A preliminary study of thermosphere and mesosphere wind observed by Fabry‐Perot over Kelan, China

Abstract

A Fabry-Perot interferometer (FPI) system was deployed in Kelan (38.7°N, 111.6°E), center China in November 2011, which observes the airglows at wavelengths of 892.0 nm, 557.7 nm, and 630.0 nm from OH and OI emissions in the upper atmosphere, to derive the wind and temperature at heights around 87 km, 97 km, and 250 km, respectively. From late 2011 through 2013 a series of more than 4500 measurements at each height are validated according to manufacture data quality criteria. By using these data, the morphology of wind in the mesosphere and thermosphere is investigated in this study. Preliminary results are as follows:(1) As for the diurnal variation, meridional and zonal winds at heights of 87 km and 97 km, which are derived through 892.0 nm and 557.7 nm airglows, usually range from À50 m/s to 30 m/s and À50 m/s to 50 m/s, respectively, with typical random errors of about 6-10 m/s at 87 km and 2-3 m/s at 97 km. Meridional winds usually are northward at dusk, southward at middle night, and back to northward at dawn; and zonal winds usually are eastward at dusk, westward at middle night, and back to eastward at dawn. The monthly mean winds are in good agreement with those of HWM93 results. Meridional and zonal winds at a height of 250 km, which are derived through 630.0 nm nightglow, range from À110 m/s to 80 m/s with typical random errors of about 8-10 m/s. Meridional winds usually are northward at dusk, southward at middle night, and back to northward at dawn; and zonal winds usually are eastward at dusk, zero at middle night, and westward at dawn; and they are also well consistent with HWM93 results. (2) As for the seasonal variation, meridional winds at the heights of 87 km and 97 km have a visible annual variation at 12-17 LT and with a little semiannual variation at all other hours, but the zonal winds at the heights of 87 km and 97 km have a semiannual variation all night. The seasonal dependence of the winds, both meridional and zonal winds, at the height of 250 km is generally annual, but isolated cases of semiannual variation are observed. (3) The horizontal winds at 250 km evidently respond to the two storms of July 2012, apparent enhancement of the velocity of the southwestward wind. But no other obvious storm effects can be found from the winds at 87 km and 97 km during the same period.

Properties of the Long-Term Oscillations in the Middle Atmosphere Based on Observations from TIMED/SABER Instrument and FPI over Kelan

“…More details of the mechanism can be found in Yu et al [30]. Here we use the data from July 2013 to November 2014, and focus on altitudes of 87 and 97 km in the middle atmosphere.…”

“…Comparisons have been made between the FPI wind products and those from horizontal wind models and meteor radar, indicating that the FPI is a reliable instrument in the wind measurements [30,31]. Since our data are limited, we will mainly focus on the nighttime long-term variations of AO and SAO.…”

“…The LS fitting is applied to obtain the amplitude and phase of AO and SAO. The results are shown in Figure 13 and Table 1. wind measurements [30,31]. Since our data are limited, we will mainly focus on the nighttime longterm variations of AO and SAO.…”

Thermospheric Nocturnal Wind Climatology Observed by Fabry-Perot Interferometers over the Asia-Oceania Region

“…quiet/disturbance cases Most TW climatological studies eliminate cases of geomagnetic disturbance (i.e., Kp > 3 (Emmert et al 2006a) or Dst < −100 (Yu et al 2014)) to emphasize the response of the TW to geomagnetic disturbances (Emmert et al 2006b). In contrast, our purpose is to obtain long-term mean values.…”

“…Observations of TWs over the Asia-Oceania region have not yet been fully understood, except there have been recent studies in China (Yuan et al 2013;Yu et al 2014). The climatological TWs are dependent on the geographical latitude, season, and solar activity (e.g., Emmert et al 2006a).…”