dyrland

An update from Longyearbyen,
Svalbard (78°N)
Margit Dyrland and Fred Sigernes
NDMC
Oberpfaffenhofen, May 2011
Optical measurement season at Kjell Henriksen
Observatory (KHO) from November-March
Project-title: High Arctic gravity waves and their impact on middle atmospheric circulation and
temperature
Project leader: Margit Dyrland, The University Centre in Svalbard (UNIS)
NFR funding: FRINAT 204993
The KeoSentry4ix imager is
designed to image nearinfrared emissions from the
OH(6-2) band of airglow.
KeoSentry4ix airglow imager. (1) Mamiya RB67 fish-eye lens, (2) collimator lens, (3)
filter wheel, (4) Smart motor system, (5) relay optics, and (6) CCD detector.
OH(6-2) band investigated
Auroral line
8446Å
“auroral
contamination”
8465Å: OH(6-2) P1(4)
8400Å: OH(6-2) P1(2)
Ratio of P1(2) and P1(4)
should give temperature!
Hope to use it as a
“MTM”
Configuration:
• Filters: 8446, 8400, 8465A
(18A fwhm, 4 inch diameter)
• AND… NIR wideband with notch
centered at 8446A, 180A fwhm
• Background to be determined from the
spectrometer measurements
Installed and in use since November 28.
 Auroral contamination
Main scientific questions:
1. What are the characteristics of mesopause region gravity waves (GWs)
observed by an all-sky airglow imager at the high arctic location
Svalbard (78°N)
2. Is there a direct coupling between the GW activity above Svalbard and
the circulation and temperature of the middle atmosphere?
3. Are there major differences or correlations between modelled and
observed GWs at high arctic latitudes, and those at other latitudes?
Tasks:
- Two-dim Fourier analysis of images
(after flattening, star removal etc.)
- Comparing with data from Ebert-Fastie
(temperatures)
- Input of GW characteristics in models?
(KMCM - Erich Becker, IAP-KBORN)
- Comparing with models and
measurements at other latitudes.
- Connection with circulation?
Illustration by WMO, 1985, adapted from Hoppe,
2001
An update on the OH(6-2) temperature series from
Longyearbyen, Svalbard (78°N)
• Ebert-Fastie spectrometer measuring
OH(6-2) band in Longyearbyen since 1983
• Data until 2005 published in Dyrland and
Sigernes, CJP, 2007.
• Problems with signal to noise ratio since
changing some parts in January 2007
• Moved autumn 2007
• PMT tube changed fall 2010 – improved
s/n ratio
• Finally the last seasons have been
analysed :o)
OH(6-2) temperatures from the last 5 seasons
PSC above Longyearbyen 22. February 2011
Thank you for your attention!