Observations of mesospheric winds over a period of four years with the partial re ̄ection radar at Tirunelveli (8.7°N, 77.8°E), India, are presented in this study. The emphasis is on describing seasonal variabilities in mean zonal and meridional winds in the altitude region 70±98 km. The meridional winds exhibit overall transequatorial ̄ow associated with di€erential heating in the Northern and ...

In this paper, we report on a wind observation method based the movement of hot-air balloons (HABs). A quality assessment was carried out by comparing against observations at meteorological tower Cabauw in Netherlands during May–September 2018, and obtained standard deviations error were σ u = 0.65 ms − 1 $$ {\sigma}_u=0.65\;{\mathrm{ms}}^{-1} v 0.69 {\sigma}_v=0.69\;{\mathrm{ms}}^{-1} for meas...

Eddy–zonal flow interactions in the annular modes are investigated in this study using a modified beta-plane multilayer quasigeostrophic (QG) channel model. This study shows the different response of highand lowphase-speed (frequency) eddies to the zonal wind anomalies and suggests a baroclinic mechanism through which the two eddies work symbiotically maintaining the positive eddy feedback in t...

This study investigates the effect of stratospheric sudden warmings (SSWs) on planetary wave (PW) activity in the mesosphere–lower thermosphere (MLT). PW activity near 95 km is derived from meteor wind data using a chain of eight SuperDARN radars at high northern latitudes that span longitudes from 150W to 25 E and latitudes from 51 to 66 N. Zonal wave number 1 and 2 components were extracted f...

A VHF atmospheric radar (wind profiler) was used to study tropospheric winds during DAWEX. The profiler, which operated at a frequency of 54.1 MHz, was located at Pirlangimpi (Garden Point) (11.4S, 130.5E) on the Tiwi Islands. Observations were made regularly up to heights near 8 km, with maximum heights occurring when convective activity was strongest. Mean winds observed between October and D...

We examine the mean zonal momentum balance in the tropical mid-Pacific using a year of acoustic Doppler current profiler velocities and conductivitytemperature-depth profiler densities from the Hawaii-to-Tahiti Shuttle Experiment. All significant contributions from the mean, annual cycle, and higher-frequency flow fields are determined with the exception of the vertical stresses. We find that e...

This paper investigates the dynamical processes throughwhich the Tibetan Plateau (TP) influences theEast Asian summer monsoon (EASM) within the framework of the moist static energy (MSE) budget, using both observations and atmospheric general circulation model (AGCM) simulations. The focus is on the most prominent feature of the EASM, the so-called meiyu–baiu (MB), which is characterized by a w...

The National Institute of Oceanography, Goa deployed moorings with several subsurface current meters at 0◦, 93◦E (in February 2000) and 0◦, 83◦E (in December 2000) in the eastern Indian Ocean. Observed meridional current at all depths has a 10-20 day (or biweekly) variability that is distinct from longer period (20-60 day) subseasonal variability. Lags between different instruments suggest the ...

Data obtained by the GONG and MDI instruments over the last seven years are used to study how solar dynamics — both rotation and other large scale flows — have changed with time. In addition to the well known phenomenon of bands of faster and slower rotation moving towards the equator and pole, we find that the zonal flow pattern rises upwards with time. Like the zonal flows, the meridional flo...

the direction and speed of winds play an important role in the occurrence of pollutions and dust stormas well as location placement for the establishment of industries and the expansion of cities. yazd is a dry area of iran, and constantly exposed to the dust particles in the air; and this in terms of human life and health issues are of special importance. in this paper a day when due to the am...