A closer look at the relationships between meridional mass circulation pulses in the stratosphere and cold air outbreak patterns in northern hemispheric winter

2018 ◽  
Vol 51 (7-8) ◽  
pp. 3125-3143 ◽  
Author(s):  
Yueyue Yu ◽  
Ming Cai ◽  
Rongcai Ren ◽  
Jian Rao
Keyword(s):  
Cold Air ◽  
Cold Air Outbreak ◽  
Northern Hemispheric ◽  
Meridional Mass Circulation ◽  
Mass Circulation

scholarly journals Dynamic Linkage between Cold Air Outbreaks and Intensity Variations of the Meridional Mass Circulation

2015 ◽  
Vol 72 (8) ◽  
pp. 3214-3232 ◽  
Author(s):  
Yueyue Yu ◽  
Rongcai Ren ◽  
Ming Cai
Keyword(s):  
Mass Transport ◽  
Western Europe ◽  
Peak Time ◽  
Cold Air ◽  
Continental Scale ◽  
Icelandic Low ◽  
Meridional Mass Circulation ◽  
Azores High ◽  
Mass Circulation ◽  
Cold Air Outbreaks

Abstract This study investigates the dynamical linkage between the meridional mass circulation and cold air outbreaks using the ERA-Interim data covering the period 1979–2011. It is found that the onset date of continental-scale cold air outbreaks coincides well with the peak time of stronger meridional mass circulation events, when the net mass transport across 60°N in the warm or cold air branch exceeds ~88 × 109 kg s−1. During weaker mass circulation events when the net mass transport across 60°N is below ~71.6 × 109 kg s−1, most areas of the midlatitudes are generally in mild conditions except the northern part of western Europe. Composite patterns of circulation anomalies during stronger mass circulation events greatly resemble that of the winter mean, with the two main routes of anomalous cold air outbreaks being along the climatological routes of polar cold air: namely, via East Asia and North America. The Siberian high shifts westward during stronger mass circulation events, opening up a third route of cold air outbreaks through eastern Europe, where lies the poleward warm air route in the winter-mean condition. The strengthening of the Icelandic low and Azores high during stronger mass circulation events acts to close off the climatological-mean cold air route via western Europe; this is responsible for the comparatively normal temperature there. The composite pattern for weaker mass circulation events is generally reversed, where the weakening of the Icelandic low and Azores high, corresponding to the negative phase of the North Atlantic Oscillation (NAO), leads to the reopening and strengthening of the equatorward cold air route through western Europe, which is responsible for the cold anomalies there.

Cold air outbreak over the Kuroshio extension region

OCEANS 2009 ◽  
2009 ◽  
Author(s):  
T. G. Jensen ◽  
T. Campbell ◽  
T. A. Smith ◽  
R. J. Small ◽  
R. Allard
Keyword(s):  
Kuroshio Extension ◽  
Cold Air ◽  
Cold Air Outbreak ◽  
The Kuroshio ◽  
Kuroshio Extension Region

scholarly journals A case study of snowstorm gusts and blowing/drifting snow

1993 ◽  
Vol 18 ◽  
pp. 142-148 ◽  
Author(s):  
Masayuki Maki ◽  
Sento Nakai ◽  
Tsuruhei Yagi ◽  
Hideomi Nakamura
Keyword(s):  
Doppler Radar ◽  
Gravity Current ◽  
Ground Surface ◽  
Leading Edge ◽  
Radiosonde Data ◽  
The Sea Of Japan ◽  
Cold Air ◽  
Drifting Snow ◽  
Cold Air Outbreak ◽  
Strong Winds

The mechanisms of strong winds associated with snow clouds, and the relationship between strong winds and blowing/drifting snow, were investigated. A snowstorm occurred with a typical L-mode snow band which was generated and organized longitudinally during a continental cold-air outbreak over the Sea of Japan. Doppler radar observations revealed that the snow band consisted of small echo cells arranged along the direction of the snow band. When one of the echo cells passed, blowing/drifting snow was generated and intensified by a snow cloud-induced gust, and the horizontal visibility near the ground surface was significantly decreased. Doppler radar and radiosonde data showed that the gust was due to the cold air outflow (CAO) from the snow clouds. The leading edge of the CAO was about 9 km ahead of the center of the snow cloud and the depth of the CAO was about 600 m near the forward flank of the snow cloud. The CAO was caused by a downdraft at the center of the snow cloud, which was initiated at a height of about 1.3 km and with a velocity in excess of 1 ms−1. The observed CAO speed was explained by the theory of the gravity current.

A cold air outbreak near Spitsbergen in springtime — Boundary-layer modification and cloud development

1992 ◽  
Vol 61 (1-2) ◽  
pp. 13-46 ◽  
Author(s):  
Burghard Brümmer ◽  
Birgit Rump ◽  
Gottfried Kruspe
Keyword(s):  
Boundary Layer ◽  
Cold Air ◽  
Cold Air Outbreak ◽  
Cloud Development

On the use of a coupled ocean–atmosphere–wave model during an extreme cold air outbreak over the Adriatic Sea

2016 ◽  
Vol 172-173 ◽  
pp. 48-65 ◽  
Author(s):  
Antonio Ricchi ◽  
Mario Marcello Miglietta ◽  
Pier Paolo Falco ◽  
Alvise Benetazzo ◽  
Davide Bonaldo ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Wave Model ◽  
Cold Air ◽  
Cold Air Outbreak ◽  
Ocean Atmosphere ◽  
Extreme Cold

The Climatology, Meteorology, and Boundary Layer Structure of Marine Cold Air Outbreaks in Both Hemispheres*

2016 ◽  
Vol 29 (6) ◽  
pp. 1999-2014 ◽  
Author(s):  
Jennifer Fletcher ◽  
Shannon Mason ◽  
Christian Jakob
Keyword(s):  
Boundary Layer ◽  
Layer Structure ◽  
Zonal Flow ◽  
Heat Fluxes ◽  
Pressure Gradients ◽  
Cold Air ◽  
Surface Heat Fluxes ◽  
Cold Air Outbreak ◽  
Wide Range ◽  
Cold Air Outbreaks

Abstract A comparison of marine cold air outbreaks (MCAOs) in the Northern and Southern Hemispheres is presented, with attention to their seasonality, frequency of occurrence, and strength as measured by a cold air outbreak index. When considered on a gridpoint-by-gridpoint basis, MCAOs are more severe and more frequent in the Northern Hemisphere (NH) than the Southern Hemisphere (SH) in winter. However, when MCAOs are viewed as individual events regardless of horizontal extent, they occur more frequently in the SH. This is fundamentally because NH MCAOs are larger and stronger than those in the SH. MCAOs occur throughout the year, but in warm seasons and in the SH they are smaller and weaker than in cold seasons and in the NH. In both hemispheres, strong MCAOs occupy the cold air sector of midlatitude cyclones, which generally appear to be in their growth phase. Weak MCAOs in the SH occur under generally zonal flow with a slight northward component associated with weak zonal pressure gradients, while weak NH MCAOs occur under such a wide range of conditions that no characteristic synoptic pattern emerges from compositing. Strong boundary layer deepening, warming, and moistening occur as a result of the surface heat fluxes within MCAOs.

scholarly journals Charge and discharge of polar cold air mass in northern hemispheric winter

2015 ◽  
Vol 42 (17) ◽  
pp. 7187-7193 ◽  
Author(s):  
Yuki Kanno ◽  
Muhammad Rais Abdillah ◽  
Toshiki Iwasaki
Keyword(s):  
Air Mass ◽  
Cold Air ◽  
Northern Hemispheric
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