Flashcards in Chp 13 Atmosphere Deck (54)
What is the most polluting fossil fuel?
What do SO2 emissions lead to?
What can happen to fish in acidified lakes?
Die of starvation due to the loss of their food sources
What gases are the atmosphere made up of?
78% nitrogen (n2)
21% oxygen (o2
1% other (including argon)
How many layers of the atmosphere are there and how do they differ?
four different layers. differ in temperature, density and composition.
the thin layer of gases that surrounds earth
What is a PERMANENT gas?
A permanent gas in the atmosphere remains at STABLE conditions
What were the dominant gases in Earths early atmosphere?
Carbon dioxide(CO2), Nitrogen (N2), carbone monoxide(CO), and hydrogen (H2)
What started the change in our early atmosphere to the our atmosphere today? (2.7 bill yrs ago)
The emergence of Autotrophic microbes that emit oxygen as a by product of photosynthesis.
What is the TROPOSPHERE?
The troposphere is the most BOTTOM layer of the atmosphere (0-10km)
In the troposphere, temperature declines the higher you go
What is the STRATOSPHERE?
Second layer of atmosphere. 11-50 km above sea level.
More dry and less dense than the troposphere. Contains UV radiation, blocking ozone.
Highest layer of earths atmosphere, 80-500km
In the mesophere temperatures ________ with altitude
What is atmospheric pressure?
Force per unit of area produced by a column of air.
Atmospheric pressure ______ with altitude(in troposphere)
Why do mountain climbers have a hard time breathing the higher they climb?
Air pressure decreases the higher you go up. At the halfway point of mount everest for example, 50% of air molecules are below you. At mount everests peak, you are above two-thirds of air molecules in the atmosphere.
The gases in the stratosphere experience little VERTICAL MIXING, that is...
when substances(such as pollutants) enter the stratosphere, they tend to remain there for a long time.
Why is the ozone layer important? Where does it lie in the atmosphere?
Ozone greatly reduces the amount of UV radiation(which can damage living tissue and create DNA mutations). 17-30 km above sea level.
What is the RELATIVE HUMIDITY of air?
the ratio of water vapour in a volume of air, to the maximum amount it could potentially contain at a given temperature.
Why does humidity make it feel hotter than it is?
We sweat to cool our bodies down. When humidity is high, the air is holding nearly as much water as it can. So, that means our sweat evaporates slowly and the body cannot cool itself efficiently.
What is air mass?
a large volume of air that is fairly uniform internally, in temperature, relative humidity and air pressure
Why is it hottest at the equator?
Sunlight hits the equator directly(perpendicular angle), so the air absorbs less solar energy due to the shorter path through the atmosphere
What causes the change in seasons?
Because the earth is tilted, during a half of the year, as it travels through its orbit around the sun, the earths northern hemisphere faces towards the sun , while the southern hemisphere faces away from the sun (this is true conversely for the other half of the year). The hemisphere that faces towards the sun experiences direct sunlight, while the half away from the sun experiences indirect sunlight (less concentrated). Equatorial region is barely effected by this.
the boundary between air masses that differ in moisture content and temperature, (where we typically experience the most active weather)
How do cold fronts cause thunderstorms and tornadoes?
A cold front displaces warmer air masses. The warm air rises, expands, and cools to form clouds that produce these thunderstorms.
The rising of less dense, warmer air, creates vertical currents.
What is the urban heat island effect?
Cities often have temperatures that are hotter than surrounding suburbs and rural areas. Results from the concentration of heat generating buildings, cars, factories and people.
the normal direction of temperature change is inverted. can cause air pollution to be trapped and move towards the ground, instead of diluting upwards