How to Measure the Coastal Currents of Bude

1. Where is Bude?

Bude is a small coastal town in Cornwall, England, on the Atlantic Ocean. Its geographical position has provided it with a long - standing and intimate connection with the sea, which has been a source of its development, economy, and lifestyle of its inhabitants.

Bude has a rich history. It was once a small fishing village, which has evolved into a large tourist resort. The buildings in Bude are a mix of Cornish traditional appeal and modern functionality. In the town center, there are old-fashioned stone-built houses with typical features. The houses have robust, durable walls, small-framed windows, and slate-tiled roofs, giving a traditional Cornish sea charm. The town also boasts of modern homes, including present shops, cafes, and accommodation centers, for the bulk of tourists who visit annually.

The people of Bude have a long-standing relationship with the sea. Fishing has been an age - old occupation passed down from generations. Although the fishing industry has had to undergo changes, there remain some local fishermen who leave from the harbor. They come back with a haul of mackerel, bass, and other shellfish. The harbour is not just a hub of fishing but a popular destination where holidaymakers and locals take boat cruising. Locals can enjoy the sea air, the sight of seabirds above, and the magnificent views of the Atlantic Ocean.

The seas and beaches in and around Bude are highly significant to the local ecosystem. The Atlantic Ocean water in this area holds a diverse richness of sea life. Seals are commonly observed on sandbanks, and seabirds such as gulls, terns, and cormorants are common visitors. The bottom is complicated in its landscape, made up of sandy periods, scattered outlying rocks, and underwater channels. These land features support high diversity and play an important part in the circulation of the water.

2. What's the Case with Coastal Currents along Bude?

There are various factors that affect coastal currents in Bude. Among them are tidal forces. Tidal forces make notable contributions to tidal movements along coasts and shores like around Bude, for example, those around western Cornwall in general, along both northwest Britain. The tidal range is variable, and the resulting tidal currents are as much as 2 - 3 knots in some areas, especially around small inlets mouths or where there is well-defined coastal form. During high tide, water comes ashore carrying with it sediments and nutrients from the outside ocean. The local sea environment is thus enriched with nutrients and habitat for various marine organisms. When the tide is low, water recedes to sea and regions in between the intertidal surfaces are remnant with miniature crabs, sea anemones, as well as various species of seaweeds.

Wind is another key performer. South-westerly predominant winds will cause onshore surging surface waters in order to increase coastal flow. These are the same winds responsible for building up waves to become mingled in the flow in producing complex design. Northwesterly winds can force the water offshore. The shape of the Cornish coastline, headlands, and bays, and the specific outline of the North Cornwall coastline cause the currents to converge and diverge at many places. Subsurface rocky outcrops and sandbars increase the complexity of the current system. They can be channels or barriers, deflecting the water flow and creating areas of still or agitated water. Additionally, the freshwater from small local rivers can affect the local current patterns. The freshwater, being less dense than seawater, forms a surface layer and flows out to the sea, where it interacts with the tidal and wind-driven currents.

3. How to Observe the Coastal Water Flow of Bude?

Surface Drifting Buoy Method

Surface drift buoys are a simple but effective method of tracking the surface - level currents off Bude. GPS or satellite - based tracking systems are installed on the buoys. As they are launched into the water, the surface currents carry them. Scientists can track their journey over time. By studying the trajectory of the buoy, they can estimate the speed and direction of the surface waters. But this method is only effective for the upper few meters of the water column. It might not be showing what is happening in the deeper parts of the water, where the currents could be changing due to changes in temperature and salinity.

Moored Ship Method

In the moored ship method, a ship is anchored at a particular location near Bude's shore. Then, current-measuring instruments like electromagnetic current meters are employed. These are capable of measuring the water flow at different depths. They provide an accurate vertical profile of the direction and velocity of the current. But this method is restricted to a single point. Further, the ship itself can disrupt the natural water flow. The shape of the ship's hull and the way it is docked can cause turbulence in the water, and this can disrupt measurements.

Acoustic Doppler Current Profiler (ADCP) Method

Coastal current measurement near Bude has been revolutionized by ADCPs. ADCPs are able to measure the velocity profile of the whole water column from the sea surface down to the bed. ADCPs use sound waves to non-intrusively measure water flow. They emit acoustic pulses and measure the Doppler shift of the backscattered signals from suspended material in the water, such as sediment, plankton, or small bubbles. From these, they are able to establish the velocity of the current at different depths. This gives an overall indication of the structure of the current and is therefore extremely well placed to examine the complex patterns of coastal currents off Bude.

4. What Does High-Quality Measurement of Bude Coastal Currents Demand?

Equipment Material Reliability

In high-quality measurement of coastal currents off Bude, material reliability of the equipment is imperative. The casing of the ADCP flow meter should be made of a material strong enough to sustain the harsh marine environment of the Atlantic Ocean. The ideal material is titanium alloy. Its rigidity is sufficient to resist the stress of strong water currents, potential impacts from floating debris, and corrosiveness of seawater. Its low elastic modulus ensures flexibility, which reduces the risk of mechanical stress damage. Moreover, its high corrosion resistance allows the ADCP profiler to remain in seawater for extended monitoring without any significant deterioration.

Low Size, Lightweight, Low Power Consumption, and Low Cost

The lighter and smaller ADCP meter is easier to install and operate. It can be installed on a small research vessel, attached to a buoy, or placed on the sea bed. It also causes less disturbance in the natural flow of water, and this leads to more accurate measurements. Low power consumption is necessary for long-term independent observation, especially if battery - powered systems are employed. Low-cost ADCP will permit mass deployment. This is needed for fully understanding the complex coastal current dynamics around Bude. By having other ADCPs sited at multiple locations, we can have a better idea of how the currents vary across the area.

5. What is the Way to Choose the Right Equipment to Measure Currents?

By Application

• Shipborne ADCP: Can be utilized for the retrieval of real-time current data along a ship path near Bude. It may be used in oceanographic surveys, study of the overall circulation in the area, and to optimize shipping lanes, if any, in the region.
• Bottom-mounted ADCP: Well suited to long - term monitoring of the seabed current in fixed locations. It applies well in researching the long - term coastal trend currents, for instance, how the coastal marine environment is influenced by climate change.
• Buoy-mounted ADCP: Appropriate for tracking surface-level currents across a wide area since the buoy floats along with the water. It helps in understanding the spatial variability of the surface currents and how the coastal waters penetrate the open Atlantic Ocean.

Based on Water Depth

• 600kHz ADCP: Ideal for water depths of approximately 70m, providing high-resolution values in the comparatively shallow Atlantic waters off Bude.
• 300kHz ADCP: Ideal for water depths of approximately 110m, which would be useful for areas of slightly deeper patches in the Atlantic waters off the town.
• 75kHz ADCP: Designed for deep-water work. While waters off Bude are usually not deep, there is still scope for using it in research of the deeper-layer currents or deeper channel sections with a facility of measuring currents down to 1000m.

There are several established ADCP brands on the international market, such as Teledyne RDI, Nortek, and Sontek. If a budget-option is being sought after, then China Sonar PandaADCP, made of all-titanium alloy, offers a great quality and value compromise. You can learn more at (https://china-sonar.com/).

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