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