Accidental release of hydrogen sulfide in Nagylengyel, Hungary November 14, 1998 - a trajectory study

Abstract

The movement of air parcels polluted due to an accidental release of H_2S close to the Croatian border is examined. Emission started on November 13, 1998 at around 2330 UTC. Trajectories starting at 0000 UTC were calculated by a dynamic method which provides realistic nonlinear variations of the wind field in space and time. Pressure gradients were calculated from the ECMWF surface pressure forecasts using two finite-difference schemes: centered and off centered. According to one-day forward trajectories, polluted air was transported over Hungary, Slovakia and Ukraine. Furthermore, measurements of daily mean S0_2 concentrations in the air for 5 locations in Croatia confirm that concentrations were not affected by the accidental emission.