Circulation of the Upper Atmosphere and Oceanic Circulation

Question 1

High Pressure often causes a Temperature Inversion. How?

Answer 1

The TI is a “cap” (layer) of warm air atop cooler air that keeps air from rising, cooling, and precipitating. Sinking air from STH is warming, while air near surface is sometimes cooler especially at night or over water

Question 2

What does surface temperature inversion mean?

Answer 2

Extreme stability

Question 3

What does lack of condensation/ rainfall create?

Answer 3

Desert climate

Question 4

What is upper troposphere air flow primarily ?

Answer 4

Westerly air flow from subtropics to polar front. Two jet streams

Question 5

How many jet streams are per Hemisphere?

Answer 5

2 Jet streams per hemisphere

Question 6

What is the Polar Jet and what does it affect?

Answer 6

is a narrow ribbon of high speed winds in upper ATM 100–300 miles wide and up to a mile thick. The Polar Jet affects mid-latitude weather.

Question 7

What is the Subtropical Jet

Answer 7

The Subtropical Jet is not as strong because there is less temperature and pressure contrast

Question 8

What does the Polar Jet stream separate?

Answer 8

Polar Jet Stream separates cold and warm air masses

Question 9

What can jet stream wind speeds exceed?

Answer 9

300 mph!

Question 10

Where does the polar jet stream occur?

Answer 10

The Polar Jet Stream occurs where pressure and temp gradient is greatest

Question 11

How does the polar jet stream cycle?

Answer 11

The Polar jet cycles from nearly ZONAL flow (parallel to latitude) to an UNDULATING pattern and back again over several weeks

Question 12

When is the polar jet stream fastest?

Answer 12

In the winter

Question 13

What do undulating waves do?

Answer 13

Undulating waves develop in the Polar Front that bring cold air equatorward and warm air poleward.

Question 14

How many undulating waves may be present on the earth at one time?

Answer 14

There may be 3-6 present on earth at one time.

Question 15

What does strong wind development produce?

Answer 15

Strong wave development produces Low and High pressure cells that move across the mid-latitudes: Mid-latitude cyclones

Question 16

What do low pressure troughs do?

Answer 16

Low pressure “troughs” steer “tongues” of cold air into mid-lats

Question 17

Why are oceans important?

Answer 17

Oceans are reserves of energy that help power global weather

Question 18

How to oceans transfer energy?

Answer 18

Oceans transfer energy from overheated tropics to underheated poles

Question 19

What are ocean currents like?

Answer 19

Ocean currents are more-or-less continuous or permanent directed movement of ocean water

Question 20

What factor/force mainly drives ocean surface currents?

Answer 20

Wind. Surface currents reflect average wind conditons

Question 21

How does surface ocean currents flow?

Answer 21

Surface ocean currents (upper 400 m) flow in loops or gyres that follow STH circulation,

Question 22

What do continents do to ocean currents?

Answer 22

Block free flow

Question 23

What does Deep Ocean Circulation do? What is it important to?

Answer 23

Deep Ocean Circulation (Thermohaline) acts as a “giant conveyor belt” that transports heat toward poles. Important to regional climate.

Question 24

What drives deep ocean circulation?

Answer 24

Gravity

Question 25

What are the Younger Dryas and what may have caused them?

Answer 25

The Younger Dryas, a return to glacial conditions occurred about ~12,000 yr BP) long after warming (interglacial conditions) had begun (~18,000 yr BP). Likely related to decreased or halting of thermohaline circ and negative feedback

Question 26

Could warming cause cooling again, like in the little ice age?

Answer 26

Some models predict 5-9°F cooling in N. Atlantic region if conveyor shuts down

Question 27

Where are the strongest surface currents?

Answer 27

The strongest surface currents are on west sides of oceans, where water piles up, e.g., Gulf Stream

Question 28

What happens on E. sides of ocean where surface water is leaving the coast?

Answer 28

Cold water upwelling

Question 29

How does cold water upwelling work?

Answer 29

Surface water moves AWAY from west coasts, UPWELLING of COLD water into that space

Question 30

How does cold water upwelling affect climate and vegetation?

Answer 30

Cold water surface chills air above it, causing condensation, fog (more about condensation next week) sometimes the fog moves over land but no rainfall. COLD air cannot rise! Deserts form.

Question 31

What are some major areas of cold upwelling and dry condition?

Answer 31

Coastal Chile/ Peru, and Namibia

Question 32

What does very strong cold water upwelling cause?

Answer 32

Coastal deserts

Question 33

What are some other effects of cold upwelling?

Answer 33

Upwelling of cold water increases nutrient availability near the surface, supports plankton (bottom of food chain)

Question 34

What are some biological effects of cold water upwelling?

Answer 34

If there is high nutrient availability in the ocean then there will be large fish populations, and lots of fish eating birds. Lots of fish eating birds produce lots of bird shit.

Question 35

What is "El Nino"?

Answer 35

Unusually warm surface water in the equatorial Pacific that lasts 1-2 years

Question 36

When does El Nino occur?

Answer 36

It occurs every 2-7 years (about 30 times per century)

Question 37

Why is it called El Nino?

Answer 37

It is simplified Nino for "Southern Oscillation - ENSO

Question 38

What is walker circulation?

Answer 38

Walker circulation (normal condition): Normally, water piles up in western Pacific due to easterly currents; sea level is about 40 cm higher in Australia/Indonesia

Question 39

What are El Nino Conditions?

Answer 39

El Niño Conditions: Pressure gradient between E. & W. Pacific weakens and Easterly Trade winds relax or reverse! Cold upwelling ceases and piled up warm water in W. Pacific sloshes back to east causing increased rainfall in an otherwise dry region.

Question 40

What are the climatic effects in the normally arid tropical eastern pacific region (south america)?

Answer 40

* Heavy rain * Flooding * Mudslides along coasts that are usually very DRY with sparse vegetation * Major fish die off because the water is too warm

Question 41

What are the climatic effects in the normally wet western pacific region (SE Asia, Indonesia, Australia)

Answer 41

* Drought | * Fires

Question 42

What are El Nino Effects around the globe?

Answer 42

“TELECONNECTIONS” | Unusual weather patterns around the globe

Question 43

How do climatic effects of ENSO (el nino) vary?

Answer 43

Climatic effects of ENSO around the globe vary by place, season, episode intensity AND coincidence of other major climatic oscillations such as North Atlantic Oscillation (NAO) and Pacific Decadal Oscillation (PDO)

Question 44

What are some effects of ENSO on the U.S.?

Answer 44

* Check out California—dry place gone wet * Southeast and midwest—much wetter than normal * Northwest—dry * Weak-Moderate episodes: more widespread drought * beach erosion * landslides/ mudslides * some diseases increase during ENSO events (not just in U.S.)