antarctic ozone evolution since 1898 and the international polar years
TRANSCRIPT
Antarctic ozone evolution since 1898 and the International Polar Years
Christian MullerBelgian Institute for Space Aeronomy and B.USOC
Ozone hole during 7 October 2008 as measured by the Scan-ning Imaging Absorption Spectrometer for Atmospheric Car-tography (SCIAMACHY) atmospheric sensor onboard ESA’s Envisat. SCIAMACHY is a tri-national instrument (Germany, Netherlands and Belgium). The 2008 record ozone hole corre-sponding to the IPY is slightly more important than the 2009 ozone hole. (image produced using the assimilation tools of KNMI)
Monthly averages of total ozone values for September over the South Pole for the last 10 years using measure-ments from the Scanning Imaging Absorption Spectrome-ter for Atmospheric Cartography (SCIAMACHY) sensor aboard ESA's Envisat, the Global Ozone Monitoring Ex-periment (GOME) aboard ESA ERS-2 and its follow-on in-strument GOME-2 aboard EUMETSAT MetOp. The vortex broke early in 2002. All three sensors have important Bel-gian participation. (image produced by DLR)
IPY 2008 The ozone hole is a yearly total ozone minimum observed in Sep-tember and October in Antarc-tica, three conditions are neces-sary to start it: the Antarctic vortex which isolates the Ant-arctic atmosphere, the formation of stratospheric clouds and the presence of active chemical spe-cies (chlorine and bromine) trans-ported from lower latitudes.
1898
1932
1958
1983
Cloud observations of Dobrowolski, these cor-respond to Polar strato-spheric Clouds which cause the present ozone hole when activated by chlorine.The wind roses show an early Antarctic vortex.
The Belgica wintering of 1898-1899 was the first real scientific expedi-tion to Antarctica with an international team of 7 scientists, Henryk Arctowski was the chief meteorologist.
An observation of PSC’s (Polar Stratospheric Clouds over the Australian Antarctic base Davis 4 (68° 34' 35.8" S 77° 58' 02.6" E) - 19 September 2001- Photo by M. Lambert, the latitude corresponds to the Belgica wintering.
No ozone measurements are performed in Antarctica, however stratospheric ozone monitoring has systematically begun with the Dobson network and Chapman has formulated a first ozone theory. Belgium participates to the IPY through a geomagnetic station in Elisabethville.
With Chapman as presi-dent, Marcel Nicolet as secretary, the CSAGI gives a priority to Ant-arctic ozone and mete-orology, again Belgium reacts by installing a Dobson instrument in Congo.
A CSAGI meeting in Moscow.
Picture by Derek Ward of Halley Bay in 1958.
A first Dobson in-strument is in-stalled in the Brit-ish Halley Base in 1957 during IGY.
"It was clear that the winter vortex over the South Pole was maintained late into the spring and that this kept the ozone values low". (Dobson over the first Antarctic data). After, more stations were added including a Belgo-Dutch station at Base Roi Baudouin in 1965-1967.It was the Syowa Japanese station that made in 1984 the first announcement of abnormal Octo-ber values in 1982 and 1983. The British Antarctic survey publication in NA-TURE in 1985 is however the publication which alerted the scientists over the ozone hole prob-lem. Its chemical explanation was given in 1987 after two American led campaigns in Antarctica and precipitated the signing of the Montréal protocol.
Figure showing the Halley Bay results together with Syowa and Roi Baudouin Antarctic 1958 values of ozone compared to Spitsbergen averages.: a dissym-metry appears.
No polar year was scheduled in 1983, if one would have been organised, the ozone hole would have been discovered two years ear-lier by the synergetic exploitation of polar year specific campaigns.
A CSAGI meeting in Brussels.