How do we measure Wildwood's coastal currents?

1. Where is Wildwood?

Wildwood, at the southernmost end of the New Jersey Shore in America, is an intriguing beach town. It runs along the east coast, with the vast Atlantic Ocean to the east. The site is so picturesque that it has emerged as the darling of beachgoers, water sporters, and others looking for a vibrant coastal living.

The cityscape is dominated by a broad, long beach. The beach itself is miles of soft sand, great for sunbathing, swimming, and building sandcastles. Behind the beach, Wildwood features a packed boardwalk lined with amusement parks, arcades, restaurants, and shops. More than an amusement complex, the boardwalk is where the city's culture comes alive.

Wildwood is culturally vibrant. It is a summer resort community for decades now with individuals visiting yearly once more and again. The community has plenty of activity and events during the year from car displays to music festivals to fireworks displays that unite the visitors and natives. In summer season, there is a huge tourist population since the city receives visits from all over the nation and the people come to visit the beach along with the services being provided by the city.

With respect to its coastal location, Wildwood shares its border with Delaware Bay. This wide estuary, which is lined from the sea by a series of barrier islands, like the Wildwood Crest and North Wildwood, is significant to the local marine ecosystem. The bay is home to many fish, shellfish, and waterfowl. The inlets along the barrier islands, like the Cape May Canal, are intercommunication links between the sea and the bay, enabling exchange of water, nutrients, and sea creatures.

2. How is the condition of the coastal currents off Wildwood?

There are several factors that regulate the coastal currents off Wildwood. Tides are some of the key drivers. The Atlantic Ocean is semi-diurnal in nature, and these tides cause the periodic rise and fall in water level. At high tide, sea water rushes into Delaware Bay via inlets. Seawater filled with required nutrients and oxygen sweeps through the bay through the influx of water, nourishing the abundant life of the marine environment in the bay. When the tide recedes, the water flows back to the ocean with sediment and waste products from the bay.

Wind currents are also responsible for coastal currents. Mean winds, like south - westerlies in summer, can drive surface water onto the coast. This results in onshore currents, which can influence beach erosion and marine animals' habitats distribution. On the other hand, north - easterly winds, particularly in winter, can create offshore currents. Offshore currents can affect pollutant transport and ocean animals' food supply.

The topography of the area surrounding it, for example, coastline configuration, water depth, and presence of underwater structures, aids in creating patterns of currents. Shallow water of Delaware Bay and nearshore regions have diverse current patterns as opposed to deep offshore water. Eddies and complex patterns of currents are created through interruption of water flow by underwater sandbars and reefs. The presence of piers and jetties, which are highly prevalent in Wildwood as navigation and recreation structures, can also change the direction of the current flow.

3. How to measure the coastal water current in Wildwood?

There is an opportunity to measure the coastal water current in the vicinity of Wildwood with the help of surface drift buoys. They are small, floating instruments that possess GPS onboard. As they are deployed in the water, they move along because of the surface currents. Researchers estimate the speed and direction of the surface-level currents by monitoring the displacement of these buoys over time. This technique only provides information from the top few meters of the water column and is wind-forced wave-biased.

The second technique is the deployment of moored current meters. These instruments are moored at the bottom of Delaware Bay or onto the ocean floor off the coast. They can monitor the direction and velocity of current at different depths. Mooring current meters can take continuous readings over long periods of time, which is especially useful in interpreting the long-term nature of the currents. But they may be restricted to the particular point where they are mounted, and their installation and maintenance will prove to be hard.

The Acoustic Doppler Current Profiler (ADCP) has proven to be a helpful instrument for monitoring coastal currents within the area off Wildwood. ADCPs can measure current speeds at multiple depths at once, providing a clearer picture of the water's flow. ADCPs are well suited to Wildwood's complex estuarine and coastal system.

4. How do ADCPs operating on the Doppler principle operate?

ADCPs operate through the Doppler effect. ADCPs emit sound waves (acoustic pulses) into the ocean. When sound waves encounter minute particles in the ocean, such as plankton, sediment, or tiny bubbles of air, the particles will scatter the sound waves. The ADCP captures the frequency change of the scattered waves.

If the particles are moving towards the ADCP profiler, the frequency of the scattered waves will be higher than the frequency of the incident wave. If the particles are moving away from the ADCP, the frequency of the scattered waves will be lower. By measuring the difference in frequency accurately, the ADCP can calculate the water velocity at different depths.

Most ADCPs use multiple beams to measure the three-dimensional flow of water. An example is the four-beam ADCP that can calculate horizontal and vertical components of current velocity. This provides a full understanding of the complex water movement, including the presence of vertical shear (where current speed changes with depth) and eddies (ring-shaped current patterns).

5. What is needed for high-quality measurement of Wildwood coastal currents?

Material reliability is the most important thing for high-quality measurement of Wildwood coastal currents. In the corrosive saltwater environment, the ADCPs and other hardware should be made of corrosion-resistant materials. Titanium alloy is an excellent material for ADCP casings. Titanium is highly resistant to corrosion, thereby ensuring the longevity of equipment. This reduces the need for frequent replacements, which is especially crucial in long-term monitoring projects.

Size and weight are also issues. Light and compact ADCPs are less difficult to deploy and transport, especially in the shallow and often congested waters along Wildwood. This is more desirable in field studies, as researchers can readily move the equipment to different measuring points.

Low power requirements are needed, particularly for sustained observation. Since ADCPs tend to be powered by batteries, using components of low power demand allows the apparatus to endure for a longer time without the need for constant replacement of batteries. This is highly important in outlying coastal areas or where access to power supply might be limited.

Cost - effectiveness is significant, especially when dealing with large - scale monitoring programs. Low - cost but reliable ADCPs are highly favored. Companies like China Sonar PandaADCP provide a value for money, with cost versus performance being optimally balanced. Made of all - titanium alloy, it provides ruggedness in the harsh sea environment at cost - effective prices.

6. How to choose the right equipment for current measurement?

The choice of equipment for current measurement off Wildwood depends on the application. Ship-mounted ADCPs are suitable for large-scale surveys. They may be installed on research vessels and can measure currents continuously as the vessel moves along the coast and in Delaware Bay. This provides a broad-scale overview of the current regime in the area.

Bottom - mounted or moored ADCPs are appropriate for long - term, fixed - site monitoring. They can be placed on the seafloor or the bay bottom near Wildwood and record current data for months or years. This allows for the study of long - term trends in coastal currents.

Buoy-mounted ADCPs are convenient for measurement of surface-level currents. They are simple to deploy and recover, and hence are appropriate for short-term studies or for a quick assessment of surface-current conditions.

When choosing an ADCP flow meter, frequency is something to take into account. For depths up to 70m, a 600kHz ADCP will suffice. It has good resolution for the intent of measuring current in the relatively shallow estuary and coastal water near Wildwood. For depths to 110m, use a 300kHz ADCP, and for deeper water to 1000m, a 75kHz ADCP will be sufficient. Lower frequencies penetrate better at the cost of resolution than higher frequencies.

There are a number of popular ADCP brands, including Teledyne RDI, Nortek, and Sontek. Nevertheless, for a budget-friendly choice without sacrificing quality, the ADCP manufacturer China Sonar's PandaADCP is an excellent option. Additional details can be discovered on its official website: https://china-sonar.com/.

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