The main emphasis of this research project is on partitioning of mass and energy fluxes between vegetation and soil at the FIFE site, preparation of data from the FIFE Information System for an international thermal data set comparison, and studying the relation between surface temperatures observed from satellites and in situ measurements of surface temperature

Norman, John M.

English

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NASA-CR-191801
Report On Second Twelve Months Research on NASA Grant
/,__ k
Entitled
MODELING ENERGY AND MASS FLUXES FROM PRAIRIE CANOPIES
Principal Investigator
John M. Norman
Department of Soil Science
1525 Observatory Dr.
University of Wisconsin
Madison, WI 53706
March, 1, 1992 - Aug. 31, 1992
Grant # NAG 5-1416
(NASA-CR-191801) MODELING ENERGY
AND MASS FLUXES FROM PRAIRIE
CANOPIES Annual Research Report, 1
mar. - 31 Aug. 1992 (Wisconsin
Univ.) ? P
63/43
N93-18232
Uncl as
0141018
https://ntrs.nasa.gov/search.jsp?R=19930009043 2020-03-17T07:45:36+00:00Z
OBJECTIVES
The main emphasis of this research project is on partitioning of mass and energy
fluxes between vegetation and soil at the FIFE site, preparation of data from the FIFE
Information System for an international thermal data set comparison, and studying the relation
between surface temperatures observed from satellites and insitu measurements of surface
temperature.
A FIFE THERMAL DATA SET FOR ALGORITHM COMPARISON
The complete data from FIFE for two days (August 15, 1987 and Aug. 4, 1989) was
provided to the International Geosphere-Biosphere Program (IGBP) Working Group on Data
and Information Systems for an international study on comparison of surface temperature
retrieval algorithms. The total data set consists of two 6250 BPI magnetic tapes (one for each
day of data) and three high density diskettes with documentation. This data was sent to M.
Stoll of ENSPS, Strasbourg, France on December 11, 1991. In January 1992 we received
notification that the data was received and no difficulties were encountered with reading the
tapes and diskettes. In March, 1992 the FIFE data set was distributed along with data sets
from NESDIS, CSIRO in Australia and HAPEX from France.
COMPARISON OF INSITU AND SATELLITE OBSERVATIONS OF SURFACE
TEMPERATURE
Surface temperature estimates from the NOAA-9 and NOAA-10 satellites have been
made for the entire FIFE site and compared with infrared thermometer (IRT) measurements
averaged over the automated meteorological stations (AMS). The results indicate good
agreement between surface temperature estimates from atmospherically corrected AVI-IRR
channel 4 for surface temperatures below 25 C (Fig. 1). Above surface temperatures of 25 C
the AVHRR surface temperature estimates are 2 to 5 C higher than the infrared thermometer
averages over the AMS sites (Fig. 1). These high temperatures occur during afternoon hours
with a dry soil surface that can become elevated to temperatures of 50 C or more.
Infrared thermometers can be prone to errors. In an effort to evaluate possible errors
in the AMS infrared thermometers, we compared IRT measurements with predictions of
canopy temperature from the Cupid model (Norman et al., 1992). Predictions of infrared
canopy temperatures from cupid have been compared with directional measurements made
using a Barnes Modular Multiband Radiometer and generally found to agree within about 1
C. Input data for the Cupid model is derived primarily from observations at the AMS.
Figure 2 contains the diurnal course of solar radiation, air temperature at a two-meter height,
soil surface temperature, vegetation (canopy) temperature and nadir infrared temperature.
Clearly the differences in the various temperatures can be considerable. Figure 3 shows the
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Fig. l. Comparison of surface temperature estimates for the entire FIFE site from
atmospherically corrected AVHRR observations and an average of the infrared thermometer
measurements from the automated meteorological stations.
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Fig. 2. Predictions of various temperatures from the Cupid model along with measurements of
the incoming solar radiation.
Model Calculated vs AMS measured
Temperatures ( 15-AUG-87; STN '
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Fig. 3. Comparison of predicted infrared temperature from Cupid with IRT measurements for
nadir view. NOAA AVHRR satellite overpasses are indicated.
diurnal course of predicted nadir infrared temperature and measured nadir infrared
temperature. The two temperatures agree within about 2 to 3 C with predictions indicating
lower night-time and higher day-time temperatures. Considering typical spatial variability
associated with surface temperature measurements, this agreement is encouraging and suggests
that the IRT measurements may be reasonable.
References
Norman, J.M., N.S.Goel, J.Chen and S.F. Sun. 1992. Relating directional infrared canopy
temperatures to plant water stress. IGARSS-92 Symposium, IEEE cat. no. 92CH3041-1,
Piscataway, N.J., Vol. 1, pp. 755-756.
PUBLICATIONS UNDER THIS GRANT:
Norman, J.M., R.Garcia and S.B. Verma. 1992. Soil surface CO 2 fluxes and the carbon budget
of a grassland. J. Geophys. Res. 97:18,845-18,853.
Norman, J.M. and L.K. Balick. 1992. Directional temperature and emissivity of vegetation:
Model and measurements. COSPAR Book of Abstracts, p. 320.
Norman, J.M., F. Becker and M.P. Stoll. 1992. Intercomparison of methods for land surface
temperature retrieval from space - An IGBP/DIS program: Early systhesis of Results.
COSPAR Book of Abstracts, p. 318.
Norman, J.M., J.M. Welles and D.McDermitt. 1992. Scaling leaf gas exchange measurements
to estimate canopy fluxes. Agronomy Abstracts, Amer. Soc. Agronomy, Madison, WI. p.20.
PRESENTATIONS UNDER THIS GRANT:
Norman, J.M. and L.K. Balick. 1992. Directional temperature and emissivity of vegetation:
Model and measurements. Symposium on Methods and Challenges in Estimating Surface
Temperature from Spacecraft, Aaircraft and Ground-Based Platforms. 29th Plenary Meeting of
the Committee on Space Research (COSPAR), 28 Aug. - 5 Sept., 1992, Washington, D.C.
Norman, J.M., F. Becker and M.P. Stoll. 1992. Intercomparison of methods for land surface
temperature retrieval from space - An IGBP/I)IS program: Early systhesis of Results.
Symposium on Methods and Challenges in Estimating Surface Temperature from Spacecraft,
Aaircraft and Ground-Based Platforms. 29th Plenary Meeting of the Committee on Space
Research (COSPAR), 28 Aug. - 5 Sept., 1992, Washington, D.C.
4
Norman,J.M.,J.M. WellesandD.McDermitt. 1992.Scalingleaf gasexchangemeasurements
to estimatecanopyfluxes.Amer. Soc.Agronomy AnnualMeetings,Minneapolis,MN, Nov.
1-6, 1992 (Invited).
Norman,J.M. 1992.Thermal algorithms for surface state. ISLSCP Americas Workshop on
Remote Sensing of the Land Surface for Studies of Global Change: Models, algorithms and
experiments. Sponsored by NASA. June 23 - 26, 1992, Washington, D.C.


Modeling energy and mass fluxes from prairie canopies

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