Week 3 - Heat and temperature of the Earth Flashcards
What is energy?
It’s a property of substances; it’s the ability to do work on mass.
What is temperature?
It is average kinetic energy, as well as the property that dictates the flow of heat energy.
How is temperature measured?
“Hot” and “cold” with a thermometer.
What is heat and how does it relate to temperature?
Heat is the flow of energy from something that is relatively warm to something that is relatively cold; it will continue to flow until the temperature of the two things are the same.
How is heat transferred?
It can be transferred via radiation, conduction, or convection/advection.
What is solar altitude?
Solar altitude is the angle of the sun above the horizon.
How much is the Earth’s axial tilt?
23.4
At what latitudes are the tropics and polar circles?
23.5, 66.5
What is axial parallelism?
As the Earth rotates around the sun, its axis is always parallel to itself, no matter what its position to the sun is.
What is normal lapse rate?
It’s the rate at which atmospheric temperature drops in relation to increased altitude.
What is the average normal lapse rate?
6.5 C
What is specific heat?
The amount of heat energy required to raise the temperature of a substance.
Land has ___ specific heat.
Land has low specific heat; it’s quick to heat and cool.
Water has ___ specific heat.
Water has high specific heat; it’s slow to heat and cool.
What is continentality?
The fact that places inland have higher temperature variations due to the low specific heat of land.
What are the main geographic controls on Earth’s temperature?
Latitude, altitude, land cover, continentality.
What is air pressure?
It’s the force exerted by the weight of air molecules.
What is high pressure in terms of altitude and temperature?
Low altitude, low temperatures.
What is low pressure in terms of altitude and temperature?
High altitude, high temperatures.
Where does air flow, pressure-wise?
From high to low pressure.
How do we measure air pressure?
With a barometer.
How does a barometer work?
When air pressure is high, it exerts more force on the mercury, causing it to rise from the dish into the tube.
What’s an isobar?
It’s a line on a map connecting places with the same atmospheric pressure.
What does a bigger pressure gradient mean?
It means a greater difference in pressures closer together, which creates much higher wind speeds.
What is the Coriolis Effect?
It’s the apparent deflection in the paths of objects—e.g. planes, wind, ocean currents—caused by the rotation of the Earth.
What controls the Coriolis Force?
The Earth’s rotation.
Explain the pattern of highs and lows around the world.
The Inter-Tropical Convergence Zone (ITCZ) – low pressure; Hadley Cells (northeast and southeast trade winds); Sub-Tropical High – high pressure; Ferrell Cells (westerlies); Polar Front (mid-latitude cyclone areas) – low pressure; Polar Cells (polar easterlies); Polar Vortez – high pressure
What sort of climate is the sub-tropical high associated with?
Deserts.
What are the two main controls on the strength of the Coriolis force?
Latitude (absent at equator, stronger at poles) and wind speed.
Which way does the Coriolis force deflect?
If you are looking in the direction that the wind is blowing, it deflects to the right in the N. hemisphere and to the left in the S. hemisphere.
What is teleconnection?
A strong connection between weather events in distant parts of the globe associated with large-scale atmospheric waves or circulation patterns.
What are the two main forces that control air movement?
The pressure gradient and the Coriolis force.
Low altitude / low temp =
high pressure
High altitude / high temp =
low pressure
The direction of the pressure gradient force is always _______ to the isobars.
perpendicular
If the isobars are far apart, what does that mean for the pressure gradient force and wind speeds?
Both will be relatively low.
In which direction does the Earth rotate?
Looking down from the North Pole, counter-clockwise.
What are the “normal” conditions for trade winds in the equatorial Pacific?
They blow from the east.
Under “normal” conditions in the equatorial Pacific, where would you find warmer sea surface temperatures?
In the western Pacific (Indonesia and Australia).
What is upwelling and, under “normal” conditions in the equatorial Pacific, where does it occur?
Upwelling is deep, cold, nutrient-rich water being brought up from the deep, and it occurs under normal conditions off the coast of Ecuador and Peru. Great for fisherman!
Under “normal” conditions in the equatorial Pacific, where would you find the most precipitation?
In the western Pacific, where warm air rises, cools, and sheds the moisture it picked up while travelling across the Pacific. The eastern Pacific region is relatively dry.
What is the Walker Circulation?
Basically, a causal description of “normal” conditions in the equatorial Pacific.
What is ENSO?
The El Niño Southern Oscillation; a flip-flopping of conditions in the equatorial Pacific.
What is El Niño?
A reversal of normal conditions in the equatorial Pacific.
What is La Niña?
A strengthening of normal conditions in the equatorial Pacific.
Are El Niño and ENSO the same thing?
No, because ENSO is a combination of both La Niña and El Niño.
What are the effects of El Niño in California?
Usually (though not always) storms, landslides, and floods.
What are the effects of El Niño in Northern US and Canada?
The jetstream is pushed northward, so relatively mild winters. The East is relatively moist.
What are the effects of El Niño in Peru?
Heavy rain, floods, landslides.
What are the effects of El Niño in Australia?
Droughts and bush-fires.
What are the effects of El Niño in India and Oceania?
Erratic or failed monsoons.
What are the effects of El Niño in Africa?
Possible drought and famine.
What are the effects of El Niño in eastern Pacific?
Lots of tropical cyclones.
What are the effects of El Niño in western Atlantic?
Less tropical cyclones.
What is it called (in the equatorial Pacific) when conditions are fairly neutral?
La Nada.
What does PDO stand for?
Pacific Decadal Oscillation.
What is the PDO?
Warm or cool waters in the Pacific north of 20 degrees.
What happens during a warm (positive) phase of the PDO?
The east Pacific is warm and the west Pacific is cool
What happens during a cool (negative) phase of the PDO?
The east Pacific is cool and the west Pacific is warm.
What are the major patterns whose teleconnections account for much of the weather variability around the world?
ENSO, PDO, Northern Annular Mode (NAM), Southern Annular Mode (SAM), etc.
The Northern Annular Mode (NAM) is closely associated with which two oscillations?
North Atlantic Oscillation (NAO) and Arctic Oscillation (AO)
What are annular modes?
Hemispheric-scale circulation pattern defined by changes
in the westerly winds at mid-latitudes.
How do the annular modes oscillate?
See-saw (dipole) pattern between positive and negative
phases.
What are the two annular modes?
NAM (also called the Arctic Oscillation and closely related to the NAO) and SAM (also called the Antarctic Oscillation)
How is ENSO measured?
By measuring trade winds, measuring pressure and calculating the Southern Oscillation Index (SOI), and by measuring sea surface temperatures using the TAO array and calculating an index.
How are PDO and ENSO related?
PDO tends to amplify ENSO.
Which annular mode are we most affected by?
The Arctic Oscillation
If there is higher pressure at the poles, what happens to the Polar Front?
It’s pushed down toward the equator.
What is a front?
It’s a LINE that separates warm air masses from cold air masses.
Why does precipitation occur when fronts move in?
Because dew point temps are reached.
Why does cold air generally tend to over take warm air in mid-latitude cyclones?
Because it’s higher pressure and therefore moving with more force.
What controls solar altitude?
It is controlled by many factors, including the Earth’s rotation, the Earth’s axial tilt, and the progression of the equinoxes or march of the seasons.
