SEBAL - Dca.ufcg.edu.br

where;⎛ 2 ⎞⎜1+ x(0.1m)Ψ = 2⎟h( 0.1m)ln⎜ 2 ⎟(36b)⎝⎠x ( 200m)0.25⎛ 200 ⎞= 1 − 16(37a)⎜⎝L⎟⎠x ( 2m)0.25⎛ 2 ⎞ = 1 − 16(37b)⎜⎝0.25⎟L ⎠⎛ 0.1⎞x( 0.1m)= ⎜1− 16 ⎟⎝ L ⎠(37c)If L>0; stable conditions:⎛ 2 ⎞ψm(200m)= −5⎜⎟⎝ L ⎠(38)⎛ 2 ⎞ψ h( 2m) = −5⎜⎟⎝ L ⎠(39a)⎛ 0.1⎞ψ h( 0.1m) = −5⎜⎟⎝ L ⎠(39b)If L=0; neutral conditions: ψ m and ψ h = 09. A corrected value for the friction velocity (u * ) is now computed for each successiveiteration as:u*uk200= (40)⎛ 200 ⎞ln⎜ − Ψz⎟⎝ 0m⎠m (200m)where; u 200 is the wind speed at 200 meters (m/s), k is von Karman’s constant (0.41),z om is the roughness length for each pixel (m), and ψ m(200m) is the stability correction formomentum transport at 200 meters (equation 35 or 38). This computation is carried outin model F14.10. A corrected value for the aerodynamic resistance to heat transport (r ah ) is nowcomputed during each iteration as:33