AIR POLLUTION – MONITORING MODELLING AND HEALTH

Air Pollution in Mega Cities: A Case Study of Istanbul 99
of January 17, a surface temperature inversion was formed. On January 17, the first day of
the episode, the surface pressure was rather high over the entire Balkans and Eastern
Mediterranean. The light surface winds blew from southern directions, weak at noon and
from SW at night (Fig.9). The thermodynamic structure of the lower atmosphere during the
episode shows that during the night of 17 January, a strong surface inversion was formed
with a depth of 230 m more than 5 o C in strength as result of warm advection. On that night
surface atmospheric pressure was 1028 hPa and surface winds measured at the Goztepe
meteorological stations from 17th January 00Z to 19 January 12 Z were light (~1 m/s)
throughout the night and daytime period. around 1 m/s were at the south and southwest
Fig. 8. Skew T log P diagram at 00Z on 17th Jan 1993.
directions. The pollutants (SO 2 and TSP) were accumulated during the following day due to
the stagnant weather conditions. Very dramatic concentrations of SO 2 and TSP (4070 and
2662 μg/m3) on 18th January 1993 were measured to be associated with very strong surface
inversion and stagnant conditions during the poor quality coal usage in the European and
west parts of Istanbul. The episode ends on January 20, when a strong low pressure system
moves over the Black Sea.