4. Ozone and Water Vapor
S. Oltmans (Editor), M. Clark, R. Evans, E. Hackathorn, J. Harris, B. Johnson, G. Koenig,
M. ONeill, D. Quincy, and H. Vömel
4.1. Continuing Programs
4.1.1. Total Ozone Observations
Total ozone observations continued throughout 1996 and 1997 at 15 of the 16 stations that comprise the U.S. Dobson spectrophotometer network (Table 4.1). Of the 16 stations, 5 were operated by CMDL personnel, 5 by the National Weather Service (NWS), 2 are domestic cooperative stations, and 4 are foreign cooperative stations. All stations are either fully or semiautomated. A Brewer ozone spectrophotometer was operated at Boulder during this period.
TABLE 4.1. U.S. Dobson Ozone Spectrophotometer Station Network for 1996-1997
Station |
Period of Record |
Instrument No. |
Agency |
||
Bismarck, North Dakota |
Jan. 1, 1963-present |
33 |
NOAA |
||
Caribou, Maine |
Jan. 1, 1963-present |
34 |
NOAA |
||
Wallops Is., Virginia |
July 1, 1967-present |
38 |
NOAA; NASA |
||
SMO |
Dec. 19, 1975-present |
42 |
NOAA |
||
Tallahassee, Florida |
May 2, 1964-Nov. 30, 1989; Nov. 1, 1992-present |
58 |
NOAA; Florida State University |
||
Boulder, Colorado |
Sept. 1, 1966-present |
61 |
NOAA |
||
Fairbanks, Alaska |
March 6, 1984-present |
63 |
NOAA; University of Alaska |
||
Lauder, New Zealand |
Jan. 29, 1987-present |
72 |
NOAA; NIWA |
||
MLO |
Jan. 2, 1964-present |
76 |
NOAA |
||
Nashville, Tennessee |
Jan. 2, 1963-present |
79 |
NOAA |
||
Perth, Australia |
July 30, 1984-present |
81 |
NOAA; Australian Bureau Meteorology |
||
SPO |
Nov. 17, 1961-present |
82 |
NOAA |
||
Haute Provence, France |
Sept. 2, 1983-present |
85 |
NOAA; CNRS |
||
Huancayo, Peru |
Feb. 14, 1964-Dec. 31, 1992 |
87 |
NOAA; IGP |
||
BRW |
June 6, 1986-present |
91 |
NOAA |
||
Fresno, California |
June 22, 1983-March 13, 1995 |
94 |
NOAA |
||
Hanford, California |
March 15, 1995-present |
94 |
NOAA |
||
The Peruvian station was still out of operation at the end of 1997, although reports indicate a new baseline monitoring station is almost completed. A date for beginning Dobson observations has not yet been established. The Tallahassee station moved from the regional airport to the Florida State University (FSU) campus when the building housing the National Weather Service Office (NSWO) was demolished. The NWSO is temporarily located in the Tallahassee airport terminal until the permanent station is completed on the FSU campus.
Provisional daily total ozone amounts, applicable to local apparent noon for the stations listed in Table 4.1, were archived at the World Ozone and Ultraviolet Radiation Data Centre (WOUDC), 4905 Dufferin Street, Ontario M3H 5T4, Canada, in Ozone Data for the World. Table 4.2 lists the monthly mean of the total ozone amounts measured at the various stations. (Monthly means are made for stations where observations were made on at least 10 days each month.)
TABLE 4.2. Provisional 1996 Monthly Mean Total Ozone Amounts (DU)
Station |
Jan. |
Feb. |
March |
April |
May |
June |
July |
Aug. |
Sept. |
Oct. |
Nov. |
Dec. |
|
1996 |
|||||||||||||
Bismarck, North Dakota |
343 |
367 |
364 |
367 |
346 |
317 |
314 |
292 |
293 |
275 |
301 |
324 |
|
Caribou, Maine |
353 |
373 |
377 |
371 |
391 |
341 |
333 |
312 |
291 |
289 |
289 |
321 |
|
Wallops Is., Virginia |
320 |
340 |
339 |
348 |
338 |
315 |
304 |
301 |
286 |
269 |
282 |
283 |
|
SMO |
240 |
241 |
237 |
247 |
244 |
241 |
245 |
250 |
256 |
266 |
257 |
253 |
|
Tallahassee, Florida |
285 |
303 |
312 |
313 |
317 |
- |
- |
- |
- |
- |
267 |
256 |
|
Boulder, Colorado |
328 |
324 |
337 |
329 |
305 |
294 |
286 |
279 |
281 |
269 |
265 |
294 |
|
UAF-GI, Alaska |
- |
[377] |
384 |
379 |
356 |
339 |
311 |
291 |
309 |
[318] |
- |
- |
|
Lauder, New Zealand |
259 |
265 |
262 |
273 |
289 |
306 |
329 |
368 |
356 |
360 |
344 |
306 |
|
MLO |
245 |
250 |
268 |
276 |
280 |
276 |
267 |
261 |
256 |
252 |
239 |
237 |
|
Nashville, Tennessee |
309 |
326 |
333 |
333 |
300 |
307 |
306 |
296 |
285 |
272 |
272 |
284 |
|
Perth, Australia |
272 |
260 |
- |
- |
- |
- |
- |
302 |
310 |
313 |
303 |
280 |
|
SPO |
266 |
246 |
[238] |
[222] |
[234] |
[230] |
[193] |
- |
142 |
176 |
283 |
||
Haute Provence, France |
338 |
363 |
337 |
355 |
349 |
336 |
334 |
307 |
317 |
286 |
290 |
303 |
|
Huancayo, Peru |
Station closed |
||||||||||||
BRW |
- |
- |
394 |
420 |
362 |
338 |
315 |
296 |
293 |
[314] |
- |
- |
|
Hanford, California |
307 |
320 |
322 |
321 |
316 |
314 |
301 |
291 |
287 |
280 |
266 |
275 |
|
1997 |
|||||||||||||
Bismarck, North Dakota |
349 |
353 |
355 |
371 |
329 |
325 |
309 |
293 |
274 |
283 |
297 |
333 |
|
Caribou, Maine |
376 |
363 |
382 |
381 |
359 |
347 |
332 |
318 |
291 |
289 |
303 |
334 |
|
Wallops Is., Virginia |
294 |
304 |
317 |
339 |
330 |
323 |
319 |
304 |
294 |
291 |
292 |
308 |
|
SMO |
[244] |
- |
- |
241 |
241 |
235 |
231 |
238 |
244 |
252 |
261 |
250 |
|
Tallahassee, Florida |
[266] |
300 |
[297] |
305 |
299 |
297 |
289 |
285 |
291 |
- |
|||
Boulder, Colorado |
310 |
323 |
310 |
348 |
315 |
302 |
298 |
284 |
273 |
280 |
293 |
310 |
|
UAF-GI, Alaska |
- |
[403] |
386 |
397 |
[378] |
327 |
319 |
280 |
282 |
[328] |
- |
- |
|
Lauder, New Zealand |
279 |
- |
265 |
271 |
276 |
297 |
306 |
324 |
324 |
326 |
317 |
299 |
|
MLO |
224 |
250 |
- |
- |
265 |
273 |
265 |
259 |
256 |
253 |
254 |
246 |
|
Nashville, Tennessee |
292 |
295 |
291 |
322 |
319 |
[323] |
301 |
288 |
280 |
282 |
297 |
303 |
|
Perth, Australia |
258 |
251 |
270 |
261 |
257 |
261 |
275 |
288 |
307 |
298 |
292 |
278 |
|
SPO |
277 |
275 |
- |
[260] |
[265] |
[268] |
[265] |
[247] |
- |
136 |
203 |
274 |
|
Haute Provence, France |
330 |
318 |
322 |
328 |
333 |
354 |
339 |
312 |
293 |
280 |
291 |
312 |
|
Huancayo, Peru |
Station closed |
||||||||||||
BRW |
- |
[401] |
390 |
388 |
374 |
335 |
315 |
287 |
288 |
- |
- |
- |
|
Handford, California |
291 |
304 |
294 |
328 |
307 |
317 |
308 |
[295] |
[272] |
284 |
279 |
304 |
|
Monthly mean ozone values in square brackets are derived from observations made on fewer than 10 days per month.
An analysis of this data was made to ascertain the trend in total ozone and the results published by Komhyr et al. [1997]. The resultant trends are summarized in Table 4.3.
TABLE 4.3. Annual and Seasonal Trends (in % per Decade) Derived From Re-Evaluated Dobson Spectrophotometer Total Ozone Data Obtained During 1979-1996 at 16 NOAA and Cooperative Station, Allowing for Solar and QBO Equatorial Wind Effects
Annual |
Dec.-Feb. |
March-May |
June-Aug. |
Sept.-Nov. |
||||||||||||||
Station |
Latitude |
Longitude |
Trend |
Std. Error |
Trend |
Std. Error |
Trend |
Std. Error |
Trend |
Std. Error |
Trend |
Std. Error |
||||||
Caribou, Maine* |
46.9°N |
68.0°W |
-3.75 |
0.64 |
-4.46 |
1.54 |
-4.67 |
1.02 |
-3.21 |
0.71 |
-2.28 |
1.02 |
||||||
Bismarck, North Dakota* |
46.8°N |
100.8°W |
-2.86 |
0.59 |
-2.50 |
1.33 |
-4.81 |
0.93 |
-2.00 |
0.86 |
-1.70 |
0.88 |
||||||
Boulder, Colorado* |
40.0°N |
105.3°W |
-3.34 |
0.57 |
-2.77 |
1.20 |
-5.94 |
1.11 |
-2.51 |
0.65 |
-1.51 |
0.83 |
||||||
Wallops Is., Virginia* |
37.9°N |
75.5°W |
-3.52 |
0.66 |
-4.01 |
1.30 |
-4.46 |
1.19 |
-3.05 |
0.80 |
-2.29 |
1.04 |
||||||
Fresno, California* |
36.8°N |
86.6°W |
-3.15 |
0.66 |
-3.46 |
1.16 |
-4.65 |
1.25 |
-2.46 |
0.86 |
-1.72 |
1.13 |
||||||
Tallahassee, Tennessee* |
119.7°W |
-3.74 |
1.17 |
-2.81 |
1.72 |
-4.27 |
2.53 |
-3.70 |
1.48 |
-4.14 |
1.15 |
|||||||
Nashville, Tennessee* |
36.3°N |
84.3°W |
-3.41 |
0.69 |
-2.10 |
1.21 |
-4.36 |
1.30 |
-3.36 |
1.10 |
-3.67 |
1.21 |
||||||
MLO* |
19.5°N |
155.6°W |
-0.37 |
0.70 |
-0.91 |
1.06 |
-0.39 |
1.28 |
-0.17 |
0.86 |
-0.02 |
0.68 |
||||||
SMO* |
14.3°S |
170.6°W |
-1.30 |
0.61 |
-1.37 |
0.85 |
-1.75 |
0.76 |
-1.24 |
0.99 |
-0.86 |
0.81 |
||||||
Huancayo, Peru |
12.1ºS |
75.3°W |
-1.85 |
0.43 |
-0.63 |
0.63 |
-1.29 |
0.68 |
-3.74 |
0.81 |
-1.64 |
0.73 |
||||||
Perth, Australia |
31.9ºS |
116.0°E |
-0.79 |
0.66 |
-2.79 |
0.84 |
-0.80 |
1.35 |
0.96 |
1.52 |
-0.53 |
0.98 |
||||||
Lauder, New Zealand§ |
45.0ºS |
169.7°W |
0.93 |
1.03 |
-3.34 |
1.12 |
-0.58 |
1.79 |
5.02 |
2.34 |
2.51 |
2.13 |
||||||
Poker Flat, Alaska¥ |
65.1ºN |
147.5°W |
-5.61 |
2.13 |
- |
- |
-8.70 |
3.20 |
-4.03 |
1.92 |
-1.27 |
4.65 |
||||||
BRW*¥ |
71.3ºN |
156.6°W |
-3.25 |
1.14 |
- |
- |
-4.40 |
1.61 |
-3.01 |
1.19 |
-1.14 |
2.36 |
||||||
Haute Provence, France |
43.9ºN |
5.7°E |
-4.31 |
1.08 |
-5.26 |
2.33 |
-7.96 |
1.90 |
-2.22 |
1.26 |
-0.25 |
1.43 |
||||||
SPO*¶ |
90ºS |
24.8°W |
-12.18 |
2.20 |
-7.09 |
1.23 |
-5.90 |
1.81 |
-10.20 |
1.93 |
-19.58 |
4.34 |
||||||
Average over first five stations (1979-1996) |
-3.32 |
-12.18 |
2.20 |
-7.09 |
1.23 |
-2.64 |
-1.90 |
|||||||||||
Average over first five stations (1979-1995) |
||||||||||||||||||
Average over first five stations (1979-1994) |
||||||||||||||||||
Estimated trend uncertainties are standard errors (s.e.) where 2 (s.e.) ~95% confidence interval.
*Period of record: 1979-1996
Period of record: 1984-1996
Period of record: 1979-1992
§Period of record: 1987-1996
¥For Poker Flat and BRW the annual trend estimates are based on March through October data only, while September-November trend estimates are based on September-October data only.
¶For SPO the annual trend is based on daylight (October 15 through February) data only. The March-November. trend is for October 15-31 and November data only.