Ambient Ozone in Californian and Central European Mountains

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1 Ambient Ozone in Californian and Central European Mountains Andrzej Bytnerowicz 1, Michael Arbaugh 1 and Witold Frączek 2 1 USDA Forest Service, Pacific Southwest Research Station, Riverside, CA, USA 2 Environmental Systems Research Institute, Redlands, CA, USA

2 Why ozone? Ambient concentrations have been rising since 1880s Criteria pollutant toxic to humans and vegetation Levels of >30-40 ppb potentially toxic to plants (NRC need for ecologically-oriented ozone secondary standard) By 2050 ~60% of N. Hemisphere forests will be affected by ambient ozone

3 Background O 3 concentrations In a global and regional perspective, the background region for atmospheric pollutants is referred to as the area where the atmosphere is not directly influenced by local and anthropogenic sources. Such regions are limited due to extensive human activities in most of the continental areas and possible background may be limited to the central Pacific, Middle Atlantic and central Eurasia (Pochanart et al., 2003).

4 Continental background concentrations of ozone, annual averages - 1 Location Concentration (ppb) Reference Asia Mondy Mt (China) 43.5 Pochanart et al., 2003 Happo (Japan) 44.4 Pochanart et al., 2004 Mt. Abu (India) 48.1 Naja et al., 2003 Pacific Mauna Loa (Hawaii) Vingarzan, 2004 Indian Ocean Mt. Abu data 33.4 Naja et al., 2003

5 Continental background concentrations of ozone, annual averages - 2 Location Concentration (ppb) Reference Europe Finland 30 Laurila & Lattila, 1994 Arosa, Swiss Alp 35 Pochanart et al., 2001 North America US, inland Altshuller & Lefohn, 1996 US, coastal Ibidem US, East Liang et al., 1998 US, West Ibidem Canada Vingarzan, 2004

6 CASTNET - Annual Mean O 3 Concentrations (ppb) for 2002

7 CASTNET- Peak SUM06 Values (ppm-hr) for 2002

8 Our approach to characterizing air pollution status in mountain terrain Use of reliable, easy to use passive samplers allowing for monitoring air pollutants in remote areas where electronic monitors cannot be used In selected location, collocation of portable UV absorption real-time monitors Development of maps of ozone distribution with geostatistical models

9 Ogawa Passive Sampler

10 Passive samplers for O 3 and HNO 3 vapor in Sierra Nevada

11 Advantages of using passive samplers Low cost Simple design and operation Low maintenance needs No need for electric power Possibility for dense deployment Reliable results Integration of long-term exposure regimes

12 Limitations of passive samplers No information on diurnal, real-time concentrations (needed for understanding toxic potential) Changes in climatic conditions (wind, temperature, RH) affect samplers performance Need for calibration against real-time monitors

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14 ESRI Geostatistical Analyst Extension of ARC/INFO 8 generates predictive surfaces from data points using geostatistical tools and analyzing error of the resulting estimations. Numerous kriging and predictive tools are the center of the extension.

15 Ozone distribution in the Sierra Nevada

16 Mountains as barriers for air pollution transport 2002 studies Hypothesis 1. River valleys are natural corridors for moving pollutants across mountain ranges. Hypothesis 2. High mountain ranges may be very effective barriers preventing long-range transport of polluted air masses.

17 2002 intensive studies Lake Tahoe and the San Joaquin River transect

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19 Ozone on the San Joaquin River transect in summer 2002 Ozone seasonal averages Auberry Redinger Lake Italian Bar Mammoth Powerhouse Rock Creek Mammoth Pool Hells Half Acre Squaw Dome Cattle Mtn Fish Creek Starkweather Lake Mammoth Mtn Sherwin Creek SNARL 395 Lookout Bishop Creek Oak Creek Olancha Pass Chimney Peak ppb

20 Lake Tahoe air pollution monitoring summer 2002

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31 B Technology Monitor Real-time Ozone Data Fenced Meadow, 7/23/15:45-8/5/14:00/ hours ozone (ppb)

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33 Locations of the 32 Measurements Sites

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36 Air quality in the Tatra Mountains is affected by transport of polluted air masses from many European countries

37 Distribution of ozone in complex mountain terrain is difficult to predict

38 Information on ozone levels helps to understand risks to sensitive plants such as ponderosa pine or Swiss stone pine

39 Elevated levels of ozone predispose trees to drought stress and insect attacks

40 Conclusions - 1 North America and European mountains experience elevated levels of tropospheric O 3 potentially toxic to humans and vegetation Long-range transport, including trans-pacific transport from Asia, is responsible for significant increases of ambient O 3 levels Better understanding of temporal and spatial distribution of O 3 in western mountains is needed

41 Conclusions - 2 Polluted air masses can move across mountain ranges along river valleys (example - San Joaquin River drainage). Mountain ranges can prevent movement of polluted air masses acting as pollution barriers (example Desolation Wilderness west of Lake Tahoe)

42 Conclusions - 3 Forest fires are important sources of VOCs and NO x and promote O 3 formation Passive sampler networks can effectively point to hot spots for ambient O 3 and other pollutants There is a need for translating long-term average O 3 concentrations into real-time values (models are already available)

43 Thank you!!!