frequency of favorable meteorological combinations provides a means for considering

meteorological differences as a mitigating factor in observed ozone trends.

More recently, Milanchus, et al. (1998) and Hogrefe, et al. (2000) have described a

procedure which is able to suppress short term variability in observed ozone attributable to

diurnal and synoptic differences (i.e., general differences over a wide area or seasonal

variations) so that underlying base level trends can be discerned.

Perhaps the simplest procedure for normalizing an observed trend for meteorological

differences is to fit a curve through observed values of a trend parameter over the 10 years

preceding the mid-course review. In the following discussion, this is illustrated for the

maximum observed ozone design 9across all monitors in the area) value in each year. The

fitted curve is used in concert with observed maximum design values in each year to calculate

residual values for each year (i.e., the difference between the design value indicated by the

fitted curve and the actual observation). These residuals may be used to account for

variability in meteorology as described in the following paragraphs.

To illustrate, Table 2.2 shows hypothetical data for a 10-year period.

Table 2.2. Example Of Best Fit Design Values And Residuals

n1201 - n1202 - n1203 - n1204 - n1205 - n1206 - n1207 - n1208 - n1209 - n1210 - n1211 - n1212 - n1213 - n1214 - n1215 - n1216 - n1217 - n1218 - n1219 - n1220 - n1221 - n1222 - n1223 - n1224 - n1225 - n1226 - n1227 - n1228 - n1229 - n1230 - n1231 - n1232 - n1233 - n1234 - n1235 - n1236 - n1237 - n1238 - n1239 - n1240 - n1241 - n1242 - n1243 - n1244 - n1245 - n1246 - n12247 - n1248 - n1249 - n1250

castellano: DISPER CUSTIC DESCAR RADIA italiano:

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

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