long-term variability
61White dwarf — For other uses, see White dwarf (disambiguation). Image of Sirius A and Sirius B taken by the Hubble Space Telescope. Sirius B, which is a white dwarf, can be seen as a faint pinprick of light to the lower left of the much brighter Sirius A …
62Global Energy and Water Cycle Experiment — The Global Energy and Water Cycle Experiment (GEWEX) is a research program of the World Climate Research Programme intended to observe, comprehend and models the Earth s water cycle. The experiment also observes how much energy the Earth receives …
63continental landform — ▪ geology Introduction any conspicuous topographic feature on the largest land areas of the Earth. Familiar examples are mountains (including volcanic (volcanism) cones), plateaus, and valleys. (The term landform also can be applied to… …
64Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
65Speech repetition — Children copy with their own mouths the words spoken by the mouths of those around them. This enables them to learn the pronunciation of words not already in their vocabulary. Speech repetition is the saying by one individual of the spoken… …
66Cooperative Institute for Research in Environmental Sciences — The Cooperative Institute for Research in Environmental Sciences (CIRES) is a research institute that is sponsored jointly by the National Oceanic and Atmospheric Administration (NOAA)/Office of Oceanic and Atmospheric Research (OAR) and the… …
67Climate of the Arctic — The climate of the Arctic is characterized by long, cold winters and short, cool summers. There is a large amount of variability in climate across the Arctic, but all regions experience extremes of solar radiation in both summer and winter. Some… …
68Australia — /aw strayl yeuh/, n. 1. a continent SE of Asia, between the Indian and the Pacific oceans. 18,438,824; 2,948,366 sq. mi. (7,636,270 sq. km). 2. Commonwealth of, a member of the Commonwealth of Nations, consisting of the federated states and… …
69environment — environmental, adj. environmentally, adv. /en vuy reuhn meuhnt, vuy euhrn /, n. 1. the aggregate of surrounding things, conditions, or influences; surroundings; milieu. 2. Ecol. the air, water, minerals, organisms, and all other external factors… …
70Variable star — A star is classified as variable if its apparent brightness as seen from Earth changes over time, whether the changes are due to variations in the star s actual luminosity, or to variations in the amount of the star s light that is blocked from… …
