Environmental Engineering Reference
In-Depth Information
In April 2001, a 1-million-ton dust cloud—one of the largest on
record—developed in Asia, crossed the Pacifi c Ocean, left its trail
across the United States from Alaska to Florida, and continued
well out into the Atlantic Ocean before it dissipated. The extent to
which that cloud interfered with precipitation isn't really known,
but the cloud was very real. The dust storm was caused by winds
from Siberia that kicked up dust in Mongolia and China! (Don't
think all the dust comes from Asia. The United States exports its
own dust and pollutants, which continue their eastward trek across
the Atlantic Ocean.)
10
Volcanic effect: snow in Alabama in July? Water quality expert
and long-time hydrologist William R. Waldrop, PhD, remembers
as a child hearing his grandfather talk about it. Says Waldrop, also
president of Tennessee-based Quantum Engineering Corp., “My
granddad talked about the snow in Northern Alabama, but every-
one fi gured he didn't remember it right because he was just a kid at
the time. I went back and checked, and the snow did occur a year
after Krakatoa erupted on the other side of the world!” (The big-
gest volcanic eruption in modern history, Krakatoa exploded in
1883 in Indonesia, destroying most of the island and killing tens of
thousands of people.)
Major volcanic eruptions
can
export weather effects across the
globe as they spew gas and particulates high in the sky. Sometimes
it's easy to pinpoint exactly what's happened, and sometimes it's
not, says Brian Fuchs, a climatologist with the National Drought
Mitigation Center at the University of Nebraska-Lincoln and an
author of the U.S. Drought Monitor. The 2010 eruption of Iceland's
Eyjafjallajökull sent plumes of ash into the air that clogged air travel
in Europe for days. But, says Fuchs, its effect on world weather
hasn't really been determined.
Volcanic eruptions can cool the atmosphere if the particles
remain in the stratosphere, explains Douglas Le Comte, a meteo-
rologist now retired from NOAA's Climate Prediction Center. “This
rarely happens with eruptions outside of the tropics, so it is basically
tropical eruptions that affect the climate, and this is over a several-
year period. The last important climate-affecting eruption was
Pinatubo in 1991 in the Philippines. This contributed to the cool
U.S. summer of 1992,” he adds.
