WMOD00590

• Title: Analysis and Classification of Mesoscale Cloud and Precipitation Systems
• Date: 8/1/1983
• Weather Modification - Doc Type: Report

The value, Dn is the difference between the observed data value
and its first estimate value at the same point. A simple biquadratic
interpolation between the values of fo(i,j) at the four nearest grid
points is used to estimate fo(x,y). Barnes has shown that the final

response is a function of wavelength ~, is:

R = R (1 + Rg-l_R g)
000

(6)

where:

Ro = exp (_~24c/\2)

(7)

The same procedure is followed using a second low-pass filter to
determine the band-pass field, which is the difference between the two
low-pass analyses. The band-pass analysis is performed using weight
function constants, such that the filter response (BR) is peaked at a
specific wavelength of interest shown in Fig. 3.1. The band-pass field
defines the mesoscale features which occur at the wavelength of interest.
The total field is then computed as the sum of the macroscale (first
low-pass) field and the mesoscale (band-pass) field. This analysis

system is fast, economical, and enables the meteorologist to specify a
response on the appropriate scale of the mesoscale triggering phenomena

and density of observations.

The response curves for the filters used in the following examples
are shown in Fig. 3.1. The low-pass responses Rl and R2 used to define
the mesoscale band-pass BR response are shown. Note the peak at maximum

of 500 km. The total field response (TR) is the sum of the BR and R2

response curves. Appendix A provides an example of the families of

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