Mesopause dynamics from the scandinavian triangle of radars within the PSMOS-DATAR Project

Abstract

Abstract. The "Scandinavian Triangle" is a unique trio of radars within the DATAR Project (Dynamics and Temperatures from the Arctic MLT (60-97 km) region): Andenes MF radar (69 • N, 16 • E); Tromsø MF radar (70 • N, 19 • E) and Esrange "Meteor" radar (68 • N, 21 • E). The radar-spacings range from 125-270 km, making it unique for studies of wind variability associated with small-scale waves, comparisons of large-scale waves measured over small spacings, and for comparisons of winds from different radar systems. As such it complements results from arrays having spacings of 25 km and 500 km that have been located near Saskatoon. Correlation analysis is used to demonstrate a speed bias (MF smaller than the Meteor) between the radar types, which varies with season and altitude. Annual climatologies for the year 2000 of mean winds, solar tides, planetary and gravity waves are presented, and show indications of significant spatial variability across the Triangle and of differences in wave characteristics from middle latitudes.

Dynamics of the Antarctic and Arctic mesosphere and lower thermosphere – Part 1: Mean winds

“…Engler et al (2008) estimated the winds measured by MF radar in the upper mesosphere to be too small by anywhere between 20-40%. Similar results have been found by, e.g., Stubbs (1973), Cervera and Reid (1995), Hocking and Thyaparan (1997), Manson et al (2004), Jacobi et al (2009). The exact cause of these differences remains uncertain.…”

“…These differences have been characterised by, e.g., Hocking and Thyaparan (1997), Manson et al (2004). In general at heights above about 85-90 km MF radars record significantly weaker winds than meteor radars.…”

“…These two radars are similar in design and are located at conjugate geographical latitudes in each polar region, allowing a comparison of observations free from biases caused by different techniques or small differences in latitude. The use of an identical technique is particularly important because there are known and significant biases between some of the most common techniques used for measuring MLT-region winds (e.g., Meteor and MF radar, Manson et al, 2004). A second companion study, part 2, will report the inter-hemispheric observations of the 12-and 24-h tides, in the MLT region, also using the same two systems.…”

Characteristics of Mesosphere Echoes over Antarctica Obtained Using PANSY and MF Radars

“…The ratio for the meridional component is from approximately 0.85 to 1 above 70 km, but gradually decreases with decreasing height and reaches 0.7 at 60 km. It is known that wide beam MF radars such as the Syowa system tend to underestimate wind velocities (e.g., Manson et al 2004;Tsutsumi and Aso 2005) and that such radar data should be carefully treated (e.g., Reid 2015). The somewhat reduced Syowa MF meridional winds seem to be at least partly due to the low signal-to-noise ratio of one of the four antennas, at the northernmost corner of the triangle-shaped receiving array, located close to the radar hut.…”

Comment on "Global structure, seasonal and interannual variability of the migrating semidiurnal tide seen in the SABER/TIMED temperatures (2002–2007)" by Pancheva et al. (2009)

“…Phases/directions of the wind vectors were in very good agreement, as also noted in several references provided in their paper; this is consistent with an absence of group-retardation effects during winter in the MFR data. In an earlier such paper, Manson et al (2004c) compared speeds from the Andenes/Tromso-MFRs and the Esrange-MWR, which is only 200 km south-east. Speedratios were tabulated for the first time by months as well as height: the MWR speeds were larger than the MFR by median-factors of 1.21 in summer, 1.31 in September and 1.75 in winter for the altitude range 94-97 km.…”