Short‐wave radiation balance in an urban aerosol layer

1979 ◽  
Vol 17 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Wayne R. Rouse ◽  
Richard L. Bello
Keyword(s):  
Short Wave ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Urban Aerosol ◽  
Aerosol Layer ◽  
Short Wave Radiation

Cloud effects on surface radiation balance at Helheim and Jakobshavn Glaciers (Greenland) using ground-based observations 

2021 ◽  
Author(s):  
Georges Djoumna ◽  
Sebastian H. Mernild ◽  
David Holland
Keyword(s):  
Short Wave ◽  
Surface Radiation ◽  
Radiation Budget ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Short Wave Radiation ◽  
Radiative Fluxes ◽  
Long Wave ◽  
Transmittance Factor ◽  
Cloud Metrics

<p>The surface radiation budget is an essential component of the total energy exchange between the atmosphere and the Earth’s surface. Measurements of radiative fluxes near/on ice surfaces are sparse in the polar regions, including on the Greenland Ice Sheet (GrIS), and the effects of cloud on radiative fluxes are still poorly studied. In this work, we assess the impacts of cloud on radiative fluxes using two metrics: the longwave-equivalent cloudiness, derived from long-wave radiation measurements, and the cloud transmittance factor, obtained from short-wave radiation. The metrics are applied to radiation data from two automatic weather stations located over the bare ground near the ice front of Helheim (HG) and Jakobshavn Isbræ (JI) on the GrIS. Comparisons of meteorological parameters, surface radiation fluxes, and cloud metrics show significant differences between the two sites. The cloud transmittance factor is higher at HG than at JI, and the incoming short-wave radiation in the summer at HG is 50.0 W m−2 larger than at JI. Cloud metrics derived at the two sites reveal   a high dependency on the wind direction. The total cloud radiative effect (CREnet) generally increases during melt season at the two stations due to long-wave CRE enhancement by cloud fraction.  CREnet decreases from May to June and increases afterward, due to the strengthened short-wave CRE. The annually averaged CREnet were 3.0 ± 7.4 W m-2 and 1.9 ± 15.1 W m−2 at JI and HG.  CREnet estimated from AWS indicates that clouds cool the JI and HG during melt season at different rates.</p>

The radiation balance of an apple tree

1972 ◽  
Vol 50 (8) ◽  
pp. 1731-1740 ◽  
Author(s):  
J. T. A. Proctor ◽  
W. J. Kyle ◽  
J. A. Davies
Keyword(s):  
Reflection Coefficient ◽  
Apple Tree ◽  
Short Wave ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Net Radiation ◽  
Short Wave Radiation ◽  
Radiative Processes ◽  
Long Wave ◽  
Long Wave Radiation

Measurements of radiation balance components over an apple tree on 7 days during the growing season showed that 17% of the short-wave radiation was reflected, 17% was lost as long-wave radiation and net radiation amounted to 66%. The reflection coefficient exhibited a characteristic diurnal variation, demonstrating its dependence on solar zenith angle, and varied little over the season. Within the orchard, surfaces ranked in order of increasing reflection coefficient as tree, dry orchard grass, and intertree space.Correlation coefficients relating hourly values of net radiation to incoming short-wave radiation and net short-wave radiation, and net long-wave radiation to net short-wave radiation were highly significant. The heating coefficient was positive and decreased slightly at the end of the season. The long-wave exchange coefficient was negative and exhibited no seasonal trend. This coefficient was closely correlated with screen temperature and may provide a basis for interpretation of surface radiative processes.

scholarly journals The Energy-Balance Structure of the Antarctic Ice Sheet/Atmosphere System as an Index of Antarctic Glaciation

1983 ◽  
Vol 29 (102) ◽  
pp. 240-249
Author(s):  
V. G. Aver’yanov
Keyword(s):  
Phase Transition ◽  
Ice Sheet ◽  
Short Wave ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Short Wave Radiation ◽  
Antarctic Ice Sheet ◽  
Long Wave ◽  
The Antarctic ◽  
Long Wave Radiation

Abstract Mean multi-year values of the components of external mass and energy exchange in the ice sheet, moisture, radiation, and heat balances in the system Antarctic ice sheet/atmosphere have been estimated by various methods. The major features of the above-mentioned balances have been determined as absolute and relative values. For the moisture balance, income of advective moisture is equal to 100%; loss due to accumulation of moisture in the ice sheet is 83%, due to sink into the atmosphere is 15%, and sink from the ice sheet surface is 2%. As for the radiation balance it has been found that income due to radiation at the top of the atmosphere and absorbed by the atmosphere long-wave radiation are 57% and 43%, respectively; loss due to reflected short-wave radiation is 35%, atmospheric long-wave radiation is 78%, and net outgoing radiation from the surface is 9%. Heat budget components have been found as follows: income due to absorbed short-wave radiation is 49%, advection of heat is 40%, and latent heat from phase transition of advective moisture is 11%; loss due to outgoing long-wave radiation is 98%, heat from phase transition of atmospheric moisture is 2%. The Antarctic ice sheet is a vast area of heat sink. Constant negative surface radiation balance and low temperature of the ice sheet suggest that the latter will exist at any small amount of precipitation and, therefore, current glaciation of Antarctica is rather stable.

scholarly journals The Energy-Balance Structure of the Antarctic Ice Sheet/Atmosphere System as an Index of Antarctic Glaciation

1983 ◽  
Vol 29 (102) ◽  
pp. 240-249
Author(s):  
V. G. Aver’yanov
Keyword(s):  
Phase Transition ◽  
Ice Sheet ◽  
Short Wave ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Short Wave Radiation ◽  
Antarctic Ice Sheet ◽  
Long Wave ◽  
The Antarctic ◽  
Long Wave Radiation

AbstractMean multi-year values of the components of external mass and energy exchange in the ice sheet, moisture, radiation, and heat balances in the system Antarctic ice sheet/atmosphere have been estimated by various methods.The major features of the above-mentioned balances have been determined as absolute and relative values. For the moisture balance, income of advective moisture is equal to 100%; loss due to accumulation of moisture in the ice sheet is 83%, due to sink into the atmosphere is 15%, and sink from the ice sheet surface is 2%. As for the radiation balance it has been found that income due to radiation at the top of the atmosphere and absorbed by the atmosphere long-wave radiation are 57% and 43%, respectively; loss due to reflected short-wave radiation is 35%, atmospheric long-wave radiation is 78%, and net outgoing radiation from the surface is 9%. Heat budget components have been found as follows: income due to absorbed short-wave radiation is 49%, advection of heat is 40%, and latent heat from phase transition of advective moisture is 11%; loss due to outgoing long-wave radiation is 98%, heat from phase transition of atmospheric moisture is 2%.The Antarctic ice sheet is a vast area of heat sink. Constant negative surface radiation balance and low temperature of the ice sheet suggest that the latter will exist at any small amount of precipitation and, therefore, current glaciation of Antarctica is rather stable.

scholarly journals Evaluating the Effects of Façade Greening on Human Bioclimate in a Complex Urban Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Britta Jänicke ◽  
Fred Meier ◽  
Marie-Therese Hoelscher ◽  
Dieter Scherer
Keyword(s):  
Heat Stress ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Long Wave ◽  
Building Facades ◽  
Urban Heat ◽  
The Mean ◽  
Human Bioclimate ◽  
Radiant Temperature

The evaluation of the effectiveness of countermeasures for a reduction of urban heat stress, such as façade greening, is challenging due to lacking transferability of results from one location to another. Furthermore, complex variables such as the mean radiant temperature(Tmrt)are necessary to assess outdoor human bioclimate. We observedTmrtin front of a building façade in Berlin, Germany, which is half-greened while the other part is bare.Tmrtwas reduced (mean 2 K) in front of the greened compared to the bare façade. To overcome observational shortcomings, we applied the microscale models ENVI-met, RayMan, and SOLWEIG. We evaluated these models based on observations. Our results show thatTmrt(MD = −1.93 K) and downward short-wave radiation (MD = 14.39 W/m2) were sufficiently simulated in contrast to upward short-wave and long-wave radiation. Finally, we compare the simulated reduction ofTmrtwith the observed one in front of the façade greening, showing that the models were not able to simulate the effects of façade greening with the applied settings. Our results reveal that façade greening contributes only slightly to a reduction of heat stress in front of building façades.

scholarly journals Albedo of Melting Sea Ice in the Southern Beaufort Sea

1971 ◽  
Vol 10 (58) ◽  
pp. 101-104 ◽  
Author(s):  
M.P. Langleben
Keyword(s):  
Sea Ice ◽  
Northwest Territories ◽  
Beaufort Sea ◽  
Ice Cover ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Melting Period ◽  
Fast Ice ◽  
Made In

AbstractTwo Kipp hemispherical radiometers mounted back to back and suspended by an 18 m cable from a helicopter flying at an altitude of about 90 m were used to make measurements of incident and reflected short-wave radiation. The helicopter was brought to a hovering position at the instant of measurement to ensure that the radiometers were in the proper attitude and a photograph of the ice cover was taken at the same time. The observations were made in 1969 during 16 flights out of Tuktoyaktuk, Northwest Territories (lat. 69° 26’N., long. 133° 02’W.) over the fast ice extending 80 km north of Tuktoyaktuk. Values of albedo of the ice cover were found to decrease during the melting period according to the equation A = 0.59 —0.32P where P is the degree of puddling of the surface.

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