55 2160 McElroy, Tom;Midwinter, Clive;Barton, David;Hall, Bob;Kerr, James;Wardle, David ENVIRONMENT CANADA, Dowsview, Ontario, CANADA M3H 5T4 (416) 739-4630 Brewer Ozone Spectrophotometer data at Moffett Field ( 37.42, 122.58) STRAT 1 1 1996 01 30 1996 01 30 0 13 elapsed time in UT seconds from 0000 hours on the day given in DATE Station name 9 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 99 99 99 999 999 999 999 999 999 hour minute second airmass ozone [DU] (Dobson Units) ozone error [DU] (Dobson Units) SO2 [DU] (Dobson Units) SO2 error [DU] (Dobson Units) Number of data points in row 9 0 1 1 1 1 1 1 1 1 1 99 9999 999 999 99999 999 999 999 999 number of observations instrument number station latitude (degrees) station longitude (degrees) station elevation (m) daily mean O3 [DU] (Dobson Units) daily mean O3 error [DU] (Dobson Units) daily mean SO2 [DU] (Dobson Units) daily mean SO2 error [DU] (Dobson Units) 1 *** preliminary data *** 16 The Brewer Ozone Spectrophotometer is a 15-cm focal-length, modified Ebert-Fastie spectrograph which makes rapid, time-multiplexed measurements in the UV-B region of the solar spectrum. A typical direct sun observation is the average of 5 separate observations. If the standard deviation of the measurements is less than 2 DU, the measurement is taken as acceptable. If the standard deviation is larger, it is interpreted as indicating variability of the solar intensity, i.e.: clouds or other optical attenuation. Each of the five ozone measurements which contributes to the average value are composed of 40 short observation samples. A cycle of 2 samples on each of the five wavelengths takes place in about 1.2 seconds. The usual measurement of 20 cycles takes under 30 seconds. Daily averages are calcluted using all good observations and are reported as the last line in the data table. Moffett Field 4 009 37.42 122.58 0.0 321.2 1.6 -1.6 0.1 64112 17 48 32 2.426 315.7 3.7 -1.3 0.9 5 64626 17 57 06 2.330 320.1 1.8 -1.7 0.3 5 65140 18 05 40 2.246 322.3 1.9 -1.5 0.5 5 70089 19 28 09 1.803 339.9 4.8 -0.6 2.0 5