Journal of Mountain Science

, Volume 11, Issue 5, pp 1138–1153 | Cite as

Observations and modeling of incoming longwave radiation to snow beneath forest canopies in the west Tianshan Mountains, China

  • Heng Lu
  • Wen-shou WeiEmail author
  • Ming-zhe Liu
  • Xi Han
  • Wen Hong


Forest canopy reduces shortwave radiation and increases the incoming longwave radiation to snowpacks beneath forest canopies. Furthermore, the effect of forest canopy may be changed by complex topography. In this paper, we measured and simulated the incoming longwave radiation to snow beneath forest at different canopy openness in the west Tianshan Mountains, China (43°16′N, 84°24′E) during spring 2013. A sensitivity study was conducted to explore the way that terrain influenced the incoming longwave radiation to snow beneath forest canopies. In the simulation model, measurement datasets, including air temperature, incoming shortwave radiation above canopy, and longwave radiation enhanced by adjacent terrain, were applied to calculate the incoming longwave radiation to snow beneath forest canopy. The simulation results were consistent with the measurements on hourly scale and daily scale. The effect of longwave radiation enhanced by terrain was important than that of shortwave radiation above forest canopy with different openness except the 20% canopy openness. The longwave radiation enhanced due to adjacent terrain increases with the slope increase and temperature rise. When air temperature (or slope) is relatively low, the longwave radiation enhanced by adjacent terrain is not sensitive to slope (or air temperature), but the sensitivity increases with the decrease of snow cover area on sunny slope. The effect of longwave radiation is especially sensitive when the snow cover on sunny slope melts completely. The effect of incoming shortwave radiation reflected by adjacent terrain on incoming longwave radiation to snow beneath forest canopies is more slight than that of the enhanced longwave radiation.


Incoming longwave radiation Snow beneath forest canopy Simulation model Complex topography Sensitivity study 


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Copyright information

© Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Heng Lu
    • 1
    • 2
  • Wen-shou Wei
    • 3
    Email author
  • Ming-zhe Liu
    • 1
    • 4
  • Xi Han
    • 3
  • Wen Hong
    • 1
    • 2
  1. 1.Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqiChina
  2. 2.Graduate School of Chinese Academy of SciencesBeijingChina
  3. 3.Institute of Desert MeteorologyChina Meteorological AdministrationUrumqiChina
  4. 4.Tianshan Station for Snow & Avalanche ResearchUrumqiChina

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