Search Results
the Arctic stratospheric vortex were unusually cold ( Fig. 3 ). In November–December 2015, the Arctic vortex was minimally disturbed by upward-propagating planetary waves ( Matthias et al. 2016 ) and the polar cap minimum temperature T MIN between 65° and 90°N dropped well below the climatological mean. The red T MIN line in Fig. 3 reveals that the threshold of T NAT at 50 hPa was already reached at the beginning of December 2015, and T MIN dropped below T FROST at the end of 2015
the Arctic stratospheric vortex were unusually cold ( Fig. 3 ). In November–December 2015, the Arctic vortex was minimally disturbed by upward-propagating planetary waves ( Matthias et al. 2016 ) and the polar cap minimum temperature T MIN between 65° and 90°N dropped well below the climatological mean. The red T MIN line in Fig. 3 reveals that the threshold of T NAT at 50 hPa was already reached at the beginning of December 2015, and T MIN dropped below T FROST at the end of 2015
about 10–30 km apart ( Figs. 2 and 3 ). Most of the bands were nearly linear with a roughly constant length and width, although some bands were less so (i.e., over Oklahoma in Figs. 2b and 3b ). Others with smaller wavelengths formed over the crest of the Appalachian Mountains (e.g., Fig. 3d ). It is possible that the topography, either directly (e.g., gravity waves) or indirectly (e.g., modification of the planetary boundary layer), played a role in those particular bands, but that is not
about 10–30 km apart ( Figs. 2 and 3 ). Most of the bands were nearly linear with a roughly constant length and width, although some bands were less so (i.e., over Oklahoma in Figs. 2b and 3b ). Others with smaller wavelengths formed over the crest of the Appalachian Mountains (e.g., Fig. 3d ). It is possible that the topography, either directly (e.g., gravity waves) or indirectly (e.g., modification of the planetary boundary layer), played a role in those particular bands, but that is not
United States. The trough was also detectable in the water vapor loop. Associated with this trough was a strong jet of 140 kt (72 m s −1 ) on the east side in the southern United States. The west side of the trough was oriented nearly meridionally from New Mexico to North Dakota with winds generally less than 65 kt (34 m s −1 ). A ridge at the upper levels dominated the western United States. Embedded within the synoptic field, a short-wave trough, defined by a wind shift line, sliced through the
United States. The trough was also detectable in the water vapor loop. Associated with this trough was a strong jet of 140 kt (72 m s −1 ) on the east side in the southern United States. The west side of the trough was oriented nearly meridionally from New Mexico to North Dakota with winds generally less than 65 kt (34 m s −1 ). A ridge at the upper levels dominated the western United States. Embedded within the synoptic field, a short-wave trough, defined by a wind shift line, sliced through the
