February 21, 2013
10:00 am – 11:30 am


Every air pollution employee should have a good working knowledge of meteorology. When we think of meteorology, we usually think of weather patterns – things like rain, wind, cold or hot weather. But meteorology is more than that, especially as it concerns the transport, dispersion, or trapping of air pollution.

In this webinar, we will discuss the basics of meteorology, air pollution in the Mid-Atlantic region and the effects of natural events on air pollution.

The presenter for this webinar is Sean Nolan of the Pennsylvania DEP.

Certificate Information:

If you are interested in receiving a certificate, you must complete the 3rd section of the survey which is labeled “Certificate.” Please make sure you complete all the questions in that section. We encourage but do not require you to complete the other two sections for a certificate.


Full Colored Presentation – 2 slides per page (PDF Format – 7.6 MB)

Printer Friendly Version – 3 slides per page (PDF Format – 2.5 MB)



Question and Answers

During the recent webinar, MARAMA received some questions that were not answered on the webinar. Here are the questions along with the responses.

1. The ozone monitors in the region are at ground level. Where do you get the altitude readings. Satellites? Balloons?

The altitude readings are from ozone monitors at higher elevations. For instance, the approximate base elevation of the three monitors, which I mentioned during the webinar on Thursday, February 21, are as follows:

Methodist Hill, PA – 2000 feet (610 meters) Piney Run, MD – 2500 feet (760 meters) Shenandoah National Park, VA – 3500 feet (1070 meters)

Compare these elevations to monitors situated in urban sectors along the I-95 corridor:

(Philadelphia Area): Bristol, PA – 34 feet (10.4 meters)
(Baltimore Area): Edgewood, MD – 28 feet (8.5 meters)
(Washington DC): Alexandria, VA – 225 feet (68 meters)
(Richmond, VA Area): Math & Science Center – 160 feet (48.8 meters)

Other cases in the presentation where altitude was mentioned:

a.) The discussion about the collection of upper air data. This data is collected via a weather balloon, known as a radiosonde. Radiosondes generally measure temperature, pressure, wind speed and wind direction.

b.) The discussion regarding upper level ozone measurements. This discussion details results either by ozonesondes (think radiosonde, only it collects ozone readings) or by aircraft measurements. The most recent developments in the field of aloft ozone and precursor measurements can be found at NASA’s Discover-AQ project website: http://discover-aq.larc.nasa.gov/

2. For sounding data used for AERMET/AERMOD, I used to be able to download them (FSL files) from NCDC. Do you know the latest download site or link?

It appears that the site formally known as the FSL (Forecast Storm Lab) webpage has closed down. The new site for available Radiosonde Observation (RAOB) sounding data is available at the following website: http://www.esrl.noaa.gov/raobs/.

3. What happens to all of the air pollutants that are created over time . How are they dispersed?

The dispersion characteristics of air pollutants can depend on the type of pollutant and whether it can undergo a chemical reaction within the atmosphere. It also depends on the local meteorological conditions, downwash effects, etc. More details can be found here:

US EPA: http://www.epa.gov/eogapti1/course422/ce1.html
Coursework from U. of Washington: http://courses.washington.edu/cee490/PlumeD4.pdf