WMOD00309 ‎(2)‎

• Title: Weather Modification Programme - Catalogue of Data Sets for the International Cloud Modelling Workshop/Conference
• Date: 6/1/1984
• Weather Modification - Doc Type: Report

5. Twenty-five Bureau of Reclamation PROBE micronet stations which
measured winds, temperature, pressure, relative humidity, and
precipitation

6. Rawinsonde sites, one 60 km upwind, the other 30 km downwind of
the barr'i er

7. Satellite images from the GOES West satellite and NMC synoptic data
3.1.2.2 Closed data set

A similar COSE data set is available for the closed orographic experiment. The
initial flow conditions and soundings will be provided in the same format as the
open case from the three-dimensional model.

3.2 Sensitivity tests

Any of the open data sets may be used for model sensitivity cases; however in
order to facilitate comparisons among models four cases are proposed for speci-
fic tests.

3.2.1 Fluid dynamics
3.2.1.1 Initialization

A. GATE 226 - August 14, 1974

GATE experiment operations on August 14, 1974 were specifically designed to
study the structure of the boundary layer in relation to a line of towering
cumulus over the tropical ocean. Hence this case which was selected for the
open data set in experiment 3.1.1.1.1 is appropriate for boundary layer sen-
sitivity analyses also. Please refer to section 3.1.1.1.1 for a description of
this case.

This case provides relatively simple, weakly forced conditions in which complete
aircraft observations of low level convergence are available. Thus it offers
a good opportunity for sensitivity tests of convergence, thermal, or moisture
perturbation and combinations of the two mechanisms.

B. CCOPE - June 20, 1981

Numerical studies of the evolution of convection under conditions of weak large
scale forcing have been conducted on this case by Smolarkiewicz and Clark
(1984). This case was selected for model initialization experiments because
convection that developed early in the day w,as driven by local heating without
large scale forcing. Cumulus clouds developed in the morning and were studied
by two cloud physics ai rcraft as described by Fankhausl~r et al. (1983). Cloud
bases ranged from 1.9 to 2.5 km. Cloud tops reached 6.0 km by early afternoon.
Time lapse cloud photographs from 0700 to 1300 LST indicated cumulus humilis and
cumulus congestus clouds with diameters of -5 km and durations -20 min. Later
in the day larger clouds moved into the network.

19.