Relationships among the surface wind, horizontal synoptic-scale
pressure gradient and topography are studied in the Willamette Valley
in western Oregon. Terrain features alter the standard surface wind-pressure
gradient relationship such that the angle between the surface
wind and the surface geostrophic wind is most frequently 60°.
In winter the surface...
Surface meteorological data collected at a mesonetwork in
Colorado during the 1973 National Hail Research Experiment were
analyzed to see if a diurnal oscillation of boundary layer wind exists
and also to determine the mechanism that drives the wind system.
The average temperature, pressure, and wind velocity for a month's...
High resolution data of moisture, temperature and wind velocity
collected by aircraft during the 1975 Air Mass Transformation
Experiment (ANTEX '75) provide information for detailed investigations
of the phenomena occurring at the top of a cloud-topped mixed
layer.
Joint frequency diagrams of humidity and temperature reveal that
for parts of...
A method of calculating surface evapotranspiration by separately
including the effects of vegetation and atmospheric evaporative demand
under the condition of nonlimiting soil moisture is presented. A
literature survey is conducted to determine the effects of plants on
evapotranspiration.
To represent the atmospheric evaporative demand, the original
potential evaporation equation...
The influence of boundary layer pumping on an externally-forced
synoptic-scale flow is examined. The results follow earlier theories of
stratified incompressible Boussinesq flow. These theories state that
the spin-down time scale and the penetration depth of the influence of
boundary layer pumping are inversely proportional to the stratification
and directly...
An analytical two-layer model consisting of a time-dependent stratified
boundary layer topped by stratified free flow is developed in order
to study atmospheric boundary layer production of vertical motion. To
avoid use of a constant eddy viscosity, the boundary layer equations are
layer-integrated over a fixed depth, and surface stress...
In plume theory it is generally assumed that a plume issuing from a round source maintains a round cross section throughout. The consequences of this hypothesis are significant; this fact should motivate research into its validity. This paper investigates conditions and analyzes mechanisms that cause fluid plumes to undergo systematic...
Globally intermittent turbulence is characterized by sudden switching from significant turbulence to weak turbulence and back on time scales ranging from seconds to tens of minutes as opposed to microscale intermittency, which is due to organization of small scale gradients by individual eddies on scales as small as the Kolmogorov...
The very stable boundary layer is a region of the atmosphere typified by large
vertical gradients of temperature and momentum. Analysis of very stable atmospheric
flows is complicated by the presence of nonlinear interactions among gravity waves, shear-driven
overturning circulations, two-dimensional vortical modes and intermittent turbulence
in various stages of...
Sudden changes occur where the mean values associated with two adjacent non-overlapping
windows of data are anomalously different, and the transition between the
window means occurs over a scale that is small relative to the scale of the windows.
Positions of sudden changes can be economically retrieved. The sudden change...
The stability of steady-state solutions of the equations governing two-dimensional,
homogeneous, incompressible fluid flow are analyzed in the context
of shear-flow in a channel. Both the linear and nonlinear theories are
reviewed and compared. In proving nonlinear stability of an equilibrium,
emphasis is placed on using the stability algorithm developed...
Several horizontal flight segments from SESAME and
ALPEX are studied using structure functions and specral
analysis methods. Theoretical analysis of the relative
errors in structure function and correlation function in
the presence of large scale wave activity is presented. The
effect of stratification and shear on the -5/3 inertial
subrange...
An eigenvector analysis of the velocity-temperature correlation
matrix is applied to clear-air turbulence measured by aircraft in the
Bora. The eigenvectors are identified with the main eddies of the
turbulence. This study attempts to infer the three-dimensional
structure of these eddies. The results are compared with turbulent
structures in the...
A two-scale approach for the turbulent mixing of momentum in an unstable stratified boundary layer is proposed in an attempt to eliminate existing inconsistencies between parameterized mixing of heat and momentum. The parameterization of the large eddy stress is suitable for simple boundary layer models where computational efficiency is important....
The statistics describing variations of turbulent motions within the so called inertial range of length scales depend on the scale over which the motions are varying and the "average" rate at which the turbulent kinetic energy is being dissipated on the molecular scale. This hypothesis stemmed from the similarity arguments...
This study concentrates on analysis of LongEZ aircraft data taken offshore of the Atlantic Coast of the United States. Due to the land structure of the region, it was possible to isolate the effect of narrow land on air as it flows offshore. The narrow land (Outer Banks) separates inland...
The use of efficient basis functions to model and represent flows with
internal sharp velocity gradients, such as shocks or eddy microfronts, are
investigated. This is achieved by analysing artificial data, observed atmospheric
turbulence data and by the use of a Burgers' equation based spectral
model. The concept of an...
Atmospheric boundary layers become stably stratified at night over land when the surface becomes colder than the air layer above. In stable nocturnal boundary layers (SNBL), turbulence becomes weak and intermittent, terrain-induced phenomena such as drainage currents or gravity-waves emerge and the surface heterogeneity is enhanced. Because of their complexity...
Purpose of the Study
The study was designed to determine whether the amount of
formal education industrial education teachers have completed does
affect their (1) attitude toward teaching and (2) performance in the
classroom. The specific questions formulated to investigate this research
were:
1. Will the amount of formal education...
Purpose of the Study
The purpose of this study was to determine and analyze criteria
and procedures used in the selection of occupational advisory committee
members in Oregon community colleges. The existence of a
common core of criteria and procedures for selecting occupational
advisory committee members was investigated. Further, the...
Purpose of the Study
The purpose of this study was (1) to identify the educational and
socio-economic characteristics of enrollees in the In-School Neighborhood
Youth Corps Program and (2) to determine those educational
and socio-economic characteristics that would predict potential achievement
in the In-School Neighborhood Youth Corps Program.
Procedures
A...
Purposes of the Study The study had several purposes, the major one being to
determine the common professional education competencies needed by
community college instructors of trade and industrial education. Two
other purposes of the study were to determine if differences existed
among community colleges according to scores trade and...
Purpose of the Study
The purposes of this study were to (1) identify the educational
and socioeconomic characteristics of Latin American students who
have graduated from the California State College system, (2) to identify
those characteristics which significantly affect academic success,
utilization of training and return home to Latin America...
The study was designed to determine if students using the individualized
instruction method, scored significantly higher on a 30 question
achievement test than did students in more traditional group paced
programs. The study also attempted to determine if attitudes displayed
by educators, as measured on an attitude scale, aided in...
The purpose of this study, to examine the relevance of U.S.
graduate education in agriculture to careers in agricultural
development of East African agriculturalists, was examined in
terms of three problems:
Problem 1: Was U.S. graduate education in agriculture
relevant to careers in agricultural development of East
African agriculturalists?
Problem...
Recent trends in higher education have led to the development of
alternatives to traditional on-campus graduate degree programs. There is a
concomitant need to understand student experience in field-based programs
which support continuing education and career development for employed
adults. The central purpose of this research was to explore the...
This qualitative study describes and interprets the interactions of participants in a
community college writing class delivered by computer-mediated communication
(CMC). The class represented a best practice model of learner-centered instruction in a
CMC class. The description and the discussion are framed by five aspects of CMC
instruction: (1) context;...
The purpose of this study was to improve instructional system design at Small
Business Development Centers by developing a best practice model for assessing client
training needs. Two research questions were addressed:
1. Is self-directed learning an appropriate framework for instructional system design at
Small Business Development Centers?
2. What...