Weather is |
the short term condition of the atmosphere |
over the last two decades, costs for weather-related destruction has, on an annual basis |
increased five-fold |
earth is properly characterized as |
the water planet |
Water covers ______ of Earth's surface |
71 percent |
Water has a density of |
1 g/ cm |
when water freezes, its density |
decreases |
which of the following is true of the distribution of land and water on Earth? |
the southern hemisphere is dominate by water |
the largest portion of fresh water today is located in |
ice caps and glaciers |
other than ice sheets and glaciers, the largest repository of fresh water is located in |
ground water |
water molecules bind tightly to one another. This is the result of |
hydrogen bonding |
water is a good solvent because |
it has an asymmetrical charge distribution (one end is positive and the other negative) |
surface tension and capillarity are the result of |
hydrogen bonding between water molecules |
Deposition refers to |
water vapor freezing to ice |
what is the heat energy involved in change of state, or phase, in water? |
latent heat |
which of the following phase changes involves the greatest number of calories? |
sublimation |
when water condense, it _____ heat energy and _____ the surrounding air |
releases; heats |
when frost forms, it |
warms the air by releasing 680 calories of heat energy to the air gram of water |
when water evaporates, it ______ heat energy and ________ the surrounding air |
absorbs; cools |
In winter, freezing water can break pipes and even crack engine blocks. Why does this happen? |
water expands in volume as it freezes in response to hydrogen bonding |
water vapor in the atmosphere is called |
humidity |
relative humidity |
the amount of water vapor in the air at a given temperature expressed as a percentage of the moisture capacity of the air |
the capacity of the air to hold water vapor is basically a function of |
the temperature of both the water vapor and the air |
a mass of air always becomes saturated when it reaches the |
dew-point temperature |
specific humidity |
a humidity measure that remains constant as temperature and pressure change, and is expressed as a mass of water vapor per mass (g/kg) of air |
as temperature increases during the day, relative humidity usually |
decreases |
the elevation at which the bottom of the clouds begin to form represents the elevation at which |
dew point occurs relative humidity reaches 100 percent |
stability |
the tendency of a parcel of air to either remain in place or change its initial position |
an air parcel is considered unstable when it |
continues to rise until it reaches an altitude at which the surrounding air has a similar density |
All adiabatic temperature changes occur as a result of |
expansion or compression of the air |
assume a warm air parcel at Earth's surface has a temperature of 21 degrees C (70 degrees F) and begins to rise upward. Assume it becomes saturated at 1000 m (3300 ft) altitude, and continues to rise to 2000 m (6600 ft) altitude. What would the approximate temperature of the parcel be at an elevation of 2000m (6600 ft)? |
5 degrees C (41.0 degrees F) |
Air that is not saturated will cool or heat at a rate of _______ as it rises or descends, respectively |
10C degrees per 1000 m (5.5F degrees per 1000 ft) |
The wet adiabatic rate is _____ than the dry adiabatic rate because_______ |
less; condensation heats the air |
Areas between 25 degrees to 35 degrees latitude usually become _______ because this area is dominated by air that is sinking and being ______. |
deserts; heated by compression |
cumulonimbus |
clouds that have a vertical development and produce precipitation associated with tornado development |
cumuliform |
puffy or globular clouds |
Altostratus |
middle- level cloud |
cirrus |
a good indicator of an arriving storm, say within the next 24 hours |
radiation fog |
results after cooling of a surface overnight that chills the air layer directly above that surface |
advection fog |
fog that develops when warm, moist air blows over a cold current (such as the California current) |
Evaporation fog |
on cool spring mornings, veils of fog can often be seen rising above warm lakes and ponds |
air masses are |
homogeneous in terms of temperature and humidity |
cP air masses |
air masses that develop over Canada |
What are the characteristics of a well-developed, newly formed cP air mass? |
cold temperatures, clear skies, and high pressure |
mT air masses |
wetter than a cT air mass and forms over the ocean |
Intertropical convergence zone is characterized by |
warm, wet rising air |
orographic |
forced uplift due to the presence of a physical barrier |
the highest rainfall in the world occurs in an area where rainfall is generated by |
orographic uplift of warm, moist air |
west side |
the wetter, intercepting slope of a mountain |
east side |
the drier, downwind slope of a mountain |
storm tracks across the United States and Canada generally |
shift to the south in winter, and toward the north in summer |
Where will thunderstorms not develop? |
under areas of strong high pressure |
From where do hurricanes derive their energy? |
the heat of condensation |
What are the peak months of occurrence for hurricanes in the western Atlantic? |
August to October |
Eye |
the part of a hurricane that consists of dry, subsiding air |
Why are the winds in a hurricane and tornado so strong? |
the pressure gradient is strong the pressure at the center of the storm is very low tremendous amounts of condensation occur in the center of the storm |
Why do hurricanes die when they move over land? |
evaporation and subsequent condensation are no longer sufficient to sustain them |
When hurricanes first form in the Northern Hemisphere, they usually travel from _______, and later from _______ after they move to higher latitudes. |
east to west; west to east |
convergent lifting |
results when air flows toward an area of low pressure |
convectional lifting |
happens when air is stimulated by local surface heating |
orographic lifting |
occurs when air is forced over a barrier such as a mountain range |
frontal lifting |
occurs as air is displaced upward along the leading edges of contrasting air masses |
cold front |
leading edge of a cold air mass greater density and uniform characteristics compared to the warmer air mass is displaces in advance of front, warm, moist air lifts upward abruptly and experiences the same adiabatic rates of cooling and factors of stability |
warm front |
leading edge of a warm air mass |
hail |
ice pellets larger than .5 cm that form within cumulonimbus clouds |
cyclogenesis |
the atmospheric process in which low-pressure wave cyclones develop and strengthen |
humidity |
the water vapor content of the air hotter air can hold more water |
midlatitude cyclone |
migrating low-pressure weather systems that occur in the middle latitudes, outside the tropics low pressure center with converging, ascending air spiraling inward counterclockwise in the Southern Hemisphere |
EF-5 |
windspeeds greater than 322 kmph (200 mph) with incredible damage |
dry adiabatic rate |
the rate at which dry air cools by expansion (or warms by compression) dry- less than saturated 10 degrees Celsius / 1000 m |
moist adiabatic rate |
the rate at which an ascending air parcel that is moist or saturated, cools by expansion MAR= 6 degrees Celsius/ 1000 m |
cirrostratus |
form a veil of ice crystals that creates a halo around the Moon or Sun |
open stage |
a part of the midlatitude cyclone in the Northern Hemisphere, warm air begins to move northward along an advancing front, while cold air advances southward to the west of the center |
adiabatic |
air temperature of a parcel changes but without loss or gain of heat to surroundings rising air expands due to lower pressure it cools due to the environmental lapse rate |
dew point |
100% relative humidity addition of more water or decrease in temperature leads to condensation of liquid water |
vapor pressure |
portion of air pressure attributed to water vapor milibars |
saturation vapor pressure |
air contains as much water vapor as it can |
thunderstorms |
develop where moist air is forced aloft occurs frequently in tropics, nearly daily in some locations most frequent region in the Gulf South absolute peak in Florida as the state extends into warm waters |
tornadoes |
rapid, rotating, lifting winds beneath cumulonimbus clouds usually short lived lasting only a few minutes, but some have lasted for hours |