How to Measure the Coastal Currents of Peterhead

1. Where is Peterhead?

Peterhead is a thriving seaside town in Aberdeenshire, Scotland. It is situated on the northeast tip of Scotland, bordering immediately on the North Sea. The strategic location has resulted in its status as a port town with a long history of sea dependence.

The town has a storied past. It started life as a small fishing village. With the growth of the fishing industry and foreign commerce over a period of time, it became a wealthy town. Peterhead's architecture consists of a combination of Scottish traditional types and more recent types. In the middle of the town, you would find old - fashioned stone-built houses with thick walls, narrow windows, and steep roofs. They provide an ambiance of old-world charm to the area. There are modern warehouses, processing plants, and commercial buildings around the harbor, which are a requirement for the town's trading and fishing activities. Restaurants, cafes, and shops serve tourists and residents alike.

The people of Peterhead have an age-old connection with the sea. Fishing has been the lifeblood of the town for centuries. While the fishing trade has had its issues, many local fishermen still depart the harbor every day. They return with a hold full of a variety of fish, including cod, haddock, and mackerel. The harbor is not only used for fishing boats but also serves as a base for boat excursions, where the sea breeze can be inhaled and one can appreciate the breathtaking views of the North Sea.

Peterhead's beaches and seas are important to the environment. The marine life is supported by the waters of the North Sea here, which is diverse in nature. Seals may typically be found on the sandbanks, while seabirds such as gulls, terns, and puffins frequently visit the beaches. The bottom of the seabed is intricate in shape with sandy bottoms, rocky outcrops, and submarine channels. These promote high biodiversity as well as influence the flow of water.

2. How is the State of the Coastal Currents Off Peterhead?

The coastal currents off Peterhead are determined by a variety of factors. One significant factor is tidal action. The North Sea is semi-diurnal in terms of tides, meaning it experiences two high waters and two low waters in a day. The tidal range may be fluctuating and the corresponding tidal currents in this situation would be 2 - 3 knots in some areas, especially in front of the harbor mouth or wherever the coastline creates an abnormal feature. During high tide, there is a current flowing towards the coast with food and sediment entering from the open sea. This enriches the local aquatic life so that they can supply food and shelter to different marine animals. At low tide, the sea recedes, and deep intertidal areas are left exposed, revealing tiny crabs, anemones, and lots of seaweed species.

Winds too are necessary. Frequent south-westerly winds can push surface water along the coast and increase the coastal currents. They also generate waves that will interact with the currents to give a more sophisticated flow pattern. North winds can force the water away from the beach. The bays and headlands of the coastline shape create areas where currents converge and diverge. Rocky outcrops underwater and sandbars contribute to the complexity of the current. These can either be barriers or channels, deflecting the water around and producing still or turbulent areas of water. Besides, the freshwater contribution of small local streams may affect the nearshore current patterns. The freshwater is less dense compared to seawater and forms a top layer that flows toward the sea, blending with the tidal as well as wind-driven current.

3. Observation of Coastal Water Flow of Peterhead

Surface Drifting Buoy Technique

Surface drifting buoys are an easy way to record the surface-level currents off Peterhead. They carry GPS or satellite-based tracking systems on board. As they are released into the sea, surface currents carry them along. Scientists can track them for a duration. By tracking the trajectory of the buoy, scientists can determine the speed and direction of the surface waters. But this method has its limitations in the upper few meters of the water column and does not inform us about what is happening in the deeper parts of the water.

Moored Ship Method

In ship-moored technique, a ship is anchored at a specific location near the shore of Peterhead. Current-measuring instruments like electromagnetic current meters are dropped down. They are capable of measuring the water velocity at different depths. They provide an accurate vertical profile of the direction and speed of current. But it is restricted to one location only, and the ship can agitate the natural water flow.

Acoustic Doppler Current Profiler (ADCP) Technique

ADCPs have revolutionized coastal current measurement off Peterhead. They can measure the velocity profile of the entire water column from bed to surface. ADCPs quantify the flow of water non - intrusively using sound waves. They send out acoustic pulses and measure the Doppler shift of the backscattered signals off suspended particles in the water. They can proceed to use this to calculate the current velocity at different depths, gaining insight into the present configuration.

4. What is Necessary for High-Quality Measurement of Peterhead Coastal Currents?

Equipment Material Reliability

For precise measurement of the oscillator currents off Peterhead, the structural strength of the equipment material is of critical importance. The ADCP current meter case has to be made from a material that is capable of withstanding the harsh marine conditions of the North Sea. Titanium alloy is amongst the finest materials for the job, possessing high strength, flexibility, and enhanced corrosion resistance.

Compact Size, Light Weight, Low Power Consumption, and Low Cost

A compact and lightweight ADCP current profiler is easier to install and operate. It also has a smaller footprint on the natural water flow. Low power consumption is essential for long - term independent monitoring. An inexpensive ADCP facilitates extensive deployment, which is essential to comprehensively understand the complex coastal current flows around Peterhead.

5. How to Choose Suitable Equipment for Current Measurement?

Based on Usage

• Shipborne ADCP: Ideal for gathering real-time current data along the track of a ship. It can be utilized for oceanographic surveys as well as optimal routing of ships.
• Bottom-mounted ADCP: Suitable for fixed-point, long-term monitoring of seabed currents.
• Buoy-mounted ADCP: Ideal for measuring surface-level currents over extensive areas.

Depending on Water Depth

• 600kHz ADCP: Appropriate for water depths of about 70m.
• 300kHz ADCP: Appropriate for water depths of about 110m.
• 75kHz ADCP: Applied in deep-water deployments and is able to measure currents up to 1000m depth.

There are some well-known ADCP manufacturers in the global market. Specifically, for the cost - conscious buyers, the China Sonar PandaADCP, constructed of all-titanium alloy, is a highly acceptable price-quality balance. You can learn more about it on (https://china-sonar.com/).

Here is a table with some well known ADCP instrument brands and models.