Exploring a Pollution Event

Exploring a Pollution Event

Glenn Gehring, Technology Specialist IIITribal Air Monitoring Support (TAMS) CenterInstitute for Tribal Environmental Professionals (ITEP)Northern Arizona University541-612-0899glenn.gehring@nau.eduhttp://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