GLOBAL DISTRIBUTION OF TRITIUM
665
February 1963, Antalya concentrations exceeded Tel Aviv concentra-
tions by a factor of 3, but after March Antalya concentrations were
lower by approximately the same factor. Concentrations at Antalya
were lower than those at Ankara by a factor of 5 for the comparable
months (June and July). The Ankara curve superimposes on the curve
for Vienna almost precisely, indicating that it is controlled essentially
by the same continental climatic factors. The tritium records for
Antalya and Ankara are too limited for conclusions, but the fact that
Ankara is sheltered from Mediterranean air and receives mostof its
precipitation from the north is clearly evident. On the Mediterranean
coast the local climatology dominates over the stratospheric input, and
hence the variations of the local tritium record may be useful for the
analysis of water-vapor transport in this region.
Africa
The main features of tritium variations in Southern Africa have
been discussed under the general consideration of the southern hemisphere,
Equatorial Africa illustrates the relatively sharp division of air
masses that prevails at the equator. Data from Entebbe, Uganda(S),
at 00°03'N and from Dar es Salaam (S) at 06°52’S clearly illustrate
the comparative isolation of the hemispheres. Throughout 1963 Entebbe
levels were much higher than those at Dar es Salaam, averaging 125
T.U. compared with 17 T.U. Apparently surges of northern-hemisphere
air may reach Dar es Salaam at times, as indicated by two monthly
measurements of 38 and 43 T.U. in January and September 1961 compared to an average of approximately 5 T.U.for the other months.
South Continental Asia and the Indian Ocean
In this region there is a sharp division between the sites dominated by continental air and the sites that are seasonally subject to
overwhelming air masses from the Arabian and Bengal seas. The
highest tritium levels were measured at Teheran, Iran (IA), and
Karizimir, Afghanistan (IA), both continental sites (Fig. 6). In 1962
the
peak
summer
tritium levels at Teheran appear to exceed the
Vienna level by almost 1000 T.U. In 1963 and 1964 the Teheran peaks
equal those at Vienna.
These sustained high levels are strongly contrasted with New
Delhi and Bombay (T), where the monsoon rains arrive in June and
continue through September. The January, February, and March mea-
surements in 1962 for New Delhi average as high as those for Teheran
and indicate that New Delhi is dominated by continental air at this time