Water’s
Heat Properties and 3 States- critical to powering weather systems
States of water = ice, liquid and vapor
Distribution of Water (general statistics)
71%
of earth surface (70% of our bodies)
mean
sea level risen 8-16 inches over 100 years
eustasy- changes in sea
level
isostasy- changes in
land elevation
Hemispheres- oceanic and
land
Oceans
= 97%, Freshwater = 3%, Rivers/lakes/streams = 1%
Ice/glaciers- 77% of earth’s freshwater
(+groundwater = 99% freshwater)
Lake
Baykal- Siberian Russia (biggest single volume lake water)
Moisture/Stream/Rivers= 0.033% of
freshwater
Vapor
and flowing water moves through hydrologic cycle in 2 weeks
Properties
of Water (most common compound- most uncommon properties)
Hydrogen bonding properties:
Polarity - sticks to and dissolves things-
why things are wet and dissolve
Surface
tension = things float
Capillary
action = pulls in its neighbors
Heat
Properties- change water between states needs to have heat energy absorbed or
liberated
Phase
change from liquid to solid water: 9% increase in volume
Figure 7.4- states of water and phase changes
Sublimation- change ice to
water vapor or back
Relationship
between water, heat and energy (30% of energy that powers the general
circulation of the atmosphere)
Why does ice float?- freezing water expansion
in volume and a decrease in density (ice = .91 times the density of water
Phase changes and caloric absorption and
liberation- latent heat exchange is the dominant cooling process in earth’s
energy budget- know Figure 7-4 (fill in arrows)
Humidity
Humidity (water vapor content), warm air
holds more vapor than cold. Capacity to hold water vapor is a function of
temperature
Energy
for powering weather- need water vapor content and relate this to
capacity to hold water vapor at a given temperature
Relative
humidity: ratio of amount of water vapor in air to holding capacity. Varies due to evaporation, condensation or
temperature changes.
Figure 7.7 on page 187
Saturation: At 100% relative
humidity, any change in temp (cooler) or addition of more vapor results in
condensation (precipitation)
Dew-point
temperature: temperature at which a mass of air would become saturated (when
dew-point = air temperature – air is saturated)
As temperature rises, relative humidity
falls (relative is highest at dawn)
Atmospheric
stability (read over the ideas)
Parcel- body of air
with specific temperature/humidity characteristics
Warm
air- lower density (upward buoyant force)
Cold- higher density
(downward gravitational force)
Stability- tendency of a
parcel to remain in place or change altitude
Unstable- parcel
continues to rise until an attitude with air at same density
Adiabatic- warming or
cooling rates for a parcel of expanding or compressing air
Clouds
Cloud- aggregation of
tiny moisture droplets and ice crystals suspended in air
Unstable parcels rise until saturated (air
cools to the dewpoint temperature and relative humidity = 100%)
Cloud classification- by altitude and
shape
Stratiform- horizontal,
flat and layered
Cumuliform- vertical,
puffy and globular
Cirroform- wispy and high
alititude
Cumulonimbus- thunderheads
Cloud Formation Process (Type of Clouds,
page 199-201) Know association of clouds to weather patterns.
Fog: Cloud layer on
the ground