Acronym for Global Atmospheric Gases Experiment. See
- Gaia hypothesis
The hypothesis that the Earth's physical and biological systems are
considered to be a complex and self-equilibrating entity.
See Lovelock (1979).
Acronym for Global Analysis, Interpretation and Modelling,
a subprogram of the the IGBP to analyze current
models and data, assess the capability of current models and
programs to resolve key questions, and advance and sythesize our
understanding of the global biogeochemical cycles and their links
to the hydrological cycle and to the physical-climate system as
a whole. See the
GAIM Web site.
- galactic circle
The great circle of the celestial sphere
in where it is cut by the galactic plane.
It is the primary circle to which the galactic coordinates are
- galactic plane
The plane passing as nearly as possible through the center of the belt
known as the Milky Way or Galaxy.
Acronym for the Genesis of Atlantic Lows Experiment, an extensive
study of the atmospheric processes involved in the development
of winter storms on the East Coast of the United States.
The planning phase ran from 1984-86, field operations during
1986, and the analysis phase from 1986-89.
See Dirks et al. (1988).
Acronym for the GEWEX Asian Monsoon experiment,
the goal of which is to understand the role of the Asian monsoon in
the global climate system and develop methods for long-range
forecasting. See the GAME Web site for further information.
Acronym for Global Aerosols Monitoring Experiment from Space.
- gap analysis
The evaluation of the management status of plant communities,
vertebrate species and species richness by
GIS overlay of biological distribution
data on a map of existing biological reserves. First maps
are produced at low spatial resolution to provide a broad
overview of biota distribution and their management status and
to identify landscapes that contain large numbers of potentially
unprotected vegetation types and vertebrate species. Then
the problem areas are studied in more detail as candidates
for additional management and conservation efforts.
See the UCSB Biogeography Laboratory
Gap Analysis Project Web site.
Acronym for the International Geological-Geophysical Atlases of
the Atlantic and Pacific Oceans, an ocean mapping activity
of the IOC.
Acronym for the Global Atmospheric Research Program, planned and
coordinated jointly starting in 1968 by the
WMO and the ICSU.
Abbreviation for Glace Atmosphere sur Terre et Ocean Numeriques,
a group performing numerical simulations of coupled ocean,
atmosphere and ice models. For further details, see the
GASTON Web site.
- gas-to-particle conversion
In the study of atmospheric aerosols,
GPC is a mechanism for the production
of nucleation mode type
atmospheric aerosols where condensation of gaseous substances
causes either the growth of existing nuclei (heterogeneous
nucleation) or the formation of new particles (homogeneous
nucleation). The former can proceed at minor supersaturations
while the latter requires a much greater degree of supersaturation.
Converted sulfates, nitrates and hydrocarbons are three major
components suspected of being involved in GPC.
See Jaenicke (1993b).
A class of marine invertebrates in the
Most of these have a spiral shell and a foot used for
creeping, although some are
holoplanktonic without shells
and with the foot modified for swimming, e.g. pteropods
Most of the 49,000 species in this class are marine.
1. Acronym for GARP Atlantic Tropical
2. Acronym for Global Acoustic Transmission Experiment.
- Gauss Magnetic Epoch
Normal polarity time interval extending from 2.4 to 3.3 million
years ago. See Bowen (1991).
- Gaussian distribution
More about which later.
Acronym for the Global Atmospheric Watch program, established
in 1989 by the WMO as a world wide system
of atmospheric composition monitoring and research consisting
of over 300 observation stations.
The purpose is to provide data, scientific assessments, and other
information on the atmospheric composition and related physical
characteristics of the background atmosphere from all parts of
the globe. The measurement program includes
ozone, radiation and
chemical and physical properties of aerosols, reactive gases,
related meterological parameters.
GAW Web site.
Great Barrier Reef Undercurrent.
Acronym for Global Change and Terrestrial Ecosystems, an
Abbreviation for the Global Climate Change Information
Programme, a program established in Oct. 1991 to provide an
link for information about climate change
among scientists, politicians, economists,
and the general public. GCCIP is a part of
ARIC. See the
GCCIP Web site.
Abbrevation for General Circulation Drifter.
Abbreviation for Global Change Data Center, a part of the
NASA/GSFC's ESD whose mission is to develop and
operate data systems, generate science products, and provide
archival and distribution services for earth science data in
support of the USGCP and the NASA
MTPE. See the
GCDC Web site for further information.
Acronym for Global Change Data and Information System,
a proposed IWG structure that encompasses the ensemble of
multi-agency and institution data and information systems
supporting the Global Change Research Program (GCRP) and
may be more broadly viewed as encompassing those who serve
the GCRP and the IGBP. More information can be found at the
GCDIS Web site.
Abbreviation for Global Change and Ecological Complexity, an
Abbreviation for Gulf and Caribbean Fisheries Institute.
Abbreviation for GEWEX Continental-Scale International
Project, a multifaceted group of activities designed primarily to
improve scientific understanding and the ability to model, for
climate prediction purposes, the coupling between the atmosphere and
the land surface on a continental scale. GCIP is examining the
energy budget and hydrological cycle of the Mississippi River
See the GCIP Web site for further information,
the GCIP Implementation Plan.
See general circulation model.
Acronym for Global Change Master Directory,
an electronic information resource operated at
NSSDC, providing brief
information about space and earth science data and data sets.
This is the American Coordinating Node of the
CEOS IDN and also a participant in
Free, online access allows users to identify relevant data
sets and their location, and also allows direct connection to
certain specific data centers. See the
GCMD Web site.
Acronym for the Global Climate Observing System, a global observing
program planned jointly by ICSU,
and IOC of
It was established to develop a dedicated observing system
designed specifically to meet to observation requirements
for monitoring climate, detecting climate change, and for
predicting climate variations and change. The objectives of
GCOS are to meet the observational needs for climate system
monitoring, climate change detection and response monitoring,
especially in terrestrial ecosystems; data for application
to national economic development; and research toward
improved understanding, modeling, and predicting the
A Joint Scientific and Technical Committee (JSTC) and
a Joint Planning Office (JPO) were set up to develop the plans
and strategy for implementation of the system. See the
GCOS Web site for more information.
Acronym for Global Climate Perspectives System, a joint project between
two NOAA laboratories (the NCDC
and the CDC of the ERL) to study the
existence and magnitude of climate changes on a global scale, create
high-quality global climate reference datasets and provide access to
them, and to crate a set of computer tools to aid in climate research.
GCPS Web site.
Abbreviation for the U.S. Greenhouse Climate Response Index, a means
of possible early detection and monitoring of anticipated
greenhouse-induced climate change in the U.S. It is calculated as
the arithmetic average of four indicators:
Much above and below normal are defined as falling within the highest
and lowest tenth percentile of the local, long-term record.
The GCRI has averaged 12.2% since 1976 (where the expected value for
any given year is 10%), whichis 2.8% above the average from
previous years in the century although not large or consistent
enough to be rejected the statistical possibility that this increase
is still a feature of a stable climate.
See Karl et al. (1995) and
Karl et al. (1996).
- The percent of the U.S. with much above normal minimum temperatures.
- The percent of the U.S. with much above normal precipitation during
the months October through April (the cold season).
- The percent of the U.S. in extreme or severe drought during the
months May through September (the warm season).
- The percent of the U.S. with a much greater than normal proportion
of precipitation derived from extreme 1-day precipitation events
(exceeding 2 inches or 50.8 mm).
Acronym for Global Change Research Information Office,
established under the GC Research Act of 1990 (Public Law
101-606) to provide United States generated scientific
research information in the area of global change to foreign
governments, businesses and institutions, and citizens of
More information can be found at the
GCRIO Web site.
Abbreviation for Global Change Research Program.
Abbreviation for the GEWEX Cloud System Study, a
project to develop better parameterizations of cloud systems for
climate models by an improved understanding of the physical
processes at work within various types of cloud systems. More
See Browning (1993), GEWEX Cloud System Science Team (1993) and the
GCSS Web site.
Abbreviation for Global Change and Terrestrial Ecosystems, an
IGBP core project to develop the capacity
to predict the effects of changes in climate, atmospheric
composition, and land use practices on terrestrial ecosystems,
and to determine feedback mechanisms to the physical climate
system. The operational plan to meet its objectives is
divided into a hierarchy of four foci: ecosystem physiology,
change in ecosystem structure, global change impact on
agriculture and forestry, and global change and ecological
complexity. The first two foci are designed to provide a
fundamental understanding of the impacts of global change
on ecosystem function, composition and structure, and their
feedback effects. The third and fourth are designed to
examine the most specific impacts of global change on systems
of great importance to humans.
There are four project level facilities beneath this formal
research structure to integrate the GCTE research effort:
(1) the Long-Term Ecosystem Modeling Activity (LEMA)
network of modeling centers; (2) a set of major transects
along environmental gradients such as temperature or
precipitation; (3) an international network of intensive
crop experimental sites to be used for studies of crop
performances at various points in their environmental range;
and (4) a set of experimental sites examining the impact
of elevated CO2 on ecosystem function using
GCTE Web site.
Global Drifter Center.
Abbreviation for General Digital Environmental Model, a
four-dimensional (latitude, longitude, depth, and time)
digital model of temperature and salinity for the North and
South Atlantic, the Pacific, the Indian
Ocean north of 40 S, the Arctic Ocean, the Mediterranean
Sea, and the Black Sea. It consists of coefficients of
mathematical expressions describing vertical profiles of
temperature and salnity on a half degree latitude-longitude
grid for seasonal and annual time frames, with the actual
profiles generated by combining the coefficients with the
equations. Some regions are being updated to 10 minute
Data for creating the GDEM were obtained from
the Master Oceanographic Observational Data Set (MOODS)
as well as from the Levitus climatology. It is used by
the U.S. Navy for most of its operational systems.
See Teague et al. (1990).
Global Drifter Program.
Abbreviation for Global Digital Sea Ice Data Bank.
Acronym for the Global Energy Balance Archive, a database developed
at the Swiss Federal Institute of Technology for the worldwide
instrumentally measured energy fluxes at the Earth's surface.
See Ohmura et al. (1989) and the
GEBA Web site.
Acronym for GEneral Bathymetric Chart of the Oceans, a map
series established by Prince Albert I of Monaco in 1903.
This is at present an activity of the IOC.
The GEBCO Digital Atlas is now available
Abbreviation for Global Emissions Inventory Activity, a program
of the IGAC core project of the
Its goals include establishing a framework for developing
and evaluating global emissions inventories, conducting
a critical survey of existing emissions inventories of
compounds of major importance in global atmospheric
chemistry, and generating and publishing inventories for
use by scientists worldwide. See the
GEIA Web site.
Abbreviation for geomagnetic electrokinetograph.
Dissolved material in sea water that is resistant to bacterial
attack. Its name comes from the yellow color it imparts to the
water. Brown algae, the principal algae group growing in coastal
waters of temperature and higher latitudes,
excrete phenolic compounds. These polyphenols are converted
into a brown polymer by secondary reactions with carbohydrates
and proteins of algal origin. The properties of the resulting
substance are identical with Gelbstoff. Its concentration in
sea water is around 1 mg/l and it is removed mainly by
precipitation since its phenolic nature renders it resistant
to bacterial attack. This is also known as yellow substance
See Riley and Chester (1971).
1. Acronym for the General Ecosystem Model.
See Rastetter et al. (1991).
2. Acronym for the Global Emiliania Modeling Initiative,
a program involving studies of carbon and sulphur fluxes as
well as a large geological component. The
EHUX project is part of the
Acronym for Global Environment Monitoring System, established as
part of UNEP's Earthwatch program in 1975 as a collaborative
effort of the UN system to monitor and assess the global
environment. The objectives of GEMS include to strengthen
monitoring and assessment capabilities in participating
countries, to increase the validity and comparability of
environmental data and information, to produce global/regional
assessments in selected fields and compile environmental
information at the global level, and to provide early warnings
on emerging issues of potential international importance.
GEMS Web site.
- genetic strategy
A unifying concept in ecology defined as a grouping of similar
or analogous genetic characteristics which occur widely among
species or populations and cause them to exhibit similarities
See Grime (1979).
Acronym for Global Environmental Network for Information Exchange,
a project to provide a user-sympathetic system for locating and
accessing relevant information on global environmental change.
GENIE Web site.
The science concerned with the study of the shape and size of
the earth in the geometrical sense and with the study of certain
physical phenomena, such as gravity, in seeking explanation of
fine irregularities in the earth's shape, and as such in
inextricably linked with surveying and cartography.
Acronym for Geochemistry and Dynamics of the Mediterranean,
an MTP Core Sub-project whose aims are
to monitor the evolution of the physical and chemical
characteristics of western deep water and the detect similar
changes in the different Mediterranean basins, to describe
and quantify transfer processes at air-land-sea interfaces,
and to give a new picture of phytoplankton distribution,
new production and chemical transfers.
GEODYME Web site.
- geological oceanography
Compare to biological,
A hypothetical, global, and continuous sea-level
surface perpendicular to the direction of gravity at all points.
Acronym for Geodynamics Experimental Ocean Satellite.
Acronym for Geodetic Satellite.
See Douglas and Cheney (1990).
Abbreviation for the Interactive Global Change Encyclopedia, a project
to demonstrate that satellite data and other geographic information
can be of vital importance in monitoring the global environment.
GEOSCOPE Web site.
Acronym for Geochemical Ocean Sections Study, a global survey of
the three-dimensional distribution of chemical, isotopic and
radiochemical tracers in the ocean. The expeditions were in
the Atlantic from July 1972 to May 1973; the Pacific from August 1973
to June 1974; and the Indian Ocean from December 1977 to March 1978.
The GEOSECS data set is
- general circulation model
Generally a three-dimensional time-dependent model of the atmosphere
and/or ocean circulation. The solution to a set of mathematical equations
governing the motions of a layer of fluid on a spherical planet is numerically
approximated on a three-dimensional discrete grid of points to obtain
temperatures, velocities, rainfall, pressure and any of several other
that collectively comprise the state of the
climate. Often abbreviated as GCM.
See Washington and Parkinson (1986).
- Generic Mapping Tools
A collection of around 50 UNIX
tools that allow the manipulation and graphing of X-Y and
X-Y-Z data sets and the output of the results in PostScript
format. The data can be manipulated in many different
ways and the results can be graphed on a multitude of
projections, with just about every imaginable graph
attribute amenable to modification.
The plotting capabilities include creating basemap plots,
plotting coastlines, filled continents, borders and rivers
on maps, contouring gridded data, producing images from 2-D data sets,
contouring raw data by triangulation, plotting histograms,
plotting sector or rose diagrams, and more.
Many projections are provided including conic,
azimuthal and cylindrical types.
A unique feature of GMT is the High-Resolution Coastline Database.
This is a five resolution level database of world coastlines, rivers,
lakes, and political boundaries. The maps included in the glossary
were created using this package.
GMT was written for UNIX systems in the C language as is freely
available for academic use. See the
GMT Web site.
The acronym for the Global Environmental
and Ecological Simulation of Interactive Systems model developed by
Starley Thompson and Dave Pollard at NCAR.
It is a heavily modified version of the CCM1
model also developed at NCAR. See
Thompson and Pollard (1994) and the
GENESIS Web site.
- Geophysical Fluid Dynamics Laboratory (GFDL)
A part of the NOAA ERL
network whose research goal is to expand the scientific understanding
of the physical processes that govern the behavior of the
atmosphere and the oceans as complex fluid systems.
GFDL Web site.
The potential energy per unit mass of a body due to the Earth's
gravitational field as referred to an arbitrary zero reference
level. A unit of geopotential is the potential energy acquired
by a unit mass on being raised a unit distance in a gravitational
field of unit strength.
- geopotential distance
See dynamic height.
- geopotential height
See dynamic height.
- geopotential surface
A surface to which the force of gravity is everywhere
perpendicular and equal.
No work is necessary for the displacement of mass along a
potential surface as long as no other forces act in addition to
gravity. This can also be defined as a surface of equal
dynamic height below the level of
the sea surface,
using the ideal sea surface level as a reference surface
with the potential value 0.
This has also been called a potential surface or a level surface.
- geopotential thickness
See dynamic height.
- geostationary orbit
An orbit lying above the Equator in which an artifical satellite
moves at the same speed as the Earth rotates. As such it maintains
position above the Earth's surface. Such satellites have an
altitude of 35,910 km. Satellites in this type of orbit have
a continuous view of the full disc of the Earth, although the
curvature of the Earth makes it diffucult to gather information
for latitudes higher than about 45-50 . They have a
better time resolution than polar orbiting satellites, but
are restricted to a single location.
- geostrophic approximation
The use of the geostrophic wind as an
approximation to the actual wind.
- geostrophic balance
A balance between the
and the pressure gradient (divided by the density) in a rotating
fluid subject to gravitational restoring forces.
- geostrophic current
In oceanography, the theoretical current resulting from the balance of
the pressure gradient force and the
i.e. the forces associated with horizontal changes
in density are compensated by accelerations arising from fluid motion
on a rotating Earth. Analogous to the
- geostrophic force
A virtual force used to account for the change in direction of the
wind relative to the Earth's surface. It results from the
Earth's rotation and the Coriolis force.
- geostrophic method
See dynamic method.
- geostrophic turbulence
To be completed.
- geostrophic velocity
Those velocities inferred from measurements of the oceanic
density field. These are construed to be those velocities that
result from a
geostrophic balance of
forces in the ocean.
- geostrophic wind
In meteorology, the theoretical wind resulting from the balance of the pressure
gradient force and the geostrophic force.
Analogous to the geostrophic current in
An orbit where the period of the satellite is equal to the period of
the rotation of the Earth. This is usually used synonymously with
geostationary, although the latter has the
additional qualities of being circular and in the equatorial plane.
- Geosynchronous Operational Environmental Satellite
A series of NOAA satellites used for geostationary
remote sensing. See the
GOES Web site.
There is also a
SSEC GOES Web site with further
- Gerard barrel
A barrel used to collect water samples in oceanography that
holds 250 l.
- Gerstner wave
A wave theory developed for periodic waves of finite height to
surpass the limitations of
Stokes wave theory.
The equations are simple to use and
the solutions are exact and satisfy continuity as well as the
pressure conditions at the water surface, and experimental
studies have shown that the theory closely approximates the
profiles of real waves on a horizontal bottom. Drawbacks
include that mass transport is not predicted, the velocity
field is rotational, and the particle movements are opposite
to that expected in real waves (and found in other theories).
The predictions of both Gerstner and Stokes wave theories
agree equally well with measured wave profiles. This is well
explained by the fact that if the Gerstner wave equations are
expanded into a series the first three terms are identical to
those in the Stokes solution. This similarity in predictive ability
and greater ease of use lead to the preferential use of Gerstner
wave theory in many engineering applications where its limitations
are not significant. This has also been called
trochoidal wave theory since the elevation profile takes the
form of a trochoidal curve.
See Komar (1976) and LeMehaute (1976).
Acronym for Joint Group of Experts on the Scientific Aspects of
Marine Pollution, a group comprising elements from IMO, FAO,
UNESCO-IOC, WMO, WHO, IAEA, UN and UNEP.
Acronym for the
Global Energy and Water Cycle Experiment. Initiated in 1988 by
the WCRP to observe and model the
hydrologic cycle and energy fluxes in the atmosphere, at the
land surface, and in the upper oceans. It is an integrated
program of research, observations, and science activities
leading to the prediction of global and regional climate change.
GEWEX hydrometeorology and land-surface projects include
the GRDC, ISLSCP,
GAME, LBA, and
MAGS. Radiation projects include
the BSRN, CPRP,
ISCCP, and SRB.
Modeling and prediction projects are
GCSS, G-NEP and
GEWEX Web site.
Geophysical Fluid Dynamics Laboratory.
Abbreviation for GPS Geoscience Instrument.
Global Hydrology and Climate Center.
Abbreviation for the Global Historical Climatology Network, a
comprehensive global baseline climate data site comprised of
land surface station observations of temperature, precipitation,
and pressure. All data are on a monthly basis with the earliest
record dating from 1697. See the
GHCN Web site.
- giant squid
See Architeuthis princeps.
- Gibb's phenomenon
An artifact of attempting to approximate a function or waveform
with a discontinuity using a Fourier series or some other
global, continuous basis function. The fit is poor in a region near the
discontinuity, usually characterized by large oscillations within
the region. Increasing the number of components in the approximation
decreases the region of poor fit, which theoretically vanishes with
an infinite number of components.
- Gibraltar Experiment
See Kinder and Bryden (1987).
- Gilbert Magnetic Epoch
Reverse polarity time interval extending from 3.3 to 4.5 million
years ago. See Bowen (1991).
- Gilsa Magnetic Event
Short-term normal polarity time interval about 1.6 million years
ago within the Matuyama Reverse Epoch.
See Bowen (1991).
Acronym for Global Inventory Monitoring and Modeling Studies.
- GIN Sea
Abbreviation for Greenland/Iceland/Norwegian Sea, an area that
has also variously been called the Norwegian Sea and the
Nordic Seas. The GIN Sea together with the
Polar Sea constitute the
Arctic Ocean in some classification
schemes in contrast to others including the GIN Sea within the
confines of the Atlantic. The former may perhaps be preferred
for geomorphological as well as hydrographical reasons. The
bottom is continuously oceanic in crust and depth through the
connecting passage (to the north) of Fram Strait, while the
southern connection is over a continental ridge, i.e. the
Greenland-Scotland Ridge. Also, the deep thermohaline circulation
processes of the GIN and the Polar Sea are closely linked.
The GIN Sea comprises two major basins: the Greenland Basin and
the Greater Norwegian Basins (i.e. the Norwegian Basin and the
Lofoten Basin) separated by the Mohn Ridge. It has six open
boundaries through which important exchanges occur: Fram Strait
connecting to the Polar Ocean
to the north, three boundaries over the Greenland-Scotland
Ridge that connect with the Atlantic Ocean, and two boundaries
connecting to continental shelf seas, i.e. the North Sea and
the Barents Sea.
See Hopkins (1991).
Acronym for Global Investigation of Pollution in the Marine
Environment, an international cooperative program of scientific
investigation focused on marine contamination and pollution.
It is co-sponsored by the IOC,
UNEP and IMO.
The objectives of GIPME are to create authoritative
evaluations of the state of the marine environment at
both regional and global levels, to identify the
requirements for measures to prevent or correct
marine pollution, and to create procedures for assessing
and improving compliance and surveillance monitoring of
conditions and effects in the marine environment.
See the GIPME Web site.
Acronym for Greenland Ice Sheet Project.
See the GISP Web site.
An acronym for the Goddard Institute for Space
Studies. This is also used to refer to the atmospheric GCM
developed and used at that institution. See the
GISS Web site.
Acronym for GCIP Integrated Systems Test, a
data system test taking place in the Arkansas-Red River basins
prior to the start of the 5 year GCIP Enhanced Observing Period
(1995-2000). The objectives are to: (1) demonstrate the adequacy
of the GCIP data collection and management system and (2) rectify
any data system modifications identified in time for use in the
Enhanced Observing Period. The GIST data sets can be accessed
A time when ice sheets expand and average global climates are cooler and
drier than during and interglacial.
- Glacial Geology and Geomorphology
An electronic journal of the British Geomorphological Research Group.
Selected papers are available online at the
GGG Web site.
- Glacial North Atlantic Deep/Intermediate Water
See Yu et al. (1996).
- glacial period
A time interval during which ice sheets have spread widely
across lowlands in the north. During the last million years
there have been four major glacial periods.
In chronological order they are the
Saale, and the
- glacier zones
A system for classifying zones on glaciers according to ice
temperature and the amount of surface melting. The zones are
dry snow zone,
superimposed ice zone and
See Paterson (1969).
Abbreviation for the Geoscience Laser Altimeter System, an
EOS instrument planned for the ALT
platforms. It is a nadir-pointed laser altimeter which can
measure cloud heights and aerosol vertical structure.
See Cohen et al. (1987).
A pseudomorph after a carbonate (ikaite) that
is taken in paleothermometry to
reflect cold subaqeuous depositional conditions. Ikaite
characteristically grows in cold water sediments that are rich in
organic matter, highly alkaline, reducing, and have a high
Great Lakes Environmental Research Laboratory.
Great Lakes Forecasting System.
Abbreviation for Global Imager, a spaceborne optical sensor designed
for observing reflected solar radiation from the earth's surface.
It is an ocean color sensor used for measuring the distribution
of chlorophyll, vegetation biomass, distribution of snow and ice,
albedo of snow and ice, and several other quantities.
GLI has 22 bands in the visible and near-infrared regions, 5 bands
in the shortwave infrared region, and 7 bands in the middle and
thermal infrared regions for a multispectral imaging capability.
The ground resolution ranges from 250 to 1000 meters with a swath
width of 1600 in the cross-track direction.
GLI Web site.
Acronym for Global Land Ice Monitoring from Space, a project designed
to monitor the world's glaciers using data primarily from the
GLIMS Web site.
Acronym for Global Land Information System, an interactive computer
system developed by the USGS for
scientists seeking sources of information about the Earth's
land surfaces. See the
GLIS Web site.
- Global Backscatter Experiment
Initiated in 1986, the GLOBE is
a cooperative interagency and international research program to
characterize the spatial, temporal and spectral variability of
atmospheric aerosol backscatter coefficients. See the
GLOBE Web site.
- global change
A transformation which occurs on a world-wide scale (for
example, an increase in CO2 in the atmosphere) or exhibits
sufficient cumulative effects to have world-wide impact (for
example, local species extinction resulting in global loss of
- Global Drifter Center (GDC)
An AOML data center located in Miami, Florida that
manages the deployment of drifting buoys around the world. Global
Lagrangian Drifters (GLD) are placed in areas of interest using
research ships, VOS, and U.S. Navy aircraft.
Once they are operationally verified, the data is telemetered to
the GDS and disseminated to interested parties everywhere.
GDC Web site.
- Global Drifter Program (GDP)
A NOAA AOML
program whose objectives are to: (1) described mixed-layer
velocity on a 5 degree resolution global basis and produce
new charts of seasonal surface circulation; (2) provide an
operational data stream for SST, sea level pressure, and surface
velocity data; (3) verify global climate models; (4) compute
single particle diffusivities, eddy statistics, and interannual
to annual variability; (5) construct models of wind-driven
currents; and (6) obtain high resolution coverage in special
regions for process studies. The program was started in
GDP Web site.
- global electrical circuit
See atmospheric electrical circuit.
- Global Energy and Water Cycle Experiment
GEWEX was initiated in 1988 by the WCRP
as a program designed to observe and model the
hydrologic cycle and energy fluxes in the atmosphere, at the land
surface, and in the upper oceans. The International GEWEX Project
Office (IGPO) is the focal point for the planning and development of all
GEWEX projects and activities.
See Chahine (1992a) and Chahine (1992b) and the
GEWEX Web site for further information.
- Global Geocryological Database
An internationally distributed system of linked data centers or
nodes containing information from regions of perenially and
seasonally frozen ground. The purpose of this
IPA project is to
help identify, acquire and disseminate data on permafrost and
frozen ground. See the
GGD Web site.
- Global Hydrology and Climate Center
A research center, abbreviated GHCC, whose
objective is to address global hydrological processes. See the
GHCC Web site.
- Global Precipitation Climatology Project
A GEWEX-affiliated project, abbreviated GPCP,
designed to provide global data sets
of area, time-averaged precipitation for a minimum period of 10 years
(1986-1995). This data will be produced by merging geostationary
and polar-orbiting satellite microwave and
infrared data with rain
gauge data from more than 6000 stations. More information can be
found at the
GPCP Web site.
- global radiative-convective feedback
A feedback loop that links the hydrologic cycle and the
ARC. This is a negative feedback
that works on the principle that stronger convection leads to
more high clouds, which reduces the ARC, further reducing
the precipitation rate adn the level of convective activity.
See also radiative-dynamical-convective feedback.
See Wielicki et al. (1995).
- Global Runoff Data Center
A GEWEX project, abbreviated GRDC,
to compile a global data base of stream
flow data for the development and verification of atmospheric and
hydrologic models. More information can be obtained at the
GRDC Web site.
- Global Terrestrial Observing System
The GTOS is a
global observing program planned jointly by FAO,
WMO, and UNEP.
- Global Warming Potential (GWP)
The GWP is an index of the strength of the radiative forcing induced by
It is defined in the IPCC Report
Shine et al. (1990)
as the time-integrated commitment to climate forcing from the
instantaneous release of 1 kg of a trace gas expressed relative to
that from 1 kg of carbon dioxide, i.e.
it is the ratio of the warming caused by a substance to the warming
caused by a similar mass of carbon dioxide with
the GWP of CO defined as unity.
1. Acronym for the
Global Backscatter Experiment.
2. Acronym for the Global Land One-kilometer Base Elevation
GlobalLandOne project, an international effort to develop a
best-available global digital elevation map on a 1-kilometer grid. See the
GLOBE Web site.
3. Acronym for the Global Learning and Observations to Benefit
the Environment program, a national and internationalhands-on
environmental science and education program. It uses scientific
instruments and state-of-the-art technology to make
science relevant to todays K-12 students. See the
GLOBE Web site.
Acronym for Global Ocean Ecosystem Dynamics, a component of the
IGBP developed and sponsored by
SCOR, the IOC,
the ICES, and
PICES. Its goal is advance our
understanding of the structure and functioning of the
global ocean ecosystem, its major subsystems, and its response
to physical forcing to where we can develop and capability to
forecast the marine upper trophic system response to scenarios
of global change. GLOBEC concentrates on zooplankton population
dynamics and its response to physical forcing in pursuit of this
goal. See the
GLOBEC Web site or the
U.S. GLOBEC Web site.
- globigerina ooze
A type of calcareous ooze composed of the shells of unicellular
creatures called globigerina that live in the waters of warmer
ocean regions. These oozes are seldom found above 5000 m depth
and cover about 35% of the surface of the sea floor.
See Neumann and Pierson (1966) and
Acronym for Global Change and Biodiversity in Soils.
Acronym for Global Tropospheric Carbon Dioxide Network.
Acronym for Global Change Research in the Antarctic.
Acronym for Global Atmospheric Chemical Survey.
Acronym for Global Continental Palaeohydrology Project, an activity
- Gloger's Rule
An ecogeographical rule
that states that races of warm-blooded animals
in warmer regions are more darkly colored than races in colder or
drier regions. It was established by Contantin Wilhelm Lambert
Gloger in 1833.
Acronym for Global Modeling of Atmospheric Chemistry, a
EUROTRAC program to develop a three dimensional model of the
global troposphere for simulating the transport and transformation
of trace constituents, and to use the model to answer questions
concerning the sources and sinks of tropospheric ozone and
its precursors, the influence of anthropogenic processes on
composition and climate, and the long-range transport of
sulfur compounds and other acidifying substances.
GLOMAC Web site.
Acronym for Global Meteorological Experiment.
Acronym for Global Tropospheric Ozone Network, an IGAC activity.
Acronym for Global Land-Ocean River Inputs database.
Acronym for the Global Sea Level Observing System, an
IOC-coordinated project for the establishment
of a strategic gloval core network of about 300 tide gauges around
the world for long term climate change and oceanographic sea level
monitoring. These gauges are spaced about 1000 km apart along
coastlines and on oceanic islands and provide hourly-resolution
standardized sea level data.
See the GLOSS Web page.
Abbreviation for Geoscience Laser Ranging System.
Plants intolerant to salinity.
Plants able to withstand moderate salinity, i.e. adapted to high
osmotic potentials in soil water.
Abbreviation for Geophysical Monitoring of Climate Change, an
Abbreviation for Global Multi-region Cloud System Study.
Abbreviation for Gulf of Mexico Program.
1. Abbreviation for Greenwich Mean Time.
2. Abbreviation for Generic Mapping Tools.