物理海洋学名词-A 12

Glossary of Physical Oceanography and Related Disciplines

Steven K. Baum Department of Oceanography Texas A&M University

May 26, 2004

 

AFZ Abbreviation for Arctic Frontal Zone.


AGDW Abbreviation for Aegean Deep Water.


age of tide The delay, usually a day or two, between full and new moons (when the equilibrium semi-diurnal tide is maximum) and the following spring tides. This terminology was first used to refer to this phenomenon by Whewell in 1883, although Defant referred to it as “spring retardation” in 1961 and Wood later (in 1978) used the terms “age of the phase inequality” and “age of the diurnal equality” to refer to, respectively, the ages of the semi–diurnal and diurnal tides. This delay is caused
by frictional energy dissipation in coastal seas, although a localized increase in the age of tide is also a good indication of resonances at that location. See Murty and El-Sabh [1985].


age of water The elapsed time since a given water mass was last at the sea surface. See Groves and Hunt [1980].


agger See double tide.


aggregation A process that significantly alters the sizes, characteristics and abundances of suspended particles in the ocean. There are two major mechanisms for aggregation:
• biologically mediated aggregation, which occurs when small particles are aggregated into fecal pellets through the feeding activities of animals; and
• aggregation via the largely physical processes of collision and sticking, i.e. coagulation.

The impacts of aggregation on marine ecosystems include:
• much of the particulate matter reaching the ocean interior and sea floor sinks as large, rapidly settling aggregates of detritus, mucous, algae and microorganisms in the visible size range, i.e. marine snow, so the export of carbon and nutrients from the surface ocean is directly linked to the mechanisms responsible for combining small particles into larger units capable of rapid settlement, i.e. aggregation;
• aggregation of small organisms and other organic particles affects the abilities of grazers to isolate their food from the aquatic environment and makes more food available to large–particle feeders;

• aggregation produces particles large enough to maintain unique internal chemical environments that can support unusual, microbial communities and potentially provide island–like refuges for protozoa and micorozooplankton; and
• aggregation affects the optical properties of seawater by altering the size distribution and abundance of particles available to absorb and scatter light.
See Alldredge and Jackson [1995].

 

LZZ@108,20170717

 

共收到 0 | 阅读次数 39
发表评论
请先登录再发表评论