A fine-particle sodium tracer for long-range transport of the Kuwaiti oil-fire smoke

Evidence for long‐range transport of the Kuwaiti oil‐fire smoke during the months following the Persian Gulf War has been more or less indirect. For example, high concentrations of aerosol particles containing soot and oil‐combustion tracers such as vanadium observed at great distances from the Middle East may have come from sources other than the oil fires. However, more‐recent data on the aerosol chemistry of Kuwaiti oil‐fire plumes provides a direct link between those fires and aerosols collected at the Mauna Loa Observatory (MLO) during the late spring and summer of 1991. By itself, temporal covariation of fine‐particle concentrations of elemental carbon, sulfur, and the noncrustal V / Zn ratio in MLO aerosols suggested a link to large‐scale oil‐combustion sources, but not necessarily to Kuwait. However, high concentrations of fine‐particle (0.1–1.0 µm diameter) NaCl were observed in the “white” oil‐fire plumes over Kuwait during the summer of 1991. Further analysis of the Mauna Loa data indicates strong temporal correspondence between the noncrustal V / Zn and noncrustal Na / Zn ratios and strong consistency between the noncrustal Na to noncrustal V ratios found at Mauna Loa and in the Kuwaiti oil‐fire plume. In the absence of other demonstrable sources of fine‐particle Na, these relationships provide a direct link between the Kuwaiti oil fires and aerosol composition observed at MLO.