2 Some Remarks on Variability and Trends
(K. Labitzke, B. Naujokat and M. Kunze)

2.1 The Lower Arctic Stratosphere in Winter since 1952

• 2.1.1 Early Winter

• 2.1.2 Mid-Winter

• 2.1.3 Spring

• 2.1.4 Relevance for PSC Formation

• 2.1.5 Trends at the 10-hPa level

• 2.1.6 Classification of Stratospheric Warmings

2.2 Trends through the Year

• 2.2.1 Trends over the Arctic in Summer

• 2.2.2 Vertical Meridional Sections of Temperature Trends for each Month, July 1964 - June 2001

• 2.2.3 Trends in Different Periods

2.3 Trends in the Annual Mean

• 2.3.1 Temperature Trends at the North Pole since 1956

• 2.3.2 Hemispheric Maps of Annual Trends at 30 hPa

• 2.3.3 Height and Temperature Trends between 100 and 30-hPa, 1965-2000

2.4 References