AAOE- Airborne Antarctic Ozone Experiment
AASE - Airborne Arctic Stratospheric Expedition
AATSR - Advanced Along-Track Scanning Radiometer
ABLE - Atmospheric Boundary Layer Experiment
ACATS- Airborne Chromatograph For Atmospheric Trace Species
ACCENT- Atmospheric Chemistry of Combustion Emissions Near the Tropopause
ACE-FTS- Fourier Transform Spectrometer (ACE-FTS) flown on SCISAT
ACE-Asia - Aerosol Characterization Experiment - Asia
ACMAP- Atmospheric Chemistry Modeling and Analysis Program
ACR - Active Cavity Radiometer
ACRIM - Active Cavity Radiometer Irradiance Monitor
ACSYS - Arctic Climate SYstem Study
ADALT- Advanced Radar Altimeter
ADEOS - Advanced Earth Observing Satellite (Japan)
AE - Atmospheric Explorer
AEAP- NASA's Atmospheric Effects of Aviation Project
AER-Atmospheric and Environmental Research
AES - Atmospheric Environment Service (Canada)
AESA- Atmospheric Effects of Stratospheric Aircraft program
AFGL - Air Force Geophysics Laboratory
AFGWC - Air Force Global Weather Central
AFRL - Air Force Research Laboratory (USA)
AGAGE- Advanced Global Atmospheric Gases Experiment
AGU - American Geophysical Union
AIAA - American Institute of Aeronautics and Astronautics (USA)
AIDAA - Associazione Italiana Di Aeronautica e Astronautica
AIRS - Atmospheric InfraRed Sounder
AIS - Airborne Imaging Spectrometer
aldehyde - Organic chemical compound derived from the oxidation of primary alcohols,
having the common group CHO.Used in manufacturing of dyes, resins, and organic acids.
ALE-GAGE- Atmospheric Lifetime Experiment-Global Atmospheric Gases Experiment
ALIAS - Aircraft Laser Infrared Absorption Spectrometer
AM- Ante meridiem (Latin: before midday), morning
AMRIR - Advanced Medium Resolution Imaging Radiometer
AMS - American Meteorological Society
AMSU-A - Advanced Microwave Sounding Unit-A
AMTS - Advanced Moisture and Temperature Sounder
anthropogenic - Involving the impact of man on the natural environment.
AO - Atomic Oxygen
APS - Active Pixel Sensor
ARC-Ames Research Center
ARGOS- Argos Data Collection and Location System (France)
ARISTOTELES - Applications and Research Involving Space Technologies Observing The Earth's field from a Low Earth orbiting Satellite
ARL - Airborne Raman Lidar (flown on DC-8 aircraft), measuresmethane, water vapor, and temperature
ARM - Atmospheric Radiation Measurement program
AROTEL- Airborne Raman, Ozone, Temperature and Aerosol Lidar (flown on DC-8 aircraft)
ASCII-American Standard Code for Information Interchange
ASHOE/MAESA-Airborne Southern Hemisphere Ozone Experiment
and Measurements for Assessing the Effects of Stratospheric Aircraft
ASI - Agenzia Spaziale Italiana
ATLAS - Airborne Tunable Laser Absorption Spectrometer
ATLID - ATmospheric LIDar
ATMOS - Atmospheric Trace Molecules Observed by Spectroscopy
ATOVS- Advanced TIROS Operational Vertical Sounder
ATS - Applications Technology Satellite
ATSR - Along Track Scanning Radiometer
AU - Astronomical Unit
AWIPS-90 - Advanced Weather Interactive Processing System for the 90's
BADC - British Atmospheric Data Centre
BAS -British Antarctic Survey
BIRA/IASB -Belgian Institue for Space Aeronomy
BLISS - Balloon-borne laser in-situ sensor
BMLS - Balloon microwave limb sounder
BNSC- British National Space Centre
Spectrophotometer-a Canadian ground-based instrument that measures the
amount of ozone in theatmosphere. The Brewer Total Ozone
Spectrophotometer operates at ground level, automatically
tracking the sun and reading wavelengths at 5 different
wavelengths between 306 and 320 nm that are absorbed by ozone,
sulphur dioxide and nitrogen dioxide. Over 165 Brewers are in
operation in 43 countries and Antarctica.
BOIC- Balloon Ozone Intercomaprison Campaign
bromine (Br) - Deep red, corrosive, nonmetallic, liquid halogen that gives off an
irritating reddish brown vapor.Element of halons, used in pesticides and fire extinguishers.
BUV - Backscatter Ultraviolet Spectrometer
carbon dioxide (CO2) - Odorless, colorless, incombustible, nontoxic gas that is
produced during respiration, decomposition of organic material, and combustion.Important
"greenhouse" gas that contributes to global warming by allowing solar radiation to pass through the
atmosphere and trapping radiant heat reflected from Earth's surface.
carbon monoxide (CO) - Poisonous, odorless, colorless gas, produced by incomplete
combustion of gasoline and diesel fuels.
carbon oxides - Compounds containing carbon and oxygen.
CAS -Chinese Academy of Sciences (China)
CAST -Chinese Academy of Space Technology (China)
CCD- Charged Coupled Device
CCRS -Canada Centre for Remote Sensing (Canada)
CCSDS -Consultative Committee for Space Data Systems
CEOS -Committee on Earth Observation Satellites
CFC-11 (CFCl3) - Halocarbon compound used in aerosols.One of two primary
chlorofluorocarbons that photolyze at highaltitudes to release chlorine atoms.An important factor in
ozone depletion.Also known as trichlorofluorocarbon.
CFC-12(CF2Cl2) - Halocarbon compound used in air conditioning systems as a
refrigerant.One of two primary chlorofluorocarbons that photolyze at high altitudes to release chlorine
atoms.An important factor in ozone depletion.Also known as dichlorofluoromethane.Chapman
Reactions - Stratospheric reactions in which ozone dissociates into molecular oxygen and atomic
oxygen, and the resulting free oxygen atoms recombine with ozone to form molecular oxygen.The
process was first described by a British physicist named Sydney Chapman in 1930.
Chappuis band- Ozone absorption band extending from 450 to 750 nm (very weak compared to other bands). See Hartley and Huggins bandsband
CGAM- Centre for Global Atmosphere Modelling
chlorine (Cl) - Heavy, greenish-yellow, irritating gas with a pungent odor.Capable of
reacting with almost all other elements.Catalyst for ozone destruction.
chlorine monoxide (ClO) - Intermediate product of chlorine interaction with ozone.
chlorine nitrate (ClONO2) - Compound formed by the reaction of ClO and NO2.
Slows the rate of ozone destruction, as it is much less reactive than ClO.May also react to produce
HOCl, which is rapidly photolyzed into Cl and ClO, reactive chlorine and chlorine monoxide.
chlorofluorocarbons (CFC's) - Group of inert, nontoxic, nonflammable compounds
made up of chlorine, fluorine, and carbon; used as a refrigerator coolant, foam insulation and cleaning agents as well
as aerosol propellants. CFC's were thought of as a great replacement for
ammonia because ammonia is very flammable. CFC's are safe,
nonreactive (inert) molecules in the lower atmosphere (troposphere),
but in the stratosphere, where the UV radiation is intense, CFC's are
broken down. UV light breaks the bond between the carbon and chlorine
on the CFC molecule. With the highly reactive chlorine atom, now
free, it reacts with ozone and destroys it.
CITE - Chemical Instrumentation Test and Evaluation (CITE)
climatological ozone profiles - Twenty-three standard profiles derived from a
combination of SBUV measurements taken at altitudes greater than 16-mbar and low altitude balloon
radiosonde data.Yearly averages were developed for three latitude bands: low (15°), mid (45°), and
climatological temperature profiles - Standard temperature profiles obtained from the
Environmental Science Services Administration.
CLAES - Cryogenic Limb Array Etalon Spectrometer
CMDL - NOAA Climate Monitoring and Diagnostics Laboratory
CNES- Centre National d'Etudes Spatiales
CRISTA - CRyogenic Infrared Spectrometers and Telescopes for the Atmosphere
CTM- Chemical Transport Model
DAAC -Distributed Active Archive Centre
ARA- Deutsche Agentur fr RaumfahrtAngelegenheiten (Germany)
deoxyribonucleic acid (DNA) - Self replicating nucleic acid that contains genetic code
within the cell. The primary structure consists of two long nucleotide chains that are joined by
hydrogen bonds and twisted together to form a double helix.
descending node - The point at which an orbiting object or spacecraft, moving from north to south, crosses the plane of the equator.
DIAL- Differential Absorption Lidar. DIAL technique has been in use for ozone measurements since 1966.
dichlorofluoromethane (CF2Cl2) - Halocarbon compound used in air conditioning
systems as a refrigerant.One of two primary chlorofluorocarbons that photolyze at high altitudes to
release chlorine atoms.An important factor in ozone depletion.
DOAS- Differential Optical Absorption Spectrometers
A ground-based instrument that measures the amount of ozone present
in the atmosphere. The Dobson spectrophotometer was designed by
British physicist Gordon Dobson in the 1927. The Dobson
spectrophotometer measures UV light from the sun at two to three
pairs of wavelengths in the Huggins band (310 to 350 nm). Each pair
is given a letter deignation. There are the Apair(305.5 and 32.4 nm),
the B pair (308.8 and 329.1nm), the C pair (311.45 and 332.4 nm), the
D pair (317.6 and 339.8 nm) etc. each member of a pair is separated
by approximatel 2025 cm-1.
Dobson Unit (DU) - The standard unit of measurement of total
ozone equal to 2.69 x 1016 molecules per square
centimeter.An equivalent amount of ozone, at 1 atmosphere and
273° K, would form a layer 0.001 cm thick.In otherwords if all
of the ozone from the Earth's surface to outer space were compressed
to standard temperature and pressure (STP), the ozone layer or its
thickness would be about 3 mm thick. At STP, 3mm of ozone is 300
Dobson Units (DU). 1mm = 100DU.
EASOE - European Arctic Stratospheric Ozone Experiment
Ebert-Fastie monochromatic spectrometer - Instrument used to measure energy intensity
within the ultraviolet region of the electromagnetic spectrum.
ECC - Electrochemical cell ozonesonde
ELDONET - European Light DOsimeter NETwork
ERBS- Earth radiation budget
ERBS - Earth radiation budget satellite
ENVISAT - Environmental Satellite
EOS - Earth Observing System
EP - Earth Probe
EPV - Ertel's Potential Vorticity
ER2 -European Remote Sensing-2 Satellite
ESE - NASA's Earth Science Enterprise
ESTEC- European Space Research and Technology Center
EUMETSAT - European Organisation for the Exploitation of Meteorological Satellites
EUV - Extreme ultraviolet
exosphere - Region of the atmosphere beyond 400 km. that fades into interplanetary
Fourier transform spectrometer (FTS) - Spectrometer that consists of a collimator and
beamsplitter, which divides the source beam into two parallel beams with equal amplitudes.
GARP - Global Atmospheric Research Programme
GCM - Global Circulation Model
GDAS - Global Data Assimilation System
GEO - Geostationary Earth Observatory
GEOS- DASGoddard Earth Observing System Data Assimilation System
GHIS - GOES High Resolution Interferometer Sounder
GLAS - Geoscience Laser Altimeter System
GLAS - Goddard Laboratory for Atmospheric Sciences
global warming - Rise in global temperature caused by increased amounts of
atmospheric gases that trap heat in Earth's atmosphere by absorbing longwave radiation.
global warming potential (GWP)- A relative measure of the warming effect
that the emission of a gas might have on the surface troposphere. It
is measured as a factor relative to CO2
GLOSS - UKMO data analysis system
GLRS - Geoscience Laser Ranging System
GMS - Geostationary Meteorologicl Satellite
GOES - Geostationary Operational Environmental Satellite
GOME - Global Ozone Monitoring Experiment
GOMOS - Global Ozone Monitoring by Occultation of Stars
GO3OS- Global ozone observing system
GOSCOMP -Global Operational Sea Surface Temperature Computation
GPS - Global Positioning System
GRACE - Gravity Recovery and Climate Experiment GUV Ground-based Ultraviolet Radiometer
GRAS - GNSS Receiver for Atmospheric Sounding
GRIB - Grid data in binary form
Heating effect exerted by the atmosphere
upon the earth because the atmosphere absorbs and reemits infrared
A gas that absorbs infrared radiation and in turn emits it in the
atmosphere. The net effect is a local trapping of energy and a
tendency to warm the earth's surface. Water vapour (H2O), carbon
dioxide (CO2) methane (CH4), nitrous oxide (N2O) and ozone (O3) are
the primary greenhouse gases in the Earth's atmosphere.
ground-level Ozone (bad ozone) -
Ozone that is at the surface of the Earth, and is a major component
of smog. Ground-level ozone is formed when nitrogen oxides from the
burning of fossil fuels, react in sunlight and stagnant air, with
volatile organic compounds (VOC) that come from the fumes of fuels,
solvents and other human-produced sources. Ground- level ozone is
harmful, whereas stratospheric ozone is beneficial.
ground-truth data - Field observations that are used to check the accuracy of satellite
GSFC- Goddard Space Flight Center
GSM - Global Spectral Model
GTE- NASA Global Tropospheric Experiment
GTS - Global Telecommunications System
Global Warming Potential
HALOE Halogen Occultation Experiment
halon - Compound formed when a halogen, such as fluorine (F) or bromine (Br)
attaches to a carbon atom.
Hartley band - Ozone absorption band extending from 200 to 310 nm (peaks near 255 nm) in a bell shape. (see Huggins & Chappuis bands)
HIRDLS- High Resolution Dynamics Limb Sounder
HIRIS- High Resolution Imaging Spectrometer
HIRS High Resolution Infrared Radiation Sounder
HIS- High Spectral Resolution Interferometer Sounder
HMMR- High Resolution Multifrequency Microwave Radiometer
HRDI- High Resolution Doppler Interferometer
HRIR- High Resolution Infrared Radiometer
HRIS - High Resolution Imaging Spectrometer
HSCT- High-Resolution Civil Transport
Huggins band - Ozone absortion band extending from 310 to 350 nm, weaker than Hartley band (see Hartley and Chappuis bands)
hydrogen - A highly flammable, colorless gaseous element,the most abundant element
in the universe and the lightest of all gases.
hydrogen chloride (HCl) - Important chlorine-containing compound formed from the
breakdown of chlorofluorocarbons.Also produced by volcanic eruptions.Less reactive than chlorine.
hydrogen fluoride (HF) - Important fluorine-containing compound formed from the
breakdown of chlorofluorocarbons.Also a product of volcanic eruption.
IASB-Institut d'Aeronomie Spatial de Belgique
IASI-Infrared Atmospheric Sounding Interferometer
IFOV-Instantaneous Field of View
IFS-Integrated Forecasting System (ECMWF's forecasting model)
instantaneous field of view (IFOV) - Ground or target area viewed by a sensor at a given
point in time.
IGAC - International Global Atmospheric Chemistry
IGBP- International Geosphere-Biosphere Program
IGY- International Geophysical Year
ILAS-Improved Limb Atmospheric Spectrometer
IMG-Interferometric Monitor for Greenhouse Gases
IMK-Institut fuer Meteorologie und Klimaforschung
infrared radiation - Electromagnetic radiation having a wavelength slightly longer than
visible red light, from 750 nanometers to 1 millimeter.
infrared radiometer - Sensor that measures the intensity of infrared radiation (720
nm-1500 nm) within a specific field of view.
INTERDOL-INTERcomparison of envisat chemistry instruments data to strengthen the global monitoring of the Depletion of the Ozone Layer
INTEX-A - Intercontinental Chemical Transport
Experiment, North America
IOC - International Ozone Commission
IPCC-Intergovernmental Panel on Climate Change
IRIS-Infrared Interferometer Spectrometer Radiometer
irradiance - Radiant flux per unit area of a surface.
IRTS - Infrared Temperature Sounder
ISAMS - Improved Stratospheric and Mesospheric Sounder
ISS - International Space Station
ITCT- Intercontinental Transport and Chemical Transformation
ITCZ - Intertropical Convergence Zone
ITIR-Intermediate Thermal Infrared Radiometer
ITOP- Intercontinental Transport of Pollution
ITOS-Improved TIROS Operational System
ITPR-Infrared Temperature Profile Radiometer
IUP- Bremen Institute of Environmental Physics, University of Bremen
JEM/SMILES - Superconducting Sub-Millimeter Wave Limb Emission Sounder on the Japanese
Experimental Module of the International Space Station
JGR- Journal Of Geophysical Research
JMA-Japan Meteorological Agency
JPL-Jet Propulsion Laboratory
ketones - Organic compounds in which the carbon atoms of two hydrocarbon radicals
are linked to a carbonyl group.Generally represented by the formula R(CO)R1, where R1 and R may
be the same.
KNMI-Het Koninklijk Nederlands Meteorologisch Instituut
Langrangian point -In a system dominated
by two attracting bodies (such as Sun and Earth), a point at which a
third, much smaller body (such as a satellite) keeps the same
position relative to the other two. Theoretically, the Sun-Earth
system has 5 Lagrangian points, but only two are important: L1, on
the sunward side of Earth, about 4 times the distance of the Moon,
and L2 at approximately the same distance on the midnight side.
LASA-Lidar Atmospheric Sounder and Altimeter
Laser -Light Amplification by the Stimulated Emission of Radiation. A device for producing a coherent monochromatic high-intensity beam of light.
LAWS-Laser Atmospheric and Wind Sounder
LEO-Low Earth Orbit
LIDAR (light detection and ranging)-
A technique for active remote sensing in which a light source is used
to probe the atmosphere. Laser light fired at the atmosphere is
reflected back by the atmospheric molecules to a detector and the
attenuation (reduction) of this light provides information on
atmospheric particles and molecules. Changes in the returned
wavelengths can provide information about atmospheric motion. The
primary advantage of this technique is its ability to obtain high
vertical resolution data at different altitudes. This is important
for studying how various trace gases (see Chapter 2) are transported
by the wind. Lidar is also used to measure the cloud altitude. This
information is important for pilots and for meteorological
limb emission technique-
Also called limb sounding
technique. Instruments based upon the limb emission technique infer
trace gas amounts (such as ozone) from measurements of longwave
radiation (infrared or microwave) thermally emitted in the atmosphere
along the line of sight of the instrument. The altitude to which the
instrument can see is called the tangent altitude. In theory, the
instrument could look all the way to the surface, but below a certain
altitude (under 10 km), clouds interfere with the emitted longwave
radiation. This radiation emission occurs along the geometric path
between the tangent altitude and the satellite instrument. This
horizontal path is quite long compared to the tangent altitude.
LIMS-Limb Infrared Monitor of the Stratosphere
lithosphere - Solid mass of Earth composed of rock, soil, and sediment.
LIS-Lightning Imaging Sensor
LLR-Laser Retro Reflector
LMD-Laboratoire de Meteorologie Dynamique, Paris
LOS-Line Of Sight
LRIR-Limb Radiance Inversion Radiometer
LUT-Look Up Table
LW- Long wave
Lyman-alpha emission band -
The radiation emitted by hydrogen at 1216 Angstrom, first observed in
the solar spectrum by rocketborne spectrographs. Lyman-alpha
radiation is very important in the heating of the upper atmosphere,
thus it affects other atmospheric phenomena. Also called Lyman-alpha
MAERI -Marine Atmosphere Emitted Radiance Interferometer
MAESA - Measurements for Assessing the Effects of Stratospheric Aircraft
MAESTRO - Measurements of Aerosol Extinction in the Stratospheric and Troposphere Retrieved by Occultation (flown on SCISAT)
MAHRSI - Middle Atmosphere High Resolution Spectrograph Investigation
MAPS - Measurement of Air Pollution from Satellites
MAPSCORE - Mapping of Polar Stratospheric Clouds and Ozone Levels Relevant to
the Region of Europe
MARS- Meteorolical Archive and Retrieval System (ECMWF)
MAS- Microwave Atmospheric Sounder
MASGRAS - data from combination of a passive microwave MAS, and a radio occultation instrument GRAS
mounted on the International Space Station NSS Receiver for Atmospheric Sounding
MASP - NCAR Multiangle Aerosol Spectrometer Probe
MASTER - Millimeter Wave Acquisitions for Stratosphere/Troposphere Exchange Research
The period from 1654 to 1714 when it was believed that there were no
sunspots. It is now thought that there were some sunspots during that
time but fewer than those counted after 1800. Sunspots occur in
11-year periods. They also occur in a 90-year cycle called the
Gleissberg cycle. The Maunder minimum may form part of an
as-yet-unknown larger cycle of sunspot activity whose periodicity is
longer than the historical record.
MCSST- Multichannel Sea Surface Temperatures
Mercury-Argon calibration lamp - Lamp that produces radiation centered at 253.7 nm,
which is then diffused from a diffuser plate.Radiation measurements are made at multiple
wavelengths and possible shifts are noted.
MERIS- Medium Resolution Imaging Spectrometer
mesopause - Transitional atmospheric region between the mesosphere and
mesosphere - Region of the atmosphere, between approximately 50 to 100 km, in which
temperature decreases with altitude.
METAR- Meteorological Airfield Report
METDB- METeorological Data Base (Met Office)
Meteor-3 - Third in a series of weather satellites launched by the former Soviet Union.
Launched in August 1991 with apayload that included a Total Ozone Mapping Spectrometer
METEOSAT- Meteorological Satellite
methane - Simple combustible hydrocarbon.The major component of natural gas.
METOP- Meteorological Operation Program (planned polar orbiter satellites)
METSAT- Meteorological Satellite
MHS- Microwave Humidity Sensor
microwave radiometer - Sensor that measures the intensity of
microwave radiation (0.3 cm-30 cm) within a specific field of view.
Mie scattering - Atmospheric scattering caused by large particles such as dust, pollen,
smoke, and water droplets.More prevalent in the lower atmosphere, from 0 to 5 km.
MIMR- Multifrequency Imaging Microwave Radiometer
MIPAS- Michelson Interferometer for Passive Atmospheric Sounding
MiroTops- A hand held spectrophotometer that measures the
amount of ozone in the stratosphere. By lining up the Sun in its
window, the UV intensity is measured at 3 wavelengths between 305.5
and 320 nm.
MISR- Multiangle Imaging Spectro Radiometer
mixing ratio - Relative number of molecules of a specific type in a given volume of air.
monochromator - Spectrometer that operates
within a narrow range of the electromagnetic spectrum.
protocol- The Montreal protocol is an international agreement, under the United Nations
Environmental Programme (UNEP), which implements controls on the
consumption of ozone-depleting substances.The Protocol was signed on September 16, 1987 and
originally negotiated between 24 countries. The Protocol is amended
from time to time. To date, over 175 countries have signed the
MLS - Microwave Limb Sounder
MMCC- Mission Management Control Centre
MO - The Met Office (UK)
MODIS- Moderate Resolution Imaging Spectrometer
MOPITT- Measurements of Pollution in the Troposphere
MOPS- Moisture Observation Pre-processing System
MORECS -Met Office Rainfall and Evaporation Calculation System
MOSES- Met Office Surface Exchange Scheme
MOZART -a Model for OZone and chemical tracers
MRF -Medium Range Forecast
MRIR- Medium Resolution Infrared Radiometer
MSC- Meteorological Satellite Centre
MSDOL- Monitoring of Stratospheric Depletion of Ozone Layer
MSG- Meteosat Second Generation
MSSCC- Multicolour Spin Scan Cloud Camera
MSU- Microwave Sounding Unit
MTPE- Mission To Planet Earth
MTS- Microwave Temperature Sounder
MUSE- Monitor of Ultraviolet Solar Energy
MWR- Microwave Radiometer
NACP- North American Carbon Program
nadir -The direction from a spacecraft directly down toward the
center of a planet. Opposite is the satellite zenith.
Plan for the Environmental Control of Ozone-Depleting Substances and
their Halocarbon Alternatives
NASA-National Aeronautics and Space Administration
NASDA - National Space Development Agency
NCAR-National Centre for Atmospheric Research (USA)
NCDC-National Climatic Data Centre
NCEP-National Centers for Environmental Prediction (USA)
NDSC-Network for the Detection of Stratospheric Change
NERC - Natural Environment Research Council (UK)
NESDIS-National Environmental Satellite, Data and Information Service
NESR - Noise Equivalent Spectral Radiance
NGDC- National Geophysical Data Center
NILU-Norwegian Institute for Air Research
nitrogen - A colorless, odorless, nonmetallic element that occurs as a diatomic gas and
constitutes nearly 80% of the atmosphere by volume.
nitrous oxide (N2O) - Colorless gas, naturally produced through bacteriological
decomposition of organic matter.Also produced anthropogenically and used as a mild anesthetic.
NMC-National Meteorological Centre (USA)
NOAA-National Oceanic and Atmosphere Admisistration
noctilucent clouds -
1. Relatively unusual wavy, thin, bluish-white clouds that form at altitudes of about 80 to 90 km.
2. Clouds of unknown composition that occur at great heights, 75 to
90 km. They resemble thin cirrus, but usually with a bluish or
silverish color, although sometimes orange to red, standing out
against a dark night sky. Sometimes called luminous clouds. These
clouds have been seen rarely, and then only during twilight,
especially with the Sun between 5 and 13 below the horizon. They
have been observed only during summer months in both hemispheres
(between latitudes 50 to 75 N and 40 to 60 S), and only in some
parts of these latitude belts.
NOZE - National Ozone Expedition
NPOESS- The National Polar-orbiting Operational Environmental Satellite System
NRL- Naval Research Laboratory
NRT-Near Real Time
NSBF- National Scientific Balloon Facility
NSSDC-National Space Science Data Centre
NTP - Normal temperature and Pressure
NWP- Numerical Weather Prediction
occultation technique-One of
several remote sensing techniques for measuring atmospheric trace
gases by satellite. Occultation instruments measure solar, lunar, and
even stellar radiation directly though the limb of the atmosphere
during satellite Sun, Moon, and star rise and set events (depending
on which celestial radiator is being used by the satellite
instrument). By measuring the amount of absorption of radiation
through the atmosphere at different wavelengths (e.g., UV, visible,
infrared), occultation instruments can infer the vertical profiles of
various trace constituents, including ozone. This technique offers
improved vertical resolution with solar occultation instruments
offering vertical resolutions of 1-2 km. Disadvantage is the limited
spatial coverage: measurements can only be made at sunrise and sunset
events for the solar occultation instruments, so many orbits are
required in order to get global coverage. The solar occultation
technique refers to instruments that use only solar radiation for the
occultation technique. Improved designs of occultation instruments
allow for use of the Moon and even the stars as the occulting light
sources, which will expand the spatial coverage. SAGE is an example of an
instrument employing an occultation technique.
ODP- Ozone Depleting Potential. A
measure of the capability of a particular chemical to destroy ozone,
measured against CFC-11 which has an ozone- depleting potential of 1.
For ODP values of ozone-depleting substances
ODS -Ozone Depleting Substance. A chemical compound that contributes
to stratospheric ozone depletion. ODS are stable in the troposphere
and only degrade under intense ultraviolet light in the stratosphere.
ODS-react with stratospheric ozone, either directly or through the
release of chlorine or bromine atoms after decomposition.
ODSR - Ozone-Depleting Substances Regulations, 1998
Orbiting Geophysical Observatory. OGO 1V carried UV airglow
spectrometer to make measurements of UV airglow in the 100-340 nm
region. Global ozone was measured (1967 to 1968) by observing back scattered solar
radiation in the 255-301 nm region while looking in the nadie
OMI- EOS-Aura Ozone Monitoring Instrument (to be
OMS - Observation of the Middle Stratosphere
OMPS- Ozone Mapping and Profiler Suite
OPD - Observation
OPS- Observation Processing System (data
selection and quality control system) of the Met Office
optical spectrum - Portion of the electromagnetic spectrum, from 0.30 to 15
micrometers, that can be reflected and refracted with mirrors and lenses.
OSIRIS- Optical Spectrograph and InfraRed Imager System (Canadian instrument)flown on Odin satellite, measures
ozone absorption limb spectra in the ranges 300-340 and 400-700 nm.
OVID - Optical Visible and near Infrared Detector
oxygen - A nonmetallic element that occurs as a diatomic gas and constitutes 21% of air
by volume, essential for plant and animal respiration, and required for almost all combustion.
- A gaseous form of oxygen with three atoms per molecule. Ozone is
a bluish gas that is harmful to breathe. Nearly 90% of the Earth's
ozone is in the stratosphere and is referred to as the ozone layer.
Ozone absorbs a band of ultraviolet radiation called UVB that is
particularly harmful to living organisms. The ozone layer prevents
most UVB from reaching the ground.
ozone depletion- The thinning of the earth's protective stratospheric
ozone layer. Ozone depletion occurs when the natural balance between
the production and destruction of stratospheric ozone is tipped in
favour of destruction. Human activity is the major factor in tipping
that natural balance, mostly from artificial chemicals, known as
ozone- depleting substances (ODS).
ozone hole - Region of rapid, dramatic ozone depletion over Anarctica during the polar
spring.It is confined to south of 55° latitude and disperses soon after temperatures rise above -80° C.
Though the ozone hole started in the Antarctic since mid 1970s, it was discovered by Dr. Joe
Farman of the British Antarctic Survey team in 1985.
Most of the ozone in the atmosphere is in the stratosphere (about 10
- 50 km above earth's surface). This is what is called the ozone
layer or the stratospheric ozone layer. The layer refers to the
thickness of the ozone.
OZVAL - Geophysical cross-VALidation of Envisat OZone products through assimilation in a global photochemical transport model (an ENVISAT AO proposal)
PBL-Planetary Boundary Layer
PDF -Probability Density Function
PEM-GTE Pacific Exploratory Missions
That point in a solar orbit nearest the Sun. That orbital point
farthest from the Sun is called aphelion. The term perihelion should
not be confused with parhelion, a form of halo
PHOBEA - Photochemical Ozone Budget of the Eastern North Pacific Atmosphere
peroxyacyl nitrates (PAN) - Damaging photochemical oxidants that are very irritating to
the eyes and throat.Represented as R(CO)OO(NO2) where R denotes a hydrocarbon ring or chain.
photochemical - Of or relating to the effect of radiant energy on a chemical system.
photolysis - Dissociation process driven by the Sun's radiation.
photosynthesis - Chemical process driven by solar energy in which CO2 and H2O, in
the presence of chlorophyll, are converted to oxygen and carbohydrates.Oxygen and water vapor are
released in the process.
PMD- Polarisation Measurement Device
PMR -Pressure Modulator Radiometer
PMSL- Pressure Mean Sea Level
POAM- Polar Ozone Aerosol Measurement
POD -Precise Orbit Determination
POEM- Polar Orbit Earth Observation Missions
POES -Polar Orbiting Operational Environmental Satellite
POLARIS - Photochemistry of Ozone Loss in the Arctic Region in Summer
polarization - Uniform and nonrandom elliptical, circular, or linear variation of a wave,
characteristic in light or other radiation.
polar stratospheric clouds (PSC)- High, thin
clouds composed of nitric acid and water that form in the coldest
regions of the stratosphere when temperatures drop below -80°C.
Ice crystal surfaces within these clouds are efficient in converting
inert chlorine reservoirs, such as ClONO2 and HCl, into
reactive chlorine compounds.When exposed to Sun in late August, UV radiation triggers reactions with
chlorine and bromine that destroy ozone. The result is an ozone hole.
A similar, but not as extensive destruction of ozone takes place in
the Arctic under the same conditions, but the temperatures do not get
as cold, therefore fewer PSCs form
polar vortex - Wind region around the North or South pole.The southern vortex is a
well formed circular to oblong mass of extremely cold, stagnant air, held in place by the ocean
surrounding the Antarctic land mass and a strong westerly circulation pattern produced by the coriolis
effect.The northern vortex is not as distinct because the Arctic is a frozen ocean
surrounded by rugged land masses, which causethe circulating winds to encounter a variety of
PPMV -Parts Per Million by Volume
PRT- Photochemical Replacement Time
PSAS -Physical space Statistical Assimilation System
PSC -Polar Stratospheric Cloud
PV- Potential Vorticity
quasi-biennial oscillation (QBO)- Periodic variation in the direction, either easterly or westerly,
of tropical lower stratospheric winds.The direction changes every 26 months.
Quantification and Interpretation of Long-Term UV-Vis Observations of
RA-2 Radar Altimeter 2
radiosonde - Balloon borne instrument used to measure and transmit meteorological
RAL - Rutherford Appleton Laboratory (UK)
Rayleigh scattering - Dominant form of light scattering in
the upper atmosphere, which produces the blue color of the sky.It
is caused byatmospheric particulates that have very small diameters
relative to the wavelength of the light,such asatmospheric gases
like nitrogen and oxygen. Rayleigh Scattering attenuates the
radiation with a spectral dependence varying as the inverse fourth
power of the wavelength, making it important at UV bands.
reflective spectrum - Portion of the optical spectrum, from approximately0.38 to 15
micrometers, that defines the direct solar radiation used in remote sensing.
reflectivity - Ratio of intensity of the total radiation reflected from a surface to the total
radiation incident on the surface.
residual -The vector difference y-H[x], where y is the observation vector, H is the forward model, and x is the analysis.
RFTOZ -Regional dIFferences in Transformation of Ozone
RFTOZAL - Regional dIFferences in Transformation of Ozone and AerosoL
RIS -Retrofreflector in Space
RMS - Royal Meteorological Society (UK)
RMS -Root Mean Square
ROCOZ-A - - Rocket ozonesonde-A
ROSE -Research on Ozone in the Stratosphere and its Evolution
RTM - Radiative Transfer Model
RTTOV -Radiative Transfer Model for TOVS
SABER- Sounding of the Atmosphere using Broadband Emission Radiometry
SAGE - Stratospheric Aerosol and Gas Experiment
SAMS - Stratospheric and Mesospheric Sounder
SA/CNRS-Service d'Aeronomie/ Centre National de la Recherche Scientifique (France)
SAFARI- Southern African Regional Science Initiative
SAFIRE-Spectroscopy of the Atmosphere Far Infrared Emission SAR Synthetic Aperture Radar
SAGE-Stratosphere Aerosol and Gas Experiment
SAM-Satratospheric Aerosol Measurement
SAMMOA- Spring-to-Autumn Measurements and Modelling of Ozone and Active Species
SAMS-Satratospheric and Mesopheric Sounder
SAO - Semi-Annual Oscillation.
satellite zenith angle - Angle between the position of a satellite and the zenith, which is
the point directly over the observed target.
SATOBS - Geostationary Satellite Data (Met Office data analysis system)
SBUV-Solar Backscatter Ultraviolet Instrument
SBUV/2-Solar Backscatter Ultraviolet-2 Instrument
SCAMS-Scanning Microwave Spectrometer
SCANSAR-Scanning SAR Imaging Technique (for wide swath coverage)
SCATS- Scatterometer Winds (Met Office data analysis system)
SCIAMACHY-Scanning, Imaging Absorption Spectrometer for Atmospheric Cartography
SCISAT-1 - canadian satellite (Atmospheric chemistry experiment)
SCMR -Surface Composition Mapping Radiometer
SCR-Selective Chopper Radiometer
SCS-Suite Control System (Met Office)
SEAWIFS- Sea Wide Field-of-view Spectrometer
SEM-Space Environment Minister
semi-annual oscillation (SAO)-
The oscillation in upper level stratospheric winds over the tropics
between easterly and westerly directions roughly every 6 months. It
is due to the passage of the Sun over the equator twice a year.
SEVIRI- Spinning Enhanced Visible and Infrared Imager (on MSG-1 satellite)
SHADOZ- Southern Hemisphere Additional Ozonesondes
ShAGME-Shared Assimilation for Geophysics Meteorology and the Environment (provisional)
SIRIS - Stratospheric Infrared Interferometer Spectrometer
SIRS- Satellite Infrared Spectrometer
SLIMCAT -Single layer Isentropic Model of Chemistry And Transport
SLR -Satellite Laser Ranging
SME- Solar Mesospheric Explorer carried limb scanning
ultraviolet spectrometer (200 to 340 nm spectral region) and near-IR spectrometer (1.27 micron) to measure ozone densities in the lower
SMM - Solar Maximum Mission
SMMR-Scanning Multichannel Microwave Radiometer
SMR -Sub-Millimeter Radiometer (flown on satellite Odin), measures an ozone spectral line at 501.4 GHz.
SMS - Synchronous Meteorological Satellite
SOCC-Satellite Operations Control Centre
SODA- Studies of Ozone Distribution based on Assimilated satellite measurements
SOI - Spin scan ozone imager
solar cycle - Periodic change in sunspot activity.One cycle is approximately 11.1 years.
solar zenith angle - Angle between the position of the Sun and the zenith, which is the
point directly over an observed target.
SOLSE - Shuttle Ozone Limb Sounding Experiment
SOLSTICE- Solar Stellar Irradiance Comparison Experiment
SOLVE- SAGE III Ozone Loss and Validation Experiment (SOLVE)
SONDES - radiosondes and wind profilers (Met Office data analysis system)
SONEX- SASS Ozone and NOx Experiment
SONTOS- Southern Ontario Oxidant Study
SOPRANO - Sub-Millimeter Observation of Processes in the Atmosphere noteworthy for Ozone
SOS- Southern Oxidants Study
SPADE- Stratospheric Photochemistry, Aerosols and Dynamics Expedition
SPARC -Stratospheric Processes And their Role in Climate
spectrometer - Instrument used to determine the distribution of energy within a spectrum
SPOT -Systeme Probatoire d'Observation de la Terre
SR -Scanning Radiometer
SSBUV- Shuttle Solar Backscatter Ultraviolet Instrument
SSI-Spectral Statistical Interpolation
SSM/I-Special Sensor Microwave Imager
SSM/T-Special Sensor Microwave Temperature
SSST -Skin Sea Surface Temperature
SST-Sea Surface Temperature
SSU-Stratospheric Sounding Unit
STE- Stratospheric-Tropospheric Exchange
STEP - Stratospheric-Troposphere Exchange Project
STP - Standard Temperature and Pressure
STRAT- Stratospheric Tracers of Atmospheric Transport
stratopause - Transition layer between the stratosphere and mesosphere.Marks the
maximum altitudinal temperature increase within the stratosphere.
stratosphere - Portion of the atmosphere between the tropopause, at approximately 8 to
15 km, and 50 km inaltitude, depending upon latitude, season, and weather.
STROZ-LITE - Stratospheric Ozone Lidar Trailer Experiment, a
mobile lidar system for measuring vertical profiles of atmospheric
ozone, aerosol particles, and temperature.
sulfur dioxide (SO2) - Chemical compound that absorbs radiation of the same
wavelength absorbed by ozone.Product of large volcanic eruptions.
sulfuric acid (H2SO4) - Heavy, corrosive, oily acid.Vigorous oxidizing agent.Ozone
concentrations may be affected by reactions on the surface of sulfuric acid clouds, resulting from major
sunspot - Relatively dark, sharply defined region on the Sun associated with an intense
SUSIM - Solar Ultraviolet Spectral Irradiance Monitor
SUVDAMA-Scientific UV DAta MAnagement (European project)
SYNOPS-surface synoptic reports (Met Office data analysis system)
TES-Tropospheric Emission Spectrometer (onboard EOS-Aura, to be launched in 2004)
thermopause - Transition layer between the thermosphere and exosphere, located at
approximately 600km in altitude.
thermosphere - Region of the atmosphere in which temperature increases with altitude.
Located at approximately 100 to 400 km.
THIR-Temperature Humidity Infrared Radiometer
TIP-TIROS Information Processor
TIROS-Television and Infrared Observational Satellite
TMI-TRMM Microwave Imager
TMR-TOPEX Microwave Radiometer
TOA-Top Of Atmosphere
TOMS-Total Ozone Mapping Spectrometer(measures between 312- 360 nm)
TOMS3F - Total Ozone Measurements by 3 platforms(Satellites, Sondes, and Spectrometers) at Fairbanks
TOPSE - Tropospheric Ozone Production about the Spring Equinox
TOTE/VOTE- Tropical Ozone Transport Experiment/Vortex Ozone Transport Experiment
TOTTIE-Total Ozone Tropospheric Trends In the Environment (provisional)
TOVS-TIROS Operational Vertical Sounder
TRACE-P- TRAnsport and Chemical Evolution over the Pacific
trichlorofluorocarbon (CFCl3) - Halocarbon compound used in aerosols.One of two
primary chlorofluorocarbons that photolyze at high altitudes to release chlorine atoms.An important
factor in ozone depletion.tropopause - Boundary between the troposphere and stratosphere, from 8 km
in the polar regions to 15 km in the tropics.Marks the vertical limit of most weather phenomena.
troposphere - Lowest region of the atmosphere, defined by a steady decrease in
temperature with altitude.Extends to approximately 15 km above Earth's surface.
tropospheric - Having to do with the lowest region of the atmosphere, which extends to
approximately 15 km above Earth's surface.
TWERLE-Tropical Wind Energy Conversion and Reference Level Experiment
UARP - Upper Atmosphere Research Program
UARS-Upper Atmosphere Research Satellite
UGAMP-Universities Global Atmospheric Modelling Programme (UK)
UHF-Ultra High Frequency
Meteorological Office (acronym now obsolete)
UM-Unified Model (Met Office)
Umkehr Technique- The Umkehr method is
ground based optical remote sensing. Observations are made on the
clear zenith sky as the Sun is rising or setting.Umkehr retrieved
ozone profile covers a range up to 40 km which is not reached by
operational balloon sonde. The Umkehr profile is normally
given in 10 layers.
UNEP- United Nations Environmental Program
UPMC-University of Pierre and Marie Curie, Paris, France
USGCRP-US GLobal Change Research Programme
UTC- Coordinated Universal Time
UTLS-Upper Troposphere Lower Stratosphere
UV- Ultra Violet light, wavelength region of the solar spectrum from approximately 200 to
Unharmful ultraviolet light from the Sun with a wavelength between
320-400 nm. UV-A light is not absorbed by ozone, thus all of the UV-A
light is allowed to reach the surface of the Earth.
ultraviolet light from the Sun with a wavelength between 290-320 nm.
Ozone absorbs most UV-B light before it reaches the surface of the
Earth, harmful to living organism.
high energy ultraviolet light from the Sun with a wavelength between
200-290 nm. Ozone and oxygen molecules absorb all UV-C light before
it can reach the Earth's surface.
a measure of the level of solar UV radiation at the Earth's surface
UARS - Upper Atmosphere Research Satellite.NASA satellite launched in September
1991.Platform for instruments to measure temperature, wind, and composition of the upper
atmosphere, including the stratosphere.
Var-Variational Data Assimilation
VAROBS-OBServations file used in the Variational Data Assimilation Scheme (Met Office)
VAS-VISSR Atmospheric Sounder
VDUC-VAS Data Utilization Centre
VHRR - Very High Resolution Radiometer
VIRR-Visible and Infrared Radiometer
VIRS-Visible Infrared Scanner
VIRSR-Visible Infrared Scanning Radiometer
VIS-Visible region of solar spectrum
VISSR-Visible and Infrared Spin Scan Radiometer
VMR-Volume Mixing Ratio
VTPR-Vertical Temperature Profile Radiometer
WAS- Whole Air Sampler (flown on ER-2)
WMO-World Meteorological Organization
WOUDC- World Ozone and Ultraviolet Radiation Data Centre,
managed by the Meteorological Service of Canada
WO - Harvard Water Ozone EXperiment (flown on ER-2)
WSR-Weather Service Radar