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
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
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
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 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...