Extended Abstract (168K)6.1
The Helsinki Testbed: A four-season mesoscale research and development facility
Elena Saltikoff, Vaisala Inc., Helsinki, Finland; and J. Poutiainen, J. Koistinen, W. F. Dabberdt, and H. Turtiainen
The Finnish Meteorological Institute and the Vaisala meteorological measurements company have initiated a program to establish a new mesoscale observational network in Southern Finland. Helsinki The testbed is expected to provide new information on observing systems and strategies, mesoscale weather phenomena and applications in a coastal high-latitude environment (60-61N, 24-26E ). All four seasons can be distinctly separated in this northern environment. Typically, the mean monthly temperature varies between -7°C and +17°C, annual precipitation is 600 mm, snow cover lasts for 100 days and the sea is frozen for two months. This paper describes Helsinki Testbed in detail and also serves as an open invitation to participate.
The interest focuses on meteorological observations and forecasting directed towards meso-gamma scalephenomena that typically last from a few minutes to several hours. These weather events are often too small to be detected by traditional networks. In coastal Finland, such weather events include temperature inversions, sea breeze, fog and low stratus, snow bands, urban heat island and convective storms (e.g "lake-effect" blizzards). These and related phenomena like lightning are often hazardous and cause substantial damage. For instance, fog causes considerable disruption of land, sea and air traffic. Sea breeze and its phases of development play an important role in the dispersion of atmospheric constituents. The Helsinki capitol area offers a representative study region for urban air quality research and boundary-layer modeling, especially in stable nocturnal conditions, which are dominant in the area. The Helsinki Testbed will also provide comprehensive data sets for several other research purposes including e.g. computerized nowcasting methods and mesoanalysis, remote sensing of different precipitation types, road surface and related weather modeling, and development and verification of numerical weather prediction models. The program enables testing of scientific theories, new technologies and end-user applications. It also serves as open test platform for extensive development projects and it provides a framework for atmospheric information systems integration. While facilitating experimentation with complete systems, the risk is minimized with respect to the operating environment.
The Helsinki Testbed will help to develop and test new observational instruments, systems and methods. First tests are scheduled for summer 2005. Measurements will be accomplished through five thematic, month-long, measurement campaigns. The last campaign is scheduled for August 2006. During these campaigns, the existing Finnish weather observation network will be supplemented with a large number of new observations. The area of interest covers part of the Southern Finland and the Gulf of Finland. Most of the new observation sites are located in the area of about 150 x 150 km. In particular, circa 40 communication masts, 60-100 m high, are equipped with new weather transmitters capable of measuring temperature, humidity, air pressure, rain, wind speed and direction. Each mast has at least two measurement heights, typically 2m and mast top. Additionally, the amount of radio soundings and ceilometer measurements are increased, a wind profiler will be installed and satellite and five weather radar measurements are included; all data are combined in a data warehouse. In the course of the project, all measured and NWP model data will be made available on the Internet, see http://www.fmi.fi/testbed. The testbed is an open program, which means collaborative and independent measurements are encouraged. All scientists are welcome to use the data or to implement additional observational, modeling or application tools.
Session 6, Integrated Observations from Field Experiments
Wednesday, 22 June 2005, 10:30 AM-12:00 PM, South Ballroom
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