ch 18 20

is just the pressure exerted by the weight of the air above

is defined as force per unit area

is the instrument used to measure air pressure.

mercury(liquid ) aneroid (without liquid)

the pressure rises the level of mercury in the column rises and as the pressure drops the level falls.

there is no liquid and is small and portable. It has a pointer with a dial calibrated to read in inches or millibars

air moving horizontally along the earths surface.

It is the driving force of wind as it has both direction and magnitude. Air pressure always moves from a region of higher air pressure to a region of lower pressure. When isobars (lines connecting points of equal pressure) are very close to one another then they indicate a sharp pressure gradient.

Free moving fluids or objects are deflected to the right in the Northern Hemisphere and to the left in the Southern hemisphere because of earth’s rotation

This acts to slow air movement. The frictional effect is low in flat surfaces and high in mountainous regions.

are also called cyclones and arre centers of low pressure

are also called anticuclones and are regions of high pressure

When the wind swirls clockwise in the northern hemisphere or counter-clockwise in the southern hemisphere

When the wind swirls counter-clockwise in the northern hemisphere or clockwise in the southern hemisphere,

associated with cloudy skies

with precipitation and cloudy skies.

It has the upper-level air moving towards the pole and surface air moving towards the equator.

• Equatorial Low
• Subtropical High
• Trade Winds
• Westerlies
• Polar Easterlies
• Polar Front

Regions known by alot of precipitation as the air is rising

Found around 30° latitude N and S of the equator. Locations of the major deserts of the world (Arabia, North Africa, Australia), owing to stable dry stable conditions.

Air deflicted by the Coriolis effect associated with traid and commerce

the air remaining from the trade winds traveling towards the poles fould in teh mid latitude regons

formed as a result of westerlies moving polewards

formed as a result of warm and cold fronts

Produced by high and low pressure over the oceans and pressure changes over land. Extremes of climate and ranges of temperatures.

In the Northern Hemisphere, these cells move from west to east that create an anticyclonic or clockwise flow or cyclonic or anticlockwise flow in their path

used to measure wind direction

used to measure wind speed.

Name given to periodic warming of oceans occurring in the eastern and central Pacific resulting in extreme weather.

Occurs in the central and eastern Pacific region as a result of unusually low sea-surface temperatures and strong trade winds.

This is influenced by wind and air pressure, the distribution of water and land and latitude.

the pressure exerted by the weight of the air above.

defined as force per unit area (pressure in tires).

• the terms given to a large body of air about 1000 miles in extent or more and several miles thick, characterized by similar moisture and temperature patterns regardless of
• altitude

the region where the air mass gains its properties of moisture and temperature

air masses originate in high latitudes towards the poles

which form in low latitudes

air masses that formed on land

that originate over water

dry

more humid

cold temp and no precipitation

• air masses that cross the Great Lakes during
• winter

The leading edge of an advancing air mass

When the position of a front moves such that warm air occupies the position formerly occupied by cooler air

When the position of a front moves such that cold air occupies the position, formerly occupied by warmer air

what the flow is neither towards a warm or a cold air mass

when a cold front actively surpasses a warm front

These are centers of low pressure that move from west to east and can last from a few days to a week to ten days. They are broken up into three stages: youth, maturity, and old age

Is simply the storm associated with lightening and thunder. It also frequently produces heavy rain, hail, and gusty winds. They form when humid, warm air rises in an unstable environment.

Are local storms of short duration ranking among nature’s most destructive forces. They are violent windstorms that take the form of a rotating column. Can produce high winds, heavy rainfall, and damaging hail.

Are whirling tropical cyclones having wind speeds of about 185miles per hour and constitute one of the greatest storms on earth and can result in billions of dollars worth of damage.

includes atmosphere, hydrosphere, geosphere, biosphere, and cryosphere (ice and snow on the earth’s surface).

Temperature and precipitation are the most important features when it comes to describing climatic characteristics for any place in the world as they have an impact on people and their lifestyle and activities. This leads us to classification for climate.

The best known climate classification system generally accepted is the Köppen classification

average monthly temperature, average monthly precipitation, and total annual precipitation

No winters, temperature hardly ever falls below 64°.

Mild winters, the average coldest month is below 64°F but above 27°F.

Severe winters, the average temperature of the coldest month is below 27°F.

Summerless climates, the average temperature of the warmest month is below 50°F

Classified on the basis of precipitation. Constitutes the warm desert regions of the world.

Is the climate associated with a region of high elevations as compared to the regions of the same latitude located at lower elevations.

Most extensive, occupies 36% of the earth’s land surface. They extend from 20°N to 20°S. Consistent daylength and therefore, a constant amount of energy from the sun

Occupies 27% of the earth’s land area but 55% of the earth’s population. These are regions of great weather variability and therefore, greater air mass conflicts. Differences in seasonality is evident as is reflected in the type of soil, vegetation, and human life.

Have long winters covers almost 21% of the earth’s land surface. They experience greater temperature ranges on the basis of continentality.

Have no actual summers. These are regions of permafrost. Average monthly temperatures, in the summer temperatures hardly ever rise beyond 50°F.

Covers 35% of the earth’s land surface. Classified on the basis of precipitation. The plant and animal life is unique to these regions as they have to adapt to the conditions

Difference in range of temperatures are higher for elevated regions as compared to the ones of lower elevations.

levels are rising as a result of industrial activities, deforestation, and burning and combustion of fossil fuels

it is gathered that 45 to 50% remains in the atmosphere. This results in atmospheric imbalance

• The amount of these gases is very little as compared with CO2 but they still contribute to a worldwide increase in temperature. These gases include methane
• (CH4), nitrous oxide (N2O), and certain chlorofluorocarbons (CFC’s). These result in the increases observed in temperatures and result in
• melting of the ice caps creating an atmospheric imbalance.