Ships make clouds brighter and higher close to European harbors

In the year 2001, ships consumed 280 million metric tonnes [310
million short tons] of fuel, compared to only 64.5 million tonnes [71.1
million short tons] in 1950. As one of the least regulated sources of
air pollution, emissions from ships (exhaust gases, hydrocarbons, and
particulate matter) are expected to rise. Devasthale et al. used data
collected between 1997 to 2002 by the Advanced Very High Resolution
Radiometer aboard the NOAA-14 satellite to find the effect of ship
pollution on clouds around the English Channel and the top three
polluting harbors in Europe (Rotterdam, Netherlands; Antwerp, Belgium;
and Milford Haven, United Kingdom). By dividing the region into coastal
zones, inland areas, and the sea, they found that cloud albedo
[reflectivity] increased and cloud top temperature decreased over
coastal zones, while the opposite was observed inland. The ship-related
cloud albedo increase of about 1.5 percent and cloud top temperature
decrease of about 1.4-1.9 degrees Celsius [2.5-3.4 degrees Fahrenheit]
resulted in compensating radiative effects in the solar and the thermal
range. The authors note that future studies should integrate ship
emission inventories, chemical transport models, and remote sensing
information to better quantify impacts on regional and global scales.

 

Title:Impact of ship emissions on cloud properties over coastal areas

 

Authors: Abhay Devasthale, Olaf Kr¬?ger, and
Hartmut Gra?l: Meteorological Institute, University of Hamburg, and
Max-Planck Institute for Meteorology, Hamburg, Germany.

 

Source: Geophysical Research Letters (GL) paper 10.1029/2005GL024470, 2006

 

(Credits Eurekalert)