Coordinated observations of the dynamics and coupling processes of mesosphere and lower thermosphere winds with MF radars at the middle-high latitude

Abstract

The Communications Research Laboratory (CRL) has operated the Wakkanai MF radar since September of 1996, and Yamagawa MF radar since August of 1994. Recent observation results on variations of mean wind, wind spectra and diurnal wind oscillations during a strong eastward wind, comparison experiments with the MU radar and rockets, and D-region electron density measurements by MF radar are summarized briefly. The spectra comparison of two MF radar observations show a high degree of spatial and temporal variability in a winter mesosphere in Northern and Southern Japan. Differences of mean wind in 1997 between both sites are shown for the periods of solstices and equinoxes. It is suggested that the propagation of the diurnal tide from the mesosphere into the dynamo region is disturbed by the sudden enhancements of the strong eastward wind.

Interpretation of the mesospheric and lower thermospheric mean winds observed by MF radar at about 30°N with the 2D-SOCRATES model

“…The features of the winds, tides, gravity waves, daily sporadic-E activities etc. over Yamagawa with its MF radar observations have been shown in many papers (e.g., Igarashi, 1998a,b, 1999;Igarashi et al, 1999Igarashi et al, , 2002Kishore et al, 2000;Namboothiri et al, 2000;Igarashi and Kato, 2001;Ma et al, 2001;Isoda et al, 2002). Comparisons of mean winds between these two sites show well consistent Hu et al, 2006).…”

Planetary wave coupling processes in the middle atmosphere (30–90km): A study involving MetO and MFR data

“…All five MFRs are of similar configuration, with the main characteristics listed in Table 1. The references (Manson et al, 1973;Thayaparan et al, 1995;Igarashi et al, 1999) given in the table contain more detailed description of these radars. The MFRs employ the spaced antenna technique to detect motions of weakly ionized irregularities in the ionospheric D and lower E regions.…”

“…The outputs of the assimilation are global fields of daily temperatures, geopotential heights and wind components interpolated to 22 standard Upper Atmosphere Research Satellite (UARS) pressure levels from the surface up to 0.316 hPa (0-55 km): References Manson et al, 1973;Manson, et al, 2003Thayaparan et al, 1995Igarashi et al, 1999 In October 2003 the New Dynamics version of the Unified Model was introduced and three more levels (up to 0.1 hPa) were added. The generated data fields have global coverage with 2.51 and 3.751 steps in latitude and longitude, respectively.…”

Planetary wave coupling in the middle atmosphere (20-90km): A CUJO study involving TOMS, MetO and MF radar data

“…Although a more classical method of analysis described by Briggs (1984) has been used in this case, the results of comparisons (Thayaparan et al, 1995) suggest no significant difference between the two methods. The detailed description of these radars can be found elsewhere (Manson et al, 1973;Thayaparan et al, 1995;Igarashi et al, 1999). The daily mean data from each sampled height have been employed for the wind analyses in this paper.…”