Glossary

Huge icebergs (in some cases with an area of several square kilometres) with a level, smooth surface, and which can extend up to 100 m above the water’s surface. Produced by calving from ice shelves.

The IPCC’s Third Assessment Report.

In connection with sea level, this refers to an increase in volume (and decrease in density) due to the warming of water.

Thermal hysteresis refers to the difference (hysteresis) between the melting point and freezing point of a given solution.

Thermal radiation emitted by land surfaces or objects in the longwave infrared range.

Electronic component used to measure temperature changes, which it responds to by changing its electrical resistance. The name “thermistor” is derived from the words “thermal” and “resistor”. As a rule, thermistors are made of semi-conductive materials like silicon, germanium or metal oxides, and are frequently used in a broad range of applications, e.g. in air-conditioning systems, household appliances, medical equipment, and in aerospace contexts.

A buoy equipped with a thermistor chain that measures temperature distribution from the atmosphere, through the snow and sea ice, to the ocean.

Transitional water layer characterised by rapid temperature changes.

Thermohaline circulation, colloquially referred to as the ocean conveyor belt, is an oceanographic circulation pattern at the surface of the ocean and in its depths. Connecting four of the five oceans, it forms a global cycle.

Organisms in a given ecosystem that, at the 3^rd level of the food pyramid, heterotrophically live off of secondary consumers, e.g. predatory fish.

Models that use macroeconomic theory, econometric and optimisation techniques in order to aggregate economic variables.

TOC (total organic carbon) refers to the total amount of carbon from organic compounds in a given sample.

Total primary energy supply.

All gases found in the atmosphere in lower concentrations than the three main components nitrogen (78%), oxygen (21%) and argon (ca. 1%) are referred to as trace gases.

Specific substances or materials used to track the transport or conversion of elements or compounds in a given ecosystem or biogeochemical cycle.

Tree rings or growth rings reflect different developmental phases in a vegetation period.

In IPCC Reports, a trend refers to a constant change in the value of a given variable over time.

A trophic level refers to the level or position in the food chain or food web of a given ecosystem, which is determined by the number of energy-transmitting steps that are required to reach that level (energy pyramid).

A tropical cyclone is a low-pressure system characterised by structured convection, severe storms, and a closed low-level atmospheric circulation at its centre.

The lowermost part of the atmosphere, from the Earth’s surface to ca. 10 km in the middle latitudes (ranging from 9 km in the high latitudes to 16 km in the tropics on average), where clouds and meteorological phenomena arise.

(IPCC) Technical Summary.

Refers to a vegetation zone found in Arctic and subarctic regions and characterised by extremely low temperatures and brief vegetation periods.

Old sea ice that has only survived one summer melting.