Climatology of the migrating terdiurnal tide (TW3) in SABER/TIMED temperatures

Abstract

1] The present paper is focused on the global spatial (altitude and latitude) structure and seasonal and interannual temporal variability of the migrating terdiurnal tide (TW3) seen in 8 years (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)) of observations of the kinetic temperature measured by the SABER instrument on the TIMED satellite. The tides (migrating and nonmigrating) and the planetary waves (zonally traveling and stationary) are simultaneously extracted from the satellite data. It is found that the SABER TW3 tide is dominated by different Hough modes below and above~80 to 90 km height; in the mesosphere, it reflects mainly the evanescent feature of the first symmetric mode, and in the lower thermosphere, propagating modes with shorter vertical wavelengths dominate its structure. The seasonal behavior of the terdiurnal tide at low latitudes is dominated by an annual variation with local summer amplification, while that at midlatitudes is a combination of semiannual variation with maxima in equinoxes and an annual variability with winter enhancement. The Hough modes of the solar heating from WACCM heating to a large extent determine the predominantly antisymmetric features of the SABER TW3 tide during the solstice but are not able to explain well the predominant symmetric features in the equinoxes. The TW3 tide reveals some interannual variability with a period of quasi-2 years which indicates an enhancement during the eastward phase of the stratospheric QBO.

Coordinated Observations of 8‐ and 6‐hr Tides in the Mesosphere and Lower Thermosphere by Three Meteor Radars Near 60°S Latitude

“…Shorter‐period tides at 8‐ and 6‐hr harmonics have been discerned from both ground‐ and space‐based observations (e.g., Batista et al, ; Beldon et al, ; Jiang et al, ; Kovalam & Vincent, ; Liu et al, ; Moudden & Forbes, ; Oznovich et al, ; Pancheva et al, ; She et al, ; Smith, ; Smith et al, ; Teitelbaum et al, ; Thayaparan, ; van Eyken et al, ; Venkateswara Rao et al, ; Walterscheid & Sivjee, ; Younger et al, ; Yue et al, ). At midlatitudes, the 8‐hr tides can sometimes have amplitudes as large as the 12‐ and 24‐hr tides.…”

Global distribution of the migrating terdiurnal tide seen in sporadic E occurrence frequencies obtained from GPS radio occultations

“…Also apparent is a transition layer near 100 km, where the TDT amplitude becomes more pronounced at middle and high-latitudes, while below 100 km, the amplitudes dominate in the tropics. Using a similar data set and considering the years 2002 to 2009, Pancheva et al (2013) presented seasonal patterns of the TDT. The results at 90 km display the strongest amplitudes during boreal late winter/spring and a secondary maximum in autumn near the equator and northern midlatitudes.…”

MIPAS observations of longitudinal oscillations in the mesosphere and the lower thermosphere: climatology of odd-parity daily frequency modes

“…Maxima are generally reached at 35 • , with a 5 • shift towards higher latitudes in the local summer. Previously detected TW3 latitude shifts (Pancheva et al, 2013) and the in situ DW1 evidence the same behavior. Maximum values occur in the equinoxes, coinciding with the expected maximum contribution from an overlapping DW1.…”

“…Maximum values occur in the equinoxes, coinciding with the expected maximum contribution from an overlapping DW1. Perturbations are significantly reduced over the Equator during January, as a TW3 effect would be (Pancheva et al, 2013).…”

“…Few global observations of the neutral atmosphere are available in the 100-150 km altitude range. Temperatures have generally been analyzed at the lowest altitudes of this range (generally below 115 km) using TIMED, Aura or WINDII satellite measurements (see, e.g., Wang et al, 2000;Forbes and Wu, 2006;Xu et al, 2009;Pancheva et al, , 2013Pancheva and Mukhtarov, 2011;Yue et al, 2013;Truskowski et al, 2014;Lieberman et al, 2015), or above the range, using WINDII measurements around 250 km (Shepherd et al, 2012) and CHAMP measurements of the exosphere (see e.g., Forbes et al, 2008Forbes et al, , 2014Oberheide et al, 2009;Bruinsma and Forbes, 2010). Studies of longitudinal oscillations measured by MIPAS on Envisat for this altitude range have been conducted by Xu et al (2013), but only for selected atmospheric conditions (aurorae).…”