Vikram Sarabhai Space Centre

About: Vikram Sarabhai Space Centre is a facility organization based out in Thiruvananthapuram, India. It is known for research contribution in the topics: Aerosol & Ultimate tensile strength. The organization has 2092 authors who have published 3058 publications receiving 47975 citations. The organization is also known as: VSSC.

Evidence of kilometer-scale waves in the lower E region from high resolution VHF radar observations over Gadanki

Abstract: [1] High resolution VHF radar observations made at Gadanki revealed the kilometer-scale waves in the low latitude lower E region. These waves are found to occur in a narrow altitude range of 92–97 km and have vertical wavelengths of ∼0.5 km and wave periods of ∼40 seconds. They resemble quite closely to that reported recently for midlatitude using the MU radar. The signal intensities associated with these waves, shown in SNR, are found to be as high as 25 dB, quite comparable to that observed at higher altitudes. It is in contrast to the much weaker midlatitude lower E region echoes reported by the MU radar. The wave structures show both positive and negative altitude rates with values in the range of 15–20 m s−1, which are in good agreement with the observed Doppler velocities. The spectral widths are found to be relatively lower, implying the lower E region wave structures to be less turbulent compared to their counterpart at higher altitudes. The observed wave structures bear remarkable resemblance to that simulated for the equatorial E region through nonlocal nonlinear gradient drift instability.

Inertia‐gravity waves associated with the tropical easterly jet over the Indian subcontinent during the South West Monsoon Period

Abstract: Using the MST radar located at Gadanki (13.5°N, 79.2°E) winds were measured every four hours in the troposphere and lower stratosphere during a 72-hour period from 23 to 26 September 1997 when the tropical tropospheric easterly jet (TEJ) was present south of Gadanki with its core at a height of ∼16 km. Analysis of the radar data shows the presence of ∼56 hour oscillations (close to local inertial period of ∼51 hours) in the wind components with significant amplitudes. Examination of the corresponding horizontal wind vector shows clockwise rotation with altitude (upward energy propagation) in an altitude region (17.7–20.8 km) above the TEJ and anticlockwise rotation (downward energy propagation) in another altitude region (8.3–10.5 km) below. This indicates the generation of Inertia Gravity Waves (IGW) in the TEJ and their propagation both upwards and downwards from the source region. The inferred vertical and horizontal wavelengths of the IGW are ∼0.7 and ∼75 km respectively in the stratosphere and ∼1 and ∼143 km respectively in the troposphere.