The ARM3 processor uses "domain mean" parameters to

initialize the entire modeling domain, then computes the

effects of terrain on that flow and finally incorporates the

observations into the terrain modified flow in the vicinity of

the observations. The rationale for this is the supposition

that the domain mean winds, modified for the terrain effects,

better represent the flow in data sparse areas than relatively

distant observations. In the ARM3 processor, the domain mean

wind is defined from the sounding at the "central-most"

station. The domain mean horizontal flow is modified to

account for the effects of slope flows and blocking effects.

The observations are incorporated into the modified mean flow

through a user-specified weighting factor, such that grid cells

near an observation give the observation relatively greater

weight and cells more distant from any observations are

weighted more heavily toward the modified mean flow.

The slope flow amplitude based on

the domainscale temperature lapse rate

f1(t) ±1depending on the time of day

(1 for downslope, 1 for upslope)

f2() variability of the slope speed with slope angle

where:

S the gridpoint wind speed

N the BruntVaisala frequency, defined as:

where gacceleration of gravity &

potential temperature

h the effective terrain height at the gridpoint

3-13

A slope flow vector is calculated for each grid cell and

added to the gridded domain mean (i.e., horizontally uniform)

wind field. The slope flow parameterization does not account

for any nonlinear interaction of slope flow with ambient flow.

For any slope angle, , the speed, S, of the parameterized

slope flow is defined as:

n1251 - n1252 - n1253 - n1254 - n1255 - n1256 - n1257 - n1258 - n1259 - n1260 - n1261 - n1262 - n1263 - n1264 - n1265 - n1266 - n1267 - n1268 - n1269 - n1270 - n1271 - n1272 - n1273 - n1274 - n1275 - n1276 - n1277 - n1278 - n1279 - n1280 - n1281 - n1282 - n1283 - n1284 - n1285 - n1286 - n1287 - n1288 - n1289 - n1290 - n1291 - n1292 - n1293 - n1294 - n1295 - n1296 - n1297 - n1298 - n1299 - n1300

castellano: DISPER CUSTIC DESCAR RADIA italiano:

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

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