Marine cold-air outbreaks in the North Atlantic: temporal distribution and associations with large-scale atmospheric circulation
Kolstad, Erik W.; Bracegirdle, Thomas J.; Seierstad, Ivar A.. 2009 Marine cold-air outbreaks in the North Atlantic: temporal distribution and associations with large-scale atmospheric circulation. Climate Dynamics, 33 (2-3). 187-197. 10.1007/s00382-008-0431-5Full text not available from this repository.
The spatial and temporal distributions of marine cold air outbreaks (MCAOs) over the northern North Atlantic have been investigated using re-analysis data for the period from 1958 to 2007. MCAOs are large-scale outbreaks of cold air over a relatively warm ocean surface. Such conditions are known to increase the severity of particular types of hazardous mesoscale weather phenomena. We used a simple index for identifying MCAOs: the vertical potential temperature gradient between the sea surface and 700 hPa. It was found that atmospheric temperature variability is considerably more important than the sea surface temperature variability in governing both the seasonal and the inter-annual variability of MCAOs. Furthermore, a composite analysis revealed that a few well-defined and robust synoptic patterns are evident during MCAOs in winter. Over the Labrador and Irminger Seas the MCAO index was found to have a correlation of 0.70 with the North Atlantic Oscillation index, while over the Barents Sea a negative correlation of 0.42 was found.
|Programmes:||BAS Programmes > Other Special Projects|
|Additional Keywords:||Cold air outbreak; Polar low; Arctic; Meteorology; NAO; Climatology; Climate; Extreme weather; Severe weather|
|NORA Subject Terms:||Meteorology and Climatology
|Date made live:||04 Nov 2010 14:14|
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