The Convective and Orographically‐induced Precipitation Study (COPS): the scientific strategy, the field phase, and research highlights

Abstract

Within the framework of the international field campaign COPS (Convective and Orographically-induced Precipitation Study), a large suite of state-of-the-art meteorological instrumentation was operated, partially combined for the first time. This includes networks of in situ and remote-sensing systems such as the Global Positioning System as well as a synergy of multi-wavelength passive and active remote-sensing instruments such as advanced radar and lidar systems. The COPS field phase was performed from 01 June to 31 August 2007 in a low-mountain area in southwestern Germany/eastern France covering the Vosges mountains, the Rhine valley and the Black Forest mountains. The collected data set covers the entire evolution of convective precipitation events in complex terrain from their initiation, to their development and mature phase until their decay. Eighteen Intensive Observation Periods with 37 operation days and eight additional Special Observation Periods were performed, providing a comprehensive data set covering different forcing conditions. In this article, an overview of the COPS scientific strategy, the field phase, and its first accomplishments is given. Highlights of the campaign are illustrated with several measurement examples. It is demonstrated that COPS research provides new insight into key processes leading to convection initiation and to the modification of precipitation by orography, in the improvement of quantitative precipitation forecasting by the assimilation of new observations, and in the performance of ensembles of convection-permitting models in complex terrain.

Radar climatology of the COPS region

“…The COPS summer, 2007, had the most CI days and the most thunderstorm days in this period but the majority of the COPS thunderstorms were synoptically driven (categories of frontal thunderstorms and supercells and many MCSs), rather than locally forced. This more frequent influence of synoptic forcing in generating storms is suggested in further results in this article and was also noted in Wulfmeyer et al (2011).…”

High‐resolution simulation over central Europe: assimilation experiments during COPS IOP 9c

“…The modification of the squall line by orography was another decisive feature resulting in nearly no precipitation over the COPS low-mountain ranges but strong re-activation in the lee side of the Black Forest. It is worth noting that nearly all nested D-PHASE (Rotach et al, 2009) models had problems in simulating the re-development of precipitation in the lee of the Black Forest, which is discussed later (also Wulfmeyer et al, 2011). For a more detailed description of the synoptic situation, the reader is referred to Corsmeier et al (2011).…”

Influence of the wind profile on the initiation of convection in mountainous terrain

“…On the French side of the Rhine Valley, the supersite Meistratzheim was operated with a number of instruments and a nearby X-band radar at Bischenheim. More details on the background for the campaign, its role within other international efforts, the strategy of the observations, the variety of the instruments, and some results are given in Wulfmeyer et al (2008Wulfmeyer et al ( , 2011 and Kottmeier et al (2008).…”