Vital Signs: Air and Climate

Basic Meteorology

Climate is a primary factor controlling the structure and function of ecosystems in the MOJN. Key to understanding ecosystem dynamics is an understanding of the roles of climate variability, hydrologic interactions with soils, and adaptive strategies of biota to capitalize on spatially and temporally variable moisture dynamics. Measurements of temperature, precipitation, wind, humidity, soil moisture and soil temperature can indicate changing climatic conditions and weather patterns.

Monitoring Questions:

1. Is the timing, intensity, duration, and geographic distribution of precipitation events in network parks changing over time?
2. Is the annual average temperature, minimum temperature, and maximum temperature in network parks changing over time?

Visiblity and Particulate Matter

Particulate matter is a park concern because of its negative effects on human health and visitor enjoyment of parks by obscuring scenic vistas and night skies. Particulate matter has been linked to respiratory ailments in humans, including eye irritation, bronchitis, wheezing, asthma, heart disease, and premature mortality. Portions of JOTR and MOJA are within or adjacent to San Bernardino County, the county reported in 2004 to have the unhealthiest air in the nation. Particulate matter also can combine with tropospheric ozone to produce photochemical smog, which may be of concern in areas subject to thermal inversions, such as southern Nevada and California.

Monitoring Questions:

1. Are the number of days network parks fail to meet national air quality standards for particulate matter for human health increasing?
2. Is visibility in parks changing over time?
3. What is the contribution of "in-Park" emissions (fire) to particulate matter and is it changing over time?

Ozone

Ozone damages human health, vegetation, and many common materials. It is also a key component of urban smog. JOTR also was one of nine park units that failed to meet the EPA 8-hour ozone standard based on data from 1997-1999. Most network units are in/near recently designated 8-hr ozone non-attainment areas. In 2004, NPS-Air Resources Division completed a risk assessment of foliar injury to vegetation from ozone in network parks. This assessment concluded that JOTR, MANZ, and MOJA are at high risk for foliar injury to plants from elevated ozone levels. The report also identified ozone sensitive and bioindicator plant species at DEVA, GRBA, JOTR, LAME, and MOJA.

Monitoring Questions:

1. Is the number of plants exhibiting ozone damage increasing over time in areas subject to elevated ozone levels?
2. Are concentrations of ambient ozone increasing over time in and around network parks?
3. Is the frequency and severity of air pollution effects on sensitive resources in network parks changing over time?

Wet and Dry Deposition

Sulfur and nitrogen are the principal constituents of acidic deposition, which can impact aquatic and terrestrial ecosystems as well as cultural resources. Alpine lakes and soils are particularly vulnerable to acidification due to their low buffering ability. Mojave network ecosystems may also experience significant impacts from atmospheric nitrogen deposition because they are generally adapted to low nitrogen conditions. Impacts may include an increase in density and biomass of invasive plant species, decrease in density, biomass, and species richness of native plant communities, and change in fire frequency.

Monitoring Questions:

1. Are dry deposition rates in network parks changing over time?
2. Are wet deposition rates in network parks changing over time?
3. Is soil chemistry, productivity, species richness, plant community composition, and fire frequency and intensity changing over time in areas subject to increased deposition of nitrogen?