Rapid intercontinental air pollution transport associated with a meteorological bomb

Abstract

Abstract.Intercontinental transport (ICT) of trace substances normally occurs on timescales ranging from a few days to several weeks. In this paper an extraordinary episode in November 2001 is presented, where pollution transport across the North Atlantic took only about one day. The transport mechanism, termed here an intercontinental pollution express highway because of the high wind speeds, was exceptional, as it involved an explosively generated cyclone, a so-called meteorological "bomb". To the authors' knowledge, this is the first study describing pollution transport in a bomb. The discovery of this event was based on tracer transport model calculations and satellite measurements of NO 2 , a species with a relatively short lifetime in the atmosphere, which could be transported that far only because of the high wind speeds produced by the bomb. A 15-year transport climatology shows that intercontinental express highways are about four times more frequent in winter than in summer, in agreement with bomb climatologies. The climatology furthermore suggests that intercontinental express highways may be important for the budget of short-lived substances in the remote troposphere. For instance, for a substance with a lifetime of 1 day, express highways may be responsible for about two thirds of the total ICT. We roughly estimate that express highways connecting North America with Europe enhance the average NO x mixing ratios over Europe, due to North American emissions, by about 2-3 pptv in winter.

First estimates of global free-tropospheric NO<sub>2</sub> abundances derived using a cloud-slicing technique applied to satellite observations from the Aura Ozone Monitoring Instrument (OMI)

“…This is especially important in the tropics. At middle to high latitudes, the cloudslicing NO 2 VMRs are also derived in frontal storms, where uplift of boundary layer pollution and subsequent long-range transport frequently occurs (e.g., in the so-called warm conveyor belt) (Stohl et al, 2003;Zien et al, 2014). This may also increase cloud-slicing NO 2 VMRs as compared with clear-sky conditions.…”

Megacities and Atmospheric Pollution

“…[292][293][294] Satellite plume detection can track long-range transport of gases and particles [295][296][297][298] and help researchers understand how meteorological situations influence air pollution on local, regional, and global scales. 299,300 The scanning imaging spectrometer for atmospheric chartography (SCIAMACHY) on the European Space Agency Envisat satellite detects tropospheric gases and particles from lower earth orbit. The smaller ground pixel size of SCIAMACHY (30 km ϫ 60 km) is comparable to the size of megacities, offering the possibility of estimating total emissions from these large urban expanses to create and verify inventories.…”

Long-path averaged mixing ratios of O<sub>3</sub> and NO<sub>2</sub> in the free troposphere from mountain MAX-DOAS

“…Pollutants can be transported over long distances through the FT where fast winds exist and the lifetime of minor species is longer than that in the BL (Stohl and Trickl, 1999;Stohl et al, 2003;Liang et al, 2004). Unfortunately, little is known of the amounts of BL active species in the FT that are anthropogenically produced ; the downward exchange between the FT and the lower troposphere is also unclear (Zyryanov et al, 2012).…”