Exploring a Pollution Event
Glenn Gehring, Technology Specialist IIITribal Air Monitoring Support (TAMS) CenterInstitute for Tribal Environmental Professionals (ITEP)Northern Arizona [email protected]://www4.nau.edu/itephttp://www4.nau.edu/tams
What Do These Data Mean?
Gas Analyzer Rack
Data Logger
Calibrator
Continuous Particulate
Monitor Control Units
Zero Air Generator
NOy
NOx
SO2
Ozone
Toxics Flow Controller
Continuous Particulate Sensor Unit
Vertical manifold
Tubing for NOy
EPA Protocol Gas
316 Stainless Steel 1/8 inch tubing connects regulator to calibrator
CGA 660? Fitting must match bottle
Two big factors related to pollutant dispersion:
Ventilation Index (horizontal movement)
Stability (vertical mixing)
Mixing Height & Wind = Ventilation Index
Wind
MixingHeight
NOAA ARL Stability Forecast
Zi - Boundary layer depth (meters above model terrain)
10xKz - Vertical mixing coefficient times 10 (m2/s2)
A – Extremely UnstableB – Moderately UnstableC – Slightly UnstableD – NeutralE – Slightly StableF – Moderately StableG – Extremely Stable
Includes an indication of upward push
Ozone and PM-2.5 Readily Transport long distances and React in the Atmosphere
Ozone is the Product of a Reaction Initiated by Light (Photochemical Reaction) in the Atmosphere; Ozone “Precursors,” such as NOx and VOCs are Emitted From Sources
Very important chemical reactions related to ozone:
Ozone Diurnal (daily) Patterns
Quapaw Site on July 22, 2004 – Site’s highest 8-hr Ozone
93 ppb as an 8-hour average
What were other 8-Hour ozone concentrations on July 22, 2004?
I selected ozone for one state at a time and merged the resulting data in a spreadsheet.
Since these data have spatial references for each monitoring site (lat, long) I can easily put this data into GIS software. Then I can use gradients to make higher concentrations appear as larger circles on the map.
Area 8-hr Ozone on July 22, 2004
Saint Louis
Memphis
Quapaw Site
Tulsa
KansasCity
Little Rock
OklahomaCity
I can also use GIS extensions to help illustrate.
8-hr Ozone on July 22, 2004 with Prediction Contours(ESRI Geostatistical Analyst)
Quapaw Site
I can use Air Data or other resources to get point source emissions data, map it and make the size of the circles proportional to emissions. I can also use NOAA’s Air Resources Laboratory’s HYSPLIT software to perform backward trajectories from monitoring sites on the day of concern.
July 22, 2004, 24-hour Backward Trajectories(NOAA Air Resource Laboratory HYSPLIT Model) proportional NOx point source emissions – 2002 EI
Quapaw Site
Now I have some suspect areas that may have contributed to the problem (something near the three coal-fired power plants). I can use ARL’s HYSPLIT software to run forward dispersions from the power plants to see where the model indicates their emissions were when I had the high concentration. In this example I set the model to average concentrations from 100 m to ground level and set it for a 48-hour release beginning 48-hours prior to the high concentration at the Quapaw site.
Oologah Power Plant 48-hr dispersion(NOAA Air Resource Laboratory HYSPLIT Model)
Quapaw Site
GRDA Power Plant 48-hr dispersion(NOAA Air Resource Laboratory HYSPLIT Model)
Quapaw Site
Muskogee Power Plant 48-hr dispersion(NOAA Air Resource Laboratory HYSPLIT Model)
Quapaw Site
Combined 48-hr dispersion(NOAA Air Resource Laboratory HYSPLIT Model)
Quapaw Site
Forward Trajectory from 3 Coal-Fired Power Plants on July 22, 2004(endpoints that are less than 10 meters AGL)
Forward Trajectory from 3 Coal-Fired Power Plants on July 22, 2004(endpoints that are less than 20 meters AGL)
NE Oklahoma Coal-Fired Power Plant NOx EmissionsSource: EPA AirData (1999 EI)
26.5% of Oklahoma facility NOx emissions are from Muskogee, Mayes and Rogers Counties (1999)
22.9% of Oklahoma facility NOx emissions are from three NE Oklahoma coal-fired power plants (1999)
WIND ROSE PLOT
Station #13968 - TULSA/INT'L ARPT, OK
NORTH
SOUTH
WEST EAST
5%
10%
15%
20%
25%
Wind Speed (m/s)
> 11.06
8.49 - 11.06
5.40 - 8.49
3.34 - 5.40
1.80 - 3.34
0.51 - 1.80
COMPANY NAMEMODELER
PLOT YEAR-DATE-TIME
1984 1985 1987 1988 1989 1990 1992 1991 Mar 1 - Oct 318 AM - 6 PM
DATE
DISPLAY UNIT
CALM WINDSAVG. WIND SPEED
COMMENTS
PROJECT/PLOT NO.ORIENTATION
Direction(blowing from)
WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com
Tulsa Ozone Season Wind Rose,Lines Indicate the Direction the Wind Came FROM, and Colors Indicate Wind Speed(1984-1992, March 1 to October 31, from 8 AM to 6 PM)
S
N
EW
2003 Ozone Monitoring Locations (Red Dots)
Most Relevant Winds for Ozone
What if you live here?
GIS for Air Quality Course
