1. A N EW H AMPSHIRE G ROUND -L EVEL O ZONE P OLLUTION F ORECASTING T OOL U SING M ETEOROLOGICAL C RITERIA Northeast Regional Operational Workshop Presenter: Laura Landry, Plymouth State University 2008 November 5 Courtesy: Zach Allen

2. Introduction  New Hampshire Department of Environmental Services (NHDES) has forecasted ozone pollution for over 15 years  Ozone exposure causes a wide range of respiratory problems (AIRNow 2008)  Primarily concerned with Environmental Protection Agency’s (EPA) National Ambient Air Quality Standard (NAAQS) for ozone  Based on daily maximum 8-hour average ozone concentration

3. Introduction  Since March 2008, a new NAAQS for ozone has been implemented, lowered from 84ppb to 75ppb  Previously used forecasting methods have become less accurate  Motivation: To develop a new forecasting guide for predicting the new standard of 75ppb  Results will help answer questions of:  How much variation in meteorological criteria will there be between air monitoring sites?  How will criteria compare when using two different time periods of data?

4. Introduction  Meteorological conditions behind ozone development  Sunny skies  High surface temperatures  Calm to light winds  Transport of pollution  New Hampshire lies downwind of major pollution sources

5. Methodology  Selection of air quality monitoring sites  Sites were selected base on: 1. Locations where most exceedance days occur More problematic to forecast Larger sample size on which to base the analysis 2. Locations not adjacent to each other

6. Methodology  Southern sites report most of exceedance days  Site elevations range from 0 to 150m  Miller State Park is an exception at about 700m New Hampshire

7. Methodology  Previous research conducted by Jeffs (2007), a Master’s thesis at Plymouth State University  Created an ozone forecasting guide for 65ppb  Utilized a dataset from 2002-2005  This study followed similar methodology  EPA suggests an air quality climatology as about 4 years (EPA 1999)  Used two datasets of June-August 2004-2007 2002-2007

8. Methodology  Ozone data  Daily maximum 8-hour average ozone concentration Source: NHDES  Meteorological data  Surface observations from KCON, KEEN, KASH, KPSM, and Miller State Park Source: National Weather Service, Plymouth State University, NHDES  Radiosonde data from KGYX Source: Plymouth State University

9. Methodology  Analysis was done using the Criteria Method  EPA-recommended method for creating air quality forecast guides (EPA 1999)  Subjective analysis that focuses on exceedance days  Determines threshold values

10. Methodology

11.  Meteorological parameters:  Daily maximum surface temperature  850hPa temperature (12 UTC)  Surface wind speed and direction (12 & 18 UTC)  Cloud cover (12 & 18 UTC)  Times were chosen based on:  12 UTC: morning conditions prior to a potential high ozone event  18 UTC: afternoon conditions when ozone typically reaches its daily maximum value

12. R ESULTS

13. Results  Comparing criteria of air monitoring site to site…  Daily observations Maximum surface temperature: ≥ 83˚F  12 UTC observations 850hPa temperature: ≥ 12˚C Surface wind speed: ≤ 5 knots Surface wind direction: Southwesterly to southerly Cloud cover: ≤ FEW

14. Results  Comparing criteria of air monitoring site to site…  18 UTC observations Surface wind speed: ≤10 knots Surface wind direction: Westerly to southwesterly Cloud cover: ≤ SCT  Results from Miller State Park varied most from all other sites

15. Site to Site Comparison 2004-2007 VariableThresholdNRange Max Surface Temperature ≥ 80°F1473-96°F 12 UTC OBSERVATIONS 850hPa Temperature ≥ 11.4°C18 9.4-19.6°C Wind Speed≤ 14 kts133-14 kts Wind Direction 200-260°1587-295° Cloud Cover--- 18 UTC OBSERVATIONS Wind Speed≤ 14 kts135-19 kts Wind Direction 200-250°14117-287° Cloud Cover--- Miller State ParkNashua 2004-2007 VariableThresholdNRange Max Surface Temperature ≥ 86 °F1777-95°F 12 UTC OBSERVATIONS 850hPa Temperature ≥ 12 °C17 9.4- 19.8°C Wind Speed≤ 5 kts150-6 kts Wind Direction 180-290°3 Cloud Cover≤ SCT14 CLR- BKN 18 UTC OBSERVATIONS Wind Speed≤ 10 kts161-10 kts Wind Direction 200-300°13110-300° Cloud Cover≤ SCT15 CLR- BKN

16. Results  Comparing criteria among different time periods of data among the same air monitoring site…

17. Dataset Comparison 2002-20072004-2007 VariableThresholdNRangeVariableThresholdNRange Max Surface Temperature ≥ 82°F1981-97°F Max Surface Temperature ≥ 82°F1081-95°F 12 UTC OBSERVATIONS 850hPa Temperature ≥ 12.4°C19 12.4- 20.8°C 850hPa Temperature ≥ 12.4°C10 12.4- 19.8°C Wind Speed≤ 7 kts191-8 ktsWind Speed≤ 5 kts101-8 kts Wind Direction 190-290°16150-290° Wind Direction 190-270°8150-270° Cloud Cover≤ SCT17CLR-BKNCloud Cover≤ FEW10 CLR- BKN 18 UTC OBSERVATIONS Wind Speed≤ 10 kts193-10 ktsWind Speed≤ 8 kts103-9 kts Wind Direction 180-240°17120-260° Wind Direction 180-260°9120-260° Cloud Cover≤ BKN17CLR-OVCCloud Cover≤ SCT10 FEW- OVC Portsmouth

18. Summary  This study developed an ozone forecasting guide for the NHDES  The criteria method from the EPA  Subjectively analyzed meteorological threshold values  Threshold values indicate a high probability of an exceedance day

19. Conclusions  Air monitoring site to site comparison:  Similar threshold values among sites  Miller State Park appeared to be an outlier Could be due to high elevation Transport may be more of an issue  Dataset to dataset comparison:  No significant variation in threshold values  In this study, the length of the dataset did not have a large effect on results

20. Questions? References:  AIRNow, accessed 2008: Ozone and Your Health. [http://www.airnow.gov/index.cfm?action= static.ozone2]  EPA, 1999: Guideline for Developing an Ozone Forecasting Program. EPA: Office of Air Quality Planning and Standards.  Jeffs, Kim, 2007: Development of Meteorological Criteria for Forecasting Air Quality in New Hampshire. Plymouth State University: Master of Science Thesis Project.