air mass

a huge body of air that has similar temperature, humidity, and air pressure at any given height

Meteorologists blame the heat on hot air masses moving north from Africa.

la masse d’air

air pressure

the measure of the force with which air molecules push on a surface

Differences in air pressure may cause spectacular effects when travelling by airplane.

la pression atmosphérique

cloud

a visible mass of water or ice particles suspended at a considerable altitude

But they should know that the storm clouds have just parted.

le nuage

cold front

forms when cold air moves under warm air which is less dense and pushes air up

A strong cold front will move through the interior West on Friday.

le front d’air froid

condensation

the process of changing from a gaseous state to a liquid or solid state

The condensation is usually on the tank, not the bowl.

la condensation

Coriolis effect

the way Earth’s rotation makes winds in the Northern Hemisphere curve to the right and winds in the Southern Hemisphere curve to the left

As with other cyclones, their rotation is driven by the Coriolis effect.

l’effet de Coriolis

dew point

temperature at which air is saturated and condensation begins

As the temperature increases, the dew point often does the same.

le point de rosée

evaporation

the process by which water changes from liquid form to an atmospheric gas

Warmer summers increase evaporation, which will further increase water shortage.

l’évaporation

exosphere

the layer of the atmosphere that fades into outer space

The exosphere is above that but is a minor layer of the atmosphere.

l’exosphère

freezing rain

raindrops that freeze after they hit the ground or other cold surfaces

Elsewhere, light snow and freezing rain will fall across the southern Appalachians.

la pluie verglaçante

global warming

an increase in the average temperature of the Earth’s atmosphere

The most viable hypothesis to explain coral bleaching is global warming.

le réchauffement climatique

greenhouse effect

natural situation in which heat is retained in Earth’s atmosphere

Fourier is also generally credited with the discovery of the greenhouse effect.

l’effet de serre

hail

lumps or balls of ice that fall from clouds and are formed from strong convection currents

A few of these storms will contain hail and damaging winds.

la grêle

high pressure

cool dense sinking air

High pressure will build southward from Quebec into upstate New York.

les hautes pressions

hurricane

a severe storm that develops over tropical oceans and whose strong winds of more than 120 km/h spiral in toward the intensely low-pressure storm center

But we enjoy being out of the eye of the hurricane.

l’ouragan

ionosphere

layer of electrically charged particles in the thermosphere that absorbs AM radio waves during the day and reflects them back at night

Lloyd Berkner first measured the height and density of the ionosphere.

l’ionosphère

jet stream

a high-speed high-altitude airstream blowing from west to east near the top of the troposphere

The jet stream will deliver milder, moist air to the Pacific Northwest.

le jet-stream

low pressure

warm rising area that condenses and cools; associated with cloudy skies, precipitation, and wind

This less dense warm air results in low pressure over the Plains.

la basse pression

mesosphere

the layer of the atmosphere immediately above the stratosphere where most meteors burn up

In the mesosphere, temperature decreases as the altitude increases.

la mésosphère

ozone layer

a layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the Sun

The ozone layer will probably not recover before the year 2060.

la couche d’ozone

precipitation

the falling to earth of any form of water (rain, snow, hail, sleet, mist)

With each new inch of precipitation, people grow surlier.

les précipitations

relative humidity

the ratio of the amount of water in the air at a given temperature to the maximum amount it could hold at that temperature

What is considered the ideal relative humidity for your home?

l’humidité relative

sleet

partially melted snow (or a mixture of rain and snow)

In winter, the atmosphere is often too warm for sleet.

le grésil

stratosphere

the layer of the atmosphere that is above the troposphere and in which temperature increases as altitude increases

Ozone in the stratosphere shields living organisms from harmful ultraviolet rays.

la stratosphère

thermosphere

the uppermost layer of the atmosphere, in which temperature increases as altitude increases

The temperature of the thermosphere gradually increases with height.

la thermosphère

thunderstorm

the most common severe storm, formed in cumulonimbus clouds

A few thunderstorms will develop across the high plains of Texas.

l’orage

tornado

a localized and violently destructive windstorm occurring over land characterized by a funnel-shaped cloud extending toward the ground

We learned a tornado might be on the way from Oklahoma.

la tornade

troposphere

the layer of the atmosphere that contains life and weather; the temperature decreases as you go up

The troposphere is heated directly by the Earth’s surface.

la troposphère

warm front

a front where warm air moves over cold air and brings drizzling rain

Clouds will streak across the Great Lakes ahead of a warm front.

le front chaud

weather

the condition of Earth’s atmosphere at a particular time and place

Everybody talks about the weather but nobody does much about it.

le temps