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Glossary of Terms: N
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- Native Species
- Species that normally exists and reproduces in
a specific region of the Earth. Compare with immigrant
species, indicator
species, and keystone
species.
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- Natural Gas
- Hydrocarbon based gas, mainly composed of methane,
commonly found in the pores of sedimentary
rocks of marine origin.
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- Natural Hazards
- (1) Natural phenomena that produce negative effects
on life.
- (2) The study of the hazards of natural phenomena.
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- Natural Ionizing
Radiation
- Ionizing
radiation that comes from natural
sources in the environment.
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- Natural Selection
- Environment's influence
on the reproductive success of individuals
in a population.
It results in the exclusion of maladapted genetic traits
found within individuals in a population.
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- Neap Tide
- Tide that
occurs every 14 to 15 days and coincides with
the first and last quarter of the moon. This
tide has a small tidal range because the gravitational forces of the moon and
Sun are perpendicular to each other. Contrasts
with spring
tide.
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- Needle Ice
- A form of periglacial ground
ice that consists of groups ice
slivers at or immediately below the ground
surface. Needle ice is about a few centimeters
long.
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- Negative Feedback
- Change in the state of
a system that
counteracts the measured effect of the initial
alteration.
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- Net Longwave
Radiation (Balance)
- Balance between incoming and outgoing longwave
radiation. Mathematically expressed as:
-
L* =
(LD - LU)
- where L* is net
longwave radiation at the surface,
- LD is
atmospheric counter-radiation (greenhouse effect) directed to the
Earth's surface,
- and LU is longwave
radiation lost from the Earth's
surface.
-
- Net Primary
Productivity
- Total amount of chemical energy fixed by
the processes of photosynthesis minus
the chemical energy lost through respiration.
-
- Net Radiation (Balance)
- Balance between incoming and outgoing shortwave
and longwave radiations. Mathematically expressed
as:
-
Q* =
(K + k)(1 - a) - LU + LD
- where Q* is
surface net radiation (global annual
values of Q* =
0, because input equals output, local values
can be positive or negative),
- K is
surface direct
shortwave radiation,
- k is diffused
shortwave radiation (scattered insolation)
at the surface,
- a is
the albedo of
surface,
- LD is
atmospheric counter-radiation (greenhouse effect) directed to the
Earth's surface,
- and LU is longwave
radiation lost from the Earth's
surface.
-
- Net Shortwave
Radiation (Balance)
- Balance between incoming and outgoing shortwave
radiations. Mathematically expressed as:
-
K* =
(K + k)(1 - a)
- where K* is
surface net shortwave radiation,
- K is
surface direct
shortwave radiation,
- k is diffused
shortwave radiation (scattered insolation)
at the surface,
- and a is
the albedo of
surface.
-
- Neutral
- Any substance with a pH around
7.
-
- Neutral Atmosphere
- Condition in the atmosphere where
isolated air parcels do not have a tendency
to rise or sink. The parcels of air tend to
be same temperature as the air that surrounds
them.
-
- Neutralism
- Interspecific interaction where
the species do not directly influence
each other fitness.
-
- Neutral Solution
- Any water solution that is neutral (pH
approximately 7) or has an equal quantity
of hydrogen ions (H+) than hydroxide ions
(OH-). Also see acidic
solution and basic
solution.
-
- Neutron
- Atomic sub-particle found in the nucleus of
an atom.
This particle is similar in mass to
a proton but
does not have an electromagnetic charge.
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- Névé
- Partially melted and compacted snow that
has a density of at least 500 kilograms per
cubic meter.
-
- Newton
- A unit of force that
creates an acceleration on
a mass of
1 kilogram equal to 1 meter per second with
no friction and
under the conditions of a vacuum.
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- Niche
- Adaptive role
that a species has
in a habitat. This includes its behavior
and interactions with
other species.
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- Niche Specialization
- Process where evolution,
through natural
selection, adapts a species to
a particular set of abiotic and biotic characteristics
within a habitat.
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- Nickpoint (Knickpoint
- British spelling)
- Point on the long
profile of a stream where
the gradient is
broken sudden drop in elevation. Nickpoints
are the locations of rapids and waterfalls.
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- Nimbostratus
Clouds
- Dark, gray low altitude cloud that
produces continuous precipitation in
the form of rain or snow. Found in an altitude
range from the surface to 3,000 meters.
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- Nitrate
- Form of nitrogen commonly found in the soil and
used by plants for building amino
acids, DNA and proteins.
It is commonly produced by the chemical modification
of nitrite by
specialized bacteria. Chemical formula for
nitrate is NO3-.
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- Nitric Acid
- Acid with
the chemical formula: HNO3.
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- Nitric Oxide
- A gas produced by bacterial action in
the soil and by high temperature combustion.
Nitric oxide is a component in the production
of photochemical
smog. This colorless gas has the
chemical formula is NO.
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- Nitrification
- The biochemical oxidation of ammonium to nitrite and nitrite to nitrate.
This process is carried out by specialized bacteria.
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- Nitrite
- Form of nitrogen commonly found in the soil.
It is commonly produced by the chemical
modification of ammonium by specialized bacteria. This
form is toxic to plants and animals at high
concentrations. Chemical formula for nitrite
is NO2-.
-
- Nitrogen
Cycle
- Model that describes the movement of nitrogen
in its many forms between the hydrosphere, lithosphere, atmosphere and biosphere.
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- Nitrogen
Dioxide
- A gas produced by bacterial action in
the soil and
by high temperature combustion. Nitrogen
dioxide is a component in the production
of photochemical
smog. This reddish brown gas has
the chemical formula NO2.
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- Nitrogen
Fixation
- Biological or chemical process where gaseous
nitrogen is converted into solid forms of
nitrogen. Biological fixation of nitrogen
is done by specialized organisms like microorganisms
like bacteria, actinomycetes, and cyanobacteria. Chemical fixation
occurs at high temperatures. One natural
process that can produce enough heat to
fix atmospheric nitrogen is lightning.
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- Nitrogen
Oxides
- Consists of two gases nitric
oxide (NO) and nitrogen
dioxide (NO2). These
gases are produced by bacterial action
in the soil and by the high temperature
combustion. Both gases are components
in the production of photochemical
smog.
-
- Nitrogen
Saturation
- Over abundance of nitrogen in natural
ecosystems because of human induced inputs
related to agriculture and fossil fuel combustion.
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- Nitrous
Oxide
- Gas found in the atmosphere that contributes
to the greenhouse effect. Sources for nitrous
oxide include: land-use conversion; fossil
fuel combustion; biomass burning; and soil
fertilization. Chemical formula for nitrous
oxide is N2O.
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- Nivation
- Process where snow patches initiate erosion through physical
weathering, meltwater flow,
and gelifluction.
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- Nivation
Hollow
- Ground depression found in periglacial areas
that is created by nivation.
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- Noctilucent
Clouds
- High altitude clouds composed
of ice crystals that appear to glow silver
or bright blue shortly after sunset.
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- Non-Clastic
Sedimentary Rock
- Sedimentary
rocks that are created either
from chemical precipitation and crystallization,
or by the lithification once
living organic
matter.
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- Non-Ionizing
Radiation
- A form of electromagnetic
radiation that does not have
enough energy to cause ionization of
atoms in living tissue. Examples of
this type of radiation include radio
waves, microwaves, infrared light, and
ordinary light. Also see ionizing
radiation.
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- Non-Parametric
Statistical Test
- Statistical tests that do not assume the
sample data is normally distributed.
-
- Non-Renewable
Resource
- Resource that is finite in quantity and
is being used faster than its ability to
regenerate itself.
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- Nonsymbiotic
Mutualism
- Mutualistic interaction where the mutualists live
independent lives yet cannot survive without
each other. For example, pollinating insects
like bees and some flowering plants.
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- Normal Distribution
- A common probability distribution displayed
by population data.
If the values of the distribution are plotted
on a graph's horizontal axis and their frequency
on the vertical axis the pattern displayed
is symmetric and bell-shaped. The central
value or mean represents
the peak or the most frequently occurring
value.
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- Normal
Fault
- Vertical fault where
one slab of the rock is displaced up and
the other slab down. It is created by tensional
forces acting in opposite directions.
-
- Normal Lapse
Rate
- Average rate of air temperature change
with altitude in the troposphere.
This value is approximately a decrease of
6.5° Celsius per 1000 meters rise in
elevation.
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- Northeast
Trade Winds
- See trade
winds.
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- Northing
- Second measurement of a grid reference
used to specific the location of a point
on a rectangular
coordinate system. The distance
measured northward from the origin of
a rectangular coordinate system.
-
- North Magnetic
Pole
- Location in the Northern Hemisphere where
the lines of force from Earth's magnetic
field are vertical. This point on
the Earth gradual changes its position with
time.
-
- North Pole
- Surface location defined by the intersection
of the polar axis with Earth's surface in
the Northern Hemisphere. This location has
a latitude of
90° North.
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- Nuclear
Energy
- Energy released
when the nucleus of
an atom experiences a nuclear reaction
like the spontaneous emission of radioactivity, nuclear fission, or nuclear fusion.
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- Nucleic Acid
- Is an organic compound composed primarily
of different combinations of carbon, hydrogen,
nitrogen, oxygen, and phosphorus. They are
very complex compounds being created by
the atomic linking of thousands of individual
atoms. DNA or deoxyribonucleic
acid, the genetic blueprint of life,
is an example of a nucleic acid.
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- Nucleus
- (1) Dense central portion of an atom that
is composed of neutrons and protons.
- (2) Structure found in eukaryotic cells
that contains the chromosomes.
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- Nuee Ardente
- A glowing cloud of dense hot volcanic gas
and ash that
moves downslope at high speeds, incinerating
the landscape.
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- Null Hypothesis (H0)
- Is a hypothesis that
has been suggested because it is believed
to be true or because it is to be used as
a starting point for scientific argument.
Used in statistical testing to organize
arguments.
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- Nutrient
- Any food, chemical element or compound an organism requires to live, grow, or reproduce.
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- Nutrient
Cycle
- The cycling of a single element by
various abiotic and biotic processes
through the various stores found in the biosphere, lithosphere, hydrosphere, and atmosphere.
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Citation: Pidwirny,
M. (2006). "Glossary of Terms: N". Fundamentals of Physical Geography,
2nd Edition. Date
Viewed. http://www.physicalgeography.net/physgeoglos/n.html |
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