Chapter 8 Flashcards
oceans and climate
What is Heat Budget
expression of total solar energy received on Earth and total heat
lost from Earth during some period of time
What is heat capacity
the amount of heat needed to change a substance’s temperature by one degree
What is conduction
the amount of heat needed to change a substance’s temperature by one degree
what percent of solar energy is reflected back into space from the atmosphere, clouds, and surface of the Earth
30%
what percent of solar energy is absorbed by the water vapor, clouds, and dust in the atmosphere, where it is converted into heat
23%
what percent of solar radiation is absorbed by the land and ocean, and this energy heats up the Earth’s surface
47%
what processes control the energy absorbed by earth
conduction, radiation, and latent heat (phase change)
what percent does conduction control energy transfer
7%
what is radiation
the emission of energy in the form of electromagnetic waves
what is the greenhouse effect
in the context of climate, the ability of an atmosphere to absorb infrared radiation due to the presence of greenhouse gases
what is the process of the greenhouse effect
shortwave solar radiation passes through atmosphere and reaches the surface and is absorbed. When the radiation is re-emitted by the Earth, it is now in the form of long wavelength, infrared radiation, which does not easily pass through the atmosphere. this infrared radiation is absorbed by the atmosphere, particularly by the greenhouse gases. As a result, the atmosphere heats up
what are examples of greenhouse gasses
CO2, methane, and water vapor
what is the largest pathway for heat exchange between the land or oceans and the atmosphere
latent heat (phase changes)
what is latent heat/phase changes
heat released or absorbed when water moves between solid, liquid, and vapor forms
what does the angle of incoming solar radiation
influence
heating per unit area
and reflection
how does the curvature of the earth affect the dispersion of solar radiation
sunlight only falls perpendicular to the surface at the center of the sphere (equatorial regions). At any other point on Earth, the angle between the surface and the incoming solar radiation is less than 90 degrees. the same amount of incoming solar radiation will be concentrated in a smaller area at the equator, but spread over a much larger area at the poles. the tropics receive more intense sunlight and a greater amount of heating per unit of area than the polar regions.
what is albedo
the reflectivity of a surface of a planet (expressed as the percentage of light that reflects from the surface)
what kind of surfaces have a higher albedo
Lighter surfaces are more reflective than darker surfaces (which absorb more energy), and therefore have a higher albedo. For example, the ice and snow at the poles reflect more and absorb less radiation this is why the pole are cold and tropics are warm
Greenhouse gases in the atmosphere contribute to the greenhouse effect by trapping what kind of radiation in the atmosphere?
infrared
The most important process involved in heat exchange (outgoing) between the ocean and the atmosphere is:
latent heat/phase change
what is convection
a rotating region in a fluid in which upward motion of warmer, low density fluid in the center is balanced by downward motion of cooler, denser fluid at the periphery
what is primary production
the synthesis of organic compounds from aqueous carbon dioxide by plants, algae, and bacteria
what part f the earth receives the most light
more light reaches the tropics than the poles
what is earths heat engine
coupled atmosphere and ocean circulation
what is Thermal/radiative
equilibrium
the total
heat coming into a
system is balanced by
the total heat leaving
the system
what percentage of the heat from the tropics is transported to the poles before it is emitted
20%
describe differential heating
not all parts of the Earth receive the same amount of solar radiation throughout the year
describe seasonality
Seasonality refers to the variation in climate conditions on Earth that occurs as a result of its axial tilt and its orbit around the Sun
describe Earth’s Heat Budget: Land vs. Ocean
Earth’s heat budget varies between land and ocean surfaces due to differences in specific heat capacity. Oceans have higher heat capacity, act as buffers, moderating temperature variations and influencing global climate patterns. Land areas, have lower heat capacity, experience more pronounced temperature changes, contributing to the diversity of climates observed across different regions of the Earth.
how does the thermal mixed layer in the ocean affect earths heat budget
it influences the exchange of heat between the ocean surface and deeper layers, impacting sea surface temperatures, climate patterns, and ocean-atmosphere interactions. it is essential for predicting and interpreting changes in the Earth’s climate system
what is a convection cell
a rotating region in a fluid in which upward motion of warmer, low density fluid in the center is balanced by downward motion of cooler, denser fluid at the periphery
what is the coriolis effect
The apparent deflection
of a moving object from its initial course
when its speed and direction are
measured in reference to the surface of
the rotating Earth
What is the primary driver of atmospheric circulation?
Net solar heating imbalance
true or false: The Coriolis force is strongest near the equator and weakest at the poles.
false
in the Northern Hemisphere, the apparent Coriolis deflection will always be:
to the right
in the southern Hemisphere, the apparent Coriolis deflection will always be
to the left moving from low to high speeds
what is the intertropical convergence zone
The equatorial area where the northeast and southeast trade winds converge, known for weak winds; also called the doldrums
what is a polar front
Boundary between the Polar cell and the Ferrel cell in each hemisphere around 60° latitude
what is a hadley cell
The atmospheric convection cell nearest the equator in each hemisphere. Air in these cells rises near the equator because of strong solar heating there and falls because of cooling at about 30° latitude
what are polar easterlies
Prevailing surface winds within the Polar cells. between 60 and the poles
what are subtropical highs
Area of high pressure and weak winds around 30° latitude in both hemispheres; over land, dry air falling from high altitudes produces deserts at these latitudes; also called the horse latitudes.
what are ferrel cells
The middle atmospheric convection cell in each hemisphere. Air in these cells rises at 60° latitude and falls at 30° latitude.
what are trade winds
Prevailing surface winds within the Hadley cells, that approach from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere. between equator and 30 latitude
what are westerlies
Prevailing surface winds within the Ferrel cells, that approach from the southwest in the Northern Hemisphere and from the northwest in the Southern Hemisphere. between 30 and 60 latitude
what latitude (degrees) do ferrel cells lie on earth
sinking air at 30 and rising air at 60
what latitude (degrees) do polar cells lie on earth
between 60 and 90
what latitude (degrees) do hadley cells lie on earth
30 on each hemisphere
which ways do winds blow with respect to the three convection cells
surface winds in both hemispheres blow towards the equator between 90 and 60 latitude, and between 0 and 30 latitude. Between 30 and 60 latitude, the surface winds blow towards the poles
what are high pressure zones
in atmospheric terms, a region of descending air, increasing the atmospheric pressure. Winds blow away from high pressure zones
what are low pressure zones
in terms of the atmosphere, a region of rising air, lowering the atmospheric pressure. Winds blow towards low pressure regions, which are often characterized by precipitation from rising, cooling, condensing air
what are doldrums
areas of low pressure and weak winds along the equator
what are horse latitudes
areas of high pressure and weak winds around 30 degrees latitude in both hemispheres
what is a polar front
the boundary between the polar cell and the Ferrel cell around the 60 latitude in each hemisphere
Carbon dioxide in the atmosphere contributes to the greenhouse effect by trapping what kind of radiation in the atmosphere?
infared
Desert environments are usually located in
at about 30 degrees latitude
In the southern hemisphere, the trade winds blow from what direction?
south east
The zone of calm winds around the equator is known as the
doldrums
Rain is usually associated with _____ pressure systems.
low
The percentage of incoming solar radiation absorbed by the Earth’s oceans and landmasses is about:
50%
true or false: The Coriolis force is strongest at the poles and weakest near the equator.
true
The Coriolis effect results from:
the lower rotational velocities at higher latitudes
true or false: Polar regions radiate more heat than they directly receive.
true
true or false: Albedo is higher at the poles than at the equator.
true
how do you define the direction of wind
wind is defined by where they begin. for example winds that are from the east blowing west are EAST winds
why do we experience humidity during the summer and not during the winter
Warm air contains more water vapor than cold air. the air rising at the equator is warm and full of water vapor; as it rises into upper atmosphere it cools, and the cool air can NOT longer hold as much water vapor, so the water condenses and forms rain
what weather are low pressure systems associated with
low pressure systems are associated with precipitation, and we see wet habitats like tropical rainforests near the equator
what weather are high pressure systems associated with
high pressure systems are associated with dry weather and clear skies
what is a rain shadow
arid conditions behind a mountain range, as rising air on the other side of the mountain caused rain, leaving only dry air to descend back down the mountain. In areas such as death valley and Himalayas
how do land characteristics play a role in climate and precipitation
moist air moves over land and encounters mountains it rises, expands, and cools because of the declining pressure and temperature.
what happens on the windward side of a mountain
The cool air holds less water vapor, so condensation occurs and rain falls on the windward side of the mountains. windward is he side of the mountain it hits first
what happens on the leeward side of the mountain
the air passes over the mountains to the leeward side, it is now dry air, and as it sinks the pressure increases, it heats back up, any moisture re-vaporizes, and it creates dry, deserts regions behind the mountains
what is heat capacity
the amount of heat needed to change a substance’s temperature by one degree
what is a see a breeze
winds blowing from the ocean towards the land. land warmer than ocean, high pressure at land and low pressure at ocean
what is a land breeze
winds blowing from land towards the ocean. the ocean is warmer than the land. high pressure by ocean and low pressure at land
describe wind and continentality
The presence or absence of large water bodies affects temperature moderation, precipitation patterns, and seasonal variations
what is a monsoon
a seasonal change in wind direction. continent heats up so low pressure over land. water is cooler so high pressure by water. in result there is a wet season because wind blowing from Indian oceans
describe a summer monsoon
they bring heavy rain that destroy homes and are catastrophic
describe winter monsoon
dry weather can lead to drought and crop failures because of lack of moisture
how do hurricanes form
begin as low pressure systems formed over warm, tropical water. they need the heat from the warm water to fuel the storm. heat causes even more air to rise and condense, further fueling the storm. the air rises towards the center of the storm, more warm tropical air rushes in to replace it, causing very strong winds. the air rushing towards the center will be deflected by the Coriolis Effect, causing the entire storm to rotate. once its winds exceed 74 mph the storm officially becomes a hurricane
describe the characteristics of hurricanes in the northern hemisphere
deflection is to the right causing Northern Hemisphere hurricanes to rotate counterclockwise
describe the characteristics of hurricanes in the southern hemisphere
the winds are deflected to the left, leading to a clockwise rotation
As hurricanes make landfall, two factors may contribute to increasing the damage caused by the associated storm surge
The hurricane coincides with a high tide and The hurricane makes landfall where the coastline converges
what is a tropical disturbance
A tropical weather system with organized convection
(generally 100-300 miles in diameter) originating in the tropics or subtropics,
having a non-frontal migratory character and maintaining its identity for 24 hours
or longer. It may or may not be associated with a detectable perturbation of the
wind field
what is a storm surge
an area of high water that moves with storm systems. leads to the most death and destruction
what causes a storm surge
the result of two processes; a small hill is produced due to the extreme low pressure in the eye of a hurricane, which pulls water upwards towards the eye, creating a pressure surge. A larger surge is produced by the winds blowing and piling up water in the direction the storm is traveling
Hurricanes in the northern hemisphere:
have wind speeds of at least 75 mph
what is the Paleozoic
the geologic era lasting from 541 to 252 million years ago
what is the Mesozoic
he geological era from about 252 to 66 million years ago
what is the paleocene
a geological epoch that lasted from about 66 to 56 million years ago
what is the Eocene
a geological epoch lasting from 56 to 33.9 million years ago
what are climate forcing’s
a mechanism, such as a change in greenhouse gas levels, that forces the climate to change. For example the increase in the amount of carbon dioxide (CO2) in the atmosphere that results from our use of fossil fuels
what are climate feedbacks
process by which the physical effects of a climate forcing can have other effects (either negative or positive) on the climate
what is a positive feedback
a process that results in an increase in that process (in the context of climate change it is a process that enhances the change in climate, such as the reduced reflectivity of the Earth’s surface when ice melts) Such as melting of permafrost
what is a negative feedback
a process that results in a decrease in that process (in the context of climate change it is a process that reduces the change in climate, such as the enhanced growth of vegetation in response to an increase in atmospheric carbon dioxide)
give an example of a natural climate forcing
Continental collisions leading to the formation of very high mountain ranges.
Cyclical changes in the shape of the Earth’s orbit, from close to circular to slightly elliptical
Variations in the energy emitted by the Sun since its infancy.
what is eccentricity
in the context of Milankovitch Cycles, the degree to which the Sun is offset from the geometric center of the Earth’s orbit
what is obliquity
in the context of Milankovitch Cycles, the angle of the tilt of the Earth’s rotational axis with respect to the plane of its orbit around the Sun
what is precession
in the context of Milankovitch Cycles, the variation in the direction at which the Earth’s rotational axis is pointing
what are milankovitch cycles
millennial-scale variations in the orbital and rotational parameters of the Earth that have subtle effects on the Earth’s climate
what is insolation
a measure of the intensity of solar energy at a specific location or time (expressed in W/square m)
what is the permian
a geologic period which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic period 251.902 Mya
what is the Cryogenian
The most intense glacial period on Earth around 720 to 635 million years ago, when the planet got really cold. There were big ice ages, and some scientists think the Earth might have been covered in ice. This extreme cold time is called “Snowball Earth.”
what is snowball earth
hypothesis suggesting the
Earth’s oceans and land surfaces were completely
covered by ice, from the poles to the Equator
what is the Cambrian explosion
there was a sudden and rapid increase in the diversity of life. During this relatively short time, a wide variety of complex multicellular organisms, including the ancestors of many modern animal groups, appeared in the fossil record. It was a key event in the evolution of life, marking the emergence of numerous animal body plans and ecological niches.
what are Eustatic (global) factors that cause sea level changes
Amount of water in the world ocean,
Volume of the ocean, and Temperature
what are local factors that cause sea level change
Tectonic motions and
isotactic adjustment, Winds and currents
what are Warm Cenozoic period; important tectonic
events:
India-Asia collision, Formation of the ACC (Drake passage,
Tasman gateway), Connection North and South America
