A meandering polar jet caused the development of a Saharan cyclone and the transport of dust toward Greenland
<p>In this study, we identify a new mechanism by which dust aerosols travel over long distances across the eastern side of the North Atlantic Ocean toward the Arctic. The meandering polar jet was at the origin of both dust emission through cyclogenesis over Northwest Africa and poleward transp...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-04-01
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| Series: | Advances in Science and Research |
| Online Access: | https://www.adv-sci-res.net/16/49/2019/asr-16-49-2019.pdf |
| Summary: | <p>In this study, we identify a new mechanism by which dust aerosols travel
over long distances across the eastern side of the North Atlantic Ocean
toward the Arctic. The meandering polar jet was at the origin of both dust
emission through cyclogenesis over Northwest Africa and poleward transport
of the uplifted dust towards the Arctic, through cut-off circulation. The
dust emission was associated with an intense Saharan cyclone that formed
over Northwest Africa in early April 2011. The formation of the cyclone was
caused by the intrusion into subtropics, of a high-latitude-upper-level
trough, linked to the meandering polar jet. The trough initiated
cyclogenesis over Northwest Africa after orographic blocking by the
Anti-Atlas Mountains. The still meandering polar jet led to the formation of
a cut-off low further south with which the Saharan dust-cyclone merged 2 d later and moved northward with the main stream. Beside satellite
observations, a simulation at high resolution was performed using the
prognostic-dust permitting model MesoNH. The total dust load carried during
this event to areas located north of 40<span class="inline-formula"><sup>∘</sup></span> N was estimated by the model to be
38 Tg and dust deposition was estimated to be 1.3 Tg. The Saharan dust
reaching Greenland was accompanied by warm and moist air masses that caused
a rise in surface temperature of about 10 <span class="inline-formula"><sup>∘</sup></span>C for more than 3 consecutive days
over the southeastern Greenland. Ice melt over this area of Greenland was
detected in the brightness temperature observations.</p> |
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| ISSN: | 1992-0628 1992-0636 |