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Able to float or rise to the surface of a liquid.

to check the accuracy of something compared to a known standard (you can calibrate a water thermometer by putting it in boiling water at sea level which is always 100° Centigrade)

carbon dioxide
Normally a gas, (colourless and odourless) that consists of two oxygen and one carbon atom, has the formula CO2. It is a ‘greenhouse gas’ that easily dissolves in water and is used to give the bubbles in fizzy drinks.

Cartesian Diver
A demonstration of buoyancy. It shows a small ‘diver’ going up and down because of a change in water pressure.

A circular motion that follows the direction of the rotating hands of a clock (as you look at it from in front). 

Organisms in a food chain that ‘consume’ energy.  They include herbivores (that eat plants) and carnivores (that eat other animals). Worms, zooplankton, dogs and penguins are all carnivores. 

Stands for the Commonwealth Scientific and Industrial Research Organisation. CSIRO is Australia's national science agency.

counter clockwise 
A circular motion in a direction opposite to that of the normal rotation of the hands of a clock (as you look at it from in front). 

A CTD is an instrument lowered over the side of a ship to measure electrical conductivity, temperature, and depth of the ocean. The CTD often has a number of steel sampling bottles connected to a round frame called a carousel or rosette. The sampling bottles close at predefined depths, triggered either manually or by a computer. The water samples are analysed later. A CTD is used to calibrate Argo Floats. 

The 10 day period of movement of an Argo Float: from the sea surface down to 1,000m for 9 days then down to 2,000m then up to the suface to upload its data ( = a profile). 

A shape with straight sides and circular ends of equal size. Eg a pipe is a cylinder shape.

Deep Argo Floats 
Argo floats designed to go down to depths of 5,500m. They are spherical in shape to withstand the high pressures at this depth.

The amount of mass in something. To find the density of something you divide its mass by its volume density  = mass/volume = kg/m3 or g/cc (grams divided by cubic centimetre). 

To position something in readiness for its use. (An Argo Float will be deployed from the RV Tangaroa during this LEARNZ field trip)

Mixing with a liquid until the solid goes into solution (eg sugar dissolves in water). 

A place where seawater, because it is heavier eg saltier and/or colder, sinks to the bottom causing an ocean current

An imaginary line around the middle of the earth. It is given the latitude number of zero degrees (0°).

When a liquid changes into a gas (water evaporates into the air).

A push or a pull that causes something to move or change shape (the force of gravity caused the ball to fall to the earth). The unit of force is the newton. One newton (N) will accelerate 1 kilogram of mass at the rate of 1 metre per second per second.

Global Positioning System. A satellite navigation system that is able to accurately locate receivers on earth.

An animal that eats plants.

Small animals, about 1-2cm long, that feed on smaller plants and animals. They are a very important food source for fish, penguins, seals and whales.  

Imaginary lines around the earth parallel to the equator. Latitude is used together with longitude to specify the precise location of features on the surface of the Earth. The New Zealand mainland sits between latitudes 34° and 46° south.

Imaginary lines around the earth that go through the north and south poles. LInes of longitude are not parallel. Longitude is used together with latitude to specify the precise location of features on the surface of the Earth. The New Zealand mainland sits between longitude 166° and  179° east.

Is the amount of stuff in something.  Measured in kilograms. You need to know the mass of something to find its density (density = mass/volume = kg/m3)

Kept within reasonable limits with no extremes (the sea helps to moderate the weather near the coast).

neutrally buoyant
When an object stays at the same position. It doesn’t sink or rise. The density of the object is the same as the density of the fluid it is in. 

Stands for the National Institute of Water and Atmospheric Research. It is a Crown Research Institute of New Zealand specialising in environmental sciences eg aquaculture, aquatic biodiversity, aquatic biosecurity, atmospheric science, climate change, coastal ecology, energy, fisheries, hydrology, marine geology, natural hazards (e.g. tsunami, storm surge, floods, earthquake, volcano), oceanography, sedimentology. 

Stands for the National Oceanic and Atmospheric Administration and is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere.

Means ‘open sea’. Any area of water away from land. The pelagic zone can be thought of as an imaginary cylinder or water column that goes from the surface to the bottom. Conditions change deeper down the water column: the pressure increases, the temperature drops and there is less light.

A chemical process that produces food in plants. During photosynthesis, carbon dioxide and water are combined using sunlight (photo = light, synthesis = to make).

Microscopic plants that live near the surface of lakes and the sea. They are the main food source for all ocean food chains. (phyto = plants, plankton = wanderer)

The force applied to a surface area. Pressure = force/area = newton/m2.  Pressure is measured in pascals. 1Pa = 1kg/1m2

The plants at the start of every food chain. Producers ‘produce’ food by combining water and carbon dioxide and sunlight. Grass, oak trees, phytoplankton and corn plants are producers. 

A diagram showing changing temperature and salinity as the Argo Float rises to the surface. Every 10 days the Argo Float surfaces and sends data to a satellite. The data describes a profile. There have been over a million separate Argo Float profiles uploaded since the first Argo Float was deployed in the year 2000.

Regular Argo Floats 
Steel cylinder Argo Floats designed to go down to depths of 2,000m, first used in 2007. There are now over 3,600 Regular Argo Floats in the world’s oceans. 

The amount of dissolved salt in water. Seawater usually has 35g of salt per 35kg of water =3.5%. Salinity is often measured by seeing how easily water conducts electricity

In chemistry the word salt has a special meaning. Most people think of salt as table salt which is a mineral substance made up of sodium (Na) and chlorine (Cl). Table salt or sodium choride has the chemical formula NaCl. Seawater is salty because of the large amounts of sodium chloride in the water. There are 35grams of sodium chloride in every litre of sea water.  

sea ice 
Frozen seawater. Because ice is less dense than water, it floats on the ocean's surface. The ice that forms when seawater freezes in winter in the Arctic and Antarctic takes up 7% of the world’s surface and 12% of the world’s oceans.  When seawater freezes, salt is squeezed out and collects in the water below the sea ice. This adds to the density of the water which sinks, to be replaced by warmer water from the surface. This creates a ‘conveyor belt’ motion of ocean currents.

Dissolves in water (sugar is soluble in water)

A shape like a ball. A sphere has a radius r, (the distance from the surface to a point in the middle) and a diameter d, (the largest distance through the sphere) which is twice the radius.  

A place where deep water rises to the surface and pushes the surface water away.  The rising water is usually rich in nutrients and oxygen and stimulates the growth of producers mainly phytoplankton.

Microscopic animals that feed on phytoplankton (zoo = animals, plankton = wanderer).