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<br />e <br /> <br />e <br /> <br />e <br /> <br />EM 111&-2-1406 <br />5 Ian 60 <br /> <br />different levels than those specified in equation 20, it is necessary to adjust them to the standard <br />levels, This may be accomplishcd by use of the power law variation of these elements, as set forth <br />in paragraphs 2-08 and 2-09. The correction factors are: <br /> <br />(Air tcmperature) C.F,a=1.47 Za-I/' <br /> <br />(Wind) C.F.w=1.92 Z,-l/, <br /> <br />. <br /> <br />where Za and Z, are the heights of measurement in feet above the snow surface, of thc air tempera- <br />ture and wind speed, respectively. Thc correction factor for air tempcrature "ould be applied to <br />the difference betwccn snow surface temperature and air temperature at the level of measurement <br />(for a melting snowpack, Ta~32). For partly forested areas, wind values to be applied are those <br />which are representative of the opcn portions of the basin. The reductions in wind in the forested <br />portions are accounted for in selcction of the basin convection-condensation melt coefficient, k. <br />The coefficients given in equations 20 and 21 represent mean snowmelt rates in inches per day <br />(24 hours), In some cases, it may be necessary to subdivide the day into smaller time increments <br />for computing snowmelt. This may be done by applying mean values of air temperature, wind and <br />precipitation for the particular subperiod, and dividing the computed melt by the number of sub- <br />periods per day, <br /> <br />11 <br />