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<br />1\ of': ';. Pt)s <br />... - .. ) .... <br /> <br />80 <br /> <br />UPWINDUI <br /> <br />WIND <br />- <br /> <br />70 <br /> <br /> <br /> <br />NOTATION <br />Variables <br />e:ll vapor pressure <br />T = temperature <br /> <br />The saturation vapor pressure is less; the <br />vapor pressure of the air is the same and <br />therefore the vapor pressure deficit <br />(L\.eel) i. lower than for ca<e (a). and <br />evaporation suppression will occur at <br />point I as follows: <br /> <br />eel 10.7 <br />suppression, = I --= 1- - = .42 <br />enl 18.3 <br /> <br />(3) At point 2 under natural conditions: The <br />air temperature (Tan,) has decreased <br />during the travel time across the water <br />.nd the amount of vapor in the air has <br />increased to e~lnz, Evaporation is now <br /> <br />En' = (eswn -e an,)K <br /> <br />and the vapor pressure deficit (Figure 5) <br />is l:.en,. Evaporation is less than at the <br />upwind point. <br /> <br /> <br /> <br />~ <br />VI <br />.... <br />o <br />:e <br /> <br />.-<-A.-- <br /> <br />60 <br /> <br />, <br /> <br />Subscripts <br />S = $0 turotion <br />0:1 air <br />w = water <br />n = natural <br />C = coaled (mixed I <br />Ae' Y. p. deficit <br />I . paint I. <br />Z. point 2. <br /> <br />I <br />-1. <br />I <br /><> -~lNr- <br />-;1- ~lltt~ I; <br />>-1 -#- cf <br />intc-7.4 I <br /> <br />Madel <br />ratio <br /> <br /> <br />- <br />~ <br />~ <br /> <br />50 <br /> <br />o <br />-30 <br /> <br />-20 <br /> <br />-10 0 10 <br />TEMPERATURE (OC) <br /> <br />20 <br /> <br />30 40 <br /> <br />. Figure S. Comparison of Dalton equation and slmpUfled model computatlollll. <br /> <br />w <br />a:: <br />:) <br />en <br />en <br />w <br />a:: <br />11. <br /> <br />40 <br /> <br />30 <br /> <br />a:: <br />o <br />11. <br />~ <br /> <br />eswn.:!2~~ <br />e,!!.c = 14.7~ <br /> <br />20 <br /> <br />10 <br /> <br />c <br />ean2 = 9.2__ ~ <br />~ac2 = 6.5::::....... - <br />a I=~~ <br />dew <br /> <br />(4) At point 2 under mixed conditions: The <br />air temperature (T ac,) has decreased <br />even more due to the larger gradient at <br />the interface and the amount of vapor has <br />also increased but not as much as in case <br />(c) because of the lowered molecular <br />activity at the surface ofthe cooled water. <br />Therefore eac2 is less than Can2 and evap. <br />oration is: <br /> <br />Ec' = (eswc - eac,)K <br /> <br />The deficit is now l:.ec' and therefore <br />suppression should occur at the downwind point as <br />follows: <br /> <br />l:.ec' 8.2 <br />Supp, = I -- = I -- = .37 <br />l:.ecn 13.1 <br /> <br />Suppression calculated by the model ratios <br />rather than the Dalton equation would he as <br />follow" <br /> <br />11 <br />