Das Institut für Meteorologie und Klimaforschung (Troposphäre) bedauert,
CMOS nicht wie geplant im Jahr 2004 durchführen zu können.
Wir beabsichtigen, nicht zuletzt wegen der erfreulichen Resonanz, die unser Vorhaben gefunden hat, CMOS auf das Jahr 2005 oder 2006 zu verschieben.
Vorerst bedanken wir  uns herzlich für das Interesse an CMOS.
Wir hoffen, möglichst bald das im folgenden beschriebene Projekt fortsetzen zu können.

Convection modification Study (CMOS*)

As an initiative of the Institut für Meteorologie und Klimaforschung (IMK) the ’’Convection Modification Study’’ (CMOS) on atmospheric convection is planned for the summer of 2004 in southwestern Germany above flat terrain and low mountain ranges (area of investigation). It is planned to study the causes of intensification and weakening of showers and thunderstorm cells (goals). Such convective cells (example) regularly cause large damage due to hail, stormy winds and lightning and cannot be forecasted reliably (damage). Preliminary studies in the framework of the VERTIKATOR project gave reason for the importance of convection forcing coupled on soil surface properties and orography (studies).

The most important factors influencing their development are

• the density stratification of the troposphere,
  
• the energy transformation in the Planetary Boundary Layer,
  
•  ascending and descending air motion caused by orography (triggering), and
  
•  the water vapour reservoir in the surface (LM-simulation), which

accordingly will be documented by measurements within a most flexible strategy (strategy).
It is the objective of this study to investigate these relationships in order to gain a better short range prediction of the temporal evolution of convective phenomena which might cause damage (hailstorm).
The project does not obtain third party funding and constitutes itself from contribution of participants. CMOS is a pre-study of planned larger experiments of the coming years, such as the ’’Convective Storm Initiation Project’’ (CSIP) in England in 2005 and the IOP of the Programme ’’Quantitative Precipitation Forecast’’ in 2007.

Specific attributes of CMOS are

• the acquisition of three-dimensional data on convective systems for process studies, and improvement of cloud resolving models and numerical forecast models 
  
•  tests of new transportable in-situ-sensors, radiosonde release strategies and remote sensing systems within a quasi-Lagrangian study of convective systems (equipment), 
  
•  development of observational concepts for CSIP und SPP1167 IOP,
  
•  conduction of a TRACKS pre-experiment in the framework of the TRACKS-initiative of the Centers of the German Helmholtz-Society.
  

All participating institutes will have full rights to get access and to use data and results from the experiment. They agree to participate in the scientific analysis and to contribute to a
joint scientific reviewed publication about one year after the experiment.
Additional information can be obtained from the head of the institute as well as from Dr. N. Kalthoff and Dr. U. Corsmeier.

* CMOS is part of the TRACKS concept of the Helmholtz Research Centers