SPATIAL AND TEMPORAL VARIATIONS OF 300 hPa TEMPERATURES IN THE NORTHERN HEMISPHERE BETWEEN 1966 AND 1993

✍ Scribed by WEBER, GERD-RAINER

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 251 KB
• Volume: 17
• Category: Article
• ISSN: 0899-8418
• DOI: 10.1002/(sici)1097-0088(199702)17:2<171::aid-joc116>3.0.co;2-1

✦ Synopsis

1966-1993 300 hPa temperature variations in the Northern Hemisphere are analysed on the basis of Free University of Berlin synoptic climatology group manual 300 hPa temperature analyses. For various geographical regions comparisons are made to temperature trends in the tropospheric layer 300-1000 hPa. It is found that large 300 hPa warming occurred over the lower latitudes and over the middle latitudes. Slight, but statistically non-significant cooling occurred over the higher latitudes. The largest and statistically most significant warming at 300 hPa occurred over the tropical Pacific Ocean, where, as elsewhere over the lower latitudes, 300 hPa warming was larger than warming of the entire layer 300-1000 hPa. An analysis with respect to the Southern Oscillation Index (SOI) reveals significantly enhanced low-latitude 300 hPa warming during episodes with negative SOI. Mid-latitude and high-latitude temperature departures are related closely to various measures of mid-latitude flow parameters. Possible reasons for the observed behaviour of upper tropospheric temperature trends are discussed.