Deffinitions Flashcards
Weather
the state of
the atmosphere at a place
and time with regard to
meteorological variables
such as dryness, sunshine,
wind, rain, etc.
Climate
the pattern of variation in temperature, humidity, atmospheric
pressure, wind, precipitation, atmospheric particle count and other
meteorological variables in a given region over long periods.
Climate Experiments
- Scientific procedures
undertaken to test a
hypothesis about the
climate system. - Intentional changes are
made to the input variables
and outputs observed and
quantified.
Climate Observations
- Measurements taken of the
climate system in situ or with
remote sensing (such as from
satellites). - Datasets that are built upon a
global and continuously
growing observational
network
Climate Models
- Mathematical representations of the Earth system built using fundamental
laws of physics (conservation of mass, conservation of energy, etc.). - Vary from very simple “back of the envelope” calculations to massive multi-
million-line programs run on massive supercomputing systems. - Goal: To understand interdependency and variation in the Earth system, and
as a virtual laboratory for experimenting on the Earth.
Keeling Curve
named after Charles David
Keeling, who started the CO2 monitoring program at Mauna Loa Observatory in 1958 and supervised it until he died in 2005.
Troposphere
Below the tropopause
(typically located between 10-18km
depending on latitude and season),
temperature increases strongly
towards the surface. It contains about
85% of the atmosphere’s mass and
essentially all the water vapor.
Stratosphere
Exhibits a temperature increase with altitude
due to the presence of the ozone
layer. The stratosphere is highly
stratified and poorly mixed (the
increase in temperature with
altitude makes the atmosphere
very stable).
Mesosphere
- Temperature increases towards the surface in this layer, driven by increased ozone
concentration. - Maximum concentration of ozone is
closer to 20km-30km, but it’s strong
opacity to solar radiation leads to higher
temperatures near 50km.
Thermosphere
- (Edge of Space) Temperature is very high and variable. Short wavelength ultraviolet radiation
is absorbed here by oxygen.
Molecules are dissociated with high-
energy ultraviolet radiation from the
sun (λ < 0.1 μm). Temperatures can
get very high (up to 1000K), even
though air density is very low.
Tropopause
- typically located between 10-18km
depending on latitude and season - above the troposphere
- Separates Troposphere and Stratosphere
Stratopause
- above the Stratosphere
- Separates Stratosphere and Mesosphere
Mesopause
- Above mesosphere
- Separates Mesosphere and Thermosphere
Temperature proxy
- a measurement that can be used to calculate the value of temperature (for example when direct measurements are not available).
EX:
- Tree Rings
- Ice Cores
- Coal Beds, Sand Dunes, Fossils
- Documents of Droughts, Floods, and Crop Yields
- Chemistry of Lake Bottom Sediment
- Soil Deposits
- Pollen in Deep Caves or the Growth of Stalagmites
Dendroclimatology
- studying the Earth’s climate through the study of tree rings.
- Trees grow one ring per year
- Distance between rings = Temperature, Moisture Fluctions related to Climate Variability
δ18O
- the difference in the [18O]/[16O] ratio between a sample and an
associated standard, normalized by the ratio in the standard.
Milankovich Cycles
- Refers to oscillations in the Earth’s orbital parameters that affect its climate over thousands of years.
Temperature
- Is a measure of the average kinetic
energy of molecules in a particular substance (such as a parcel of air).
Kinetic Energy (KE)
- a measure of the energy of a substance due to motion.
Conduction
- Heat transfer due to contact. Molecules of a warm object bang against molecules of a cold object, causing “cold” molecules to move faster
and “warm” molecules to move slower.
Convection
Heat transfer due to movement. A balloon full of warm air can move into a region of cold air and increase the average air temperature.
Radiation
Heat transfer due to photons (small bundles of electromagnetic energy). When these photons hit another molecule, kinetic energy is
transferred
Energy Balance
- The total energy within the
system must be unchanging - the Earth system is, to a close approximation,
in a state of energy balance
Black Body
An idealized physical body that absorbs all incident electromagnetic radiation. A black body in thermal equilibrium (constant
temperature) emits blackbody radiation in accordance with Planck’s law.
Solar Constant
- The rate at which solar energy is received by the Earth (per unit area).
Aerosols
- Minute particles suspended in the atmosphere. When these
particles are sufficiently large, we notice their
presence as they scatter and absorb sunlight.
Their scattering of sunlight can reduce visibility
(haze) and redden sunrises and sunsets.
Aerosols.
Smog
- Consists of fog or haze combined with smoke
and other atmospheric pollutants or aerosols.
PM2.5
- Particulates are a Group 1 carcinogen
(WHO). Smaller particulates below 2.5
micrometers (PM2.5) are particularly
deadly. These particles are able to
penetrate into tissues and the blood
stream after inhalation causing DNA
damage (lung cancer), heart attacks
and premature death
Air Parcel
- A body of air which represents a
collection of air particles. This is
analogous to a balloon with an
invisible boundary.
Absolute Humidity
- (also known as the density of
water vapor) is the mass of water
vapor divided by the volume of air.
Specific Humidity
- The mass of water vapor in an air
parcel divided by the total mass of
air in the air parcel.
Vapor Pressure
Measure of the contribution of water
vapor to the total pressure exerted at
the boundary of the air parcel.
Dew Point Temperature
The temperature at which an
air parcel becomes saturated, when cooled at constant specific humidity. If temperature drops further, then water vapor in the air
will begin to condense.
Saturation Vapor Pressure
- The maximum water vapor pressure that is generally possible at a given temperature before water vapor starts to condense
Saturation Specific Humidity
(q * ) is the maximum value of specific
humidity that can be attained at a
particular pressure and temperature
before condensation occurs.
Relative Humidity (RH)
- The ratio of specific humidity to the
saturation-specific humidity (often expressed as a percentage ((q/q*) x 100%)))
Water Conveyance
- Refers to canals, ditches, pipelines, or other
means of moving water.
Groundwater Overdraft
- Refers to pumping more groundwater than the system can sustain.
Mitigation
- Refers to actions aimed at limiting the magnitude of climate change.
Adaption
- Refers to actions that are aimed at minimizing the impact of climate change.
Geoengineering
- Refers to the deliberate large-scale manipulation of environmental processes that affect the Earth’s climate in an attempt to counteract climate change.
Adaptive Capacity
- A measure of the capacity and potential for
humans in a particular region to adapt to changes in climate. - is unevenly distributed across different regions and populations, and developing countries generally have less capacity to adapt.
Climate Vulnerability
- A measure of the danger posed by the changing climate to a particular region.
Environmental Justice
The equitable distribution of
environmental risks and benefits, that is fair treatment and meaningful
involvement of all people with respect to development, implementation,
and enforcement of environmental laws, regulations and policies.
Climate Justice
The framing of climate change as an ethical
and political issue, rather than a purely environmental or physical issue.
Lifting Condensation Level (LCL)
- The altitude at which
the air hits the dew point
temperature (100% relative
humidity).
-This is also the bottom (base) of the
cloud. Because temperatures are
fairly uniform horizontally, the
cloud base tends to be flat.
Insolation
a measure of the solar radiation energy
received on a given surface area and recorded during a given time.
Scattering
- The process by which a photon of light, on interacting with a molecule, changes direction.
Absorption
- The process by which a photon of light, on interacting with a molecule, is absorbed by the molecule, increasing its internal energy.
- Importantly, each type of molecule can only absorb certain wavelengths of light.
Albedo
- The ratio of reflected solar energy to incident solar energy.
Planetary Albedo
Alpha_p is the fraction of incoming solar radiation at the Earth reflected back to space averaged over the whole planet.
Emission Temperature
The black body temperature required to achieve energy balance. This is also the
temperature the planet would have if it didn’t have an atmosphere
Greenhouse Effect
- The “trapping” of terrestrial radiation
by greenhouse gasses in the atmosphere – namely, the frequent absorption and re-
emission of outgoing terrestrial radiation by the atmosphere.
Greenhouse Gas
- Gases that contribute to the greenhouse effect by absorbing terrestrial radiation
Representative Concentration Pathways (RCPs)
Estimates of atmospheric greenhouse gas
concentrations that would be expected in response to economic growth and policy scenarios.
Shared Socioeconomic Pathways (SSPs)
- Scenarios of projected socioeconimic global change up to 2100. They have been developed
for the IPCC sixth assessment report,
and incorporate both greenhouse gas
emissions and different climate policies.
