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 29 1996 01 29 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 11 009 37.42 122.58 0.0 313.7 6.4 -2.8 0.9 64716 17 58 36 2.333 302.2 2.5 -1.2 0.6 5 65229 18 07 09 2.249 307.1 2.5 -2.0 0.7 5 66442 18 27 22 2.088 313.0 3.3 -1.0 1.6 5 72796 20 13 16 1.749 305.3 3.1 1.5 1.1 5 73524 20 25 24 1.747 315.4 3.6 -2.9 0.8 5 73742 20 29 02 1.747 318.8 2.8 -3.7 0.9 5 74760 20 46 00 1.758 318.1 0.9 -3.5 0.3 5 75273 20 54 33 1.768 316.6 1.9 -3.1 0.3 5 76001 21 06 41 1.788 318.3 1.6 -3.6 0.4 5 77016 21 23 36 1.828 316.8 0.9 -2.7 0.4 5 77531 21 32 11 1.854 316.5 1.4 -3.2 0.4 5