General Circulation

Question 1

Geneal Circulation

Answer 1

What conditions (winds, pressure, precipitation, temperature) look like if we average over long periods of time, and over large areas

Question 2

Typical winds

Answer 2

Easterly in the tropics

Westerly in mid-latitudes

Question 3

Distribution of precipitation

Answer 3

Persistent rain near the equator and in mid-latitude “storm tracks” and clear skies in the subtropics

The relationships between average wind patterns and pressure patterns and upward and downward air motions

Question 4

Three-cell model of the ATM

Answer 4

Polar cell (cold, sinking air near the pole spreads equatorward at the surface)

Ferrel cell (rising motion in the mid-latitude “storm tracks”

• Polar jet aloft associated with large horizontal temperature gradient (thermal wind)

Question 5

Jet streams becomes unstable =>

Answer 5

starts getting wavy

wavy ==> mid-latitude cyclones

Question 6

Conservation of Angular Momentum:

Answer 6

Unless acted upon by some force, the angular momentum of a parcel of air does not change

Question 7

Thermal Wind

Answer 7

A horizontal change in temprature causes wind speed to increase with height

Question 8

Subtropical Jet

Answer 8

Conservation of angular momentum

Problem: jet would be way too fast, and becomes unstable. Waves start to form on the jet

Question 9

Polar / Mid-latitude Jet:

Answer 9

Strong temperature difference between tropics and high-latitudes => strong jet

Question 10

Poleward transport of energy

Answer 10

Without this transport of eneergy the poles would be much colder and the tropics much warmer

Poleward energy transport is accomplished by both the atmosphere and the oceans

The region of maximum energy transport liew between latitudes 30 degrees and 60 degrees

Question 11

Thermohaline Circulation

Answer 11

Water sinks in the North Atlantic and Antarctic, fills the deep ocean around the globe

Returns to surface in Indian, Pacific, and Southern Oceans, and returns to the Atlantic

Question 12

Thermo:

Answer 12

warm water loses heat as it moves N. in the Atlantic

Question 13

Haline

Answer 13

Evaporation causes water to become more salty as it moves North

Question 14

Thermohaline

Answer 14

Water is more dense as it moves toward the North Atlantic

Question 15

Key Features of the Tropical Pacific Mean State

Answer 15

1. Easterly winds
2. Thermocline close to surface in East
3. Cold(er) water in East - Cold Tongue
4. Warm(er) water in West - Warm Pool
5. Rainfall in West

Question 16

Thermocline

Answer 16

Large vertical temperature difference that seperates warm surface water from colder, denser sub-surface water

slopes upward toward the east

Question 17

Tropical Pacific normal conditions

Answer 17

Easterly trades cause thermocline to deepen in the west, shoal in the east

Question 18

Why is there a Cold Tongue?

Answer 18

Divergence: causes “upwelling” at the equator

Upwelling brings COLD water to surface in the eastern Pacific

Question 19

Tropical Pacific normal conditions

Answer 19

Eastelry trades cause thermocline to deepend in the west, shoal in the east

Winds also cause upwelling along the equator, bringing cooler subsurface water to the surface

Cooling from upwelling is most pronounced in the east, where the thermocline is close to the surface

Question 20

El niño

Answer 20

anomalous warming of the ocean surface in the central and eastern equatorial Pacific

Question 21

Southern Oscilation

Answer 21

Oscillation in mass (pressure) between the eastern Pacific, and the western Pacific and Indian oceans

Question 22

El Niño history

Answer 22

Señor Dr. Luiz carranza

Question 23

sourthern oscilation history

Answer 23

Sir Gilber Walker

Atmospheric component

Question 24

El Niño / Southern Oscilation

Answer 24

Jacob Bjerknes ENSO: connects el niño with the southern oscilation => it’s a coupled phenomenom

Question 25

“Proxy Data”

Answer 25

Indirect information that tells us about climatic conditions in the past

Question 26

Proxy data examples

Answer 26

Ocean Sediments - achieve past climatic info (shells, chemical composition of sediment, thickness of layers)

Ice cores - tell us about climate over last 500 ka

Tree rings (tell us about temperature and precipitation variations)Fossil corals and Speleothems: annual accumulation => temperature, precipitation

Question 27

Forcing

Answer 27

A process external to Earth’s climate that affects the climate

Volcanoes, orbital changes, changes in the sun’s strength, antropogenic processes

Question 28

Volcanic activity

Answer 28

aerosols from volcanoes reduce the amount of solar radiation reaching the surface

Question 29

Obliquity

Answer 29

the amount of “tilt” of Earth’s axis

Question 30

Eccentricity

Answer 30

How “eliptical” earth’s orbit is

More eliptical => more solar radiation at perihelion

Question 31

Some dominant forcing mechanisms

Answer 31

Aerosols

Changes in Earth’s orbit

Solar variations

Anthropogenic Greenhouse Gasses

Question 32

Anthropogenic Forcing

Answer 32

Emissions: rate at which a particular gas is being added to the atmosphere

Concentration: how much of that gas is actually in our atmosphere

Question 33

Change in Concentration =

Answer 33

Natural Emissions + Anthropogenic Emissions - Natural Sink

Question 34

Negative forcing

Answer 34

Causes cooling of the planet (aerosols)

Question 35

Feedback

Answer 35

A process that alters climate changes that are already underway

Positive feedback: amplifies change

Negative feedback:supresses change

Question 36

Snow and Ice Albedo Feedback

Answer 36

Warmer temperatures => snow melts quicker => more solar radiation absorbed => warmer temperatures

Question 37

Stefan-Boltzman Feedback

Answer 37

Warmer climate => more emitted radiation => climate doesn’t warm as much

Question 38

Water Vapor Feedback

Answer 38

Warmer temp and little change in RH => higher mixing ratio => enhanced greenhouse effect => warmer temperature

Question 39

Global temperature will rise by about

Answer 39

1-5 degrees Celsius (2 degrees Farenheight)