THE STATUS OF THE OZONE LAYER OVER THE SEYCHELLES

Background

Stratospheric Ozone (10-50km) acts as a shield to protect Earth’s surface from the sun’s harmful ultraviolet radiation. Although it represent only a tiny fraction of the atmosphere, ozone is crucial for life on Earth. Without Stratospheric Ozone, marked increase of skin cancer and cataracts can be expected.
Since 1960’s Global Ozone is being monitored.
1969 an American shuttle Nimbus 7 carrying aboard a Total Ozone Mapping Spectrophotometer (T.O.M.S) was launched. Its mission was to monitor Solar energy controlling ozone and mapped out total global ozone.
1984 replaced by Russian Meteor 3.
1991 American Earth Probe.

75-85% of Stratospheric Ozone is destroyed by man-made Chlorofluorocarbon(C.F.C’s) used mainly in Refrigerators air condition units aerosol and other propellants.
These C.F.C’s takes about 15-100 years before decaying in the atmosphere.

15-20% by natural causes such as chlorine from sea salt from oceans, but the hydrogen chloride(HC1) is moved out from the atmosphere within a couple of days to a week.

1-5% Volcanic Eruptions, can have a diminishing effect on ozone by injecting large quantities of HC1 directly into the Stratosphere but then again volcanic eruptions have about 1000 times water vapor as just plain HC1, Therefore 99% is rained back to earth.

But after Montreal Protocol came into existence on 16^th September 1987, the atmospheric growth of CFC’s, Carbon Tetrachloride, Methyl chloroform and halons 1301, 1211 have slowed down, due to substitute such as Hydro-chloro-fluorocarbon (HCFC) and hydro-fluorocarbon (HFC).

But increase of Methyl Bromine has been observed( mainly from Soil Fumigation. Biomass burning and Exhaust from vehicles using leaded gasoline)

Since Seychelles was the only island within the Equatorial Belt in the Indian Ocean, therefore it was in an ideal position to measure Ozone within that area.

So in 1976 the Station was opened by Mike LongWorth and Collin Brookes; and Seychellois staff at the Meteorological Services was trained to operate the ground equipment the Dobson Spectrophometer.

The raw data was sent to British Meteorological Department to be analysed and then sent to World Ozone and Ultraviolet Radiation Data Centre (WOUDC)

In March 1999 Dr Bojkov of W.M.O with the collaboration of Dr Karel Vanicek of the Czech Solar and Ozone Observatory of the Hydro-meteorological  Institute offered The Seychelles Meteorological Services the Dobson Software Package whereby staff can be trained to analyse the Raw Ozone Data and sent it directly to Toronto.

In 1993 Seychelles ratify the Montreal Protocol and has been given until 2002 for complete phase out of CFC’s.

Every four years with the financial aid of W.M.O and South African Republic The Seychelles ground instrument "The Dobson 57" will be sent to The South African Bureau of Standards in Pretoria for general calibration done by American Technicians from N.A.S.A.

Training for local staff is done in Czech Rep every two years. 

Station Number of Seychelles in the Ozone Data Centre (W.O.U.D.C) is 207  

Email address for further details at N.A.S.A (ozone): http://toms.gsfs.nasa.gov

Email address for Solar and Ozone web page for Ozone: http://www.chmi.cz.indexe.html/