This page gives information about ozone at Halley, Rothera and Vernadsky/Faraday stations and was last updated on 2004 June 22.
The final spring warming took place in early December and brought to an end the 2003 ozone hole. Ozone values peaked in December and then slowly declined towards the normal autumn minimum. They are now rising slightly in the normal winter circulation pattern. Ozone values are generally slightly higher around Antarctica, with lower values over the continent. They are generally close to the long term normal.
Ozone levels dropped quickly during August and September with the return of sunlight. Depletion exceeded 60% in places, with some areas registering near 100 DU by the end of September. The ozone hole grew rapidly and peaked in size at around 28 million square kilometres (roughly twice the size of Antarctica) in mid September. It was larger than previously for the time of year in August and early September, and the maximum size equalled the all time record. Ozone levels rose during October and briefly exceeded ozone hole limits in mid November. Values dropped again giving an ozone hole area of a few million square kilometres in late November. The final spring warming took place in early December, however this left many parts of Antarctica down 10 - 20% on the long term normal. The tip of South America and the Falkland Islands suffered significant ozone depletion over October 4 - 9.
Note: The ozone hole is usually largest in early September and deepest in late September to early October. September 16 is world ozone day. Prior to the formation of ozone holes, ozone values were normally at their lowest in the autumn (ie March).
Halley - Total ozone: Note that routine ozone observations prior to late September are of low accuracy due to the low solar elevation. Some
measurements made using weak moonlight in early August show ozone values around 220 DU
(25% depletion). Routine solar observations show values declining
from late August and by mid September they had dropped to around 130
DU (55% depletion). They slowly declined to around
125 DU in early October (60% depletion). Mean values rose rapidly to reach around
240 DU in late October (30% depletion). Daily values dropped to 160 DU in
mid November (mean values 210 DU, 40% depletion) and then rose to reach 300 DU in
mid December (15% depletion). They are slowly falling and had reached around 240 DU
(20% depletion) by the time the observing season ended in mid April. This figure
[updated 2004 May 6] shows the variation in 2003 - 2004 and the normal for 1957-72.
Rothera - Total ozone: In early June values began to fall,
reaching around 250 DU by the end of July. Values began to fall rapidly in August,
reaching 110 DU by early October, with day to day variation around 30 DU.
Mean values rose rapidly in October to 310 DU, and remained near this level in
early November, with a larger day to day
variation around 50 DU and a peak of 350 DU. In mid November mean values
dropped again, reaching 230 DU in late November (daily minimum 169 DU on the
26th), returning to around 290 DU in December. Values in 2004 fell slowly from 290 DU
at the beginning of the year to 270 DU at the equinox and have now risen to
around 280 DU. This figure [updated 2003 May 12] shows the variation in
2002, when the ozone hole split into two, and this figure [updated 2004 May 6] the variation in 2004.
Rothera - Ozonesondes: In late September, ozonesonde flights from Rothera showed substantial depletion between 12 and 24 kilometres, with 100% depletion at times at some
altitudes between 15 and 21 km. A flight on October 22 still showed substantial depletion between 12 and 19 km, but ozone levels
were much
higher above 19.5 km (50hPa). Our final ozonesonde flight (October 30)
shows a peak ozone partial pressure of 23 mPa at 19 km, however there is still
significant depletion between 11 and 16 km. Animation of the
ozonesonde flight results [note that although the ozone scale on these graphs
reads nanobars, it should read mPa].
Vernadsky - Total ozone: Observations show
ozone values declining from around 270 DU (10% depletion) in late July to around 130 DU
(60% depletion) at the end of September. Values rose rapidly to 290
DU in the first half of October and then more slowly to peak at around 340 DU (5%
depletion) in
early November, but with large day to day variation. They
declined to around 250 DU (35% depletion) in late November (with a daily minimum
of 211 DU on the 26th) before rising to around 300 DU (15% depletion) in early
December. They then slowly fell, to reach around 270 DU (10% depletion) in early
March before rising towards 290 DU by the end of April.
The daily mean of 160 DU on August 25
was
the second lowest recorded for the month. The monthly mean for September was the
second lowest on record. This figure [updated
2004 May 6]
shows the variation in 2003 - 2004 and the normal for 1957-72.
Temperature and PSCs: The 100 hPa pressure
level is near the base of the ozone layer, but is reached by most radiosonde
flights. The temperature of the ozone
layer above Antarctica rose rapidly in late November to summer
values. It is now cooling, but the temperature remains far too warm for PSCs to exist.
Halley reported sighting of PSC on July 28.
They photographed clouds which appear to have similarities to noctilucent clouds
on August 8 (image1 / image2).
More clouds were photographed on September 16. Vernadsky reported nacreous clouds on August
2, September 21, 23. Rothera photographed some nacreous clouds on July 16.
Halley - 100 hPa temperature: During October the 100 hPa temperature at Halley rose from winter values near -83°C to
-64°C. It paused for the first half of November, but then rose to reach
-46°C in early December. Values slowly increased to a peak of -43°C in mid
December, some 2° below the normal. By early January they had
declined to -45°C, some 5° below the normal, but then rose to -42°C in mid
month, a little below the normal of -40°C. They slowly fell until mid
March, when there was a more rapid decline to -55°C by the end of the month.
They are now around -58°C. The 100 hPa temperature was
generally been below the normal from August to February. This figure [updated
2004 May 6] shows
the variation at Halley in 2003 - 2004 and the normal for 1957-72.
Peninsula - 100 hPa temperature: The 100
hPa temperature along the Antarctic Peninsula declined from
-76°C at the beginning of August to -79°C at the beginning of October, with variation
of a few degrees on a 20 day period. During October it rose rapidly to
reach near normal values around -51°C by the end of the month. It
remained near this value, but fell to -57°C in the last week of the month
before rising to around near, though a little below, the normal at -44°C in mid
December. The temperature slowly fell to around -47°C early in January,
but returned to near normal by mid month. Since then it has slowly fallen,
remaining a little below the normal. This figure [updated 2004
May 6] (compiled
from flights from Marambio and Rothera) shows the
variation in 2003 - 2004 and the normal for 1957-72. There has been a radiosonde programme of
several flights per week
at Rothera since 2003 March, increasing to daily flights for the QUOBI project
from mid June to mid October 2003.
Satellite: Satellite imagery gives a global perspective on the ozone hole. TOVS (which can image during the polar night) and TOMS currently have significantly different calibrations, with TOVS showing lower readings than TOMS. TOMS values are close to ground-based values. Different satellite operators use slightly different criteria for defining the area of the ozone hole and hence give slightly different areas. Overall it is clear that this year we had one of the largest ozone holes on record. The ozone hole or its edge crossed the tip of South America and the Falkland Islands on September 6/7, 20/21, 27-30 and October 4-9. This region was also affected by areas of low ozone tropical air at the end of March and again around April 24 - 25, and May 4 -5. Our 2003/2004 Antarctic ozone hole movie [updated 2004 May 6] is produced from TOMS images. TOMS was out of action between November 27 and December 3. The NCEP analyses shown on the Canadian Met Service daily ozone maps pages give a good analysis in the Southern Hemisphere but the forecasts tend to increase ozone amounts within the ozone hole. US NWS CPC plots from NOAA show the current area of the ozone hole.
Arctic: Ozone values over the Arctic during the course of a year are shown in our Northern Hemisphere TOMS movie for 2002/2003 (see also this year's movie). Ozone values are declining from the spring maximum in northern temperate and polar regions. Ozone values over the UK are around the normal. Temperatures are well above the PSC threshold throughout the arctic stratosphere.
Equator: Ozone levels are normally lowest over the topics and TOMS data shows nothing unusual. TOVS data has a calibration problem and shows values that are significantly lower than those that are measured by other means.
The BAS ozone bulletins contained the actual ozone values reported together with an analysis of the situation. These were distributed by email on request, but are now superceded by this web site. The last ozone bulletin was issued on 2002 May 28.
Some data is available on line, however please note that this is provisional and likely to change without warning. To help interpret the data you should to read this description. You must request permission to reproduce the data and I may be able to supply more suitable or more up to date material.
Provisional daily mean ozone values for 2003/2004 for
Halley [Updated 2004 April 28] and Vernadsky. [Updated 2004 June 15] The data sets commence on
August 1. The instrument constants for Halley were adjusted on 2003
October 23 and those for Vernadsky on 2004 April 5.
Provisional daily mean ozone values for Faraday/Vernadsky and Halley between 1972 and 2003.
[Updated 2004 June 15]
Provisional monthly mean ozone values for Faraday/Vernadsky and Halley between 1956 and 2004.
Mean daily ozone values for the period 1957 - 1972 for
Faraday and Halley
.
Daily ozone values for the period 1957 - 1973 for Faraday and Halley .
Temperature and Ozone graphs for Halley and Vernadsky/Faraday. [Updated 2004 June 15]
Radiosondes are released daily at Halley. The 100 hPa or 70
hPa pressure level is close to the height of the maximum ozone
concentration. Over the last 30 years the mean 100 hPa
temperature has declined in most months. The most notable change
is in November at Halley.
Monthly 100 hPa temperature means for Bellingshausen/Faraday/Rothera/Marambio/Polarstern and
Halley between 1954 and 2003.
[Updated 2003 August 5]
During 2003 we carried out ozone sonde flights at Rothera as part of the QUOBI project. Data from these flights is available in NASA-AMES format.
The SAOZ instrument at Rothera has measured total column
nitrogen dioxide and ozone since 1997. The values given here are
preliminary and only show general trends in ozone amounts. In particular,
the calibration of the instrument is such that it reads about 15% lower than a
Dobson at values around 100 DU.
Total column nitrogen dioxide 1997/1998.
Total column nitrogen dioxide and ozone 1998, 1999,
2000, 2001,
2002, 2003 and
2004. [Updated
2004 May 6]
There is also a Bentham spectro-radiometer at Rothera.
Provisional values for 1997 / 1998 / 1999
/ 2000 / 2001
/ 2003 / 2004
are available [Updated 2004 April 7]. The original instrument was
destroyed in a fire on 2001 September 28, however a replacement was commissioned
and became operational on 2003 March 3.
Some background information on Halley, Rothera and Faraday stations is available from BAS. Information about Vernadsky station is also available from the Ukrainian Antarctic Centre. Information about Vladimir Ivanovich Vernadsky
Some surface and upper air synoptic data is also available on line from our public data page.
Southern Hemisphere ozone hole movies for
1997/1998 ,
1998/1999 ,
1999/2000 ,
2000/2001 ,
2001/2002 ,
2002/2003 and
2003/2004 [updated 2004 June 22]. A short sequence
of the 2001 hole.
Northern Hemisphere movies for 2000/2001 ,
2001/2002 ,
2002/2003 and
2003/2004
[updated 2004 June 22] A short sequence of ozone depletion during the
2002/03 northern winter showing the difference
from the normal.
These annual movies are each about 8Mb and are compiled from daily TOMS images. They begin
and end in June.
Today's
TOMS global image
The current
area of the hole and other
latest details are available from the NOAA Climate Prediction
Center.
Environment Canada have an excellent set of daily maps showing
both northern and southern ozone levels from a variety of sources.
Requests for permission to use this data or for further information should be sent to Jon Shanklin who maintains these pages.