Atmospheric and oceanic circulations pt.1

Question 1

Define the atmospheric circulation:

Answer 1

Atmospheric circulation is driven by the imbalance between equatorial energy surpluses and polar energy deficits, transferring energy and mass around the planet.

Question 2

How does ocean currents affect energy redistribution?

Answer 2

Ocean currents redistribute more heat in a zone straddling the equator between 17 deg. N&S.

Question 3

What is the role of the atmosphere in the energy redistribution?

Answer 3

Atmosphere is the dominant medium for redistributing energy from about 35 deg. N & S latitudes to the poles.

Question 4

What are the three levels of atmospheric circulation and describe them?

Answer 4

Primary circulation: general worldwide circulation.
Secondary circulation: migratory high-pressure and low-pressure systems.
Tertiary circulation: Includes local winds and temporal weather patterns.

Question 5

What are “meridional flows”?

Answer 5

Winds flowing principally N or S, along meridians.

Question 6

What are “ zonal flows”?

Answer 6

Winds moving E or W along parallels.

Question 7

How are aerosols spread around the planet?

Answer 7

With the wind

Question 8

Define the wind and its characteristics:

Answer 8

It’s a horizontal motion of air molecules across Earth’s surface. Turbulence adds vertical movement. Differences in air pressure(density) between place produces wind.
Principal attributes: speed (measured by an anemometer) and direction (determined by a wind vane).
Standard measurements are taken at 10 m above the ground.

Question 9

What happened in 1991 in the Philippines and what were the atmospheric effects?

Answer 9

The Mt.Pinatubo volcano erupted (after 635 dormant years) and it allowed tracking of contaminants through satellite monitoring around the planet. It caused: 13-18 million tons of ash, dust, SO2 into the atmosphere. Once in stratosphere, formed sulfuric acid aerosols that concentrated at 16-25 km altitude. 60 days after eruption, aerosols cloud covered about 42% of the planet from 20 deg. S to 30 deg. N. White is the highest concentration of concentration in the fig. 6.1)

Question 10

What are described as Aeolian?

Answer 10

Landforms, processes, and impacts of winds.

Question 11

What are polar high-pressure cells?

Answer 11

A small atmospheric polar mass is cold and dry, with weak anticyclonic high pressure. Limited solar energy results in weak variable winds called the polar easterlies. Cause: Thermal

Question 12

What are subpolar low-pressure cells?

Answer 12

Persistent lows (cyclones) over the North Pacific and North Atlantic that cause cool, moist conditions. Cold, northern air masses clash with warmer air masses to the south, forming the polar front. Cause: Dynamic.

Question 13

What are the Hadley cells?

Answer 13

In the Hadley cells, winds rise along the ITCZ (Intertropical Convergence Zone) and sweep poleward at high altitude, then sink to the surface in the subtropics, and circulate back toward the equator as the trade winds.

Question 14

What are the westerlies and where are they found?

Answer 14

The westerlies are the prevailing surface winds, formed where air sinks and diverges along the poleward border of the Hadley cells. They are found in the midaltitude circulation.

Question 15

What does ITCZ stand and what are its characteristics?

Answer 15

Intertropical Convergence Zone (ITCZ). Lying along the equator, the ITCZ is a trough of low pressure and light or calm winds: the doldrums. Moist, unstable air rises in the ITCZ, causing heavy precipitation year-round. Cause: Thermal.

Question 16

What is the consequence of air rising?

Answer 16

The pressure lowers (lower density of air molecules) and surrounding air molecules move in to replace these spread-out molecules: a principle factor in the creation of wind.

Question 17

As air sinks what does it cause?

Answer 17

It causes the pressure to increase= areas of high pressure.

Question 18

How are wind named?

Answer 18

Wind is named according to the direction from which it originates. For example: a wind from the west is a “westerly” wind. Winds are also named after local physical or cultural settings: A “Santa Ana” wind is hot, dry easterly wind from desert regions in southern California.
A “Bora” wind is unseasonally cold, dry wind around the coastal regions of the Adriatic Sea.

Question 19

Who is the Beaufort Wind Scale named after?

Answer 19

Admiral Beaufort of the British Navy(1806)

Question 20

What does Beaufort Wind Scale consist of?

Answer 20

A descriptive scale for visually estimating wind speed. It varies with land conditions and is graded with a Beaufort scale force going from force 0 to force 12, at which the wind speed increases with.

Question 21

In January how does the wind speed vary depending on the latitude?

Answer 21

It increases when you move away north or south from the equator.

Question 22

In July how does the wind speed vary depending on the latitude?

Answer 22

It’s low on the latitudes north to the equator, near the equator it’s relatively fast depending on the longitude too. And it increases when you move south near the south pole.

Question 23

What does the wind chill temperature index indicate?

Answer 23

Indicated the enhanced rate at which body heat is lost to the air. It’s a chart that includes temperatures, wind speeds, frostbite times Ex: air temp @ -10 deg. C, wind @ 20km/hr= “Feels like” -18 deg. C

Question 24

How does the rate at which body heat is lost vary?

Answer 24

As wind speed increases, heat loss from skin increases.

Question 25

How does the atmospheric pressure vary with altitude?

Answer 25

As the altitude(km) increase, the atmospheric pressure(millibars) decreases and if it decreases, pressure increases.

Question 26

Define air pressure

Answer 26

Motion, size and number of air molecules determine density and temperature of air which, in turn creates air pressure= exerting pressure on all surfaces that come into contact with the air.

Question 27

Who was the first to attempt to measure the Earth’s air pressure and how?

Answer 27

Evangelista Torricelli’s early barometer was first attempt to measure the Earth’s air pressure.

Question 28

What is the standard normal sea-level pressure`

Answer 28

1013.2 millibars `

Question 29

Normal range pressures, earth’s record low and high:

Answer 29

Normal range (strong to weak) pressures measure 1050 to 980 mb. Earth’s record low: 870 mb (“Typhoon Tip” in Western Pacific,1979)
Earth’s record high: 1084 mb (Siberia,1968)

Question 30

What do barometers indicate?

Answer 30

They indicate they weight of a column of air. Changes in barometric pressure correspond to changes in weather; pressure extremes are often associated with extreme weather events.

Question 31

What is the Canadian record low in mb and kPa?

Answer 31

940.2 mb(94.02kpa) Saint Anthony, Newfoundland Jan 1977

Question 32

What is the Canadian record high in mb and kPa?

Answer 32

1079.6 mb(107.96kkpa)
Dawson, YT
Feb 1989

Question 33

3 examples of hurricanes and their air pressure:

Answer 33

1. Hurricane Gilbert (888mb Sept 1988)
2. Hurricane Rita
   (897mb Sept 2005)
3. Hurricane Katrina
   902 mb(Aug 2005)

Question 34

Which two scientists developed the “ideal gas law”?

Answer 34

Robert Boyle (1660):
he said that air volume is inversely proportional to its pressure.
J.A.C. Charles (1802) showed that air volume is also directly proportional to its temperature.

Question 35

What is the formula for the “ideal gas law”?

Answer 35

PV=nRT

Question 36

Where is found the greatest air pressure pressing down on our bodies?

Answer 36

At sea level= 1 atm, 1013 millibars.

Question 37

Why do ear pop in airplanes?

Answer 37

As we go up in an airplane, the atmospheric pressure becomes lower than the pressure of the air inside our ears. Our ears pop because they’re trying to equalize, or match, the pressure. Same thing happens when the plane is landing.

Question 38

What are the subtropical high-pressure cells?

Answer 38

Persistent highs(anticyclones) produce regions where air is mechanically pushed downward, compressed, and warmed. Earth’s major deserts from beneath these cells. Cause: Dynamic.

Question 39

What is the correlation between pressure and volume?

Answer 39

As pressure decreases air volume increases. For example, a partially inflated helium balloon (or a bag of potato chips) seems to expand/inflate considerably when you go up in elevation. This is because, even though the temperature might not have changed, the air pressure outside decreased, and hence the balloon or the bag was able to expand until the pressure inside was the same as the pressure outside. This lower pressure corresponded to a higher volume.

Question 40

What happens when a given volume of air is compressed?

Answer 40

When a given volume of air is compressed. more molecules of the gases that compose air are present= higher density, so the volume will have a greater mass and weight more. At surface m^3 of air is about 1.225 kg/m^3’. At 11 km, it is about 0.364 kg/m^3(less than 1/3 of surface value).

Question 41

What is kinetic energy

Answer 41

Vibrational energy of molecules that we measure as temperature.

Question 42

What is the correlation between the air volume and the temperature?

Answer 42

As temperature increases, air volume increases. “A decrease in volume would correspond to a decrease in temperature if pressure is to remain constant.” .

Question 43

What is the correlation between the kinetic energy and the pressure?

Answer 43

The higher the temperature, the greater the kinetic energy, the more excited the molecules looking for a place to go (expand). In a container, the molecules hit a surface, and increase the pressure on that surface as temperature rises (think pressure cooker!).

Question 44

What is water pressure?

Answer 44

Pressure at any level in a fluid is created by the mass of the fluid above that level. Oceans of course are composed of nearly incompressible liquid (a fluid).

Question 45

At sea level, what happens to our bodies?

Answer 45

The air that surrounds us presses down on our bodies at 14.5 pounds per square inch. You don’t feel it because the fluids in your boy are pushing outward with the same force. The deeper you go in the ocean the more you will feel it.

Question 46

How does the pressure vary with water depth?

Answer 46

The pressure increases about one atmosphere for every 10 meters of water depth. At 5000 m depth= 5000 x 10^3 kg/m = 500 atmospheres.

Question 47

In ocean depth there are two things adding pressure what are they?

Answer 47

The weight of the water above and the weight of the atmosphere above the water.

Question 48

How does density differences between depth of water affect pressure at a given depth?

Answer 48

Density difference in water can affect the pressure at a given depth enough to create pressure gradients, forcing movements of water from high to lower pressure. In fact, colder, saltier deeper water will be slightly denser, that type of water will sink since it’s colder, the salt makes it also weight more on the same volume of water, so it applies more pressure to the water. Since there’s more pressure where there’s more salinity, cold and deeper, the water will want to go from high pressure to low pressure = move up = convection loop circulation.

Question 49

What makes the air compressible and not the water?

Answer 49

Air is compressible because there is a lot of space between air molecules, and these can be compressed till they are not too close to each other. For water there’s much less space between the molecules. In the graph of pressure with altitude in the atmosphere, the pressure curves because air is compressible and its density decreases with altitude while the ocean water is not very compressible, so line is basically straight.

Question 50

How does temperature create a pressure gradient?

Answer 50

warmer air is less dense, so it goes up and colder air goes down.

Question 51

What is warm air associated with?

Answer 51

Low surface pressure

Question 52

What is cool air associated with?

Answer 52

High surface pressure

Question 53

In a given isobaric surface at a given pressure how does air move?

Answer 53

If the air is heated at a Y point in the middle, at a isobar of 97 kpa it will go from the high-pressure zone (where air is heated) to the low-pressure zones on the sides. Then, from there another pressure gradient is created, the air is cooled down when it arrives to the low pressure zone which makes is sink near the ground. Then, it will go again from high pressure to low pressure, which is the point Y just above the ground. ( see figure in slide 29 of powerpoint 6)