REFERENCES

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Canada; Greenland; Newfoundland; polar night
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.394.6831; http://docs.lib.noaa.gov/rescue/mwr/086/mwr-086-01-0028.pdf

Low moved southward and then eastward but with a trough extending across southern Canada. Over the southern two-thirds of the North American continent on February 5 (fig. 6), easterly flow had become established in a temperature field indicating increase of wind speed with height. 3. CONCLUDING REMARKS The manner in which the polar night stratospheric jet stream and its associated cold core annually drift away from the pole and lose strength has only recently become observable through increasing amounts of data at 25 mb. and above. Although each year the breakup tends to occur on a different date and in a different region, it is usually accompanied by a spectacular sequence of events. The sequence of events in 1958, as illustrated here, differed strikingly from that of 1957 when the cold air entered the United States through western Canada just prior to the appearance of “explosive ” warming 25 mb. over Newfoundland. The abnormally warm air then moved northward across Greenland. In March 1956, warming moved into central and southern Canada from the Alaskan region but was not accompanied by a rapid breakdown of the circumpolar Low. Other cases studied, dating back to 1948, show a variety of breakup times and magnitudes of stratospheric warming.