522
Glossary of Chemical Oceanography Terms
Chlorofluorocarbons: CFC compounds used primarily in the blowing of foams and as
refrigerants. They have a long lifetime and can penetrate into the stratosphere,
where they are photochemically broken down to produce Cl, which can react with
ozone. The CFCs can also act as greenhouse gases.
Dobson Unit: A unit of measurement of stratospheric ozone. Regarded as a thickness of
the ozone layer if brought to standard temperature and pressure (1 Dobson unit
equals 0.1 cm of ozone).
Greenhouse Effect: The result of certain gases absorbing infrared (IR) radiative energy
and increasing the temperature of the atmosphere like a “greenhouse.” Water
vapor, CO 2 , and methane are the primary greenhouse gases.
Greenhouse Gases: Gases that absorb infrared energy in the troposphere and thus cause
an increase in the temperature of the troposphere. Examples are H 2 O, O 2 , CO 2 ,
freons, and CH 4 .
Hydrogen Peroxide, H 2 O 2 : Occurs in the atmosphere as a result of two hydroperoxyl radicals reacting and in the ocean as a result of photochemical reactions of organic
carbon. Unstable, colorless, heavy liquid; soluble in water and alcohol. Used as
a bleach.
Hydroperoxyl Radical, HO 2 : Formed from the photochemical reactions of the H radical
with O 2 . The hydroperoxyl radical can regenerate OH radicals and can lead to the
chain termination.
Interhemispheric Mixing: Time it takes for a species to be mixed in the atmosphere
between hemispheres (1–2 yr).
Intertropical Convergence Zone (ITCZ): Area close to the equator surrounding the earth
where the northeast and the southeast trade winds flow together. Characterized
by strong upward motion and heavy rainfall. Affects the transport of species from
the Northern to Southern Hemispheres and vice versa.
Intrahemispheric Mixing: Time it takes for a species to be mixed in the atmosphere within
the hemisphere (months).
Mesopause: The interface between the thermosphere and the mesosphere (100 km).
Mesosphere: The layer of the atmosphere below the thermosphere (50 to 100 km).
Mixing Time: The time it takes for a species to be mixed in the oceans or atmosphere.
Intrahemispheric tropospheric mixing generally takes on the order of weeks to
months. Interhemispheric tropospheric mixing takes on the order of years, usually
less than 10. Stratospheric mixing is generally a longer time frame activity due to
the stability of the stratosphere.
Nitrogen Cycle: The chemical cycling of nitrogen in the natural environment.
Ozone Formation: The photons with wavelengths shorter than 240 nm are absorbed by
O 2 and N 2 molecules in the upper atmosphere, which results in the formation of O 3
by the chemical equations O 2 + hn → 2O and O 2 + O + M → O 3 + M. The production is at a maximum in the lower stratosphere.
Ozone Hole: A hole that is found in the stratospheric levels of ozone above Antarctica
and to a lesser extent above the Arctic. It is a result of heterogeneous reactions of
chlorine with ozone in polar stratospheric clouds and a polar vortex that occurs
during certain times of the year.
Photochemical Gases: Gases involved in the photochemistry of the atmosphere (CO, O 3 ,
NO 2 , HNO 3 , H 2 , OH, OH 2 , H 2 O 2 , H 2 CO).
Singlet Oxygen: Molecular oxygen in which all the electrons are paired.
Solar Radiation: The flux of solar photons is a function of wavelength.
Glossary of Chemical Oceanography Terms
Chlorofluorocarbons: CFC compounds used primarily in the blowing of foams and as
refrigerants. They have a long lifetime and can penetrate into the stratosphere,
where they are photochemically broken down to produce Cl, which can react with
ozone. The CFCs can also act as greenhouse gases.
Dobson Unit: A unit of measurement of stratospheric ozone. Regarded as a thickness of
the ozone layer if brought to standard temperature and pressure (1 Dobson unit
equals 0.1 cm of ozone).
Greenhouse Effect: The result of certain gases absorbing infrared (IR) radiative energy
and increasing the temperature of the atmosphere like a “greenhouse.” Water
vapor, CO 2 , and methane are the primary greenhouse gases.
Greenhouse Gases: Gases that absorb infrared energy in the troposphere and thus cause
an increase in the temperature of the troposphere. Examples are H 2 O, O 2 , CO 2 ,
freons, and CH 4 .
Hydrogen Peroxide, H 2 O 2 : Occurs in the atmosphere as a result of two hydroperoxyl radicals reacting and in the ocean as a result of photochemical reactions of organic
carbon. Unstable, colorless, heavy liquid; soluble in water and alcohol. Used as
a bleach.
Hydroperoxyl Radical, HO 2 : Formed from the photochemical reactions of the H radical
with O 2 . The hydroperoxyl radical can regenerate OH radicals and can lead to the
chain termination.
Interhemispheric Mixing: Time it takes for a species to be mixed in the atmosphere
between hemispheres (1–2 yr).
Intertropical Convergence Zone (ITCZ): Area close to the equator surrounding the earth
where the northeast and the southeast trade winds flow together. Characterized
by strong upward motion and heavy rainfall. Affects the transport of species from
the Northern to Southern Hemispheres and vice versa.
Intrahemispheric Mixing: Time it takes for a species to be mixed in the atmosphere within
the hemisphere (months).
Mesopause: The interface between the thermosphere and the mesosphere (100 km).
Mesosphere: The layer of the atmosphere below the thermosphere (50 to 100 km).
Mixing Time: The time it takes for a species to be mixed in the oceans or atmosphere.
Intrahemispheric tropospheric mixing generally takes on the order of weeks to
months. Interhemispheric tropospheric mixing takes on the order of years, usually
less than 10. Stratospheric mixing is generally a longer time frame activity due to
the stability of the stratosphere.
Nitrogen Cycle: The chemical cycling of nitrogen in the natural environment.
Ozone Formation: The photons with wavelengths shorter than 240 nm are absorbed by
O 2 and N 2 molecules in the upper atmosphere, which results in the formation of O 3
by the chemical equations O 2 + hn → 2O and O 2 + O + M → O 3 + M. The production is at a maximum in the lower stratosphere.
Ozone Hole: A hole that is found in the stratospheric levels of ozone above Antarctica
and to a lesser extent above the Arctic. It is a result of heterogeneous reactions of
chlorine with ozone in polar stratospheric clouds and a polar vortex that occurs
during certain times of the year.
Photochemical Gases: Gases involved in the photochemistry of the atmosphere (CO, O 3 ,
NO 2 , HNO 3 , H 2 , OH, OH 2 , H 2 O 2 , H 2 CO).
Singlet Oxygen: Molecular oxygen in which all the electrons are paired.
Solar Radiation: The flux of solar photons is a function of wavelength.