Potential VirtualShip case studies

# global plot

from notebook_utils import _global_plot, REGIONS

_global_plot(width=7, height=5, regions=REGIONS)

1) Irminger Sea

The Irminger Sea is one of the windiest places in the global ocean and one of few places on Earth with deep-water formation that feeds the large-scale thermohaline circulation. The Irminger Sea, situated between southern Greenland and the Reykjanes Ridge, is a critically important area of the North Atlantic. Currents that begin in the Arctic pass through the sea and meet North Atlantic water, forming new kinds of dense water that sinks and flows to the equator.

2) California Current

The California Current is the eastward portion of the clockwise North Pacific Gyre and transports low salinity, cool water equatorward. Associated with the coastal surface flow is a poleward undercurrent, the California Undercurrent. Also, extensive upwelling of colder sub-surface waters occurs, caused by the prevailing northwesterly winds acting through the Ekman Effect. The winds drive surface water to the right of the wind flow, that is offshore, which draws water up from below to replace it. The upwelling further cools the already cool California Current. This is the mechanism that produces California’s characteristic coastal fog and cool ocean waters.

3) Gulf Stream and Deep Western Boundary Current

In the North Atlantic, there are two main western boundary currents related to the Atlantic Meridional Overturning Circulation (AMOC): the Gulf Stream flowing northward and the Deep Western Boundary Current (DWBC) flowing southward. The Gulf Stream influences the climate of the coastal areas of the East Coast of the United States, and to a greater degree, the climate of Northwest Europe. A consensus exists that the climate of Northwest Europe is warmer than other areas of similar latitude at least partially because of the strong North Atlantic Current.

4) Japan current

The Kuroshio Current is also known as the Black Current or Japan Current is a north-flowing, warm ocean current on the west side of the North Pacific Ocean basin. It was named for the deep blue appearance of its waters. The Kuroshio Current is one of the largest and strongest ocean currents in the world, flowing 2 to 4 knots on average. It can be considered as the Pacific Ocean’s equivalent of the Atlantic Ocean’s Gulf Stream, in that both currents transport the ocean’s warm, tropical and nutrient rich waters northward, up towards the Polar Regions, with a crucial effect on regional climate and human activities.

5) Atlantic Meridional Overturning Circulation (AMOC)

The Atlantic Meridional Overturning Circulation (AMOC) is part of a global thermohaline circulation in the oceans and is the zonally integrated component of surface and deep currents in the Atlantic Ocean. The general thermohaline circulation is a pattern of water flow through the world’s oceans. The AMOC consists of upper and lower cells. Observing and understanding the changes in the AMOC is critically important for identifying the mechanisms of decadal climate variability and change, and for interannual-to-decadal climate prediction. Because this is a very broad topic it would be wise to mimic one of the ongoing research programs, e.g. https://www.ocean-ops.org/oceansites/tma/move.html.

6) El Niño Southern Oscillation (ENSO)

El Niño and La Niña are the warm and cool phases of a recurring climate pattern across the tropical Pacific—the El Niño-Southern Oscillation, or “ENSO” for short. The pattern shifts back and forth irregularly every two to seven years, bringing predictable shifts in ocean surface temperature and disrupting the wind and rainfall patterns across the tropics. These changes have a cascade of global side effects.

7) North Brazil current

The North Brazil Current (NBC) is a western boundary current that flows off the coast of northeast Brazil and retroflects between 4°N and 10°N. It is predominantly a salt water current, but it does help transport fresh water from the Amazon River northward. The average salinity of the current occurs at about 5°S, where the more saline South Equatorial Current merges with the NBC. The rainfall produced at the ITCZ works to dilute the salt content of the water. The depth of the NBC is dependent on the depth of the thermocline, as well as the depth of the continental shelf.

8) Somali current

The Somali Current is a warm ocean boundary current that runs along the coast of Somalia and Oman in the Western Indian Ocean. This current is heavily influenced by the monsoons and is the only major upwelling system that occurs on a western boundary of an ocean. During the months of June to September, the warm Southwest monsoon moves the coastal waters northeastward, creating coastal upwelling. The upwelled water is carried offshore by Ekman transport and merges with water that was brought to the surface by open-ocean upwelling. Not only does the biological productivity of the region depend on these upwelling currents, they also play a large part in regulating the heat flux budget of the North Indian Ocean.

9) East Australian Current

The East Australian Current (EAC) sweeps warm water down the east coast of Australia. Like the Gulf Stream, the East Australia Current is pushed to the western edge of the ocean by the rotation of the Earth. The current carries nutrient-poor water from the Coral Sea into the cool waters of the Tasman Sea. The EAC is the largest ocean current close to Australia, moving as much as 30 million cubic meters of water per second in a broad ribbon that covers as much as 100 kilometers in width and 500 meters in depth. The current is strongest in the early months of the year— the Southern Hemisphere’s summer— and weakens during the winter, the middle of the year.

10) Drake passage

The presence of the Drake Passageway allows the three main ocean basins (Atlantic, Pacific and Indian) to be connected via the Antarctic Circumpolar current (ACC), the strongest oceanic current. This flow is the only large-scale exchange occurring between the global oceans, and the Drake passage is the narrowest passage on its flow around Antarctica. Several studies have linked the current shape of the Drake Passage to the Atlantic meridional overturning circulation (AMOC) as we know it.

11) Agulhas Leakage

The Agulhas Current is the western boundary current in the southwest Indian Ocean, flowing southward along the east coast of Africa. At the southern tip of Africa, some of the water ‘leaks’ into the South Atlantic Ocean in a process known as Agulhas Leakage. Agulhas rings (large eddies) transport warm, salty water from the Indian Ocean into the Atlantic Ocean and are a crtical component of the ocean circulation, modulating phenomena such as the Atlantic Meridional Overturning Circulation (AMOC) and global climate patterns.

12) Bay of Bengal freshwater stratification

The Bay of Bengal region experiences a strong monsoon season, which brings a massive influx of freshwater from heavy rainfall and river discharge. This influx of freshwater significantly reduces the salinity of the surface waters in the bay, leading to a stratification of the water column. The low-salinity surface layer acts as a barrier to vertical mixing, which can have important implications for nutrient cycling, primary productivity, and the overall marine ecosystem in the region. Additionally, the stratification can influence the formation and intensity of tropical cyclones in the Bay of Bengal, as well as impact regional climate patterns.

13) Brazil-Malvinas Confluence

The Brazil-Malvinas Confluence is a highly energetic region with two currents encountering eachother. The Malvinas Current is cold and nutrient-rich, flowing northward from the Southern Ocean along the continental slope of Argentina. The Brazil Current is warm and saline, flowing southward along the Brazilian coast. When these two currents collide, both currents separate from the continental slope and they create a dynamic environment with lots of eddies, as well as strong influences on regional climate and marine ecosystems.

14) Cross-shelf exchange on the European North-West Shelf Seas

The European North-West Shelf Seas are a set of shallow, dynamic seas off the northwestern coast of Europe, including the North Sea, the Irish Sea, and Celtic Sea. At the shelf-break, there is a steep cliff-edge gradient in depth, which separates the shallow shelf seas from the deep ocean. Waters typically flow onto the shelf (towards the coast) at the surface and off the shelf (towards the deep ocean) at depth (a downwelling circulation), with a complex interplay of large- and small-scale physical processes. This cross-shelf exchange is important for transporting nutrients, heat, and biology between the shelf seas and the open ocean.

15) Biogeochemical impacts of North Sea marine heatwaves

Marine heatwave occurence and strength is increasing globally due to climate change. The physical characteristics of marine heatwaves are relatively well documented, but the biogeochemical impacts of marine heatwaves are understudied. Potential impacts include changes to dissolved oxygen concentration, primary productivity, nutrient cycling, all of which can have knock-on effects for marine ecosystems. Understanding these impacts is crucial for mitigating adverse marine ecosystems responses to future climate change. The June 2023 marine heatwave in the North Sea was an unprecedented event but the biogeochemical impacts were not observed!