Geology Review Exam 1

latent heat occurs in which 2 steps?

(1) initial evaporation of water and storage of heat in water vapor and (2) later release of stored heat during condensation and precipitation, usually far from the site of initial evaporation.

What is the fundamental cause for the circulation of the atmosphere and oceans? (cf. Fig. 2-14 A and B).

(A). The resulting radiation surplus in the tropics and deficit at the poles (B) creates temperature imbalances (C) that drive the circulation of the atmosphere and oceans.

Celsius

-273 0 100 5500

Fahrenheit

-460 32 212 9981

Kelvin

0 273 373 5773

approximate latitudes for ITCZ?

0-10

approx. latitudes for easterlies?

0-30

Response Times for Mt. Glaciers?

10-100 years

Response Times for Ice Sheets?

100- 10000 years

Response Times for Deep Ocean?

100-1500 years

Typical surface albedo value for tundra?

15-35

Typical surface albedo value for grassland?

18-25

On a long-term basis, what is the percentage of solar radiation arriving is absorbed by the atmosphere ?

23% about 20%

On a long-term basis, what is the percentage of solar radiation arriving at the top of Earth's atmosphere reflected and scattered back to space?

30%

Typical surface albedo value for desert sand?

30-50

approx. latitudes for westerlies?

35-65

Typical surface albedo value for old, melting snow?

40-70%

Typical surface albedo value for clouds?

40-90

On a long-term basis, what is the percentage of solar radiation arriving is absorbed by Earth's surface?

47% about 50%

Typical surface albedo value for water?

5-10

Typical surface albedo value for forest?

5-20

Typical surface albedo value for soil?

5-30

How many monsoons worldwide? what is the biggest?

5: Asian

Typical surface albedo value for fresh snow or ice?

60-90%

What is Earth's average surface temperature at the present?

60F

What is NAO?

A fluctuation in atmospheric pressure between Iceland low and Azores high; Changes in mean wind speed and direction;Changes in number, intensity, paths of storms Changes in moisture transport; greatly affects northern hem

What is the Southern Oscillation?

A sea-saw pattern of reversing surface air pressure at opposite ends of the tropical Pacific Ocean

Why does incoming solar radiation vary with latitude?

A smaller fraction of the incoming radiation is absorbed at higher latitudes than in the tropics mainly because (1) solar radiation arrives at a less direct angle and (2) snow and ice surfaces at high latitudes reflect more radiation

What causes the monsoon circulation to reverse from summer to winter?

Air motion associated with monsoon circulations at larger scales is upward over the land and downward over the ocean in summer, but the exact reverse in winter. Precipitation is heaviest in regions of low pressure (Pr) and upward motion.

Why is the Earth's surface albedo averaged near 10%?

Because 70% of Earth's surface is low-albedo water, Earth's surface has an average albedo near 10%.

What is longwave radiation?

Carries less radiation; losing an equal amount of heat (238 W/m2) back to space. This heat loss, called back radiation, occurs at wavelengths lying in the infrared part of the electromagnetic spectrum (see Figure 2-1). Because it occurs at longer wavelengths (5-20 µm) than the incoming shortwave solar radiation

What factors drive changes in Earth's climate?

Climate Forcing (natural and anthropogenic)

What force can change wind direction but not wind speed?

Coriolis Force

What causes upwelling?

Deflection of water away from the continent; upwelling of deeper water to replace surface water

What is the lee or rain shadow?

Dry/desert like arid (leeward side)

How does the atmosphere pressure change with altitude?

Each layer of air in Earth's atmosphere presses down on the underlying layers, increasing the pressure on the lower layers and at the surface. Most of the mass of Earth's atmosphere lies at lower elevations

What kind of radiation is trapped by greenhouse gases? What is the effect on Earth's climate?

Earth's atmosphere contains greenhouse gases that absorb 95% of the longwave back radiation emitted from the surface, thus making it impossible for most heat to escape into space. The trapped radiation is retained within the climate system and reradiated down to Earth's surface. This extra heat retained by the greenhouse effect makes Earth's surface temperature 318C warmer than it would otherwise be.

Thought question: When you take a cruise from Fort Lauderdale to Grand Turk, which side of the ship do you experience more windy conditions?

East; left side

What is PDO?

El nino for 20-30yrs or la nina for 20-30 yrs.

What are the components of Earth's climate system?

Hydrosphere,Biosphere,Cryosphere,Lithosphere,Atmosphere

Which wave when absorbed causes rise in temp. ?

Infrared

Ex. of + feedback?

Lower albedo, more energy, warmer temp. ice and snow melt

Ex. of - feedback?

Lower albedo, more energy, warmer temp., clouds, higher albedo, less energy, lower temp

What is sensible heat?

Moving air Sensible heat is the product of the temperature of the air and its specific heat. It is also the heat that a person directly senses as it is carried along in moving air masses. Surfaces heated by the Sun warm the lowermost layer of the overlying atmosphere. The heated air expands in volume like any heated gas, becomes lighter (less dense), rises higher in the atmosphere, and carries sensible heat along with it in a large-scale process known as convection.

What are the two main gases in Earth's atmosphere? Are they greenhouse gases?

Nitrogen (78) and Oxygen (21); neither is a greenhouse gas because neither traps outgoing radiation

Thought question: can hurricanes form along the equator?

No, b/c they need to be in Low-pressure areas (easterly waves) Warm, moisture, unstable area Ocean surf. temp. > 26-27°C Low wind shear Sufficient Coriolis force (5-10 degrees away from the equator) Strong upper-level anticyclone.

Do positive feedbacks always make the climate warmer? How could they make it colder?

No... they make it colder through If you start with a colder temp... more ice and snow... higher albedo... lower temp.

Thought question: Which side of the Hawai'ian Islands receives most rainfall? Why?

North and east; Easterlies

Which gas is a greenhouse gas and a pollutant and a gas that blocks ultraviolet radiation and a gas that is mostly located in the stratosphere?

Ozone (O3)

What force can change both wind direction and wind speed?

PGF

Which forces that are acting on the winds aloft?

Pressure gradient force and Coriolis Effect

How many forces are acting on the winds?

Pressure gradient force, Coriolis Effect, Frictional force

What is the Ekman Spiral?

Refers to the average movement; flow.. net transport

What is the frictional force?

Resistance; Contrary force, slow wind down Changes wind speed

How are clouds formed?

Rising air expands, cools and condenses

What is La Nina?

Sea surface temperature in the central and eastern tropical Pacific Ocean colder than normal; drought

How does solar radiation arriving on Earth differ from the radiation emitted by Earth?

Solar radiation arriving at the top of Earth's atmosphere averages 340 W/m2, indicated here as 100% (upper left). About 30% of the incoming radiation is reflected and scattered back to space, nd the other 238 W/m2 (70%) enters the climate system.

What is insolation?

Stronger radiation in the tropics (low latitudes) than in the polar regions (high latitudes); the amount of solar radiation arriving at the top of Earth's atmosphere by latitude and by season.

What determines the amount of radiation emitted?

T4

Why is the planetary albedo (i.e. the Earth's reflectance from the surface and the atmosphere as a whole) approximately 30%?

The 340 W/m2 of solar energy arrives at the top of the atmosphere, mainly in the form of visible radiation. About 70% of this shortwave radiation passes through Earth's atmosphere and enters the climate system (Figure 2-3). The other 30% is sent directly back out into space after reflection (or scattering) by clouds, dust, and the more reflective regions at Earth's surface. As a result, the average amount of solar energy retained by Earth is 238 W/m2 (0.7 3 340 W/m2). Of the 70% of solar radiation that is retained within the climate system, about two-thirds is absorbed at Earth's surface and about one-third by clouds and water vapor in the atmosphere (see Figure 2-3). This absorbed radiation heats Earth and its lower atmosphere and provides energy that drives the climate system.

The greenhouse effect makes Earth's surface how much warmer than it would otherwise be?

The Earth would be 31C warmer

What is the Walker Circulation? How do they affect climate (flood/drought) worldwide and in Texas?

The Walker circulation, also known as the Walker cell, is a conceptual model of the air flow in the tropics in the lower atmosphere (troposphere). According to this model, parcels of air follow a closed circulation in the zonal and vertical directions. This circulation, which is roughly consistent with observations, is caused by differences in heat distribution between ocean and land. It was discovered by Gilbert Walker.

45. What is the thermohaline circulation?

The density-driven circulation (thermo/heat and haline/salt) Other names: the global ocean conveyor belt, or meridional overturning circulation (MOC).

How does precipitation vary with latitude?

The higher rainfall along equator and highest in the tropics and low in sub tropical and polar

What is albedo?

The percentage of incoming radiation that is reflected rather than absorbed by a particular surface

13. What are the four layers of Earth's atmosphere? Based on what are these four layers defined?

Troposphere, Stratosphere, mesosphere, thermosphere Altitude

Which wave is not visible to the human eye?

Ultraviolet

What is El Nino?

Warming of sea surface temperature in the central and eastern tropical Pacific Ocean; ever 2/7 yrs.; flooding

What are trace gases? Give examples of greenhouse gases. Why does CO2 get most of the attention when there are so many other greenhouse gases?

Water vapor (H2Ov) averages less than 1% of a dry atmosphere, but it can range to above 3% in the moist tropics. Carbon dioxide (CO2) and methane (CH4) occur in much smaller concentrations of 0.04% and 0.00018%, but they are also important greenhouse gases. continuous C02 increased by human induced activities/forcing - Keeling Curve- 1960s - C02 todays ppm is 400

What are the steps to make precipitation?

Water vapor in air, then air rises/expands/cools, condenses around nuclei to form droplets, suspended by atm upwards, collide and coalesce to form clouds and droplets diffuse into ice crystals to form cool clouds; crystals/drops fall as rain/snow when they are to heavy to be suspended

How does climate differ from weather?

Weather given time and place (get) Climate over long period of time (expect)

How is the surface circulation of the oceans formed? What is its role in climate?

Wind driven and distribute energy ; reduces pole to equator temp. differences

What is orographic precipitation?

Winds blowing moist air toward a mountain will experience orographic uplift to an elevation where dew point is reached and clouds are formed.

What are some important characteristics of water vapor that are important to the climate system?

\the most important greenhouse gas, central to the hydrologic cycle, carries latent heat, its holding capacity in air strongly depends on temperature; accounts for 60% of the atmospheric greenhouse effect; Much of the heat capacity of air is linked to the water vapor it contains.

Why is the Earth's climate system driven by heat energy from the Sun?

absorption or reflection of radiation; albedo; affects currents

Stratosphere?

also important to Earth's climate because it contains small amounts of oxygen (O2) and ozone (O3), which block ultraviolet radiation arriving from the Sun. This shielding effect accounts for a small fraction of the 30% reduction in incoming heat energy from the Sun. It also greatly reduces ultraviolet radiation

Natural Forcing?

change in suns strength, change in Earth's orbit, change in plate tectonics, volcanic activity, mt. building, ocean heat change

How do the many parts of Earth's climate system react to these driving forces and interact?

changes in ice, atm., vegetation, ocean, land surface

What are monsoons?

characterized by seasonal reversal in surface winds: rainy in summer ocean to land... H to L pressure and reverse in winter

What different and opposing roles do clouds play in the climate system?

clouds albedo can cause lower temp. because they tend to have a higher reflexivity

Why does deep water form today at higher latitudes?

cold water dense and colder at the poles

Low pressure is always ___ and high pressure is always ___?

convergence; divergence

Response Times for Ocean Surface?

days to months

How does seawater density depend on temperature and salinity? What factors affect salinity?

evaporation higher salinity melting glaciers lower salinity

What are jet streams? What are their roles in transporting energy and moisture?

fast flowing, narrow air currents found in the upper atmosphere or in troposphere; Bring warm currents to polar and cold currents to tropics

Thought question: How do the Atlantic and Pacific Oceans and global warming affect Texas drought for next two decades?

global warming has a minor impact; mainly anthropogenic;

What is convection?

heat energy moving as a fluid from hotter to cooler areas; occurs when hotter water rises and cold water sinks, which helps distribute heat energy. Warm air at the ground surface rises as a thermal bubble expands, consumes energy, and hence cools.

Conduction?

heat energy occurs as warmer molecules transmit vibration, and hence heat, to adjacent cooler molecules. Warm ground surfaces heat overlying air by conduction.

Response Times for Vegetation?

hours to decades/centuries

Response Times for Land Surface?

hours to months

Response Times for ATM?

hours to weeks

What is shortwave radiation?

incoming radiation energy from the Sun consists of visible light at wavelengths between 0.4 and 0.7 µm (1 µm, or micrometer 5 1 millionth of a meter), sometimes referred to as shortwave radiation.

13. Thought question: Why isn't outgoing longwave radiation the greatest at the equator?

lots of clouds, clouds are colder, cold temp. radiation is low

Troposphere?

most of Earth's weather/climate happens. Storm systems that produce clouds and rainfall or snowfall are almost entirely confined to this layer. Dust or soot particles that are lifted by strong winds about 80% of the gases that form Earth's atmosphere are contained within this layer

What is a subtropical ocean gyre?

north branch westerlies southern branch trade winds east/west confined by land barrier; ocean elevation associated with this gyre ocean mt.

Anthropogenic Forcing?

pollution, humans affecting surface albedos

What are the major forms of heat transfer in the climate system?

sensible heat, latent heat, conduction, convection

What determines season?

the Earth's tilt

What is latent heat?

the heat carried by the air is temporarily hidden in latent form as water vapor. Ex. Evaporation only feel during condensation

Response Times for Sea Ice?

weeks to years