Mineral dust concentrations, deposition fluxes and deposition velocities in dust episodes over Israel

Total suspended particles (TSP) and dustfall were simultaneously sampled in Jerusalem (1969–1973) and in Tel Aviv (1976–1995) to determine the deposition flux, particle concentration, and deposition velocity of the mineral dust. In addition, the deposition flux of dustfall was measured throughout Israel and in the Sinai Desert during the years 1970–1973. TSP concentrations during dust pulses (“episodes”) were from 10 to 120 times higher than the background values of ∼100 μg m−3; the maximum concentration measured was 24,000 μg m−3. The annual deposition flux (from pulses only) decreased from 90 g m−2 yr−1 in the south to 30 g m−2 yr−1 in the north. The local contribution to the annual deposition flux was ∼50% in the south and near the Judean Desert in the east but decreased to 25% in the north. Deposition velocities of the dustfall during months without dust episodes were on the order of 1.0 cm s−1, while during months when dust storms occurred, deposition velocities are from 2 to 6 times greater than the background, depending on the location. Monthly mean deposition velocities during dust episodes varied between 2.6 cm s−1 and 9.0 cm s−1; short term (1 hour) values up to 27 cm s−1 have been measured.