image: Meandering polar jet stream visible in red colors, upper-level trough visible in blue. view more
Credit: ECMWF
Fast Facts
- A new atmospheric mechanism by which dust travels from the Sahara Desert across the eastern side of the North Atlantic Ocean towards the Arctic has been discovered
- The dust emission was generated by a Saharan cyclone that was triggered by the intrusion of a trough emanating from the polar jet
- The poleward transport of warm dust was caused by a meandering polar jet stream
- Approximately half of the warming in the Arctic is being attributed to increased moisture and heat fluxes transported to the region from lower latitudes
Abu Dhabi, October 10, 2018: Research scientists at NYU Abu Dhabi, along with other global researchers, have identified a new mechanism by which warm dust travels from the Sahara Desert to the Arctic Circle, which has been proven to affect rising temperatures and ice melt in Greenland.
Their findings highlight the role that the polar jet and associated atmospheric circulation plays in the transport of mineral dust from the Sahara desert to the Arctic across eastern side of the North Atlantic Ocean.
A meandering polar jet was discovered as responsible for both the emission and transport of dust from Northwest Africa to the Arctic. The emission has been linked to an intense Saharan cyclone that formed in early April 2011, which was caused by the intrusion of an upper-level trough emanating from the polar jet.
The study has found that atmospheric circulation of this nature enables the transport of dust, warm and moist air masses from subtropics and mid-latitudes to the Arctic, where approximately half of the warming is now being attributed to increased moisture and heat fluxes transported to the region.
The warm and moist air masses accompanying the Saharan dust caused a rise in surface temperature of 10C for more than three consecutive days upon reaching southeastern Greenland. Subsequent temperature observations detected increased melting within the ice across this same area.
"The polar jet stream has been identified as the main driver for such events leading to the transport of large amount of dust to high-latitudes," said Diana Francis, atmospheric scientist at NYU Abu Dhabi and lead research scientist in this study.
"If the polar jet is set to slow more frequently due to the changes in the Arctic climate system and to the Arctic Amplification, such events are expected to become more frequent," Francis added.
The newly discovered poleward route is considered the most substantial in terms of dust load import into the Arctic, due to the minimal geographical distance between the origin point and the destination.
'The impact of dust deposition on ice in Greenland, such as darkening ice and formation of algae on ice or cryoconite, as well as the link between Saharan dust transport and the Arctic heat dome must be investigated further in collaboration with scientists in UK and Germany' Francis emphasized.
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About NYU Abu Dhabi
NYU Abu Dhabi is the first comprehensive liberal arts and science campus in the Middle East to be operated abroad by a major American research university. NYU Abu Dhabi has integrated a highly-selective liberal arts, engineering and science curriculum with a world center for advanced research and scholarship enabling its students to succeed in an increasingly interdependent world and advance cooperation and progress on humanity's shared challenges. NYU Abu Dhabi's high-achieving students have come from 120 nations and speak over 120 languages. Together, NYU's campuses in New York, Abu Dhabi, and Shanghai form the backbone of a unique global university, giving faculty and student's opportunities to experience varied learning environments and immersion in other cultures at one or more of the numerous study-abroad sites NYU maintains on six continents.