PROGRESS REPORT ON CASES DATA/ANALYSIS
CASES-97 Update 1: Jan 05, 1999
(a) surface data
Steve Oncley has made a first pass at the data, corrected the flux data for
'leveling' errors, and made two datasets available (5-min data in netCDF and
30-min data in ascii) over the Web either from the ATD web site, which is
accessible from the cases web site or through the joss web site
(www.joss.ucar.edu).
Dave Yates of NCAR has made a couple of passes through the 30-minute data and
removed suspicious data. Dave is also using various techniques to fill in data
gaps (e.g., using mean data to compute fluxes if none are available). He is
also generating a database including soil type, etc. for a long-term (1 month)
run using MM5.
Peggy LeMone has compared the downwelling radiation data (input for
surface-atmosphere interaction models as well as diagnostic for aerosol
loading) and found apparent biases between the stations. Since this bias is
such that there is more downwelling solar on the east side of the array, Steve
will put the sensors on the NCAR roof side-by-side to see if the bias is
instrumental or reflects something going on in the atmosphere (e.g., more
aerosols to the west). Peggy has looked at the aerosol data from the Twin
otter for the two IOPs for which budgets were done, and confirmed that there
are more aerosols to the west on both days.
See radiosonde data for further surface-data intercomparisons.
(b) aircraft data
Bob Grossman and Peggy LeMone have constructed budgets using an early version
of the fluxes, and they look 'reasonable.' However, intercomparisons have not
yet been done because Bob's flux program is still not operational. He is
working hard on this, and anticipates being able to run fluxer soon. Bob
McMillen helped out greatly here.
Both datasets are being put into netcdf form so that they are compatible with
NCAR and Oregon State (Mahrt) software used by Don Lenschow's group to compute
fluxes, as a backup and for comparison.
Currently Bob is going through and refining flight-leg times.
One encouraging 'intercomparison': The radiative flux divergence calculated by
Bob Grossman using the King Air data is consistent with that predicted from a
model by Stu McKeen (Aeronomy Lab/NOAA) using visibility data as input. McKeen
calculates divergence due to scattering of visible light by aerosols, to be
added on to the radiative flux divergence by gases in the air. Tom Ackerman's
student ran his radiation flux program for us to obtain these values.
Processed aerosol data from the Twin Otter data were recently made available
to Peggy LeMone from Dennis Wellman. These are not yet at JOSS.
netCDF King Air data is available from JOSS; Ron Ruth is working with Bob
McMillen to get the Twin Otter data in netCDF. These will then be transferred
to the JOSS Web site.
(c) Radiosonde data
Three versions (10-sec, and 5-mb) of the radiosonde data are
available on the web from JOSS (joss.ucar.edu). The original data are not
available over the Web, but can be obtained.
These data appear to be rather good; gradients computed from the radiosonde
data are consistent with those from aircraft to within 20%.
Bob Grossman and Agbeli Ameko have been comparing the CLASS surface station to
the ABLE AWS surface stations and found them to be in excellent agreement
(within 0.2 K temperature, and 2% relative humidity -- correct me Bob if this
is not quite correct). These data can be used along with the original data to
produce an 'improved' dataset but that has not yet been done).
(d) ABLE data (profilers, Smileyberg).
ABLE data have been available on the Web from the time of the experiment.
Profiler data have been extensively analyzed by Rich Coulter and M.S. Pekour,
who also developed a technique for removing bird effects from the Oxford
profiler (ref: Pekour and Coulter, 1999: A technique for removing the effect
of migrating birds in 915-MHz wind profiler data, to be published in JTech)
Corrected profiler data are available on the web, in pictorial and digital
form. The "raw" (by beam) data are also available on the Web.
I heard that Argonne would replace the Oxford profiler by a more modern
version; Rich -- what's the status?).
Argonne detected a wind-vane error at Smileyberg; this has been documented and
corrected.
(e) Radar data. We have not yet looked at the fair-weather radar data, but
rainfall maps have been constructed for major rain events (all but one caught
by the S-POL) by Ed Brandes and Jim Wilson of NCAR.
(f) Modeling/testing of parameterization schemes
Harukasu Nagai will come here in March from Japan to (a) test his surface
parameterization scheme, and (b) run MM5 with his scheme. He is currently
using CASES-97 data on Task (a) back in Japan.
Fei Chen (NCAR) and David Yates are planning to run MM5 for a month using the
CASES-97 dataset under a NASA Grant. Chen, Sun, LeMone, and Lenschow (all
NCAR), are applying for internal NCAR/USWRP money for further analysis of
CASES-97 and SGP-97 data, to compare the results of budget studies to those
produced in MM5 runs, and to improve the surface/PBL scheme in the model.
CASES-97 Update 2: Jan 22, 1999
---------------------------------------------------------------------
>From Marv Wesely:
Thanks for the update on CASES-97 data analysis. Jie Song, Rich
Coulter, and I have been working on the "PASS" model to simulate
evapotranspiration over the Walnut River Watershed and immediate,
enclosing, rectangular area. As part of the process, NDVI data with
atmospheric corrections using LOWTRAN7 applied to the AVHRR data for
five golden days have been produced and put on the ABLE web site;
a "readme" file is included. We are in the process of comparing
simulated fluxes with those measured by NCAR (Steve Oncley) and
comparing inferred soil moisture patterns with precipitation pattern
data provided by Ed Brandes. Other activities in progress is comparison
of inferred soil moisture content with the NCAR measurements and comparison
of water vapor flux with aircraft data. Jie Song will report on some
of these activities during two presentations at the AMS meetings.
A "final" set of data on latent and sensible heat fluxes has not
been produced yet; you know how it goes when model results are compared
with observations. We hope to compute the surface fluxes for nearly all
days of CASES-97 but have not finalized the soil moisture routines to
march forward in time beyond each golden day.
By the way, Rich and colleagues succeeded in installing a new 915-MHz
system at Oxford, and the data are on the ABLE web site.
---------------------------------------------------------------------------
>From Peggy:
An update to this update. Peggy and Bob got together with Jie at Dallas and
again at NCAR. We passed on to her some additional data (the latest version of
the Twin Otter fluxes from Bob McMillen; soil-moisture profiles at Sites 7 and
8). Also, she and David Yates got together to compare notes and discuss future
comparisons of flux-fields derived over the CASES-97 area from their
techniques.
Bob Grossman suggested that they pursue trying to get more current data on
agriculture than either group currently has; Dave was going to look into
Landsat data; Bob was going to call up the agricultural extension agent for
Butler County to see what sort of information they had.
--------------------------------------------------------------------------
>From jklazura@anl.gov Wed Jan 6 15:57:45 1999
Hi Peggy:
We have been busy installing equipment at ABLE. Last month we installed
the new Radian 915 radar at Oxford, and moved the old radar to our central
site (APO = ABLE Project Office) on Haverhill Road. All five Automated
Weather stations are now installed (Beaumont, Smileyberg, APO, Oxford,
Whitewater), and net radiometer has been added at Smileyberg. The APO
office trailer has been moved to permanent pad, and visiting scientists
parking and electrical/phone panel installed. Central site looks great,
although still porta potty and no running water. We have leased land on a
sorghum field near Rose Hill, and plan to install surface flux site there
sometime this year, perhaps after CASES-99. We plan to install an EBBR
(Energy Balance Bowen Ratio) system at Whitewater this spring.
Oregon State installed a fully automated 15-probe array system at
Whitewater this summer to monitor soil water content and soil heat
movement. The EBBR will be located right in the center of this array.
------------------------------------------------------------------------
>From Peggy:
A bibiography of CASES-97 talks at Dallas. I know of four, three of which were
joint in hydrology and boundary layers. The joint talks were part of an
SGP-CASES session where talks from the two experiments alternated -- an
excellent idea! Let's hope for more next year. Please let me know if you know
of others!
Proceedings, AMS 13th Symposium on Boundary Layers and turbulence, 10-15
January 1999, Dallas, TX.:
Coulter, R. 1999: Convergence estimates over the ABLE region during CASES-97
obtained from radar wind profiler and sodar data. 508-511.
LeMone, M.A., and R.L. Grossman, 1999: Evolution of potential temperature and
moisture during the morning: CASES-97
J. Song, M.L. Wesely, R.L. Coulter, B.M. Lesht, R.H. Cuenca, S.P. Oncley,
E.A. Brandes, 1999: Inference of extractable soil moisture in the plant root
zone at the Walnut River Watershed. 539--541.
Proceedings, AMS 14th Conf. on Hydrology, 10--15 January, Dallas, TX:
Song, J., M.L. Wesely, R. L. Coulter, B.M. Lesht, S.P. Oncley, R.H. Cuenca, and
E.A. Brandes, 1999: Diurnal evapotranspiration estimates in the Walnut River
Watershed. 102--105.
Song et. al. Inference of extractable soil moisture -- also 488--490.
Coulter, Convergence: also 454--457.
LeMone and Grossman, Evolution: 446-449.
Good to see Rich Coulter, Marv Wesely, Jie Song, Eric Woods, and many other
friends of CASES and CASES-97.