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854 JOURNAL OF APPLIED METEOROLOGY Vo~.~mml$The MicrocllmRtes of the Arctic Tundra GUNTER WELLER AND BJoalq HOLMGRENGeophysical Instilul~, Uni~-rsily of A tas~a, Fairbanks 00701(Manuscript receiYed 13 November 1973, in revised form 24 July 1974) ABSTRACT The microclimates of the arctic tundra at Barrow, Alaska, are described/or the near-surface terrestria~layers Ln
854 JOURNAL OF APPLIED METEOROLOGY Vo~.~mml$The MicrocllmRtes of the Arctic Tundra GUNTER WELLER AND BJoalq HOLMGRENGeophysical Instilul~, Uni~-rsily of A tas~a, Fairbanks 00701(Manuscript receiYed 13 November 1973, in revised form 24 July 1974) ABSTRACT The microclimates of the arctic tundra at Barrow, Alaska, are described/or the near-surface terrestria~layers Ln
June 1995. In the 0.66- μ m visible image ( Fig. 1a ), both clouds, apparent from the shadows that they cast, and frozen ponds appear bright because their reflectances are higher than those of the surrounding arctic tundra. The 11- μ m IR image in Fig. 1b displays that clouds and frozen ponds both appear to be very dark due to their cold temperatures. Using traditional threshold techniques it is almost impossible in such images to discriminate clouds from frozen ponds. In the past, many cloud
June 1995. In the 0.66- μ m visible image ( Fig. 1a ), both clouds, apparent from the shadows that they cast, and frozen ponds appear bright because their reflectances are higher than those of the surrounding arctic tundra. The 11- μ m IR image in Fig. 1b displays that clouds and frozen ponds both appear to be very dark due to their cold temperatures. Using traditional threshold techniques it is almost impossible in such images to discriminate clouds from frozen ponds. In the past, many cloud
(MODIS) and 2) to assess the accuracy of MODIS-derived surface temperatures by comparison with Thermochron-derived surface measurements. Here, we consider three Arctic domains that have different thermal characteristics: 1) snow-covered sea ice, 2) snow-covered tundra in a complex “built environment,” defined as an area with human-made structures and energy-use networks, and 3) snow-covered tundra in a homogeneous environment. Several different types of temperature sensors were used to collect an
(MODIS) and 2) to assess the accuracy of MODIS-derived surface temperatures by comparison with Thermochron-derived surface measurements. Here, we consider three Arctic domains that have different thermal characteristics: 1) snow-covered sea ice, 2) snow-covered tundra in a complex “built environment,” defined as an area with human-made structures and energy-use networks, and 3) snow-covered tundra in a homogeneous environment. Several different types of temperature sensors were used to collect an
to AVHRR data collected in the Arctic, and tested against ground-based measurements. In section 5 , algorithms to retrieve optical depth and effective radius of liquid water clouds are described, validated using in situ irradiance measurements, and applied to AVHRR images for three different arctic surface types: ocean, tundra, and snow. A summary is provided in section 6 . Satellite and field data in the arctic The National Oceanic and Atmospheric Administration (NOAA) polar orbiter data used
to AVHRR data collected in the Arctic, and tested against ground-based measurements. In section 5 , algorithms to retrieve optical depth and effective radius of liquid water clouds are described, validated using in situ irradiance measurements, and applied to AVHRR images for three different arctic surface types: ocean, tundra, and snow. A summary is provided in section 6 . Satellite and field data in the arctic The National Oceanic and Atmospheric Administration (NOAA) polar orbiter data used
OCXOB~-R1978 MING-KO WOO AND 'PHILIP MARSH 1537Analysis of Error in the Determination of Snow Storage for Small High Arctic Basins~ MING-KO WOO AND PHILIP MARSHDepartment of Geography, McMaster University, Hamilton, Ontario, Canada LSS 4K1(Manuscript received 14 November 1977, in final form 1 February 1978) ABSTRACT Water balance studies in tundra regions
OCXOB~-R1978 MING-KO WOO AND 'PHILIP MARSH 1537Analysis of Error in the Determination of Snow Storage for Small High Arctic Basins~ MING-KO WOO AND PHILIP MARSHDepartment of Geography, McMaster University, Hamilton, Ontario, Canada LSS 4K1(Manuscript received 14 November 1977, in final form 1 February 1978) ABSTRACT Water balance studies in tundra regions
effect on the albedos at this site, particularly under cloudy conditions. 1. Introduction Tundra vegetation covers approximately 6 000 000km2 of the earth's surface and occurs in a zone lyingbetween the northern limit of the boreal forest and thepermanent ice caps (Lewis and CaHaghen 1976). InAlaska, there are 220 000 km2 of tundra vegetationnorth of the Arctic Circle, and approximately 80% ofthis area is covered by tussock tundra (Miller et at.1984). Tussock tundra is dominated by tussock sedge
effect on the albedos at this site, particularly under cloudy conditions. 1. Introduction Tundra vegetation covers approximately 6 000 000km2 of the earth's surface and occurs in a zone lyingbetween the northern limit of the boreal forest and thepermanent ice caps (Lewis and CaHaghen 1976). InAlaska, there are 220 000 km2 of tundra vegetationnorth of the Arctic Circle, and approximately 80% ofthis area is covered by tussock tundra (Miller et at.1984). Tussock tundra is dominated by tussock sedge
surface heat balance equation. J. Appl. Meteor., 12, 1069-1072.Leahy, D. H., and J. P. Friend, 1971: A model for predicting the depth of the mixing layer over an urban heat island with applications to New York City. J. Appl. Meteor., 10, 1162 1173.Lord, N. W., M. A. Atwater and J. P. Pandolfo, 1974: Influence of the interaction between tundra thaw lakes and surrounding land. Arctic Alpine Res., 6, 143-150.McElroy, J. L., 1971: An experimental and numerical investiga~ tion of the
surface heat balance equation. J. Appl. Meteor., 12, 1069-1072.Leahy, D. H., and J. P. Friend, 1971: A model for predicting the depth of the mixing layer over an urban heat island with applications to New York City. J. Appl. Meteor., 10, 1162 1173.Lord, N. W., M. A. Atwater and J. P. Pandolfo, 1974: Influence of the interaction between tundra thaw lakes and surrounding land. Arctic Alpine Res., 6, 143-150.McElroy, J. L., 1971: An experimental and numerical investiga~ tion of the
minimumtemperature is below -18C on 50% of the days. Thelowest temperature on record is --49C and the highest25C. Because of the proximity of the Arctic Ocean, thetemperature regime exhibits a modified maritime pattern when the winds are from the 280- sector between210- and 130-, and more continental characteristicswhen the winds are off the tundra. This influence isparticularly striking during the summer months whenthe sea ice generally retreats some 40 to 400 km fromthe continental margins. Weaver (1970
minimumtemperature is below -18C on 50% of the days. Thelowest temperature on record is --49C and the highest25C. Because of the proximity of the Arctic Ocean, thetemperature regime exhibits a modified maritime pattern when the winds are from the 280- sector between210- and 130-, and more continental characteristicswhen the winds are off the tundra. This influence isparticularly striking during the summer months whenthe sea ice generally retreats some 40 to 400 km fromthe continental margins. Weaver (1970
Wrangell Mountains, Alaska. Ph.D. dissertation, University of Michigan, 314 pp.Terjung, W., 1969: Energy and moisture balance of an alpine tundra in mid-July. Arctic Alpin~ Res., 1~ 247-266.Weller, G., et al., 1972: The tundra microclimate during snow melt at Barrow, Alaska. Arctic, 25, 291-300.Williams, L. D., R. G. Barry and J. T. Andrews, 1972: Applica tion of computed global radiation for areas of high relief. J. Appl. Meteor., 11, 526-533.
Wrangell Mountains, Alaska. Ph.D. dissertation, University of Michigan, 314 pp.Terjung, W., 1969: Energy and moisture balance of an alpine tundra in mid-July. Arctic Alpin~ Res., 1~ 247-266.Weller, G., et al., 1972: The tundra microclimate during snow melt at Barrow, Alaska. Arctic, 25, 291-300.Williams, L. D., R. G. Barry and J. T. Andrews, 1972: Applica tion of computed global radiation for areas of high relief. J. Appl. Meteor., 11, 526-533.
-shrubs, grasses,mosses and lichens of the tundra grow. In the case ofa cooling, the trees of taiga die when exposed to temperatures lower than the acceptable range for theirhabitat; the roots decay and wind topples the trees.The arctic plants take over, that is, the tundra expandssouthward.We now simulate the climate sensitivity to the solarconstant by placing the taiga/tundra ecocline at thelatitude where the average surface temperature is -5°C.The results are presented in Table 2, columns 8 and9. The
-shrubs, grasses,mosses and lichens of the tundra grow. In the case ofa cooling, the trees of taiga die when exposed to temperatures lower than the acceptable range for theirhabitat; the roots decay and wind topples the trees.The arctic plants take over, that is, the tundra expandssouthward.We now simulate the climate sensitivity to the solarconstant by placing the taiga/tundra ecocline at thelatitude where the average surface temperature is -5°C.The results are presented in Table 2, columns 8 and9. The
