Aerosols are tiny particles that serve as nuclei for cloud droplet and ice crystal formation. Increases in aerosol concentration lead to clouds with smaller but more numerous droplets. Some recent studies have found evidence that ice crystal size in deep convective clouds is also reduced by elevated aerosol concentrations. In...
Cloud reflectivity is a function of cloud liquid water content and droplet number concentration. Since cloud droplets form around pre-existing aerosol particles, cloud droplet number concentration depends on the availability of particles that can serve as cloud condensation nuclei. Given constant liquid water amount, increased availability of cloud condensation nuclei...
The Indian Ocean Experiment (INDOEX) had as a primary objective
determining the radiative forcing due to anthropogenic aerosols over
climatologically significant space and time scales: the Indian Ocean during the
winter monsoon, January-March. During the winter monsoon, polluted, low-level
air from the Asian subcontinent blows over the Arabian Sea and...
Advanced Very-High Resolution Radiometer 4-km data were collected over the northeast Atlantic for May-August, 1995-1999. Aerosol optical depth was retrieved in cloud-free pixels. In pixels containing clouds from only single-layered, low-level systems, a retrieval scheme that accounts for partly-cloudy pixels was used to retrieve: cloud optical depth, droplet effective radius,...
Fine and coarse particles were collected for eight weeks during the
summer of 1991, at a coastal site (Yaquina Head) and a non-industrial site
(Corvallis) in Western Oregon to characterize the aerosol composition and
evaluate whether the sites are appropriate for sampling "background" marine
air. Concentrations of up to 11...
Ship tracks have proven to be an ideal laboratory for studying the response of marine
stratocumulus to an increase in aerosol pollution. Here the response of already
polluted marine stratocumulus to further pollution was examined by studying the
clouds where two ship tracks cross. 78 crossings of ship tracks were...
One kilometer Moderate Resolution Imaging Spectroradiometer (MODIS) observations for Terra (morning) and Aqua (afternoon) satellites were used to follow the morning to afternoon evolution of marine stratocumulus clouds that were affected by ship stack exhaust. The observations covered the summer months of 2002-2003 and August 2007 for marine layers off...
The objective of this research was to determine the feasibility of using chitosan as a natural flocculant to control turbidity during in-stream construction work. A series of field tests in Oak Creek, Corvallis, OR were conducted in order to test the effectiveness for turbidity control and the environmental impacts of...
The release of marine debris into the oceans and seas is a global issue of growing concern. These materials are harmful to marine environments and can also transport non-native species to novel habitats. Non-native species floating on marine litter is one of the lesser known impacts associated with marine debris....
The purpose of this study was to determine the significant
variables influencing the damage levels sustained by the residual
stand after skyline thinning of coniferous stands. Damage levels were
measured in ten study areas in western Oregon that had received their
first commercial thinning.
For this post-logging study, 38 units...
The objective of this study was to determine the effect that
ration formulation has on volatilization of gases and offensiveness of
the odor associated with the wastes produced from Holstein replacement
heifers. Six separate experiments were conducted to study the
relationships between different variables on the release of hydrogen
sulfide,...
The use of terbacil for weed control was adapted by a high percentage
of Oregon peppermint growers soon after its introduction in
1967. To help clarify some of the implications of terbacil usage,
three studies were undertaken to collect information concerning (a)
the movement and build-up of terbacil in various...
This paper examines the environmental factors influencing
the die-off and transport of fecal coliform bacteria
present in wastes applied to the land surface. These factors
are examined specifically for dairy waste management systems
and the net effect each system has on runoff water quality.
A model is developed that considers...
Two small adjacent watersheds on the west-central edge of the
Willamette Valley of western Oregon were studied. Information was
gathered on existing conditions to determine the suitability of the two
watersheds for a paired-watershed study design.
A soil survey was conducted using slightly modified soil series
previously established for the...
Diclofop-methyl [me yl 2-(4-(2,4-dichlorophenoxy) phenoxy) propanoate] hydrolysis, degradation, and leaching were studied in field and laboratory experiments. Greater than 75% of the applied diclofop-methyl hydrolyzed to diclofop in 2 days at 4°C, the prevailing soil temperature during western Oregon winters. Degradation beyond the diclofop molecule, also an active herbicide, was...
Research has been completed which identifies qualitatively and
quantitatively the deposition, persistence and fate of polynuclear
aromatic hydrocarbons (PNAH) on burned clear-cut sites in Oregon.
Eight PNAH were identified and quantified in post-burn litter samples
taken from four slash-burned sites. Deposition of lower
molecular weight, 3-4 ring compounds was considerably...
Dumping drilling mud from offshore drilling rigs into the
ocean could have a negative impact on the marine environment. Due
to this possible impact, the Offshore Operators Committee (OOC) has
deemed it necessary to predict the fate of drilling mud discharged
into the ocean. Through the funding of OOC and...
This report examines environmental factors influencing the die-off and transport of fecal coliform bacteria present in wastes applied to the land surface. These factors are examined specifically for dairy waste management systems and the net effect each system has on runoff water quality. A model is developed that considers the...
An experimental protocol to determine the effects of temperature and light on the dissipation of xenobiotic substances in pesticide deposits is presented. A factorial design laboratory experiment is used to develop isothermal models of the dissipation of compounds over time in authentic pesticide deposits on excised leaves arid glass microscope...
Stream buffer strips are an important tool for protecting the stream environment. This research documents the losses from 40 stream buffer strips, in the Western Cascades of Oregon, established 1 to 15 years before the study. Predictive equations are developed
which identify the major reasons for buffer strip losses. Losses...
Logging on skid trails restricted to 10 percent or less of the harvested stand can reduce the area of compacted soil by at least two-thirds, In a comparative study, productivity of Douglas-fir logs per hour was just as great In an area with designated trails as In an adjacent area...
Federal legislation requires that governmental programs be evaluated on a wide set of criteria to provide policymakers with information on the achievement or lack of achievement of goals and/or objectives. A methodology to identify and quantify measures of achievement is described. In addition, the methodology is designed to facilitate the...
The hydrophobicity of soils of the Deschutes National Forest was
studied. The soils are Cindery Typic Cryorthents, formed in cinders
and ash from Mt. Mazama. Ponderosa pine is the dominant overstory
vegetation. Of particular interest was the effect of prescribed
burning on hydrophobicity. Fire has been shown to cause a...
Groundwater contamination on irrigated land is of concern in this nation
and around the world. In order to reduce the potential of groundwater
contamination by agricultural practices such as irrigation, fertilizer and pesticide
application, vadose-zone monitoring and sampling are needed. The main
objective of this study was to evaluate impacts...
Groundwater at Oak Ridge National Laboratory's Field Research Center (FRC) is contaminated with U(VI) and Tc(VII), has pH values as low as 3.3, and nitrate concentrations as high as 120 mM. The objective of this research was to determine if in-situ bio-immobilization is a viable treatment alternative for this water....
With the increased recognition of moss as a secondary forest product has come an increased concern for the ecological ramifications of moss harvest. Three issues of primary concern are (1) characterizing the epiphyte communities impacted by harvest, (2) assessing the host preferences of these epiphytes, and (3) describing the availability...
Intragravel organic loading and intragravel dissolved oxygen were studied to determine the relationship between timber harvesting adjacent to first-, second-, and third-order streams and intragravel water quality. Twenty watersheds in the central Coast Range of western Oregon were studied of which five were undisturbed, nine were partially harvested, and six...
Amounts of natural debris in small headwater streams under old growth
stands of Douglas-fir vary from 6 1/2 tons per 100 ft. of stream
to 26 tons per 100 ft. of stream, depending on terrain and timber
characteristics and sequence in the natural accumulation-flushing
cycle. Approximately 10% of the weight...
Copper migration from treated wood has created concerns within the
environmental community because of the potential effects of this heavy
metal on aquatic organisms. Migration can be limited, to some extent, by
more controlled treatments and by post-treatment processing, but these
actions cannot completely overcome the problem. An alternative approach...
As the demands for forest products increase, additional timber harvesting operations can be expected on steep mountainous terrain, The resulting disruption of natural slope stability by man's disturbances (roadbuilding, logging and vegetative manipulation, etc.) may also accelerate mass movement processes in this terrain. Swanston (1969) defines mass movement as ".,...
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants formed from the incomplete combustion of organic material. These contaminants are of concern because of their widespread presence in the environment and toxic properties. In addition, PAHs encompass a class of diverse compounds with varying physicochemical properties and exist in the environment as...
Concern about heavy metal pollution has increased during the
past decade in which studies have shown that heavy metals are accumulating
in the environment and that these metals, in excess, are
toxic to organisms, including man. Because of this concern, scientists
have suggested the use of indigenous organisms as monitors...
Seasonal trends in water table level and soil moisture
for four plant community types within an irrigated eastern
Oregon riparian zone were described. Aboveground biomass,
species composition, litter, percent bareground and percent
basal cover of key plant species and life forms were measured.
The relationship between water table levels and...