Four decades after the passage of the US Clean Air Act, air-quality standards are set to protect ecosystems from damage caused by gas-phase nitrogen (N) and sulfur (S) compounds, but not from the deposition of these air pollutants to land and water. Here, we synthesize recent scientific literature on the...
The origin of the Pacific Decadal Oscillation (PDO), the leading mode of sea surface temperature variability for the North Pacific, is a matter of considerable debate. One paradigm views the PDO as an independent mode centered in the North Pacific, while another regards it as a largely reddened response to...
Intraseasonal variability of boreal summer rainfall and winds in tropical West Africa and the east Atlantic is examined using daily Tropical Rainfall Measuring Mission (TRMM) precipitation and the NCEP–NCAR reanalysis during 1998–2006. Intraseasonal precipitation variability is dominated by two significant spectral peaks at time scales near 15 and 50 days,...
The high decay resistance of western redcedar (Thuja plicata Donn) is due to the presence of toxic extractives, called tropolones, in the heartwood. Therefore, tropolone content may be used as an indicator of decay resistance. With increment core-sized samples of western redcedar heartwood, we used gas chromatography to measure tropolone...
Vapam(r) (NaMDC) is the fumigant most commonly used to arrest and control decay of utility poles. While volatile fungitoxins are detectable only 1 to 2 years after treatment, poles treated with Vapam(r) remain free of decay fungi for 6 to 17 years. Vapam(r) decomposes to produce volatile fungicides as well...
The chemical composition of the boles of 14 Douglas-fir trees growing in the central Willamette Valley of western Oregon was examined to determine whether differences in various chemical component levels might help to explain arthropod or microbial colonization patterns. Levels of nearly all cations as well as N and P...
Natural resource policymakers and planners increasingly rely on regional and national-level spatial data describing projections of future housing growth, to anticipate development impacts on natural resources and identify policy and planning needs. Such projections have not always been well-grounded in demographic and other factors that influence population and thus housing...
The nature of the teleconnection linking ENSO variability with Atlantic basin tropical storm formation is investigated. Solutions of the linearized barotropic vorticity equation forced with August–October El Niño event divergence produce upper-tropospheric vorticity anomalies over the Sahel and at the mouth of the North African–Asian (NAA) jet over the tropical...
In late May of 2008, the NASA/JPL Phoenix spacecraft will touch down near its targeted landing site on Mars (68.2°N, 126.6°W). Entry, descent, and landing (EDL) occurs in the late afternoon (~1630 hours local solar time (LST)) during late northern spring (Ls ~ 78°). Using a mesoscale and a large-eddy...
Simulations with a Mars general circulation model (GCM) are used to perform idealized tracer transport experiments, which are analyzed to yield estimates of eddy mixing coefficients as well as “stratospheric” ventilation timescales for the zonal-mean circulation. The results indicate that relatively moderate values of the vertical eddy mixing coefficient, KZ...