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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004
Figure 9. The illustration shows infrared GOES image with
lightning data represented by white cross (top figure); rain
fraction for convective (red — middle figure) and stratiform
(blue — middle figure) and instantaneous rainfall rate (button
figure) at 16:39 UTC and 20:09 UTC on 13 of January of 2000.
3.2. Daily Rainfall Rate
Following Huffman (1997) and in order to make a comparison
between the results from rainfall estimation algorithm proposed
in this work and values from the Global Precipitation
Climatology Project (GPCP) in a daily basis, it was taken
GOES data from the period of 12 to 14 of January 2000 (figure
SFT = 13 Jame 2000
1261
10). There is a spatial scale difference between the two used
data since the GCP one were obtained at resolution of 1° x 1°.
The comparison idea is to present, as shown in figure 10, the
spatial rainfall distribution estimated by the proposed algorithm
SIRT and GPCP. The results show a quite good coherence
regarding to spatial distribution point of view. Since the GCCP
spatial resolution is 10 times poorer, loosing information, the
SIRT. And the reason why the SIRT is able to observe higher
variability of the precipitation the heavy precipitation intensity
estimated by SIRT is observed in the same areas given by
GPCP.
Figure 10. Daily rainfall estimation for the method SIRT (left)
and GPCP (right), for the period12-14 of January 2000.
0 160
R(mm/h)
It has well the
precipitation field over study area. The methodology shows a
quite good performance to capture active rainy convective
areas. The adjusted curves of cloud fraction area and their
respective convective and stratiform part were inferred, and
finally the different curves of rainfall rates base on the
temperature and frequency of lightning were obtained.
The results illustrate the potential of the rainfall estimation on
areas the where a great variability in space and time of the rain
exist, and especially with great frequency of Lightning
(atmospherics discharges).
As future perspectives, efforts will be made in order to use a
larger data set aiming to reach better fitting curves.
S. ACKNOWLEDGEMENTS
The authors would like to thank to *Financiadora de Estudos e
Projetos — FINEP” for the finatial support Grant No.
23.01.0650.00
6. REFERENCES
Adler, R. F., A.J. Negri, 1988. A Satellite Infrared Technique to
Estimate Tropical Convective and Stratiform Rainfall. Journal
of Applied Meteorology, 27(1), pp. 30-51.
Anagnostou, E.N. W.F. Krajewski, and J. Smith, 1999.
Uncertainty quantification of mean-field radar-rainfall estimes.
J. Atmos. Ocean. Techn., 16, pp. 206-215.
‘Arkin, P.A., and B. N. Meisner, 1987. The relationship between
large-scale convective rainfall and cold cloud over the Western
Hemisphere during 1982-1984. Mon. Wea. Rev., 115, pp. 51-74.