The research I am conducting centers mainly on turbulence
in the atmosphere, particularly that responsible for
energy exchanges between the earth's land and ocean
surfaces and the overlying atmosphere. The transfer
rates per unit area (fluxes) of sensible heat, water
vapor and momentum are important to the overall energy
balance of the earth's climate system, as well as
in the dynamics and thermodynamics of the atmospheric
boundary layer. Recently, there has also been interest
in fluxes of trace gases such as CO2 between the atmosphere
and land and ocean.
The flow of air over the land or sea is usually
turbulent, so the fluxes are obtained in the statistical
sense of averaged covariances of vertical turbulent
velocity and the appropriate quantity being transferred:
horizontal momentum (wind), temperature (sensible
heat) and water vapor (latent heat). The study of
turbulence is important in fluid mechanics, both in
the ocean and atmosphere (geophysical turbulence)
and in engineering flows. Geophysical turbulence measurements
are often sought because the high Reynolds number
of the flow, for which asymptotic theories apply.
High fidelity measurements of these variables are
required, and large amounts of data are collected
for statistical convergence. The measurements, in
conjunction with mean wind, temperature, humidity,
pressure, etc., are used to parameterize the fluxes
for use in numerical models and other studies and
to study the physics of the boundary layer in a wide
variety of weather situations.
The measurements are usually obtained from specialized
instrumentation on research aircraft, towers over
land or unique sea-going platforms such as the Scripps
Institution of Oceanography's FLIP, a large spar buoy
that provides a stable platform on the open ocean.
Often, the turbulence measurements are part of larger
multi-disciplinary experiments involving many platforms
and investigators. Generally, one field experiment
occurs per year. In the past, these have ranged from
wind-driven coastal upwelling near the Northern California
coast, boundary- layer cloud formation in the Atlantic
Ocean, and energy exchange studies in the Western
Pacific.
Some instrumentation is provided, especially on
the research aircraft which are operated by national
facilities such as NCAR or NOAA. Some is purchased
(sonic anemometers, data systems) and some is built
in-house (fine-scale temperature and humidity sensors).
Data analysis is performed with high-capacity work
stations at UCI. Access to national super computer
facilities is obtained when required. Detailed modeling
of some of the sensors is also done.
Funding for students and the research is obtained
from the National Science Foundation Divisions of
Atmospheric Sciences and Ocean Sciences, and the Office
of Naval Research. Typically, one student is added
per year. The research group also has undergraduate
students and post-doctoral fellows. Collaboration
is maintained with fellow researchers at Scripps,
Woods Hole Oceanographic Institution, and other universities
throughout the world.