Retrieval of Precipitation from Satellites
3.0
,---...
r<)
E
'-...
(J)
2.0
'-"
'-...
E
~
'-...
~
'---'
1.0
Abs. - -
+ R.10
• 10 mm/h
o R.50
x 50 mm/h
Ext. - - -
40
FREQUENZ
60
[GHz]
257
--+... -
80
100
Figure 11.7: Comparison of mass extinction and absorption coefficients computed on the basis
of two different types of raindrop spectra for rain rates of 10 and SO mm/h. The curves labeled
R.10 and R.SO refer to the dropsize distributions by Deirmendjian (197S), the others to Willis
(1984)·
,
VOLUME ABSORPTION
RAIN RATE Imm/hl
10 20 30 40 50
-WATER
3 --ICE
E 2
:!!
.,;
VOLUME SeA TTERING
-WATER
3 --ICE
2
Figure 11.8: Volume absorption and scattering coefficient of precipitation size water and ice
particles as a function of the rainrate computed for Marshall-Palmer dropsize distributions
(Marshall and Palmer, 1948).
• Interaction parameters of rain may vary by 10% depending on droplet spectrum .
• Absorption/emission by precipitation-size ice is much smaller than by liquid partides, but
the importance of scattering by precipitation-size ice increases with frequency.