SCI 209

Few things in nature can compare to the destructive force of a tropical cyclone. Tropical cyclones usually form in southern hemisphere during summer and early fall, when ocean waters are warmest. A naturally occurring ocean disaster that results from the relationship between weather and climate is tropical cyclone Irina. The cyclone developed over an area of unstable weather in the South-West Indian Ocean when two weather fronts collided. This cyclone was produced by a tropical wave off the coast of northern end of Madagascar. It is considered one of the most devastating systems of 2012. It generated blustery winds and heavy rain throughout Madagascar, Mozambique, and South Africa.

The effects of this event showed little or no difference if it occurred at a high or low tide because very little is still known how it formed or reacted until it hit landfall. Oceans cover more than 70% of the planet’s surface and play a major part in regulating weather and climate. Ocean currents flow in complex patterns affected by wind, topography, salinity, temperature, and the Earth's rotational axis. The Sun and the Moon’s gravitational forces yield variations in sea level regularly on daily or half-daily time scales that occur during tide changes. In numerous locations the tidal sign is a combination of daily and half-daily tides. In the cavernous ocean the tidal fluctuation is predictably from a few tenths of a centimeter whereas in coastline areas it can be up to a number of meters.

The events that change the wave action of the ocean Cyclones present a main danger to seaside life and aquatic assets. The naturally occurring storm surges commonly take over waves over a gradually pitched shelf. For islands or shoreline zones where the shelf is constricted, waves move toward the seashore in advance of landfall and dominate surges. In tropical and subtropical territories, cyclone upsurges and their numerical properties perform a substantial function in building conditions for seaside and oceanic buildings. As waves advance increasingly into lower water, they breakdown and lose momentum. Altering ocean currents may bring about fluctuations of water temperature that could cause worldwide food shortages attributable to killing of fish species and marine plant life (Scott, 2008). The currents could also negatively affect the strength and regularity of storms. This event left a path of death and destruction in its wake. The loss of life, beach erosion, wildlife, and sea life that was effected puts a burden on the local ecosystem.

The most common ocean currents in the area that affected this storm were the Madagascar current, East Madagascar current, and the Agulhas current. The Madagascar current courses northwards near the western shore of Madagascar, and it is the only current that mariners can employ during voyages from India to Southern Africa. However, the current is neither as powerful nor as wide-ranging as the Agulhas current. The East Madagascar current is an oceanic tide element near Madagascar. It runs southward from Eastern Madagascar to the southern boundary at Cape Saint Marie the southernmost point of Madagascar in the region Androy and consequently strengthens the Agulhas Current. Its flow is complicated by large cyclonic and anti-cyclonic eddies. It creates high pressure areas in the region and affects the Indian Monsoon season. The Agulhas Current is the western limit flow of the South Indian Ocean that streams westward to the Southern Ocean. It is a warm, fast moving current, reaches depths of more than 800 meters, and moves a tremendous amount of water.

This disaster was mostly affected by deep water oceanic currents events. When a cyclone passes over the ocean, the powerful winds created by it stir and mix the warm surface water with the colder, deeper ocean water. This merger results in warm water driven down into the deep ocean and cold water being brought to the surface layer that is then reheated by the atmosphere.

In conclusions this was a tough assignment with not much to go on. So in following we selected and described a naturally occurring ocean disaster that results from the relationship between weather and climate. Defined what caused the natural event. Explained how the effects of this event would be any different if it occurred at a high or low tide and if it was affected how so. Described how this event changed the wave action of the ocean. Identified which ocean currents either deep or surface pass near or through the disaster impact area. Specified if the disaster affected by surface or deep ocean currents and if they were how did they.

References

Essayweb.(2008). Ocean currents. Retrieved from http://essayweb.net/geology/quicknotes/ocean_currents.shtml

Hogan, C. (2011). Agulhas Current large marine ecosystem. Retrieved from http://www.eoearth.org/article/Agulhas_Current_large_marine_ecosystem

Newton, J. (2013). How do ocean currents effect climate and weather. Retrieved from http://www.ehow.com/facts_7206208_do-currents-effect-climate-weather_.html

Scott, D. (2008). Natural disasters and their root cause . Retrieved from http://www.helium.com/items/1035805-natural-disasters-and-their-root-cause

White, N.(2008). Sea level rise. Retrieved from http://www.cmar.csiro.au/sealevel/sl_drives_short.html