Water Resources Systems—Water Availability and Global Change (Proceedings of symposium HS02a held during IUGG2003 at Sapporo, July 2003). IAHS Publ. no. 280, 2003. p. 309–317.

Effect of snow interception on the energy balance above deciduous and coniferous forests during a snowy winter

Kazuyoshi Suzuki

Frontier Observational Research System for Global Change, 3173-25 Showa-machi, Kanazawa-ku, Yokohama 236-0001, Japan

skazu@jamstec.go.jp

Yuichiro Nakai

Hokkaido Center, Forestry and Forest Products Research Institute, Sapporo, Japan

Takeshi Ohta

Nagoya University/Frontier Observational Research System for Global Change, Nagoya, Japan

Tsutomu Nakamura

Iwate University, Morioka, Japan

Tetsuo Ohata

Institute for Low Temperature Sciences of Hokkaido University/Frontier Observational Research System for Global Change, Sapporo, Japan

Abstract We discuss how snow intercepted by deciduous and coniferous forests affects their water and energy balances. Intensive micrometeorological observations above and below the canopy were carried out in deciduous (DF) and coniferous (CF) forests in the winter of 1996–97 in Sapporo, Hokkaido Island, Japan. Compared with the DF, large amounts of intercepted snow on the canopy of the CF caused a relatively large latent heat flux, which depended on the aerodynamic and canopy resistance. When the intercepted snow on the canopy disappeared from the CF, the sensible and latent heat fluxes were the same at the two sites. Canopy resistance determined the latent heat flux above the DF because the aerodynamic resistance was insignificantly small. The canopy resistance for the DF was correlated with the snow surface temperature. Differences in the amounts of intercepted snow and in the canopy and aerodynamic resistance affected the partition of the input radiative energy above the two canopies. Furthermore, the site of effective energy exchange differed in the CF and DF because the effective energy exchange in the DF occurred at the forest floor.

Keywords aerodynamic and canopy resistance; coniferous forest; deciduous forest; energy balance; snow interception