 2013) c) Satellites, like MLS (Microwave Limb Scanner) and SABER (Sounding of the Atmosphere by Broadband Emission Radiometry), provide globally distributed temperature measurements at several pressure levels throughout the vertical atmospheric column (Waters et al, 2006) (Mertens et al, 2001). Satellite based measurements provide a very good global view of the Earth's middle atmo-60 sphere but can suffer from calibration errors, temporal coverage gaps, and problems with vertical resolution.…”