GEOL 106 Lecture Notes - Lecture 30: Water Cycle, Cumulonimbus Cloud, Puffy Amiyumi
26 May 2018
School
Course
Professor
[Type here]
9.3 The Atmosphere
- atmosphere = thin gaseous envelop that surrounds Earth
o causes weather and is responsible for trapping heat that makes earth warm enough to be
habitable
COMPOSITION OF THE ATMOSPHERE
- mainly composed of nitrogen and oxygen; smaller amounts of argon, water vapour, CO2, other trace
elements
- humidity: amount of water vapour, function of T; warm air has capacity to hold more water vapour
than does cold air
o relative humidity: amount of moisture in air; ratio of water vapour present in atmosphere to
maximum amount of water vapour that could be there for given temperature
▪ presented as percentage and varies from few percent to 100 percent
- natural changes in relative humidity occur each day without significant changes in amount of water
vapour in atmosphere
- relative humidity:
o increases at night because of cooler temperature
o decreases with daytime heating
o changes in actual water vapour content of atmosphere take place where water evaporates
fro Earth’s surfae or here air asses i, either ertically or horizontally
- all water vapour in air is derived from evaporation of water from surface
o constantly being exchange between atmosphere and various parts of earth
o sleet, snow, hail, rain from atmosphere → deposit into groundwater, rives, lakes, oceans,
glaciers → evaporates and return to atmosphere to being cycle again
o hydrologic cycle
STRUCTURE OF THE ATMOSPHERE
- most gas moelcuels are concentrated below height of 100 km
- 4 major layers or spheres
1. lowest layer = troposphere: 8 – 16 km above surface of earth
a. spend our entire lives within troposphere except some jet airplane travel
b. highest mountain does not even reach upper boundary of troposphere (tropopause)
c. rapid upward decrease in temperature that results from decreasing air pressure
with increasing altitude
d. visible characteristic: troposphere is abundant condensed water vapour in form of
clouds
i. directly affect us as weather
- clouds develop when very small water droplets or ice crystals condense from atmosphere
1. cumulus clouds: puffy, fair weather, pieces of floating cotton
2. cumulonimbus: thunderstorm clouds
a. formation is associated with tremendous release of latent heat energy due to
condensation of water vapour
- most of atmospheric water vapour condenses in troposphere, leaving little water in upper layers of
atmosphere
- troposphere contains most of atmospheric CO2 and methane in addition to water vapour
o CO2 and methane: important in global warming
find more resources at oneclass.com
find more resources at oneclass.com
[Type here]
- only ozone (gas composed of O3) is significantly less abundant in troposphere when compared with
upper atmosphere
-
-
9.4 Weather Processes
- 4 aspects of atmosphere directly related to severe weather:
o atmospheric pressure, circulation patterns, vertical stability of atmosphere, Coriolis effect,
interaction of different air masses
ATMOSPHERIC PRESSURE AND CIRCULATION
- atmospheric pressure (barometric pressure): weight of column of air that is above any given point
o a e o Earth’s surfae or aoe it
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
9. 3 the atmosphere atmosphere = thin gaseous envelop that surrounds earth: causes weather and is responsible for trapping heat that makes earth warm enough to be habitable. Mainly composed of nitrogen and oxygen; smaller amounts of argon, water vapour, co2, other trace elements. Most gas moelcuels are concentrated below height of 100 km. Most of atmospheric water vapour condenses in troposphere, leaving little water in upper layers of atmosphere troposphere contains most of atmospheric co2 and methane in addition to water vapour: co2 and methane: important in global warming. Only ozone (gas composed of o3) is significantly less abundant in troposphere when compared with upper atmosphere. 4 aspects of atmosphere directly related to severe weather: atmospheric pressure, circulation patterns, vertical stability of atmosphere, coriolis effect, interaction of different air masses. Atmospheric pressure and circulation atmospheric pressure (barometric pressure): weight of column of air that is above any given point: (cid:373)a(cid:455) (cid:271)e o(cid:374) earth"s surfa(cid:272)e or a(cid:271)o(cid:448)e it.
