METO 621 CHEM. Lesson 6. A Typical Day in a Pollution Episode. A common severe pollution weather pattern occurs when high pressure is centered just west of the Mid Atlantic region. Circulation around the high pressure center moves pollution from points west into the mid-Atlantic. H.
Ozone concentration remaining constant
Ozone concentration diminishing
follows a daily
cycle with maximum
in the late afternoon.
This cycle is a signature of the dynamic processes of atmospheric air pollution
Time of day
24 hr. Back-trajectories on days of 1-hr. ozone exceedances from 1997 through 2002, Baltimore area
Upper level winds
from the west…
…are turned by the
lee side trough
Air pollution from the southwest…
…comes into Maryland overnight
Plot of low-level winds from the Fort Meade, MD wind profiler during a high ozone episode
Modes of Transport profiler during a high ozone episode
All three modes of transport are important when the highest
pollution values are observed in the mid-Atlantic.
Cars, industry, and other sources in the local area
Primarily power plants to W, though plumes from cities certainly contribute.
Primarily cars and other low level sources; moves from SW to NE
How Significant? profiler during a high ozone episode
Aug 4, 2002
Coming soon to GRL
CEM data indicate
reductions of 60-80%
L. Marufu, B. Taubman, B. Doddridge et al.