ADCP's Application to Ocean Current Measurement in Azores Ports

1. Where are the Azores Ports?

The Azores is an archipelago in the Atlantic Ocean and is an autonomous region of Portugal. It consists of nine volcanic islands, and each island has its own ports or harbors. These ports play a crucial role in the local economy, transportation, and fishing industries.

Port Scale and Throughput

The size of the ports in the Azores varies: some are small, catering for local fishing fleets and small inter-island vessels, while others have a more significant capacity and handle a range of cargo, including agricultural products, such as dairy and meat from the islands, building materials, and imported goods. The throughput is influenced by the season, with increased activity during peak tourist seasons and fishing periods.

They can receive vessels of all sizes, from small fishing boats to medium cargo and ferry boats used for inter-island transport and connections to the Portuguese mainland.

Routes and Business

Domesticated, the ports play an important role in inter-island transportation for both persons and cargo transport; secondly, the transport of goods and services, it has links with the mainlands of Portugal, which helps in the import and export of goods.

Internationally, there is some trade and shipping with other European countries and regions. The main business includes fishing activities - the processing and exporting of fish, cargo shipping, and supporting tourism by allowing the docking of cruise ships and ferry services for tourists.

Port Management and Operation

Each port is managed by local port authorities or relevant management entities. Their responsibilities include ensuring the safety and security of the port area, managing vessel traffic, and maintaining the port facilities. This includes regular maintenance of the docks, warehouses, and other infrastructure to keep them in good working condition.

They also coordinate with customs, immigration, and other regulatory agencies to handle the flow of goods and people.

Port Facilities

The ports are equipped with docks and berths suitable for different vessel sizes. There are warehouses for storing various goods, including temperature - controlled facilities for perishable items such as fish and agricultural produce. Loading and unloading equipment like cranes and forklifts are available to assist in the transfer of cargo.

Added to this are facilities for refueling ships, providing freshwater, and the repair of ships. For the cruise ship ports, there are terminals with shops, restaurants, and transportation links to the island attractions.

Channel and Direct Shipping

The ports have well-maintained channels that enable ships to come in and leave the place without much problem. Depth and width are monitored regularly in order to maintain them according to the type of vessels that utilize the ports. They have direct shipping links with other islands in the Azores and with the Portuguese mainland; some of them have links to international ports too for trade and tourism purposes.

2. Why should we measure the ocean currents in the Azores Ports?

Safety of Navigation

For safety reasons, currents should be measured in all the Azores Ports. Knowledge of the current direction and speed is of utmost importance for ship captains and pilots during berthing and departure. Starting from small fishing boats to big cruise ships and cargo vessels, exact current data may prevent collisions against port structures or other vessels.

Because of the location of the Azores in the open Atlantic, it is more subject to variable weather and sea conditions. Currents would affect a ship's maneuverability; in adverse weather, understanding the currents is even more critical for safe navigation.

Optimization of Port Operations

Information on ocean currents is very important in maximizing operation in this port. The various current states could influence the loading or unloading of cargo against the scheduled time or less effectively. For instance, high-velocity currents would involve adjustments in the ship's position or deployment of more mooring gear for stability, ensuring that personnel operating at the site remain safe and that there is no damage to cargo.

Currents are essential in understanding many fishing operations, which contribute a lot to the local economies. The knowledge of currents will enable fishermen to strategically position themselves for the most appropriate routes and times for fishing, hence better catches from fishing. With proper current measurement, port operators will have a better way of scheduling and managing such operations, thus reducing time wastage and generally raising productivity.

Port Infrastructure Planning

The knowledge of ocean currents helped in the long run for the development and expansion of the ports. The stability and durability of the structures, namely berths and piers, of a port are determined by the hydrodynamic forces of currents. This is one of the major prerequisites of information that engineers require to construct new infrastructure which would be able to resist such hydrodynamic forces.

Moreover, it helps in determining the best locations for future expansions and improvements to minimize the negative effects of the water flow. For example, knowledge of the currents can guide the placement of new docks or breakwaters to reduce erosion and damage caused by the water movement.

Acoustic Doppler Current Profiler(ADCP) represents a more sophisticated and handy means of measuring currents compared to traditional methods. It can quickly and precisely give detailed current information at different depths, offering real-time data that is indispensable for efficient operation and future development in the Azores Ports.

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

These work on the principle of the Doppler effect. ADCPs transmit acoustic signals into the water. These acoustic waves scatter off the suspended particles or other objects in the water moving with the ocean current. These waves will be reflected back to the ADCP with a change in frequency due to the Doppler effect when the waves are reflected back.

By analyzing this frequency shift, the ADCP calculates the ocean current velocity at various depths.

ADCP in Port Ocean Current Measurement: Shipborne ADCP

Shipborne ADCPs are fitted on ships operating in and around the Azores Ports. The ADCP continuously sends out acoustic signals while the ship is moving at the port area in a direction. It may measure the ocean current at several points over the track covered by the movement of the ship and give an almost comprehensive picture of the current distribution over the area as covered by the movement of the ship.

Fixed ADCP

Fixed ADCPs are usually installed at a fixed point in the port, on the seabed near some important infrastructure or at some strategic point in the waterway. It monitors continuously for a long period of time the conditions of ocean currents at that very point. It provides, therefore, with valuable data about the regular pattern of this current and its influence on the port facilities at this fixed point.

4. What is necessary for the measurement of Azores currents at high quality?

Material Reliability

Since there are certain levels of quality needed in order to measure ocean currents inside Azores Ports, these shall be done by materials the equipment will have that should be reliable. These would include harsh marine environmental conditions, such as saltwater that causes corrosion, changing pressure due to the level of depth, and constant actions from waves that will, or could, damage performance through such material choice. Material: The best material for ADCP casings would be a titanium alloy. It has very high strength and thus would be able to bear most of the mechanical forces in a marine environment; plus, its corrosion resistance is great, hence long-lasting in seawater.

Size, Weight, and Power Consumption

Other than these factors, equipment must also be of compact size, lightweight, and low power consumption. The compact size allows better installation in various areas in the port whether in ships or fixed locations; the light weight makes handling and deployment easy to manage, and low power consumption will allow operation of the equipment continuously with very minimal battery replacement or a large power supply.

Cost-Effectiveness

Following this standard, some of the key factors to consider are: - Economy, which is vital for measurement on a large scale. The cost of equipment must be within a reasonable range for extensive usage in the port for collecting overall current data.

5. How to Choose the right equipment for current measurement?

According to the Usage Purpose

• Shipborne ADCP: In cases when the task is to make mobile measurements, the ship will go across the area of the port in order to quickly get a wide vision of the current situation from different parts of the port. Therefore, for such purposes, shipborne ADCPs are appropriate. It can cover big areas during the movement of the ship itself.
• Bottom-mounted ADCP: These would be more suitable if the monitoring of ocean currents is to be carried on continuously and for longer duration at a fixed specific position in the port. The position might be near important facilities, such as areas where the impact of currents on the structure is to be viewed more closely. It can operate in a stable way in the same position every day.
• Buoy-mounted ADCP: Buoy-mounted ADCP can be used in cases when the installation of fixed equipment on the seabed or other structures is inconvenient. The buoy-mounted ADCP can measure the ocean current in the upper layers of the water body and transmit the data wirelessly.

According to Different Frequencies

• Within a 70m water depth, for example, the suitable choice in the Azores Ports is usually the 600kHz ADCP. It can offer quite good results in the current data up to that depth.
• The 300kHz is more appropriate at depths in the region of 110m and gives better capturing of the current characteristics of that depth.
• ADCP at 75 kHz is suggested to cover all areas where water is up to 1000m since it penetrates deeper into the water to collect accurate information on current.

There are well - known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, a Chinese ADCP brand, China Sonar PandaADCP, is also worth considering. It is made of all - titanium alloy materials and offers an excellent cost - performance ratio. You can learn more about it at (https://china-sonar.com/).

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