Figure 2.27: Annually averaged
trends in surface to 500 hPa precipitable water at 0000UTC for the period 1973
to 1995. Positive trends are indicated by triangles and negative trends by circles.
Filled symbols indicate the trends were statistically significant at the 5% level
according to the Spearman test. The two sizes of symbols give an indication of
the magnitude of the trend. From Ross and Elliott (2001).