Evidence of vertical coupling: meteorological storm Fabienne on 23 September 2018 and its related effects observed up to the ionosphere
<p>A severe meteorological storm system on the frontal border of cyclone Fabienne passing above central Europe was observed on 23–24 September 2018. Large meteorological systems are considered to be important sources of the wave-like variability visible/detectable through the atmosphere and ev...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-01-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/38/73/2020/angeo-38-73-2020.pdf |
| Summary: | <p>A severe meteorological storm system on the frontal border of
cyclone Fabienne passing above central Europe was observed on 23–24 September 2018. Large meteorological systems are considered to be important
sources of the wave-like variability visible/detectable through the
atmosphere and even up to ionospheric heights. Significant departures from
regular courses of atmospheric and ionospheric parameters were detected in
all analyzed datasets through atmospheric heights. Above Europe,
stratospheric temperature and wind significantly changed in coincidence with
fast frontal transition (100–110 km h<span class="inline-formula"><sup>−1</sup>)</span>. Zonal wind at 1 and 0.1 hPa
changes from the usual westward before the storm to eastward after the storm. With this
change are connected changes in temperature where at 1 hPa the analyzed area is
colder and at 0.1 hPa warmer. Within ionospheric parameters, we have
detected significant wave-like activity occurring shortly after the cold
front crossed the observational point. During the storm event, both by
Digisonde DPS-4D and continuous Doppler sounding equipment, we have observed
strong horizontal plasma flow shears and time-limited increase plasma flow
in both the northern and western components of ionospheric drift. The vertical component
of plasma flow during the storm event is smaller with respect to
the corresponding values on preceding days.</p>
<p>The analyzed event of an exceptionally fast cold front of cyclone Fabienne fell
into the recovery phase of a minor–moderate geomagnetic storm observed as a
negative ionospheric storm at European mid-latitudes. Hence, ionospheric
observations consist both of disturbances induced by moderate geomagnetic
storms and effects originating in convective activity in the troposphere.
Nevertheless, taking into account a significant change in the global circulation
pattern in the stratosphere, we conclude that most of the observed wave-like
oscillations in the ionosphere during the night of 23–24 September can be directly
attributed to the propagation of atmospheric waves launched on the frontal
border (cold front) of cyclone Fabienne. The frontal system acted as an
effective source of atmospheric waves propagating upward up to the
ionosphere.</p> |
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| ISSN: | 0992-7689 1432-0576 |