1OCEAN LITERACY

OCEAN LITERACYEssential Principles & Fundamental Concepts of Ocean Science

PRINCIPLE 3

2REVISION HISTORY

Date Version Revised By Description

Aug 25, 2010 0.0 VL Original

3ESSENTIAL PRINCIPLE 3

3The ocean is a major influenceon weather and climate

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3(a) The ocean controls weather and climate by dominating the Earth’s energy, water and carbon systems.

The Ocean Controls Weather & ClimateThe sun and moon act on the ocean to form Earth’s winds, waves, tides and currents, and to create special weather patterns. Over longer time scales, these natural forces can also result in major changes in the Earth’s climate.

The ocean dominates the Earth’s:• Energy System – e.g. winds, waves• Water System – e.g. Water Cycle• Carbon System - e.g. Carbon Cycle

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3(b) The ocean absorbs much of the solar radiation reaching Earth. The ocean loses heat by evaporation. This heat loss drives atmospheric circulation when, after it is released into the atmosphere as water vapor, it condenses and forms rain. Condensation of water evaporated from warm seas provides the energy for hurricanes and cyclones.

Heat & Energy• The ocean absorbs solar radiation from the Sun.• The ocean loses that heat by evaporation.• The heat loss drives atmospheric circulation.• The water vapor rises, cools and condenses to form rain.• The condensation provide the energy for hurricanes and cyclones.

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3(c) The El Niño Southern Oscillation causes important changes in global weather patterns because it changes the way heat is released to the atmosphere in the Pacific.

El Niño-Southern Oscillation (ENSO) El Niño-Southern Oscillation (ENSO) is a continual but irregular cycle of shifts in ocean and atmospheric conditions that affect global weather patterns.

It’s effects vary widely. For people who live in Indonesia, Australia, or S.E. Africa, El Niño can mean severe droughts and deadly forest fires. Ecuadorians, Peruvians, or Californians, on the other hand, associate it with heavy rains that can trigger devastating floods and mudslides. Severe El Niño events have resulted in several thousand deaths worldwide, left thousands of people homeless, and caused billions of dollars in damage. Yet residents on the N.E. seaboard of the U.S credit El Niño with milder-than-normal winters and more benign hurricane seasons.

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3(d) Most rain that falls on land originally evaporated from the tropical ocean.

Most Rain Originally Evaporated From The Tropical OceanThe sun heats water in the ocean. Some of the water evaporates into the air as water vapour. Ice and snow can also sublimate directly into water vapour. Rising air currents take the water vapour into the atmosphere along with water from evapotranspiration (water transpired from plants and evaporated from soil).

Cooler temperatures here cause the vapour to condense into clouds. As air currents move clouds around the globe, cloud particles collide, grow, and fall from the sky as precipitation – i.e. rain, sleet or snow.

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3(e) The ocean dominates the Earth’s carbon cycle. Half the primary productivity on Earth takes place in the sunlit layers of the ocean and the ocean absorbs roughly half of all carbon dioxide added to the atmosphere.

Carbon CycleCarbon dioxide produced by animals and from humans burning fossil fuels is absorbed by microscopic plants and by chemical processes in the ocean.

Dead animals and plants decay and decompose over millennia to become fossils and fossil fuels.

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3(f) The ocean has had, and will continue to have, a significant influence on climate change by absorbing, storing, and moving heat, carbon and water.

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3(g) Changes in the ocean’s circulation have produced large, abrupt changes in climate during the last 50,000 years.