CLI2201 Definitions Flashcards
(95 cards)
1
Q
M1 - What is the difference between weather and climate?
A
Weather is the state of the atmosphere variables (such as air temperature, precipitation, wind, cloud, etc.) at a particular time and location. Climate is the synthesis of weather observed over a period of many years.
2
Q
M1 - What is the definition of climate variability?
A
Variations in the mean state (and occurrence of extremes, etc.) of the climate on all temporal and spatial scales beyond that of individual weather events. May be natural internal processes (i.e. ENSO) or external variability (i.e. anthropogenic forcings).
3
Q
M1 - What is the Goyder line?
A
An early attempt to classify Australia’s climate, it was the 300mm annual mean contour of equal rainfall line – assumed that rainfall south of this line would allow wheat to be grown safely.
4
Q
M1 - What is the definition of climate change?
A
Any change in climate over time, whether due to natural variability or anthropogenic forcings.
5
Q
M1 - What is the definition of weather?
A
The state of the atmosphere at a particular time and location.
6
Q
M1 - What is the meaning of the acronym AR5?
A
Intergovernmental Panel on Climate Change Assessment Report 5
7
Q
M1 - What is explained by the astronomical theory of climate?
A
Ice age cycles are undoubtedly linked in some manner to the variations in the Earth’s orbit.
8
Q
M1 - What is physical climatology?
A
Applies the laws of physics to describe, understand, and study underlying climate processes. Prognostic and diagnostic application of models are possible.
9
Q
M1 - What is the acronym ECMWF?
A
European Centre for Medium-Range Weather Forecasts
10
Q
M2 - What is a possible definition for the cryosphere?
A
The collective portions of the earth where water is found in solid form, including snow cover, ice caps, floating ice, permafrost, ice sheets and seasonally frozen ground.
11
Q
M2 - What is a possible definition for permafrost?
A
Permanently frozen ground.
12
Q
M2 - What is latent heat?
A
A form of energy that is required in the phase change of water from ice to liquid to gaseous.
13
Q
M2 - What are the climate system components that are referred to as active climate system components?
A
Active means important upon the human and non-geological time scale – the atmosphere is the most active, followed by the ocean, continents and the Earth mantle.
14
Q
M3 - What is the meaning of NADW, AAIW, and AABW?
A
Antarctic Intermediate Water: The water constituting this return path, primarily Antarctic Intermediate Water (AAIW) is colder and fresher than the ocean return flow within the surface.
Antarctic Bottom Water: may be formed around the whole of the Antarctic Continent. It is the coldest
and heaviest of the global scale water masses and fills up the deep ocean basins
North Atlantic Deep Water: NADW enters the deep ocean leading to a renewal process of deep water on centennial time scales. The deep water contains the memory of past atmospheric conditions.
15
Q
M3 - What is the Pacific Ocean Warm Water Pool?
A
A region of warm water in the western equatorial Pacific Ocean, created by persistent easterlies along the equator, which push warmer and less dense surface water towards the west, creating a warm water pool.
16
Q
M3 - What is the permanent thermocline?
A
A region characterised by a large temperature gradient between bout 500 – 1000m. Basically divides ocean into two regions: the upper (influenced by interaction between ocean and atmosphere, where temperatures can vary from 25 degrees to around 5 degrees), and the lower (where temperature is cold and shows little variation)
17
Q
M3 - What are isotherms and isohalines?
A
An isotherm is a line of constant temperature; isohalines are lines of constant salinity
18
Q
M3 - What is a temperature-salinity (T/S) diagram?
A
A diagram that shows where the coldest and saltiest (high density) water is found (in the deep ocean) and warm and low salinity (freshest) water is found (on the surface).
19
Q
M3 - What is the environmental lapse rate?
A
About 6.5 degrees per km height, but varies in location, season and height. Can be 0 degrees per km in the arctic
20
Q
M4 - What is the Earth’s albedo?
A
It is the percentage of incoming solar energy reflected by the planet back into outer space (depends on land, water, ice, atmospheric composition, etc.). Its value is 0.3 or 30% for earth or the planet as a whole, 0.1 for oceans and approx. 0.9 for ice.
21
Q
M4 - What is the meaning of P-E?
A
Precipitation - Evaporation
22
Q
M4 - What is the perihelion?
A
The name for the point of closest approach during Earth annual pathway around the Sun.
23
Q
M4 - What is the aphelion?
A
The name for the point of furthest distance during Earth annual pathway around the Sun
24
Q
M5 - What is the Hamilton operator?
A
This is the general equation of motion with the terms on the right hand side of the equation representing firstly, the pressure gradient forces, secondly, the gradient of the Earth’s gravitational potential, and thirdly, the frictional forces.
25
M5 - What is the definition for the pressure gradient force?
Pressure Gradient Force = Coriolis Force ± Centripetal Force
AND
Centrifugal Force = Pressure Gradient Force
26
M5 - What is the definition for Newton’s 2nd Law of Motion?
Acceleration of a particle is equal to the vector sum of forces acting upon that particle.
27
M5 - What is the South Pacific Convergence Zone?
The name for the region that is characterised by convergent air associated with could formation and delivering rainfall to the South Pacific Island nations
28
M5 - What is an isobar?
A constant line of pressure
29
M6 - What is the definition of the oceanic mixed layer?
Expressed in simple terms, the Oceanic Mixed Layer is the surface layer that has been homogenised by wind, cooling or processes such as evaporation or sea ice formation.
30
M6 - What is the definition of the global thermohaline circulation?
The Global Thermohaline Circulation (GTC) refers to the part of the large scale ocean circulation that is driven by density currents created by surface heat and freshwater fluxes.
31
M6 - What is the definition of an Ekman Layer?
The Ekman Layer is the layer in a fluid where there is a force balance between pressure gradient force, Coriolis force and turbulent drag.
32
M6 - What is WOCE?
World Ocean Circulation Experiment (A decade long continuous international effort that provided a snapshot of the distribution of temperature, salinity, and other ocean properties such as derived density.
33
M6 - What are AAIW, AABW, NADW and SW?
Antarctic Intermediate Water: The water constituting this return path, primarily Antarctic Intermediate Water (AAIW) is colder and fresher than the ocean return flow within the surface.
Antarctic Bottom Water: may be formed around the whole of the Antarctic Continent. It is the coldest
and heaviest of the global scale water masses and fills up the deep ocean basins
North Atlantic Deep Water: NADW enters the deep ocean leading to a renewal process of deep water on centennial time scales. The deep water contains the memory of past atmospheric conditions.
* The above 3 are the deep mixing regions
Surface water
34
M6 - What is expressed by the Sverdrup model?
The mass transport resulting from both the geostrophic and Ekman component.
35
M7 - What is non-seasonal climate variability?
Non-seasonal climate variability is a world-wide phenomenon of the global climate system. It occurs on inter-annual, intra-annual, decadal, centennial and longer time scales.
36
M7 - What are climate indices?
They are often used to monitor climate variability, and include: SST, SLP, Nino & PDO.
37
M7 - What are the similarities between El Nino and the Pacific Decadal Oscillation?
PDO can be referred to as a long lived Nino (lasting 20-30 years to Nino's approximate year) causing Niño-like pattern of Pacific Ocean climate variability in climate elements such as wind speed, sea level pressure, and sea surface temperature
38
M7 - What are associated time scales?
The association between the time scale of an event (ie. 30-60 days) and the event (ie. MJO).
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M7 - What is the definition for PDO?
Pacific Decadal Oscillation: The PDO is a reversal in ocean surface temperature (SST) that occurs every 20-30 years over the northern Pacific Ocean.
40
M7 - What is the definition for ACW?
Antarctic Circumpolar Wave: The ACW is a wave-like feature that is observed in sea surface temperature and pressure patterns throughout the Southern Ocean. It circulates around Antarctica in about six to eight years. It is dominated by a wave 2 phenomenon (two ridges and two troughs) and therefore appears to circulate the Southern Hemisphere every four years. The wave moves eastwards with the prevailing currents.
41
M7 - What is the definition for MJO?
Madden Julian Oscillation: The MJO is an equatorial eastward travelling zone of anomalous rainfall that is of planetary scale. It forms over the western Indian Ocean and travels eastwards towards Indonesia region and finally weakens over the central Pacific Ocean. Each cycle lasts between 30-60 days and exhibits significant interannual variability related to ENSO activity. Its passage influences the onset of the Indian monsoon and the modulation of tropical cyclones.
42
M7 - What is the definition for QBO?
Quasi Biennial Oscillation: The QBO is a periodic reversal (approximately every 13 months) of the wind direction in the upper parts of the tropical atmosphere, and is best observed in the stratosphere over the equatorial regions.
43
M7 - What is the definition for IOD?
Indian Ocean DiPole: The IOD is an aperiodic oscillation in the sea surface temperatures and other climate elements over the tropical waters in the Indian Ocean. A positive (warm) phase of the IOD is linked to below average rainfall in south east Australia.
44
M7 - What is the definition for IPO?
Interdecadal Pacific Oscillation: The IPO is an oscillation in the ocean-atmosphere system that affects the climate of the Pacific region on a time scale of one to three decades
45
M8 - How is the Southern Oscillation defined?
A coherent interannual fluctuation of atmospheric pressure over the tropical Indo-Pacific region. The Southern Oscillation is the atmospheric component of a single large-scale coupled interaction called the El Niño/Southern Oscillation (ENSO), and can understood using the SOI.
46
M5 - What are the definitions for Earth’s angular velocity and momentum?
Angular velocity is defined as W = 2p/t with t (time) being the length of the day on the planet Mars.
47
M8 - What is a Southern Oscillation?
The Southern Oscillation is a fluctuation in the intertropical sea level pressure, wind, sea surface temperature and rainfall and an exchange of air between the southeast Pacific subtropical high and Indonesian equatorial low in the western Pacific Ocean.
48
M8 - What is the SOI?
The Southern Oscillation Index is a measure for the state of the Southern Oscillation, i.e. the fluctuation of sea level pressure between Tahiti in the east and Darwin in the west tropical Pacific that is associated with the Walker circulation.
49
M8 - Define El Nino
El Niño is characterized by a large scale weakening of the trade winds and warming of the surface layers in the easternand central equatorial Pacific Ocean. El Niño events occur irregularly at intervals of 2-7 years, although the average is every 3-4 years. It is also referred to as the warm phase of the ENSO and it is characterised by a strongly negative SOI. El Niño usually terminates about 12-18 months after its commencement
50
M8 - Define La Nina
The Southern Oscillation’s tendencies for unusually
low pressures west of the date line and high pressures east of the date line have also been linked to periods of anomalously cold equatorial Pacific sea surface temperatures which are referred to as La Niña. It can also be referred to as the cold phase of ENSO characterised by a strongly positive SOI. La Niña events
are less frequent than warm events with about 21 events during the last one hundred years.
51
M8 - Define ENSO
ENSO (El Nino Southern Oscillation) is a condition in the
tropical Pacific whereby the reversal of surface air pressure at opposite ends of the Pacific Ocean induces westerly winds, a strengthening of the equatorial counter current and extensive ocean warming.
52
M8 - Define El Nino Modoki
The El Niño Modoki is characterised by a positive warm central equatorial Pacific Ocean sea surface temperature anomaly and two cold anomalies in the western and eastern equatorial Pacific Ocean.
53
M8 - Define La Nina Modoki
The corresponding negative, cold central equatorial Pacific Ocean anomaly. It shows two warm anomalies in the west and east.
54
M9 - What is an equatorial kelvin wave?
An oceanic wave that travels eastward along the Equatorial Ocean and extends several 100 kms north and south of the equator with decreasing amplitude. The wave is associated with the advection of warm water that surges eastward. It manifests itself in changes
to the depth of the tropical thermocline and sea level and anomalies travel at a speed of about 2.8 ms-1, taking about 2-3 months to cross the Pacific Ocean. It
is usually associated with a change in the surface wind stress and westerly wind bursts.
55
M9 - What is a Rossby wave?
A Rossby Wave is an ocean wave of low frequency that is reemitted after the passage of a Kelvin wave from the west coast of South America. This waves travels westward to the north and south of the equator at
a latitude of ~10º-15º and eventually reaches the western Pacific Ocean after 6- 9 months. They are more difficult to detect than Kelvin waves.
56
M10 - What is the ICTZ?
The Intertropical Convergence Zone (ITCZ) is a zone where persistent convergence of airflow occurs in the lower troposphere and subsequent rising leads to the formation of clouds and rainfall at low latitudes.
57
M10 - What is the SPCZ?
The South Pacific Convergence Zone (SPCZ) is a zone of persistent convergence, cloudiness and rainfall that occurs in the tropical and subtropical Southwest Pacific Ocean.
58
M10 - What is a monsoon?
The Monsoon is a system showing a pronounced seasonal variation of airflow in the lower troposphere in tropical and subtropical regions. There are five main monsoon systems recognised globally and this
includes the African, Indian, East Asian, Australian and Eastern North Pacific monsoons.
59
M10 - What is the Walker Cell?
The Walker Cell is a thermally driven longitudinal cellular
circulation extending across the Pacific Ocean from Indonesia to close to the Peruvian coast and forming a component of the Southern Oscillation.
60
M10 - What is the Hadley Cell?
The Hadley Cell is a meridional circulation of air in low
latitudes, consisting of two opposing cells, each having air rising in the intertropical convergence zone and sinking in the adjacent subtropical zone.
61
M12 - What are Statistical Global Climate Models?
Statistical Global Climate Models are based on
mathematical/statistical examination of data that represents the past observed behaviour of the forecasted weather element. Currently previous values of the SOI are used to predict seasonal rainfall over Australia.
62
M12 - What are Physical Global Climate Models?
Physical global climate models are based on many physical equations that represent the physical processes observed in the climate system and include equations like the Navier Stokes equations, equations of
continuity and hydrostatic balance. They also include many biological, oceanic and terrestrial processes that feedback into the climate system, as well as the associated boundary conditions like orography and initial conditions such as sea surface temperatures.
63
M6 - What is the approximate definition of wind stress?
Where the surface winds exert a frictional force at the ocean surface.
64
M2 - Define residence time
T = V/ F; T = residence time
| s), V = volume (m3), and F the flux (m3.s-1
65
M2 - What is the physical unit for a flux?
[m^3] per [s]
OR
(m^3xs^-1)
66
M2 - Define climate system
The climate system is composed of the ocean, atmosphere, biosphere, cryosphere and land and includes a range of complex processes within and exchanges between these climate system components.
67
M3 - A lapse rate specifies the declining temperature with altitude. What are the physical units for the lapse rate formula?
Γ [ºC/km],
T= temperature [ºC],
z = height [km].
The lapse rate is a gradient, i.e. the change of temperature ΔT = (T2-T1) between two locations Δz = (z2-z1).
68
M3 - Define hydrostatic balance
The balance between the pressure gradient, i.e. the term to the right of the equation and the gravity force, i.e. the term to the left of the equation
69
M3 - Define salinity
Total amount of dissolved material in grams in one kilogram of sea water."
For example, 35 grams of salts per kilogram of seawater is often written as 35 ppt or 35 ‰
70
M4 - Define Stefans Law
The total energy per unit surface area emitted by
a black body is proportional to the fourth power of the temperature:
F = σ . T4
The physical units for F are (J.s-1.m-2 = W.m-2)
71
M4 - Define Luminosity
Lo is defined as the total amount of energy emitted
| by Sun. It is calculated by integrating F obtained from Stefan’s Law over the surface area of the sun.
72
M4 - What is the physical unit for the wavelength The physical unit for λ?
(μm)
73
M4 - What does W.m-2 mean?
Watts per square metre
74
M4 - How is the Solar Constant calculated?
Referred to as So, it is calculated from the sun’s luminosity by:
So = Lo ÷ 4 × π × r2
75
M4 - Define eccentricity
The elliptical path of the Earth around the sun which slowly changes and has a period of about 100,000 years.
This motion has been linked to the cycles of glaciation and deglaciation and is referred to as an astronomical theory of the ice ages. The theory was developed
by Milutin Milankovitch.
76
M4 - Define obliquity
Obliquity describes the tilt of Earth’s axis relative to the
plane of orbit and varies between 22o and 24.5o over a period of ~41,000 years.
It is at 23.5 at present and defines the location of the Tropics of Cancer and Capricornia.
77
M5 - What is vorticity?
The measure of spin of a fluid or the atmosphere. By convention, vorticity is defined to be positive (+)
when the motion is cyclonic and negative (-) in the case of anticyclonic motion.
78
M5 - Define geostrophic wind
A horizontal wind blowing in a straight path, parallel to isobars at a constant speed caused by the exact balance of the Coriolis force and the horizontal pressure gradient force.
79
M5 - Define thermal wind.
A wind component determined by the occurrence of horizontal temperature gradients in the atmosphere, and associated with the vertical shear of geostrophic wind
80
M5 - Define gradient wind
A theoretical wind that blows parallel to curved isobars and represents the balance between the Coriolis,
centrifugal and horizontal pressure gradient forces
81
M5 - Define inertial wind
Results from the balance between Centrifugal and Coriolis force and is more common in the ocean than the atmosphere.
82
M5 - Define cyclostrophic wind
A balance between the pressure gradient and the centrifugal force in small scale synoptic features
83
M5 - What is the coriolis force?
The Coriolis Force is an apparent force that acts upon a moving object in a rotating coordinate system.
84
M6 - What is the steady state flow?
Steady-state flow refers to the condition where the fluid properties at any single point in the system do not change over time. These fluid properties include temperature, pressure, and velocity.
85
M6 - What are the physical units for
i) Annual freshwater flux
ii) Annual surface heat flux
i) m.year-1
| ii) W.m-2
86
M/C Quiz: What are greenhouse gases?
(a) Greenhouse gases absorb outgoing long wave radiation.
(b) Greenhouse gases absorb outgoing short wave radiation.
(c) Greenhouse gases make up most of the atmospheric.
(a) Greenhouse gases absorb outgoing long wave radiation.
87
M/C Quiz: Which of the following statements defines the physical property
energy flux best?
a) The physical property energy flux F can be defined as the amount of energy
transferred every second [s] through a unit surface area [m2]. The physical unit
for energy flux is [kg.s-1.m-2] or [W.m-2] with the physical unit for energy is
[J].
b) The physical property energy flux F can be defined as the amount of energy
transferred every second [s] through a unit surface area [m3]. The physical unit
for energy flux is [J.s-1.m-3] or [W.m-3] with the physical unit for energy is [J].
c) The physical property energy flux F can be defined as the amount of energy
transferred every second [s] through a unit surface area [m2]. The physical unit
for energy flux is [J.s-1.m-2] or [W.m-2] with the physical unit for energy is [J].
c) The physical property energy flux F can be defined as the amount of energy transferred every second [s] through a unit surface area [m2]. The physical unit for energy flux is [J.s-1.m-2] or [W.m-2] with the physical unit for energy is [J].
88
M/C Quiz: Which of the following statements defines Luminosity best?
a) The Luminosity Lo is defined as the total amount of long-wave energy emitted
by Sun.
b) The Luminosity Lo is defined as the total amount of energy emitted by Sun.
c) The Luminosity Lo is defined as the total amount of energy per unit surface
area [m2] emitted by Sun.
b) The Luminosity Lo is defined as the total amount of energy emitted by Sun.
89
M/C Quiz: What defines Wien’s Law best?
a) Wien’s Law states that the maximum emission wavelength of radiation (λ) is
inversely proportional to the black body temperature (T).
b) Wien’s Law states that the maximum emission wavelength of radiation (λ) is
directly proportional to the black body temperature (T).
c) Wien’s Law states that the maximum emission wavelength of radiation (λ) is
not proportional to the black body temperature (T).
a) Wien’s Law states that the maximum emission wavelength of radiation (λ) is inversely proportional to the black body temperature (T).
90
M/C Quiz: What define the Stefan-Boltzman Law best?
a) Stefan-Boltzman Law states that the total energy per unit surface area
emitted by a black body is proportional to the third power of the temperature.
b) Stefan-Boltzman Law states that total energy per unit surface area emitted by
a black body is proportional to the fourth power of the temperature.
c) Stefan-Boltzman Law states that total energy per unit surface area emitted by
a black body is proportional to the fifth power of the temperature.
b) Stefan-Boltzman Law states that total energy per unit surface area emitted by a black body is proportional to the fourth power of the temperature.
91
Random: What are the Western Boundary Currents?
Western boundary currents are warm, deep, narrow, and fast flowing currents that form on the west side of ocean basins due to western intensification. They carry warm water from the tropics poleward. This is the western edge of an ocean basin, and is the strongest current in the oceans (partly due to Coriolis effect at higher latitudes)
92
Random: What are the Eastern Boundary Currents?
They are the relatively shallow, broad and slow flowing currents that flow equatorward, and promote upwelling. This upwelling is driven by Northerly winds (in the Southern Hemisphere)
93
M1 - What is the differeence between the following approaches to climatological studies?
i) Physical climatology
ii) Statistical climatology
iii) Descriptive climatology
i) applies the laws of physics to describe,
understand, and study underlying climate processes
ii) applies the language of mathematics to describe
the distribution of climate elements such as temperature, precipitation and identifies pattern e.g. correlations in time and space, mean, median, maximum and minimum values.
iii) the traditional way, which is more a descriptive
approach similar to that applied in geography.
94
M2 - Define the hydrological cycle
The global hydrological cycle of water involves the continues exchange of freshwater between the ocean, atmosphere, and land.
95
M2 - Define the global carbon cycle
The global cycle of carbon involves the continues exchange of carbon between the ocean, atmosphere, biosphere and soils. The ocean is the largest of the carbon reservoirs.
