Stilling and its Aerodynamic Effects on Pan Evaporation


  • Qiang Liu Key Laboratory for Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing,100875, China
  • Sirui Yan Key Laboratory for Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing,100875, China
  • Liqiao Liang Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research,Chinese Academy of Sciences, Beijing 100101, China;Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China
  • Liya Su Key Laboratory for Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing,100875, China



Declines in wind speed (u) (termed as “stilling”) has been reported in many regions of the world. To explore the temporal trends of u and its aerodynamic effects is vital to understand the changes in water resources. This study analyzed the changes of temporal trends for u and its aerodynamic effects using the data during 1959-2000 at 266 stations across China. The improved PenPan model was used to estimate pan evaporation (Epan) and quantify the contribution of radiative and aerodynamic components (aerodynamic component separated into wind speed u, vapour pressure deficit D, and air temperature Ta). Climate factors include Epan measured with the standard Chinese 20 cm diameter pan, u, Ta, relative humidity (rh) and sunshine hours (sh). The results showed: stilling occurred in most of stations (206 among 266) and 105 stations presented significant decreasing trends at 99% confidence level; stilling was the main cause for controlling the trends in Epan in most part of China, especially in the west and north of China. The results indicated that decreasing trends in Epan due to stilling would inevitably alter water resources, and should be put further investigation incorporation other factors.


Wind speed, Pan evaporation, Stilling, PenPan model, Aerodynamic effect


[1] Roderick, M.L., Rotstayn, L.D., Farquhar, G.D., Hobbins, M.T. On the attribution of changing pan evaporation. Geophysical Research Letters, 2007, 34: L17403. DOI: 10.1029/2007GL031166

[2] McVicar, T.R., Van Niel, T.G., Roderick, M.L., Li, L.T., Mo, X.G., Zimmermann, N.E., Schmatz, D.R. Observational evidence from two mountainous regions that near-surface wind speeds are declining more rapidly at higher elevations than lower elevations: 1960-2006. Geophysical Research Letters, 2010, 37: L06402. DOI: 10.1029/2009GL042255

[3] McVicar, T.R., Roderick, M.L., Donohue, R.J., Li, L.T., Van Niel, T.G., Thomas, A., Grieser, J., Jhajharia, D., Himri, Y., Mahowald, N.M., Mescherskaya, A.V., Kruger, A.C., Rehman, S., Dinpashoh, Y. Global review and synthesis of trends in observed terrestrial near-surface wind speeds: Implications for evaporation. Journal of Hydrology, 2012a, 416-417: 182-205.

[4] Guo, H., Xu, M., Hu, Q. Changes in near-surface wind speed in China: 1969-2005. International Journal of Climatology, 2011, 31(3): 349-358.

[5] Vautard, R., Cattiaux, J., Yiou, P., Thépaut, J.-N., Ciais, P. Northern hemisphere atmospheric stilling partly attributed to increased surface roughness. Nature Geoscience, 2010, 3 (11): 756-761.

[6] Lim, W.H., Roderick, M.L., Hobbins, M.T., Wong, S.C., Groeneveld, P.J., Sun, F.B., Farquhar, G.D. The aerodynamics of pan evaporation. Agricultural and Forest Meteorology, 2012, 152: 31-43.

[7] Lim, W.H., Roderick, M.L., Farquhar, G.D. A mathematical model of pan evaporation under steady state conditions. Journal of Hydrology, 2016, 540: 641- 658.

[8] Kohler, M.A., Noredenson, T.J., Fox, W.E. Evaporation from Pans and Lakes. US Weather Bureau Research Paper 38. US Weather Bureau, Washington, D.C, 1955.

[9] Allen, R.G., Pereira, L.S., Raes, D., Smith, M. Crop evapotranspiration-Guidelines for computing crop water requirements. FAO Irrigation and Drainage Paper 56, Rome, Italy, 1998.

[10] Roderick, M.L., Farquhar, G.D. The cause of decreased pan evaporation over the past 50 years. Science, 2002, 298: 1410-1411. DOI:10.1126/science.1075390-a

[11] Qian, Y., Kaiser, D.P., Leung, L.R., Xu, M. More frequent cloud-free sky and less surface solar radiation in China from 1955 to 2000. Geophysical Research Letters, 2006, 33: L01812. DOI: 10.1029/2005GL024586

[12] Shen, Y.J., Liu, C.M., Liu, M., Zeng, Y., Tian, C.Y. Change in pan evaporation over the past 50 years in the arid region of China. Hydrological Processes, 2010, 24(2): 225-231.

[13] Liu, X.M., Luo, Y.Z., Zhang, D., Zhang, M.H., Liu, C.M. Recent changes in panevaporation dynamics in China. Geophysical Research Letters, 2011a, 38: L13404. DOI: 10.1029/ 2011GL047929

[14] Liu, X.M., Zheng, H.X., Zhang, M.H., Liu, C.M.. Identification of dominant climate factor for pan evaporation trend in the Tibetan Plateau. Journal of Geographical Sciences, 2011b, 21(4): 594-608.

[15] Zhang, Q., Qi, T.Y., Li, J.F., Singh, V.P., Wang, Z.Z. Spatiotemporal variations of pan evaporation in China during 1960-2005: changing patterns and causes. International Journal of Climatology, 2015, 35: 903- 912.

[16] Rotstayn, L.D., Roderick, M.L., Farquhar, G.D. A simple pan-evaporation model for analysis of climate simulations: Evaluation over Australia. Geophysical Research Letters, 2006, 33: L17715. DOI: 10.1029/2006GL027114

[17] Linacre, E.T. Estimating United States Class-A pan evaporation from few climate data. Water International, 1994, 19(1): 5-14.

[18] Thom, A. S., Thony, J. L., Vauclin, M. On the proper employment of evaporation pans and atmometers in estimating potential transpiration, Quarterly Journal of the Royal Meteorological Society, 1981, 107: 711- 736.

[19] Yang, H., Yang, D. Climatic factors influencing changing pan evaporation across China from 1961 to 2001. Journal of Hydrology, 2012, 414-415:184-193.

[20] Xie, H., Zhu, X., Yuan, D.Y. Pan evaporation modelling and changing attribution analysis on the Tibetan Plateau (1970-2012). Hydrological Processes, 2015, 29: 2164-2177.

[21] Xu, M., Chang, C.P., Fu, C.B., Qi, Y., Robock, A., Robinson, D., Zhang, H.M. Steady decline of East Asian monsoon winds, 1969-2000: evidence from direct ground measurements of wind speed. Journal of Geophysical Research-Atmospheres , 2006c, 111: D24111. DOI: 10.1029/2006JD007337

[22] Fu, G.B., Yu, J.J., Zhang, Y.C., Hu, S.S., Ouyang, R.L., Liu, W.B. Temporal variation of wind speed in China for 1961-2007. Theoretical and Applied Climatology, 2011, 104(3-4): 313-324.

[23] Jiang, Y., Luo, Y., Zhao, Z.C. Maximum wind speed changes over China. Acta Meteorologica Sinica,, 2013, 27(1): 63-74.

[24] Li, Z., Yan, Z.W., Tu, K., Liu, W.D., Wang, Y.C. Changes in wind speed and extremes in Beijing during 1960-2008 based on homogenized observations. Advances Atmospheric Sciences, 2011, 28(2): 408-420.

[25] Chen, L., Li, D., Pryor, S.C. Wind speed trends over China: quantifying the magnitude and assessing causality. International Journal of Climatology, 2013, 33(11): 2579-2590.

[26] Zhang, C., Liu, F., Shen, Y. Attribution analysis of changing pan evaporation in the Qianghai-Tibetan Plateau, China. International Journal of Climatology, 2018, 38 (Suppl. 1): e1032-e1043.

[27] Yin, Y. H., Wu, S. H., Chen, G., Dai, E. F. Attribution analyses of potential evapotranspiration changes in China since the 1960s. Theoretical and Applied Climatology, 2010, 101(1-2): 19-28.

[28] Rayner, D.P. Wind run Changes: Dominant factor affecting pan evaporation trends in Australia. Journal of Climate, 2007, 20(14): 3379-3394.

[29] Roderick, M.L., Hobbins, M.T., Farquhar, G.D. Pan evaporation trends and the terrestrial water balance, I. Principles and observations. Geography Compass 3/2, , 2009: 746-760.

[30] Liu, Q., Yang, Z.F., Cui, B.S., Sun, T. The temporal trends of reference evapotranspiration and its sensitivity to key meteorological variables in the Yellow River Basin, China. Hydrological Processes, 2010, 24: 2171-2181.

[31] Donohue, R.J., McVicar, T.R., Roderick, M.L.. Assessing the ability of potential evaporation formulations to capture the dynamics in evaporative demand within a changing climate. Journal of Hydrology, 2010, 386: 186-197.

[32] McVicar, T.R., Roderick, M.L., Donohue, R.J., Van Niel, T.G. Less bluster ahead? Ecohydrological implications of global trends of terrestrial near-surface wind speeds. Ecohydrology, 2012b, 5(4): 381-388.



Article Type