3.2.3.1

Short Term ModelOptions.The syntax and type of the Short Term AVERTIME keyword are summarized below:

Syntax:CO AVERTIME Time1 Time2 Time3 Time4

MONTH PERIODor

ANNUAL

Type:Mandatory, Non‑repeatable

where the parameters Time1 . . . Time4 refer to the user‑specified short term averaging periods of 1, 2, 3, 4, 6, 8, 12, or 24 hours, the secondary keyword

MONTHrefers to monthly averages (for calendar months), the secondary keywordPERIODrefers to the average for the entire data period, and the secondary keywordANNUALrefers to an annual average. Any of the short term averaging periods listed above may be selected for a given run, up to the maximum number of short term averages set in the computer code by the parameter NAVE. The initial values for NAVE are given in Sections 2.3 and 4.2.2. The monthly averages are treated as short term averages, and selection of theMONTHaverage counts toward the limit of NAVE. Since the monthly averages are treated as short term averages, the user can select appropriate output options, such as the second highest values by receptor, on the OUtput pathway. The user may specify either thePERIODkeyword or theANNUALkeyword, but not both. For concentration calculations, thePERIODandANNUALkeywords produce the same results. They both may be used to calculate the annual average for a full year of meteorological data, or to calculate the period average for a period other than a year. For deposition calculations, thePERIODkeyword will provide a total deposition flux for the full period of meteorological data that is modeled in units of g/m^{2}, including multiple-year data files, whereas theANNUALkeyword will provide an annualized rate of the deposition flux in units of g/m^{2}/yr. For meteorological periods of less than a year, theANNUALdeposition rate is determined by dividing by the length of the period in years. For meteorological periods of longer than a year, the model will assume that full years of data are provided and divide by the number of years, rounded to the nearest whole number. The treatment of short term averages with multiple-year data files is comparable to their treatment when the CO MULTYEAR option is used (see Section 3.2.11).

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APLICACIONES castellano: DIS CUS DES RAD english: DIS CUS DES RAD

português: DIS CUS DES RAD italiano: DIS CUS DES RAD