Exceptional Events in North Carolina

Exceptional Events in North Carolina Chris Misenis Meteorologist NC DENR – Division of Air Quality March 19, 2009

Overview • Exceptional Events ‘protocol’ • Long Range Strategy • 2007 Georgia Fire (Approved) • 2007 Idaho / Montana Fires (Not Approved)

Protocol • Maintain an exceptional events mailing list • Fast response to ongoing events • Collect data as quickly and early as possible • Measurements, news stories, meteorological data • Conduct Analysis • QA procedures, trajectory work

Distant Fires • More difficult to prove impacts than closer fires • Harder to show impacts from trajectories • But-For Analysis more difficult due to wider dispersion of smoke • Smoke becomes more difficult to spot on satellite images • Local wind speed becomes less important and trajectories become more important • V-smoke useless beyond ~100 miles

Long Range Trajectory ‘Strategy’ • Smoke/air parcel that ultimately impacts a monitor could originate on various heights and days • Forward trajectories from fire • Release trajectories in 500m height increments from surface to 5000m every 3 hours • May have to start 10 or more days prior to impact for fires in Northwest US or Canada • Filter trajectories that come within 200 miles of monitor and are below 1500m (the top of the PBL on a sunny summer day)

2007 Georgia Fires

Georgia Fires

Georgia Fires • Impacts limited to southeast NC (Robeson County monitor in Linkhaw) • 36 μg/m3 exceedance on May 3, 2007 • But-For analysis ‘easy’, lower PM2.5 immediately to north/west

Forward Trajectories 50m 100m

Backward Trajectories 50m 100m

Georgia Fires – EPA ruling EPA agreed with our analysis

Idaho-Montana Fires NIFC large fires August 1, 2007

Impacts in NC • 35-45 μg across central NC and much of southeast • But-For more difficult; PM2.5 outside of smoke was typical of a high summertime episode (~30 μg)

Modis Satellite Smoke Aug 2

Forward Trajectories

Backward Trajectories Example: Hickory, NC

Soundings and Profiler data PBL was nearly 2 km and any smoke at or below that level would have mixed down.

Idaho Fires – EPA ruling EPA denied our EE request

Thoughts • NC disagrees with EPA and feels the Idaho fires had some impact on PM2.5 • Readings were > 5 μg higher than any episode since 2002 (when forecasting began) • Trajectories and satellite clearly showed impacts • But-For failed because of regional ‘background’ episode

Thoughts (continued) • We are not saying there was no PM2.5; the fires contributed ~ 10 μg • Probably need to use Calpuff or CMAQ to model impacts of fires • Would require time and $$$

Recent Events • Evans Road Fire (2008)

Evans Road Cont. Package may be composed entirely of pictures!

Thanks! For more info: • Ambient Monitoring: • J.P. Chauhan: jp.chauhan@ncmail.net • Trajectory Analysis: • Nick Witcraft: nick.witcraft@ncmail.net

Exceptional Events in North Carolina