1. Where is Reine?
Reine, a picturesque village in Moskenes municipality of Lofoten archipelago in Nordland county, Norway, is a true coastal paradise. Perched on the western edge of the archipelago, it gazes out over the tremendous sweep of the Norwegian Sea, flanked by the awe-inspiring profile of the Lofoten Wall—a spine-chilling sequence of serrated, snow-capped mountains rearing out of the ocean. The dramatic land-sea contrast thus created is a feast for the eye, and Reine is the most photographed and populated spot in Norway.
The village itself is a charming cluster of old red-painted rorbu cottages hugging the waterfront, remembering its profitable fishing heritage. Fishing has always been the mainstay of Reine for centuries and remains a significant industry of the regional economy nowadays. The fishermen here venture out into the fertile waters of the Norwegian Sea to catch sought-after varieties of fish like cod, haddock, and halibut. Apart from fishing, Reine has become a mass-tourism spot lured by its own sheer natural beauty. The surrounding landscape holds pristine white-sand beaches, deep fjords, and a merciless coastline broken by tiny, rocky islands. During summer, midnight sun lights the village with perpetual light, but during winter, the sky erupts in the magical dance of the Northern Lights, rendering Reine even more attractive. The coastal currents around Reine are part of an affluent and vibrant sea environment, influenced by the convergence of the warm Gulf Stream and cold Arctic currents, which nourish a diverse range of marine life ranging from the seals and sea birds to the whales and other fish species.
2. What is the status of the coastal currents around Reine?
The coastal currents off Reine are the result of a complex interplay of various variables. One factor is the tides, as the region experiences semi-diurnal tides with a tidal range of up to 2.5 meters (8.2 feet) in some areas (source: Norwegian Hydrographic Service). These produce a pulsating flow of water into and out of the fjords and channels of the Reine region. The flowing and ebbing tides not only affect the sailing of boats but also contribute to the patterns of marine life and nutrients within the area, forming the local ecosystem.
Wind is also a power to be heard with that plays a huge role in the coastal currents. The harsh, unstable Arctic winds, particularly the north and west, are able to churn up the surface waters and form large-scale circulation patterns. In winter, the winds are powerful enough to be gale-force and splash waves onto the rocky coastline and reverse the direction and speed of the currents. Wind-drifted currents interact with the intricate seafloor topography of the Lofoten region, such as deep fjords, submarine ridges, and shallow banks. For example, undersea ridges serve as a barrier and force the water to travel over and around them, creating eddies and turbulence to further disorient the current streams.
The interaction of the warm Gulf Stream and cold Arctic water in the area around Reine also greatly affects the coastal currents. The difference in temperature and density of the two water masses creates the water motion, which results in the formation of unique current systems. Introduction of fresh water from small rivers and local streams may also change the salinity and density of the coastal waters, influencing the buoyancy and stream motion of the currents, and creating a dynamic and constantly evolving marine environment.
3. Measurement of the Reine coastal water current
There are a variety of methods to measure the coastal water current of Reine, each having its pros and cons. The surface drifting buoy method is the traditional method. Drifting buoys equipped with GPS tracking devices are thrown into the water and carried away by the currents. By monitoring the movement of such buoys over time, researchers can gain valuable information about the direction and speed of surface-level currents. However, this method is likely to provide information primarily about the upper layers of the water column and may be affected by wind drift, a condition that may lead to the inaccurate representation of the real current structures at deeper levels.
Anchored ship method involves taking a ship to a position and anchoring it, then using instruments onboard the ship to record the currents surrounding them. The method allows for more accurate measurements over a small area, as the instruments can be placed at different depths. However, it has limited spatial coverage because it can only record currents in the surrounding area of the ship. Moreover, the existence of the ship can sometimes disrupt the natural flow of the water and thus lead to measurement errors.
Nonetheless, the Acoustic Doppler Current Profiler (ADCP) method has been found to be a highly advanced and effective means of measuring coastal currents along Reine. ADCPs use sound waves to profile the currents in the entire water column, from the surface to a few meters above the bottom. By transmitting acoustical pulses and monitoring the Doppler shift of the backscattered pulses from suspended particles in the water, such as plankton and sediment, ADCPs can determine the velocity of the water at multiple depths simultaneously. This provides a complete three - dimensional representation of the flow of the water, enabling scientists to study the intricate and dynamic current regimes in exquisite detail. ADCPs are also capable of being operated continuously and collecting data for extended periods of time, which is required in an effort to understand the long-term fluctuations and trends of the coastal currents.
4. How do Doppler principle ADCPs work?
ADCPs operate on the Doppler principle. ADCPs transmit sound waves into the water column at a selected frequency. Sound waves encounter suspended particles within the water column, such as sediment, plankton, and other microorganisms. When water is in motion, particles move with it, causing a shift in the frequency of the backscattered acoustic signals upon their arrival at the ADCP back.
By accurately measuring this change in frequency, or the Doppler shift, the ADCP is able to compute the water velocity at various depths. Many ADCPs contain several transducers that transmit and receive in various directions. This permits the instrument to make measurement of the three - dimensional current velocity components, namely the east - west, north - south, and vertical components. The ADCP goes on to interpret this data to create the fine-scale current profiles, providing information on the magnitude and direction of the water movement at various levels within the water column. For example, if the ADCP radiates a 300 kHz signal and the echo signal returns at a higher frequency, then the water is approaching the ADCP, and the magnitude of the frequency shift will be utilized in the computation of the water's velocity at that particular depth.
5. What's required for high-quality measurement of Reine coastal currents?
To measure Reine coastal currents of good quality, the equipment needs to possess some essential characteristics. Since the Arctic marine environment around Reine is harsh, comprising extremely cold temperatures, strong currents, high salinity, and ice in winter, the materials of the equipment should be highly reliable. The equipment needs to perform well under such severe conditions without any failure or degradation, delivering a consistent and reliable measurement over a long duration.
Light weight, compactness, and low power are also essential. Compactness and light weight in handling and transportation make it convenient to deploy and transport, especially to remote and remote - difficult locations like Reine. Low power ensures the apparatus remains functional for an extended period on board ships, buoys, or seabed - based platforms without frequent replacement of batteries or recharging, which is essential in autonomous monitoring systems.
Cost - effectiveness is likewise a vital consideration. Cost - effective but reliable - quality measurement devices make it possible for the technology to be used for science and applied purposes from research into ocean ecosystems to security for maritime navigation.
The casing of an ADCP is of most concern. The ideal material for the casing of an ADCP is titanium alloy. It. It possesses a great strength-to-weight ratio, which enables it to withstand higher hydrostatic pressure at lower levels of fluid depth without adding too much bulk to the device. Its better corrosion resistance keeps ADCP in working condition and remains accurate even after prolonged exposure to seawater, making replacement and maintenance less frequent. Additionally, the lighter weight of titanium alloy makes deployment and recovery less complicated, which is suitable for being applied in the rugged waters off Reine.
6. How to Choose the appropriate equipment for current measurement?
The selection of the right equipment for current measurement in Reine depends on several parameters, including the specific application, water depth, and budget. For measurement from a boat in motion, the shipboard ADCP is the correct choice. Shipboard ADCPs are installed onboard the ships and can measure currents continuously as the ship sails across the water. Shipboard ADCPs typically have more power and a wider range of operational frequencies, allowing them to sample currents at greater depths and over a broader area, which is useful in mapping the big coastal waters off Reine.
While, for the measurement of currents at a single point on the seabed, a bottom - mounted (or moored) ADCP is a suitable choice. They are suspended down to the seabed and monitor the local current conditions continuously for an extended period of time. They are employed over regions of particular interest, for instance, surrounding valuable fisheries grounds or aquaculture farms, to study the long - term change and trends in the currents.
To achieve independent and versatile monitoring of extended areas, a buoy - mounted ADCP is an excellent option. The ADCPs are installed on floating buoys, which can be positioned in key areas to record information regarding the current patterns. Buoy - mounted ADCPs are best suited to study the spatial and temporal variability of the currents since they can be moved and realigned as desired to monitor various areas of interest.
The sampling frequency of the ADCP is also critical and needs to be selected based on the depth of water. A 600kHz ADCP can be used with up to a 70-meter depth of water, and it can be used for measuring current in shallow coastal waters and nearshore water. A 300kHz ADCP is appropriate for depths of a maximum of 110 meters, a wide range for typical depths in Reine fjords and channels. For deeper water parts, like open Norwegian Sea beyond Lofoten islands, a 75kHz ADCP can be used because it can detect currents to depths of a maximum of 1000 meters.
Some of the well-known ADCP brands include Teledyne RDI, Nortek, and Sontek, which are extremely popular for their quality and durability products. However, for others who want economical yet quality solutions, ADCP supplier China Sonar PandaADCP is a highly recommended product. With full titanium alloy as the material used to manufacture it, it is of extremely high cost-effectiveness and, therefore, is a highly appropriate choice for economic measurement of the current. It also has advanced signal processing technology and simple user interfaces, rendering it suitable for use by a wide user group from professional researchers to small environmental monitoring agencies. To learn more about this great product and its capabilities, visit https://china-sonar.com/.
How do we quantify Reine's coastal currents?