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...