Evaporation for December, 1985 - 1999

When looking at any evaporation map it is important to keep in mind temperature and sunshine, because these are the main drivers of evaporation. But evaporation can not actually take place if there is no water available.

Comparing one month over a number of years is one way of detecting extremes because exceptions to the average links to water resources and impacts on water availability.

December

1988 – 1989- 1990: when looking at these in sequence it is clear there is a difference with evaporation in 1989 higher for N. America and Europe but lower in Southern Africa and Australia: this is the influence of La Nina. The affects of La Nina typically cause dry areas of the world to be dryer and wet areas wetter. Wetter conditions over N. America and Europe could be one reason for an increased estimation in evaporation for these areas.

June

1991 – 1992 – 1993: look at these in sequence and the pattern over Europe changes with 1992 having the lower estimate in evaporation. One cause could be an El Nino event. El Nino is typically a warming event and is linked to warmer summer and dryer conditions over Europe.