Hey any help would be great! The following data was collected in Lake Hefner, Ok
ID: 159846 • Letter: H
Question
Hey any help would be great!
The following data was collected in Lake Hefner, Oklahoma, on September 10th 2013. Calculate the free water evaporation rate (cm/day) by
(A) Mass transfer,
(B) Energy Balance
(C) Combination Approaches
Average air temperature 2 m above water surface (Ta, C): 22.3
Average relative humidty 2 m above the water surface (Wa): 0.68
Average air speed m above the water surface (Va, m/s): 2.16
Average temperature of the water surface (Ts, C): 23.7
Average atmospheric pressure on lake surface (P, kPa) : 97.3
Daily short wave radiation absorbed by the lake surface (Kin ): 16.2 MJ/(m2 day) = 1620
J/(cm 2 day) average albedo of the water surface (aw= .057
Daily long wave radiation absorbed by the lake surface (L at ) : 30.6 MJ/(m2day)=3060
J/ (cm2 day) emissivity of water w = .97
Explanation / Answer
Amount of evaporated water persecond = evaporation coefficient *water surface area (humidity ratio in saturated water - humidity ratio in air )/3600
For calculating the coefficient we use (25+19*velocity of air above the water surface )
By energy equation :- E= 1/LvROHwA*(Rn-H-G)
For aerodynamic method Ea =B(eas-ea)
By combined method E= 1.3 delta/delta+gama *Er
These are the equations to calculate the evaporation rate