Zobrazeno 1 - 10
of 118
pro vyhledávání: '"A. Osepian"'
Publikováno v:
Annales Geophysicae, Vol 33, Pp 609-622 (2015)
A small, 54 MHz wind-profiler radar, MARA, was operated at Troll, Antarctica (72° S, 2.5° E), continuously from November 2011 to January 2014, covering two complete Antarctic winters. Despite very low power, MARA observed echoes from heights of
Externí odkaz:
https://doaj.org/article/27e8b6cbc3cf4ad7ab2cb635dad077bd
Publikováno v:
Annales Geophysicae, Vol 33, Pp 561-572 (2015)
Precipitation of high-energy electrons (EEP) into the polar middle atmosphere is a potential source of significant production of odd nitrogen, which may play a role in stratospheric ozone destruction and in perturbing large-scale atmospheric circu
Externí odkaz:
https://doaj.org/article/c81f154a27b74557a6558d7d4f3d42fc
Publikováno v:
Annales Geophysicae, Vol 32, Pp 207-222 (2014)
Mesospheric water vapour concentration effects on the ion composition and electron density in the lower ionosphere under quiet geophysical conditions were examined. Water vapour is an important compound in the mesosphere and the lower thermosphere
Externí odkaz:
https://doaj.org/article/08d94bf5e0ca4ade88340a8f6c2dd757
Publikováno v:
Annales Geophysicae, Vol 30, Pp 1345-1360 (2012)
The theoretical PGI (Polar Geophysical Institute) model for the quiet lower ionosphere has been applied for computing the ionization rate and electron density profiles in the summer and winter D-region at solar zenith angles less than 80° and lar
Externí odkaz:
https://doaj.org/article/9bddec9f8749459ea3fe57fef635e81e
Publikováno v:
Annales Geophysicae, Vol 30, Pp 1143-1157 (2012)
Comprehensive analysis of the wave activity in the Antarctic summer mesopause is performed using polar mesospheric summer echoes (PMSE) measurements for December 2010–January 2011. The 2-day planetary wave is a statistically significant periodic
Externí odkaz:
https://doaj.org/article/f18c79d2fcea47ada4ee5eb37e99626a
Publikováno v:
Annales Geophysicae, Vol 28, Pp 1333-1343 (2010)
Radar reflectivities associated with Polar Mesosphere Summer Echoes (PMSE) are compared with measurements of ice mass density in the mesopause region. The 54.5 MHz radar Moveable Atmospheric Radar for Antarctica (MARA), located at the Wasa/Aboa st
Externí odkaz:
https://doaj.org/article/562565891bbe482d86b772adbef7a5c2
Publikováno v:
Annales Geophysicae, Vol 27, Pp 3713-3724 (2009)
Accurate measurements of electron density in the lower D-region (below 70 km altitude) are rarely made. This applies both with regard to measurements by ground-based facilities and by sounding rockets, and during both quiet conditions and conditio
Externí odkaz:
https://doaj.org/article/15e742aec39042c4a0673208b794774b
Publikováno v:
Annales Geophysicae, Vol 27, Pp 577-589 (2009)
A numerical model of D-region ion chemistry is used to study the influence of the ozone concentration in the mesosphere on ion-composition and electron density during solar proton events (SPE). We find a strong sensitivity in the lower part of the
Externí odkaz:
https://doaj.org/article/4736054098504927a4b7ecac99ff28b5
Publikováno v:
Annales Geophysicae, Vol 26, Pp 131-143 (2008)
The influence of atomic oxygen concentration on the height distribution of the main positive and negative ions and on electron density in the mesosphere is studied for the conditions prevailing during the solar proton event on 17 January 2005. It
Externí odkaz:
https://doaj.org/article/42bf6d5386024b5eac51e842212f5a31
Publikováno v:
Annales Geophysicae, Vol 23, Pp 1239-1247 (2005)
On 30 October 2004 during a strong solar proton event, layers of enhanced backscatter from altitudes between 55 and 75km have been observed by both ESRAD (52MHz) and the EISCAT VHF (224MHz) radars. These echoes have earlier been termed Polar Mesos
Externí odkaz:
https://doaj.org/article/ddaf7bdbfd0048d0bbe279cfb3cc762e