Chapter 1 Reading Flashcards
climate=
the synthesis of the weather in a particular region
How can climate be defined quantitatively?
by using the expected values of the meteorological elements at a location during a certain month or season
What are climatic elements?
the expected values of meterological elements
- include variables like avg temp, precipitation, wind, pressure, cloudiness, and humidity
the distribution of vegetation and soil type over land areas is determined primarily by __ ___
local climate
T/F
we are as sensitive now as we have ever been to climate fluctuations and climate change
true
Why might climate fluctuations cause serious difficulties for humanity in our modern society?
food, water, and energy supply systems are strained to meet demand, and they’re optimized to current climate conditions.
Population is large enough to absorb max agricultural productivity of earth, so starvation is a huge risk during climate fluctuations
The climate of a region depends on __itude, ___itude, and orientation in relation to ___ bodies, ____, and prevailing ___ directions
latitude
altitude
water bodies
mountains
prevailing wind directions
Which 2 weather elements are of greatest interest when defining earth’s climate? Why?
temperature and precipitation
- these two factors together largely determine the species of plants/ animals that survive in a particular location
The climate system of earth determines the distribution of ____ and ___ near the surface and consists primarily of: the ______, _____, and _____
energy
water
(ie temp and precipitation)
atmosphere
oceans
surface (land)
What is the average temp at the surface of Earth (2016)?
288K
15C
What is the global mean lapse rate of the troposphere?
6.5K/km
ie the temp decreases 5 Kelvin for every 1km you go up
In the stratosphere, temperature increases with height (up to ~50km). Why?
Because of the absorption of solar radiation by ozone
Above the stratosphere, temp ___ with height in the ____
decreases
mesosphere
What is the temp range and height of the troposphere
15-20km thick
range: ~300K at surface to 190K at top
What is the height and temp range of stratosphere?
~30km
190K at bottom, 270K at top
What is the height and temp range of the mesosphere?
~85km
270K at bottom, 180K at top
Why does the temp of the atmosphere rapidly increase above about 100km?
Because of heating produced by absorption of ultraviolet radiation form the sun, which dissociates oxygen and nitrogen molecules and ionizes atmospheric gases in the thermosphere
Maintaining the Earth’s surface temp is very dependent on the decrease of temp with altitude in the ____
troposphere
The further north you are, the ____ the height of the troposphere
lower
eg. troposphere is ~18km at equator and ~9km at 80N
T/F
The VERTICAL DISTRIBUTION of temperature varies with latitude and season
true
At polar latitudes the tropospheric lapse rate is ____ than at the equator
less
Temperature inversion=
give example
a region of inverse lapse rate
- eg. at high latitudes, the temp actually increases with altitude in the troposphere in the winter and spring
Why does a temperature inversion happen in polar regions?
because the surface cools very efficiently through emission of infrared radiation in the absence of insolation during winter darkness. The air doesn’t emit radiation as efficiently as the surface, and heat transported poleward in the atmosphere keeps the air in the lower troposphere warmer than the surface
The ___ _____ is the coldest part of the lowest 20km of the atmosphere in annual mean temp
tropical tropopause
seasonal variation of troposphere temps is much lower in the southern hemisphere. Why?
there is a larger fraction of ocean-covered surface there (water stores heat very effectively)
Rank the mass of the atmosphere, solid earth, and oceans
smallest: atmosphere (5.14x10^18 kg)
med: oceans (1.39x10^21kg)
largest: solid earth (5.98x10^24kg)
-
-
nitrogen (78%)
oxygen (21%)
argon (1%)
T/F
The atmospheric gases that are important for absorption/
emission of radiant energy make up less than 1% of the atmosphere’s mass.
true!
In order of importance for surface temperature, list the 5 main greenhouse gases
- water vapor
- carbon dioxide
- ozone
- methane
- nitrous oxide
the atmosphere is composed of gases held close to the surface of the planet by ___
gravity
The vertical forces acting on the atmosphere are ___, which pulls the air molecules toward the center of the planet, and the ____ ____ ____, which tries to push the atmosphere out into space
gravity
pressure gradient force
what is the hydrostatic balance?
the balance of the force of gravity and the pressure gradient force
What is atmospheric humidity and how can is be measured?
= the amount of water vapor carried in the air
can be measured as vapor pressure, mixing ratio, or specific humidity
specific humidity=
the ratio of vapor mass to total air mass
mixing ratio=
the ratio of the mass of vapor to the mass of dry air
the partial pressure of water vapor in the atmosphere ____ very rapidly with altitude
decreases
the amount of water vapor in the atmosphere at the equator is ~__x ____(< or >) than at the poles
10x greater
The rapid upward and poleward decline in water vapor abundance
in the atmosphere is associated with the strong ____dependence
of the saturation vapor pressure
temperature
The temperature dependence of saturation pressure of water vapor over a water surface
is governed by the ______-________ _____
Clausius–Clapeyron relationship
First law of thermodynamics=
energy is conserved, so that for a unit mass of gas, the applied heat is equal to the sum of the change in internal energy and the work done
Adiabatic process=
Adiabatic refers to a process in which no heat is transferred into or out of a system, and the change in internal energy is only done by work
When moisture is present in air and an air parcel is raised adiabatically, the parcel can become _____such that the water vapor
condenses and latent heat is _____.
supersaturated
released
The saturated adiabatic lapse rate is generally ____(more/ less) than the dry adiabatic lapse rate, and becomes _____ (</>)as the temperature rises.
less
smaller
When moisture is present in air and an air parcel is raised adiabatically, the parcel can become ___ such that the water vapor condenses and latent heat is released
supersaturated
As a saturated parcel rises, water ___, latent heat is released, and the parcel ___ more slowly with increasing ____ than an unsaturated (dry) parcel
condenses
cools
altitude
What is Equivalent Potential Temperature?
the temp that would be obtained by a moist air parcel is it were first raised moist-adiabatically until all of its water compressed out, and then brought back adiabatically to a reference surface pressure
T/F
If the equivalent potential temp increases with height, then the parcel is absolutely stable
true
If the equivalent potential temp decreases with height, then the air parcel is absolutely unstable
false!
only conditionally unstable
It’s unstable only if it becomes saturated
List the following in order from higher fraction of the total water in the climate system to the least
Lake/ streams
atmosphere
oceans
icecaps/glaciers
groundwater
soil moisture
- oceans 97%
- icecaps and glaciers 2.2%
- groundwater
- lakes and streams
- soil moisture
- atmosphere has the least! (0.0009%)
ocean currents move heat ___ward to cool the ___and heat the extratropics
pole
tropics
The world ocean is the reservoir of water that supplies atmospheric water vapor for rain and snow over land. What is the world ocean?
Since all of the oceans are connected to some degree, we can think of them collectively as one: the world ocean
T/F
the ocean plays a key role in determining the composition of the atmosphere through the exchange of gases and particles across the air-sea interface
true
The ocean ___ CO2 from the atmosphere and produces molecular ______
removes
molecular oxygen
thermocline=
a region of rapid temp change with depth in the first km or so of the ocean. Below the thermocline is a deep layer of almost uniform temp
T/F
A thin, mixed surface layer of the ocean is stirred by winds, so the temperature and salinity are almost independent of depth
true
Variations in the ____ of seawater drive the deep-ocean circulation.
This is critical for __ storage and recirculation of important _____
density
heat
nutrients
In the deep ocean, salinity
variations are much smaller than near the surface. Why?
because the sources and sinks of freshwater are at the surface and the deep water comes from a few areas in high latitudes
In subtropical latitudes (10-30 deg), the surface salinity is large. Why?
Because evaporation exceeds precip. and leaves the saltwater enriched in salt
Why are surface ocean salinities quite low in mid-high latitudes?
precipitation of freshwater exceeds evaporation
T/F
near the equator, a thin layer of very saline water sits atop less salty water below
false
the opposite is true
a thin layer of fresh water from precip. sits atop more saline water below
T/F
The Atlantic is much less salty than the Pacific, so the deep ocean is much colder in the Pacific
false
Atlantic saltier than Pacific
so cold, salty water that can sink to the bottom is much more common in the Atlantic
T/F + explain why
For climate, it is not often the mass of ice that is of primary importance, but the surface area that is covered by ice (of any depth)
true!
b/c surface ice (of any depth) is a more effective reflector of solar radiation than the underlying surface.
Also, sea ice is a good insulator and allows air temperature to be very different from that of the seawater under just a few meters of sea ice
Presently, about ___% of earth’s land area is in the Northern hemisphere
68%
much more land here than in S hemi!
