ISSN:
1573-0662
Keywords:
Arctic haze
;
pollution in the Arctic
;
long-range transport of pollutants
;
cloud scavenging
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
Notes:
Abstract Airborne observations during August 1985 over Greenland and the North American Arctic revealed that dense, discrete haze layers were common above 850 mb. No such hazes were found near the surface in areas remote from local sources of particles. The haze layers aloft were characterized by large light-scattering coefficients due to dry particles (maximum value 1.24 × 10−4m−1) and relatively high total particle concentrations (maximum value 3100 cm−3). Sulfate was the dominant ionic component of the aerosol (0.06 – 1.9 μg m−3); carbon soot was also present. Evidence for relatively fresh aerosols, accompanied by NO2 and O3 depletion, was found near, but not within, the haze layers. The hazes probably derived from anthropogenic sources and/or biomass burning at midlatitudes. It is hypothesized that the scavenging of particles by stratus clouds plays an important role in reducing the frequency and intensity of hazes at the surface in the Arctic in summer. Since the detection of haze layers aloft through measurements of column-integrated parameters from the surface (e.g., by lidar) cannot be carried out reliably when clouds are present, such measurements have likely underestimated the occurrence of haze layers in the Arctic, particularly in summer.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00052828
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