This page is an english translation of the original Micromet page, hosted by the University of Cologne.

The program Micromet simulates the behavior pattern of a thermal bubble and its associated convective cloud development based on the surrounding airmass. Micromet was developed specifically for needs of the soaring pilots in mind. On the basis of midnight soundings of temperature, humidity and wind, Micromet will develop numerous graphic prognostic evaluations of these soundings.

Sample: horizontal cut

The advective inflow of air masses will be analysed within the convection forecast. This is calculated through reverse trajectories within the stationary airflow of the midnight soundings.

Sample: trajectories

These, in such manner, forecasted vertical profiles of temperatures and humidity will be first warmed up in the lower layers based on seasonal and diurnal differences of the sun's radiation in accordance with the method of Gold (1933). Any intervening cloud cover (calculated on the humidity content of the air mass) and the geography of the area will be considered in the forecast.

The following simulation of the convection is based on a model of Okura and Takahashi (1971), which simulates the behavior of a thermal bubble in a cylinder with a constant radius (in this case 600 m). For this simulation the temperature of the air in contact with the ground is warmed by 1.2 Kelvin relative to the surrounding air, to produce a lifting motion to this parcel of air.

This micro scale model also considers dynamic entrainment, horizontal advection and turbulent entrainment of the surrounding air, the temperature and humidity is being kept constant during the simulation. The program also contains equations to calculate by simple assumptions the rate of change for condensation, suspended water droplets, rain and ice particles. Also, with a vertical movement equation is the descend rate of rain droplets and ice particles considered in order to simulate any precipitation.

Sample: CB Simulation

The program also calculates the development of the convective conditions throughout the day. The hourly simulation continues until maximum convection is reached, but does not, contrary to the full program version consider ice particles or rain droplet content.

Sample: convection forecast

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URL: http://wie-im-flug.net/wetter/micromet.html
(c) R. Blazek, A. Fink, F.J. Molé, P. Speth
(c) 2003 Dr. Guido Scholz, D-84508 Burgkirchen (info@wie-im-flug.net)
(c) 2003 Frank Pennauer (translation and co-writing)
Last Update: 02.04.2013