On the impact of non-sphericity and small-scale surface roughness on the optical properties of hematite aerosols

2011 ◽  
Vol 112 (11) ◽  
pp. 1815-1824 ◽  
Author(s):  
Michael Kahnert ◽  
Timo Nousiainen ◽  
Päivi Mauno
Keyword(s):  
Surface Roughness ◽  
Optical Properties ◽  
Small Scale ◽  
The Impact ◽  
Scale Surface

scholarly journals Effect of small-scale snow surface roughness on snow albedo and reflectance

2021 ◽  
Vol 15 (2) ◽  
pp. 793-820
Author(s):  
Terhikki Manninen ◽  
Kati Anttila ◽  
Emmihenna Jääskeläinen ◽  
Aku Riihelä ◽  
Jouni Peltoniemi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Laser Scanner ◽  
Small Scale ◽  
Snow Surface ◽  
Roughness Effects ◽  
Bidirectional Reflectance Factor ◽  
Reflectance Factor ◽  
Bulk Volume ◽  
The Impact ◽  
Scale Surface

Abstract. The primary goal of this paper is to present a model of snow surface albedo accounting for small-scale surface roughness effects. The model is based on photon recollision probability, and it can be combined with existing bulk volume albedo models, such as Two-streAm Radiative TransfEr in Snow (TARTES). The model is fed with in situ measurements of surface roughness from plate profile and laser scanner data, and it is evaluated by comparing the computed albedos with observations. It provides closer results to empirical values than volume-scattering-based albedo simulations alone. The impact of surface roughness on albedo increases with the progress of the melting season and is larger for larger solar zenith angles. In absolute terms, small-scale surface roughness can decrease the total albedo by up to about 0.1. As regards the bidirectional reflectance factor (BRF), it is found that surface roughness increases backward scattering especially for large solar zenith angle values.

Experimental Modeling of Wind-Driven Bin-by-Bin Resuspension Factors of Freshly Fallen Radionuclides After an Energetic Release From a Radiological Dispersal Device

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Sharman Perera ◽  
Edward Waller ◽  
Ali Akhtar
Keyword(s):  
Surface Roughness ◽  
Wind Tunnel ◽  
Lanthanum Oxide ◽  
Experimental Modeling ◽  
Small Scale ◽  
Particle Sizes ◽  
Particle Resuspension ◽  
Measuring Devices ◽  
Radiological Dispersal ◽  
The Impact

Small-scale experiments were carried out to characterize the resuspension factor of radioactive lanthanum oxide powder in an environmentally controlled wind tunnel, with the majority using particle sizes less than 10 μm in order to assess the impact of wind resuspension stresses and surface roughness conditions on resuspension. Operational principles of the measuring devices used in the radionuclide resuspension experiments and corresponding uncertainties are discussed. The average bin-by-bin particle resuspension factors (ki) for particle sizes, in the range of 0.25–7.00 μm and 7.00–12.5 μm for downwind fallout locations, were calculated and are reported here as 1.14×10−3 1/m and 4.39×10−2 1/m, respectively.

Sea ice small-scale surface roughness estimation based on AMSR-E observations

2013 ◽  
Vol 34 (12) ◽  
pp. 4425-4448 ◽  
Author(s):  
Haibo Bi ◽  
Xiaofeng Yang ◽  
Ziwei Li ◽  
Xuan Zhou
Keyword(s):  
Surface Roughness ◽  
Sea Ice ◽  
Small Scale ◽  
Surface Roughness Estimation ◽  
Scale Surface
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