Ir. Saunders et Wg. Bailey, RADIATION AND ENERGY BUDGETS OF ALPINE TUNDRA ENVIRONMENTS OF NORTH-AMERICA, Progress in physical geography, 18(4), 1994, pp. 517-538
Recent physical climatology research from North American alpine tundra
environments is summarized and directions for further research sugges
ted. Despite a rather limited database, the essential themes in the ph
ysical climatology of alpine tundra are understood. With numerous perm
utations of slope angle, azimuth and surface types in the alpine zone,
generalizations of alpine tundra radiation and energy balances are ha
rd to define. Several aspects of the alpine tundra radiation budget ar
e very similar to nonalpine ones, such as the controls exerted on net
radiation by atmospheric and surface conditions, and the strong relati
on between global solar radiation and net radiation. The larger inputs
of solar radiation experienced at high altitudes are typically offset
by the moderating effects of orographic clouds. Turbulent energy flux
partitioning is dependent upon both the effects of macroscale weather
and microscale variations in surface soil moisture. Evaporation regim
es tend to be moisture-limiting in the dry tundra and energy-limiting
in wetter alpine/ subalpine meadows, but there are also significant se
ason-to-season variations. Theory suggests that the surface heterogene
ity common to the alpine zone must at times stimulate vigourous horizo
ntal heat advection at a wide range of spatial scales, but the true si
gnificance of this process remains almost entirely undocumented. Sugge
sted future research directions include analyses of the spatial variat
ions of albedo, the role of sloping surfaces, and the relative importa
nce of atmospheric and surface controls on the energy balance.