MICROFRONTS 1995
The following ATD facilities used in MICROFRONTS95:
- ASTER was used as the base for the turbulence and radiation measurements,
including those by the hot-wire anemometer.
- CLASS made soundings, mostly concentrated around frontal passages.
In addition, other organizations took data:
- Tethersonde data were taken several times during the program by
Iowa State University/University of Kansas at the El Dorado Reservoir.
- Profiler and surface station data (including fluxes) were made by
the Department of Energy ARM program in Kansas and Oklahoma.
- National Weather Service soundings from 8 sites North and West of the
ASTER site.
The UCAR Office of Field Program Support
(OFPS) has National Weather Service
products, and will eventually have all of the above data, available through
their
CODIAC
system.
(The following is paraphrased from the "MICROFRONTS EXPERIMENT Operations and
Data Management Plans" by W. Blumen and L. Mahrt.)
This experiment was to study coherent structures in the atmospheric
surface layer since they are responsible for most of the transport of
momentum, heat, and other scalar quantities. Hotwire anemometer
measurements were made at high temporal resolution to investigate the
edges of these structures, known as microfronts. The specific
scientific objectives were:
- Measure direct dissipation using the hotwire anemometers to test whether
inertial subrange estimates of dissipation are correct in various atmospheric
conditions (including synoptic frontal zones).
- Make dissipation measurements in frontal zones to determine the mechanisms
which limit frontal contraction.
- Examine how thermals organize transport.
- Test bulk parameterizations of the surface heat flux using surface
radiative temperatures.
- Study air modification by lakes. The ASTER measurements will provide
an upwind state to compare with weather stations set up around the
El Dorado Reservoir by Ray Arritt (Iowa State University).
- Check whether there is a relation between instability of the nocturnal
boundary layer and gravity waves. A small network of five microbarographs
were deployed by Carmen Nappo (NOAA/ORNL) to detect gravity waves.
Photos
South Tower Site (with North Towers in the
background).
|
North Tower Site
|
Radiation Stand
|
Radiation Sensors
|
Shelter for Hotwire Electronics
|
ASTER and CLASS Trailers
|
Panoramic View near the South Site (taken
during the site survey in October, 1994) with views (from top to bottom)
to the SW-W, NW-N, NE-E, and SE-S.
Steven Oncley<oncley@ucar.edu>
Last modified: Thu Sep 12 15:18:23 1996