Abstract
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.
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References
Davis R, Hardy J, Ni W, et al. (1997) Variation of snow cover ablation in the boreal forest: A sensitivity study on the effects of conifer canopy. Journal of Geophysical Research 102(D24): 29389–29395. DOI: 10.1029/97JD01335.
Duguay CR (1993) Radiation modeling in mountainous terrain review and status. Mountain Research and Development 13(4): 339–357. DOI: 10.2307/3673761.
Dozier J, Frew J (1990) Rapid calculation of terrain parameters for radiation modeling from digital elevation data. Geoscience and Remote Sensing, IEEE Transactions on 28(5): 963–969. DOI: 10.1109/36.58986.
Ellis C, Pomeroy J (2007) Estimating sub-canopy shortwave irradiance to melting snow on forested slopes. Hydrological processes 21(19): 2581–93. DOI: 10.1002/hyp.6794.
Ellis C (2011) Radiation and snowmelt dynamics in mountain forests. PhD thesis, University of Saskatchewan, Saskatoon.
Essery R, Pomeroy J, Ellis C, et al. (2008) Modelling longwave radiation to snow beneath forest canopies using hemispherical photography or linear regression. Hydrological processes 22(15): 2788–2800. DOI: 10.1002/hyp.6930.
Fassnacht S, Snelgrove K, Soulis E (2001) Daytime long-wave radiation approximation for physical hydrological modelling of snowmelt: a case study of southwestern Ontario. IAHS Publication No 270. Netherlands. pp 279–286.
Frazer G, Canham C, Lertzman K (1999) Gap Light Analyzer (GLA), Version 2.0: Imaging software to extract canopy structure and gap light transmission indices from true-colour fisheye photographs, users manual and program documentation. Simon Fraser University, Burnaby, British Columbia, and the Institute of Ecosystem Studies, Millbrook, New York.
Gao WD, Wei WS, Zhang LX (2005) Climate changes and seasonal snow cover variability in the Western Tianshan Mountains, Xinjiang in 1967–2000. Journal of Glaciology and Geocryology 27: 68–73. (In Chinese)
Granger R, Gray D (1990) A net radiation model for calculating daily snowmelt in open environments. Nordic hydrology 21(4–5): 217–234. DOI:10.2166/nh.1990.017.
Gryning S, Batchvarova E, De Bruin H (2001) Energy balance of a sparse coniferous high-latitude forest under winter conditions. Boundary-Layer Meteorology 99(3): 465–88. DOI: 10.1023/A:101 8939329915.
Hardy J, Davis R, Jordan R, et al. (1997) Snow ablation modelling at the stand scale in a boreal jack pine forest. Journal of Geophysical Research 102(D24): 29397–29406. DOI: 10.1029/96JD0 3096.
Hardy J, Melloh R, Koenig G, et al. (2004) Solar radiation transmission through conifer canopies. Agricultural and Forest Meteorology 126: 257–270. DOI: 10.1029/97JD00198.
Hu RJ, Ma H, Jiang FQ (1997) Geographical environment in the area of Tianshan Station for Snow & Avalanche Research, Yili, Xinjiang, China. Arid land geography 20(2): 25–33. (In Chinese)
Iziomon M, Mayer H, Matzarakis A (2003) Downward atmospheric longwave irradiance under clear and cloudy skies: Measurement and parameterization. Journal of Atmospheric and Solar-Terrestrial Physics 65(10): 1107–1116. DOI: 10.1016/j.jastp.2003.07.007.
Link TE, Marks D, Hardy JP (2004) A deterministic method to characterize canopy radiative transfer properties. Hydrological processes 18(18): 3583–3594. DOI: 10.1002/hyp.5793.
Liston G, Elder K (2006) A meteorological distribution system for high-resolution terrestrial modeling (MicroMet). Journal of Hydrometeorology 7(2): 217–234.
Olyphant G (1986) Longwave radiation in mountainous area and its influence on the energy balance of alpine snowfields. Water Resources Research 22(1): 62–66. DOI: 10.1029/WR022 i001p00062.
Mahat V, Tarboton DG (2012) Canopy radiation transmission for an energy balance snowmelt model. Water Resources Research 48: W01534. DOI:10.1029/2011WR010438.
Mahat V, Tarboton DG (2013a) Representation of canopy snow interception, unloading and melt in a parsimonious snowmelt model. Hydrological processes. DOI: 10.1002/hyp.10116.
Mahat V, Tarboton DG, Molotch NP (2013b) Testing above- and below-canopy representations of turbulent fluxes in an energy balance snowmelt model, Water Resources Research 49: 1108–1122. DOI:10.1002/wrcr.20073.
Pomeroy J, Dion K (1996) Winter radiation extinction and reflection in a boreal pine canopy: measurements and modelling. Hydrological processes 10(12): 1591–1608. DOI: 10.1002/(SICI)1099-1085(199612)10:12〈1591::AID-HYP503〉3.0.CO;2-8.
Pomeroy J, Marks D, Link T, et al. (2009) The impact of coniferous forest temperature on incoming longwave radiation to melting snow. Hydrological processes 23(17): 2513–2525. DOI: 10.1002/hyp.7325.
Price A, Petzold D (1984) Surface emissivities in a boreal forest during snowmelt. Arctic and Alpine Research 16(1): 45–51. DOI: 10.2307/1551171.
Rowlands A, Pomeroy J, Hardy J, et al. (2002) Small-scale spatial variability of radiant energy for snowmelt in a midlatitude sub-alpine forest. 2002. Proceedings from the 59th Eastern Snow Conference. pp 109–117.
Sicart J, Essery R, Pomeroy J, et al. (2004) A sensitivity study of daytime net radiation during snowmelt to forest canopy and atmospheric conditions. Journal of Hydrometeorology 5(5): 774–784.
Sicart J, Pomeroy J, Essery R, et al. (2006) Incoming longwave radiation to melting snow: observations, sensitivity and estimation in northern environments. Hydrological processes 20(17): 3697–3708. DOI: 10.1002/hyp.6383.
Tian H, Wen J, Ma YM, et al. (2007) Estimation of solar radiation over the complex terrain of Heihe River Basin. Plateau Meteorology 26(4): 666–676. (In Chinese)
Wei WS, Qin DH, Liu MZ (2001) Properties and structures of the seasonal snow cover in the continental regions of China. Annals of Glaciology 32: 93–101. DOI: 10.3189/172756401781819328.
Wilson R, Petzold D (1973) A Solar Radiation Model for Sub-Arctic Woodlands. Journal of Applied Meteorology 12: 1259–66. DOI: 10.1175/1520-0450(1973)012〈1259:ASRMFS〉2.0.CO;2.
Yokoyama R, Shirasawa M, Pike R (2002) Visualizing topography by openness: a new application of image processing to digital elevation models. Photogrammetric engineering and remote sensing 68(3): 257–266.
Zhang Z, Liu P, Ding Y, et al. (2010) Species compositions and spatial distribution pattern of tree individuals in the schrenk spruce forest, northwest China. Journal of Nanjing Forestry University (Natural Science Edition) 34: 157–160. (In Chinese)
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Lu, H., Wei, Ws., Liu, Mz. et al. Observations and modeling of incoming longwave radiation to snow beneath forest canopies in the west Tianshan Mountains, China. J. Mt. Sci. 11, 1138–1153 (2014). https://doi.org/10.1007/s11629-013-2868-1
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DOI: https://doi.org/10.1007/s11629-013-2868-1