Za-Zz

 

Zanclean

The first of two ages in the Pliocene epoch (coincidental with the Early Pliocene), lasting from 5.3 to 3.4 Ma. It is preceded by the Messinian age of the Miocene epoch and followed by the Piacenzian age.

 

zenith angle

The angle between the local normal to the Earth's surface and a line between a point on the Earth's surface and the sun.

 

zephyr

A westerly breeze with pleasant warm weather supposed to prevail at the summer solstice.

 

zero velocity surface

A reference level at which the horizontal velocities are thought to be practically zero.

 

Zimmerman, W. F. A. (1797-1864)

See Peterson et al. (1996), p. 91.

 

zonal mean wind

The distribution of the zonal mean of the eastward component of the wind through latitude and height. This is westerly through most of the troposphere, and peaks at speeds exceeding 30 m/s in the subtropical jet stream. Near the surface the zonal mean winds are westerly at most latitudes between 30 and 70 , with easterly winds prevailing a latitudes less than 30 . See Hartmann (1994).

 

zonda

A hot, sultry wind that brings tropical air from the north in Argentina and Uruguay. It is analogous to the Australian brickfielder and usually precedes the pampero. The locals tend to enjoy this sort of thing.

 

zone fossil

In biostratigraphy, a type of fossil.

 

zoobenthos

That part of the benthos consisting of animal life.

 

zooplankton

One of two groups into which plankton are divided, the other being phytoplankton. Zooplankton are a large group of micro- and macroscopic animals ranging in size from a fraction of a millimeter to 30-50 millimeters, with a few, such a certain jellyfish, being up to a meter in diameter. Some plankton, called permanent plankton or holoplankton, are adapted to a pelagic mode of existence and remain floating or feebly swimming throughout their entire life cycle. Others, called temporary plankton, are the transitory floating stages such as eggs, larvae, and juveniles of the benthos and nekton. This latter category is usually seasonal in occurrence and the abundance is primarily neritic since it derives from the benthos and nekton of shallow areas. See Johnson (1957) and Riley and Chester (1971).

 

Zoppritz, Karl

A German fluid dynamicist who was a pioneer in applying modern fluid dynamical methods to questions of the large-scale oceanic circulation. See Peterson et al. (1996), p. 98.

 

ZUDIS

Acronym for the Zentrales UmweltDaten Informations System, a meta-database tool for making available information about the significant environmentally related activities in Germany to scientists, decision makers, and others. See the ZUDIS Web site.

 

Zuricho-Montpellier school

See Braun-Blanquet school.