Underlying Causes of Waves Typified by The Caribbean Sea
The Caribbean Sea has a significantly different set of features providing an interesting backdrop for waves. It is a semi-enclosed sea, framed on the east by the South American Plate and on the west by the Caribbean Plate which is a distinct feature of the Caribbean. To the north it is bounded by sea-level isobars and tropical cyclones, while to the south it is bounded by strong westerly winds, as well as waves which act to influence the wave formation.
The Caribbean is also home to a variety of islands, cays and coral reefs, with these features affecting the reflectivity, diffractivity and turbulence of waves in the region. Wind, local currents and eddies, ocean tides, and submerged obstacles, such as reefs and shoals, can all combine to create distinctive wave climates in the region. Analysis indicates that this propagation is a major factor in determining the wave heights and periods that can be expected at any given location in the Caribbean.
The Caribbean Sea has a unique wave-making environment. The region is surrounded by shallow water, which is typically a few hundred kilometers wide. This shallow region acts as an effective barrier to the propagation of waves from the distant waters of the Atlantic and Pacific oceans. Additionally, there is no large landmass to block the waves and cause their re-direction or refraction. As a result, the Caribbean Sea tends to have very low, highly predictable wave heights and periods.
The Caribbean Sea’s Wave Climate
The Caribbean Sea’s wave climate is comparatively consistent throughout most of the seasons. During an average year, nearly all of the wave energy is driven by the wind, mainly in the form of low-frequency swell. The majority of this swell energy is generated in the North Atlantic and propagates towards the Caribbean Sea. This swell is followed by short-period wind-driven waves which can reach the coastline in 2-4 days. In the Caribbean region, waves typically have periods between 5 and 20 seconds, with the average wave height at most locations in the Caribbean ranging from 0.7 to 1.2 metres throughout most of the year.
The Caribbean Sea’s wave climate also experiences a variety of distinctive ocean oscillations over the course of a year. Perhaps the most notable are the strong westerly winds which can cause temporary wave heights much higher than the average Caribbean wave. The mixture of ocean currents, seasonal winds, and temperature changes in the Caribbean Sea can lead to an unpredictable and sometimes dangerous wave climate. It is common for the sea to be more calm one day and then drastically different the next day due to a change in wind direction or an ocean storm passing through.
Impact of Weather on the Sea’s Wave Climate
Weather is a key factor in determining the characteristics of the Caribbean Sea’s wave climate. The Caribbean Sea is especially prone to typhoons (tropical cyclones) occurring during the summer months. These typhoons are often accompanied by strong winds which can produce short-period and large-height waves. In such instances, wave heights of 2 to 3 metres can be expected along the coastlines. However, these typhoons generally only last for a few hours, and the wave heights subside soon afterwards.
Besides storms, the Caribbean Sea is also affected by the mid-Atlantic subtropical high-pressure system. This high-pressure system brings dry, stable weather throughout the spring and winter months which reduces wind speeds and therefore results in calmer seas. This calmer period is also characterized by an increase in low-frequency swell energy which helps to maintain a moderate sea state during this part of the year.
Modification of Waves in the Caribbean Sea
Edges of the Caribbean Islands, their cays and coral reefs can modify the waves reaching their shores. Waves traveling over shallow water, especially of depths less than 3 meters, tend to slow down and gain energy, thus increasing their height and amplitude. Specifically, in the Caribbean, these influences are usually felt more during the summer as waves are typically higher during this season.
Also, as waves approach the shore and interact with various obstacles like cays and reefs, they can form waves of a shorter period which can lead to higher heights and a rougher sea state. These obstacles also act to direct the waves in specific directions, thus creating some degree of directionality in the onshore seas. This directional component further adds to the unpredictability of the Caribbean Sea’s wave climate.
Expected Wave Heights
In the Caribbean, wave heights typically range between 0.7 and 1.2 meters. However, under certain conditions, such as the presence of a tropical storm or a gale system from the north, waves of up to 2 to 3 meters are possible. Additionally, the presence of low-frequency swell has been observed in the Caribbean and can lead to higher wave heights in some locations.
Although the frequency of these extreme wave events is low, sea conditions can quickly become hazardous and it is advised that those spending time on the water exercise caution and be aware of the potential for sudden and unexpected wave conditions. Additionally, when wind speeds reach above 30 knots, caution should still be taken as wave heights may reach heights greater than the usual expectations.
Safety Considerations
Due to the potential for larger-than-average wave heights and the unpredictability of the sea in the region, cruise ships, swimmers, and beachgoers should practice caution and be aware of their surroundings. Those on the water should be aware of the potential for strong, and sometimes unexpected, wave action as well as the potential for strong currents and underwater obstacles. Additionally, when the winds exceed 30 knots, vessels should avoid navigating in shallow waters, seek protected areas and exercise caution when navigating in the region.
Although the Caribbean Sea can be a hazard to the unwary boater, it can also provide many areas of safe and enjoyable boating. With its warm waters, stunning scenery and diversity of marine life, navigating the Caribbean Sea can be a safe and enjoyable experience. Knowing the average wave heights, understanding the underlying causes influencing the wave climate and exercising caution, even on seemingly calm days, will help to ensure safe and enjoyable travels in the Caribbean Sea.
Vertical Mixing of The Caribbean Sea
Vertical mixing of the Caribbean Sea is an integral part of its wave-making environment. The Caribbean Sea’s unique geography and bathymetry cause interaction between the water of the deep sea and the water of the shallow coastal zones. This interaction between coastal and open-ocean waters can lead to increased wave heights depending on the intensity of the wind-driven sea state. This vertical mixing can also help to mitigate the decrease in wave heights as waves pass through shallow coastal regions, thus mitigating against the risk of extreme wave heights.
In the Caribbean, vertical mixing influences the shapes of the waves in the area. The mixing of the water in the shallow coastal regions leads to an increase in wave energy, resulting in a distinct “steeper-than-normal” wave shape that can be noticed as the waves reach the beach or shoreline. Additionally, these vertical mixing processes tend to create a greater range in the wave heights, even for otherwise low-energy waves.
Caribbean Currents influencing Wave Heights
Furthermore, the Caribbean Sea is highly influenced by currents. The Caribbean current system moves in a circular pattern driven by wind patterns and by the movement of water from the South Atlantic and the Gulf of Mexico. This current system can act to increase wave heights, especially near the coastal regions, as well as forming large eddies in the open sea which can help to modify the wave direction and wavelength.
The combination of the Caribbean’s unique geography, bathymetry and current system has an immense effect on the wave heights of the region. The Caribbean’s wave climate can vary significantly from place to place depending on a variety of underlying factors. Understanding these factors, as well as their effect on the wave making environment, can greatly assist those navigating the Caribbean Sea.
Conclusion
The Caribbean Sea has a unique wave climate, with its wave-making environment highly influenced by the region’s geography and bathymetry, the seasonal winds, and the movements of the Caribbean Currents. The Caribbean Sea’s wave climate is generally very predictable, with wave heights typically ranging between 0.7 to 1.2 metres. However, under certain conditions, such as the presence of tropical storms, wave heights of up to 2 to 3 metres can be expected.
Consequently, it is important to be aware of the potential for these higher wave heights, as well as the potential for significant wave directionality due to the various cays and reefs in the Caribbean Sea. By understanding the wave-making environment, as well as the various underlying factors which influence it, those navigating the Caribbean Sea can do so safely and enjoyably.
