Seminars

Lecturer: David Newnham, British Antarctic Survey
Date: 2013-11-22 10:30
Place: Aniara

Observations of the polar middle atmosphere from Halley, Antarctica

The British Antarctic Survey (BAS) operates a suite of co-located, ground-based instrumentation at its Halley and Rothera bases for studies of the polar stratosphere and mesosphere-lower thermosphere (MLT). Halley is located at high latitude (75.62°S, 26.23°W geographic; -62.0°, 28.9° geomagnetic), inside the stable, southern hemisphere winter‑time polar vortex. It is on the edge of the auroral zone but pole-ward of the South Atlantic Magnetic Anomaly, in the region where increased flux of higher‑energy (300 keV‑several MeV) electrons impacts on atmospheric chemistry.

Established measurements at Halley include temperature at ~87 km from hydroxyl (OH) Meinel band spectrometers, horizontal winds at 90 km from a SuperDARN radar, and 30 MHz wide‑beam riometers for identifying periods of increased energetic particle precipitation (EPP). Recent additions include a passive microwave radiometer measuring nitric oxide (NO), ozone (O3), and carbon monoxide (CO) vertical profiles over 35‑90 km and a 2.7 MHz medium frequency (MF) radar measuring horizontal and vertical winds over 60‑95 km. VLF receivers have been deployed to provide additional local and inter-hemispheric ionisation and electron data from the AARDDVARK global network.

I will present an overview of the new Halley VI station, describe the microwave radiometer and planned upgrades, and summarise studies by BAS and its partners investigating changes in middle atmosphere chemical composition and dynamics arising from EPP.

Created 2013-08-15 11:09:09 by Uwe Raffalski
Last changed 2013-11-14 16:28:32 by Uwe Raffalski