Ln-Lz

 

LOC

Abbreviation for limit of convection.

 

local elevation angle

The angle of the sun above the local horizon. This depends on the latitude and longitude of the location as

where is the time of day in Coordinate Universal Time, the local elevation angle, the latitude, the longitude, the solar declination angle, C the circle circumference, and the length of the day.

 

local range biozone

In biostratigraphy, a type of biozone in which the total known range of the zone fossil defines the limit of the unit. See Briggs and Crowther (1990), pp. 466-467.

 

loess

An unconsolidated sediment composed chiefly of silt-sized particles laid down by the wind.

 

LOICZ

Abbreviation for Land Ocean Interactions in the Coastal Zone, an IGBP project directed at an assessment of fluxes of matter between land, sea and atmosphere through the coastal zone; the responses of the land-sea interface to global change, particularl sea level rise; the biogeochemical responses of coastal systems to global change, with emphasis on the carbon cycle and exchanges of certain atmospheric trace gases; and the socio-economic implications of the degradation of the coastal zone and the need for development of new policies for the integrated management of coastal environments. See the LOICZ Web site.

 

LOIS

Acronym for Land-Ocean Interaction Study, the U.K. contribution to LOICZ. The project aims to quantify and simulate the fluxes and transformations of materials, e.g. sediments, nutrients, contaminants, into and out of the coastal zone, extending from the catchment to the edge of the continental shelf. The main study area is the U.K. East Coast from Berwick upon Tweed to Great Yarmouth, concentrating on the Humber River and its catchment. See the LOIS Web site.

 

longshore current

More later.

 

LOTUS

Acronym for Long Term Upper Ocean Study, Woods Hole, 1983., Woods Hole, 1983.

 

low

Abbreviated form of low pressure center.

 

low pass filter

In data or signal analysis, a filter that passes frequencies below some cutoff frequency while attenuating higher frequencies.

 

low pressure center

In meteorology, a region of relatively low barometric pressure. These are characterized by upward moving air at altitude and convergence near the ground. These predominate in midlatitudes, i.e. around 40-50 . These are also known as cyclones and as such rotate clockwise/counterclockwise in the southern/northern hemisphere. Low pressure systems are generally characterized by clouds, precipitation, and occasionally thunderstorms, all of which are facilitated by the upward movement of moist air from near the ground.

 

LSP

Abbreviation for Land Surface Parameterization scheme, and method for parameterizing plant growth, soil moisture, and other processes occurring at or near the land surface in terms of atmospheric GCM output variables (e.g. temperature, precipitation, etc.). Examples of LSPs are BATS, BEST, CLASS and SECHIBA.

 

LSW

Abbreviation for Labrador Sea Water.

 

LTE

See Laplace's tidal equations.

 

LTER

Abbreviation for the Long Term Ecological Research Program, established by the NSF to support research on long-term ecological phenomena in the U.S. See the LTER Web site.

 

LUCC

Acronym for Land Use/Cover Change, a core project of the IGBP designed to improve understanding and projections of the dynamics of land-use and land-cover change as inputs to and consequences of global environmental change and as elements of sustainable development. The research agenda consists of five themes: integrated global and regional models, land-cover patterns, land-use processes, database and classification development, and cross-scale or scalar dynamics. See the LUCC Web site.

 

lunear month

See synodic month.

 

lunation

See synodic month.

 

Luterbacher Predictive Model

A model, supported by CIESIN, foretelling impacts of global change on socioeconomic behavior.

 

Lutetian

The second of four ages in the Eocene epoch (the first of two ages in the Middle Eocene), lasting from 52.0 to 43.6 Ma. It is preceded by the Ypresian age and followed by the Bartonian age.

 

LWC

Abbreviation for liquid water content, a component of CWC.

 

lysimeter

An instrument for measuring the amount of water lost by evapotranspiration. It is a container of soil set on a balance or provided with some other means of measuring water content.

 

lysocline

The upper portion of the transition zone in sediments between supersaturated (shallow) and undersaturated (deep) sediments in the ocean. The transition is between the burial and dissolution of CaCO3 sediments. See Najjar (1991).