CHARACTERISTICS OF THE INTERANNUAL AND INTERDECADAL TIMESCALES OF EVAPORATION IN NORTHERN CHINA IN THE RECENT 115 YEARS

Evaporation plays an important role in water balance on the land surface. In Northern China, the evaporation series of the recent 115 years was reconstructed on the basis of Thornthwaite evaporation formula. The characteristics of the reconstructed series were analyzed using 10-year running mean filter, power spectrum method, and running t-text of abrupt changes on the paper. The results showed that there were remarkable interannual fluctuations with timescales of about quasi-8-year, 3-4-year, and quasi-2-year, and interdecadal oscillations with timescales of 57.5-year, quasi-23-year, and 11.5-year. Meanwhile, the abrupt changes of the evaporation series were also of interdecadal timescale. Either interannual fluctuations or interdecadal oscillations of evaporation were closely related to variations in air temperatures and precipitation.