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Marit Finne Editor-in-Chief Vaisala News Vaisala Helsinki Finland The R/V Aranda in the drifting marginal sea ice zone in the Weddell Sea. Vaisala’s radiosonde equipment and weather station are used for marine meteorological research on board the Aranda. Photo courtesy: FINNARP/Jouko Launiainen. Two-thirds of the earth is covered by oceans, home to an abundance of life and many unique ecosystems. In order to understand the sea, we need information about it. In Finland, this work is done by the Finnish Institute of Marine Research. The Institute uses Vaisala’s MILOS 500 data collection systems to measure the sea water level at their thirteen stations along the Finnish coast. From the left: Osmo Korhonen, Hannu Vuori (both from FIMR) with Markku Sinkkonen and Hannu Kokko (both from Vaisala). 22 147/1998 MILOS 500 Data Collection System Supports Marine Research T he Finnish Institute of Marine Research (FIMR), located in Helsinki, carries out research in the fields of physical, biological and chemical oceanography. Its main area of interest is the Baltic Sea. FIMR upgrades its water level stations In late 1994, FIMR began upgrading its entire network of water level stations with digital equipment. All 13 water level stations were equipped with Vaisala’s MILOS 500-based data collection system by the end of 1997. The new measuring system is very flexible. In addition to water level data, other measurement parameters, including the surface temperature of the water, are easy to add. Mr. Osmo Korhonen, Head of the Field and Service Group at FIMR, was one of the key people behind the Institute’s selection of Vaisala’s MILOS 500 equipment. The system was installed at the water level station in Helsinki in 1994. This station has a long history. Measurements were first made here as far back as 1904. The day Vaisala News visited, Mr. Korhonen explained the observations made at the station. As he reported, the Institute has been very satisfied with the reliable operation of the MILOS 500 equipment. During the installation stage, FIMR designed a special access and configured their own equipment to allow integration with the new data collection system. The observation data is collected and saved in the memory, which has sufficient capacity for one year of measurement data (observations once every minute). The sea level measurements are accurate to within one millimeter. The measurement data is sent every hour via telephone lines to a computer at FIMR’s central office. The same real-time data is also available to the public through a phone service. The Finnish Institute of Marine Research also carries out advanced research on wave action. Their high-level expertise has many practical applications. Water level research is mainly used for improving safety at sea and supporting the construction of waterways, harbors and coastal buildings. Osmo Korhonen (FIMR) describes the Vaisala MILOS 500 data collection system used for water level measurements at the Helsinki station. Leif Granholm, M.Sc. Senior Consultant Tekla Oy Helsinki, Finland Falling water level along the Finnish coast As many sailors and boaters have noticed, the water level along the Finnish coast has fallen during the past two years. The sea level was especially low in 1996, when the annual mean level for the year set a new record. In these conditions, shallow water can pose a safety threat for boaters. In the longer term, however, the water level of the Baltic Sea has been exceptionally high in the past few years, so the figures for 1996 did not have a major impact on the mean values. The higher than normal sea levels in the Baltic probably stem from changes in wind conditions on the Atlantic, and especially in the strait of Denmark. Because the strait is very narrow, the water level can be up to 50 cm above or below the surface of the Baltic, depending on the wind conditions. Determining the theoretical mean water level The annual mean sea level is also one of FIMR’s research areas. The theoretical mean water level is a defined forecast of the long-term mean water level value. Both the normal upheave of the earth and the slow rise in sea level are taken into account in the calculation of this value, which has a number of practical applications. The theoretical mean water level is not constant, but varies from year to year. These water level values are necessary for planning and constructing water channels and harbors, for example. The theoretical mean water level is also utilized to determine the actual position of the coastline and the boundaries of Finnish territorial waters. Statistical applications are another impor■ tant use. Vaisala’s wind monitoring system in front of the emergency exit in a Helsinki underground station. Wind data improves safety in underground stations: A Vital Tool for Fire and Rescue Operations A fire or the release of toxic gases in underground tunnel systems is a frightening scenario for all fire and rescue services. In case of such an event, the primary concern is the safe evacuation of the people in the tunnel. To make emergency management easier, Helsinki City Transport has purchased a new wind monitoring system for its underground stations. Vaisala environmental sensors are a critical component of this system. F ire fighting and rescue operations are a difficult and dangerous challenge in tunnels and underground metro stations. Accurate measurements of wind direction and speed can play a key role in the safe outcome of these efforts. To provide this information, a consortium of Finnish companies has developed a system to track and monitor wind conditions. The Tekla Information System was installed in the underground stations in Helsinki, Finland, in December 1997. The system can also be used at mines, chemical plants, harbors and railway stations. The environmental monitoring system that Vaisala is supplying for the new wind monitor contains sensors, as well as 147/1998 23