ADCP's Application to Ocean Current Measurement in the Port of Kilronan

1. Where is the Port of Kilronan?

The Port of Kilronan is located on the Aran Islands in Ireland. It is an important entrance to the sea for the island. The port is small in scale. Its throughput consists mainly of local fishing activities and ferry services bringing in tourists and supplies. Fishing vessels account for a significant proportion of the port's activity, with catches landed and processed. Ferry services play a vital role in connecting the island to the mainland, enabling the movement of people, vehicles, and essential goods.

Routes and Business

The port of Kilronan has ferry routes that connect the island to the mainland ports. In fact, these ferry services are vital for tourism, as well as the supply of goods. The local fishing fleet fishes in the surrounding waters and has its network of fishing routes. Servicing, such as repairing and maintaining fishing boats and ferries, also falls under the business of this port. Furthermore, there is also a trade in fishing equipment and supplies.

Port Management and Operation

The port management concerns the effective running of the fishing and ferry services within the port. The management provides berthing facilities for both fishing boats and ferries. Safety is also a vital concern, particularly for the ferry services carrying passengers. The port is responsible for receiving fish catches and storing and delivering them appropriately. There are rules and regulations in maintaining the cleanliness and orderliness of the port area.

Port Facilities

The port facilities are basic but workable. There are berths for fishing boats and ferries. There are storage areas for fish and other cargo. For the ferry services, there are waiting areas for passengers and facilities for loading and unloading vehicles. The port also has equipment like cranes and forklifts to handle the movement of goods.

Channel and Direct Shipping

The port's channel is maintained to ensure the safe passage of vessels. Regular dredging operations are carried out to keep the water depth suitable for fishing boats and ferries. It has direct shipping connections through its ferry services to the mainland ports for the transportation of goods and people.

2. Why should we measure the ocean currents in the Port of Kilronan?

It is very important to measure ocean currents in the Port of Kilronan. Accurate current data is indispensable in vessel navigation for safety. Ferry services have to go in and out from this port safely. Sometimes, unpredictable currents may become a risk to the ferries when passengers and vehicles are on board. The same goes for fishing vessels, which have to go back into port safely with their catch. With accurate current measurement, the port is well-placed to give improved navigational guidance that could help reduce accidents.

Current measurements are, secondly, important for good port operations. Currents can affect the docking and loading/unloading processes. For example, a strong current can make it difficult to position a ferry or a fishing boat accurately. Accurate current data will allow the port to optimize these operations, reduce waiting times, and make the best use of its berthing facilities.

Additionally, from an environmental perspective, knowledge of the ocean currents contributes to the monitoring of the health of the local marine ecosystem. Currents can affect the distribution of nutrients, fish larvae, and other biological elements. Measuring the currents helps the port contribute to better understanding and conservation of the surrounding marine environment. An Acoustic Doppler Current Profiler (ADCP) provides a more advanced and convenient way of measuring these currents compared to traditional methods.

3. How do ADCPs using the principle of Doppler work?

ADCPs work on the principle of the Doppler effect. They send acoustic signals into the water. These signals scatter off moving particles in the water, such as suspended sediments or small organisms. When the acoustic signals are reflected back to the ADCP profiler, a frequency shift occurs due to the Doppler effect. The ADCP measures this frequency shift and calculates the velocity of the water particles, which in turn gives the velocity of the ocean current.

Ship-borne ADCP

Ship-borne ADCPs can be installed on ferries or fishing boats. While the vessel travels around the port and adjacent waters, the ADCP current meter sends out acoustic pulses in various directions, normally downward and sideways. The device will measure the current velocity at multiple depths as the vessel travels. This gives a very detailed profile of the current conditions along the vessel's path and provides a comprehensive understanding of the current patterns in the areas the vessel covers.

Fixed ADCP

Fixed ADCPs can be deployed at locations within the port, on the seabed near the berths or at the entrance of the channel. These ADCPs continuously measure the current at a single point over long periods. Data gathered over time is valuable for determining the long-term characteristics of the current in key areas of the port, like the entrance of the channel or near the berths.

4. What is required to have high-quality measurements of the currents of Kilronan port?

The equipment used for the measurement of the ocean currents in the Port of Kilronan must be made from reliable materials since seawater is corrosive and physical damage from the marine environment may occur. It also needs to be small in size, light in weight, and with low power consumption. A compact and lightweight ADCP flow meter will be more easily installed and operated at a fixed location or on a boat. The power consumption is low enough for continuous operation without frequent replacement of batteries or large amounts of energy. Cost-effectiveness is also another factor in enabling wide-scale deployment in the port area.

The casing of ADCP current profiler is preferably made of titanium alloy. The use of a titanium alloy allows for excellent corrosion resistance in seawater, ensuring the integrity of the device over a long period. Besides, it has a high strength-to-weight ratio, which means it can be strong and durable while maintaining a relatively low weight. In addition, titanium alloy is biocompatible, which reduces the potential negative impact on the marine environment.

5. Selection of appropriate equipment for current measurement?

Selection of the right equipment for current measurement at the Port of Kilronan will depend on particular requirements.

Ship-borne ADCP

This is quite apt for when a wide-ranging, large overview of the conditions, existing in the port part(s), is sought, while the vessel makes turns across the port, to achieve wide-ranging observation data, from multiple positions - about the pattern existing amongst current flows within the waters constituting the port.

Bottom-mounted (Sitting on the seabed) ADCP

This type of ADCP meter is ideal for long-term fixed-point monitoring. It can be installed at strategic points in the port, such as at the entrance of the channel or near the berths, to continuously monitor the current conditions in those specific areas.

Buoy-mounted ADCP

Buoy-mounted ADCPs are advantageous when not many circumstances allow their fixing on the bottom or placing a vessel-based device there. They may be released within open areas of a port to obtain current velocities in different water layers.

Regarding frequency selection, different frequencies are appropriate for different water depths. A 600 kHz ADCP is suitable for water depths up to 70 meters, a 300 kHz ADCP for depths up to 110 meters, and a 75 kHz ADCP for much deeper waters at up to 1000 meters.

There are well - known ADCP brands like Teledyne RDI, Nortek, and Sontek. However, there is also a Chinese ADCP brand, China Sonar PandaADCP. It is made of all-titanium alloy material, which ensures its durability in the marine environment and offers an excellent cost-performance ratio. You can find more information on its website: (https://china-sonar.com/).

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