Variability of complementary relationship and its mechanism on different time scales
| Autor: | Dawen Yang, Hanbo Yang, Fubao Sun, Zhentao Cong, Zhidong Lei |
|---|---|
| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Science in China Series E: Technological Sciences. 52:1059-1067 |
| ISSN: | 1862-281X 1006-9321 |
| DOI: | 10.1007/s11431-008-0197-3 |
| Popis: | In the complementary relationship (CR) between actual and potential evapotranspiration, wet environment evapotranspiration (Ew) is usually calculated using the Priestley-Taylor (P-T) equation. Based on the data obtained from 38 catchments of the Haihe River basin and the Weishan experiment site in Shandong Province of China, this study has found variations in the Priestley-Taylor parameter α (e.g. increase in values with increase in the amount of precipitation on annual scale, seasonal fluctuation noted to be at a maximum during winter and at a minimum during summer, and increased values in the forenoon and decreased values in the afternoon on an hourly scale). This paper explains that the inter-annual variation in α is due to the negative feedback of atmosphere in response to changes in actual increase in evapotranspiration, which is weakened because the atmosphere system is open. The parameter α undergoes a seasonal fluctuation brought about by seasonal changes in advection between continent and ocean; α likewise undergoes a daily variation as a result of atmospheric hysteresis in response to the changes in land surface energy. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|