 |
| Titel |
Proof-of-Concept Study for Ground-based Millimetre-wave Observations of Horizontal Winds in the Polar Stratosphere and Mesosphere |
| VerfasserIn |
George Ford, David Newnham, Hugh Pumphrey |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250106173
|
| Publikation (Nr.) |
 EGU/EGU2015-5826.pdf |
|
|
|
|
|
| Zusammenfassung |
| We demonstrate the feasibility of stratosphericmesospheric zonal and meridional wind
observations using ground-based passive millimetrewave radiometry with lownoise receivers
and high-resolution spectrometers. Detailed observations of winds in the Polar Regions
are essential to understand chemical transport, atmospheric dynamics, waves and
tides, and improve knowledge of polar and global climate systems. Measurements
in the altitude range 2070 km would fill the ‘radar gap’ and address the current
sparse wind observations for the upper stratosphere and mesosphere that limits
our understanding of vertical wave propagation and its impact on planetaryscale
circulation.
The Atmospheric Radiative Transfer Simulator (ARTS) and Qpack retrieval code is used
to retrieve vertical wind profiles from simulations of lineofsight Doppler-shifted atmospheric
emission lines above Halley station (75Ë 37’S, 26Ë 14’W), Antarctica. The ozone lines
centred at 231.28ÂGHz, 249.79ÂGHz, and 249.96ÂGHz and the 230.54 GHz carbon
monoxide line are used. The effect of clearsky winter/summer conditions, zenith angle,
system temperature (Tsys), and spectrometer frequency resolution on the altitude coverage,
measurement uncertainty, and height and time resolution of the retrieved wind profiles is
presented. For radiometric observations of Dopplershifted ozone emission lines arising from
horizontal winds in the range 1040Âm s-1, and with Tsys = 1400ÂK, we estimate that daily
mean zonal and meridional wind profiles covering the altitude range 2575 km with typical
measurement uncertainty of 5Âm s-1 and vertical resolution of ~12 km could be achieved. |
|
|
|
|
|
|