# Earth Science

## 45 terms

### Wind

The horizontal movement of air relative to Earth's surface.

### Zonal Flow

A predominately WE or EW wind flow.

### Meridional Flow

A predominately SN or NS wind flow.

### Microscale

Light wind that flutters leaves.

### Mesoscale

Stronger Winds that last hours or days. Beach Winds. Local Winds.

### Synoptic

Winds that last days or weeks. Hurricanes, Cyclones.

### Planetary

Winds that last weeks or months. Prevailing Westerlies ( mid lats), Trade winds (lower lats).

### Newtons 1 law

An object stays at rest or in motion unless acted upon by another force. Law of Inertia.

### Newtons 2 law

Things move faster when pushed harder. f=m X a

### Newtons 3 law

For every action there is an equal or opposite reaction.

### Friction

The resistance of motion between things that touch.

### mass

The measure of an object

Drives air from areas of higher barometric pressure to areas of lower barometric pressure, causing winds. To the Right of the winds. Vertical and Horizontal PGFs. Horizontal= bathtub

the amount of pressure change occurring over a given horizontal distance

### Isobars

Lines connecting areas of equal pressure. More closely spaces isobars on a map indicate areas where the horizontal pressure gradient is strongest.

### Coriolis Force

deflects a freely moving object to the right in the northern hemisphere. It only influences wind direction, never speed.

### Coriolis Force magnitude

Proportional to the wind speed and latitude.

### High surface winds in the N hemisphere

Move clockwise and out

### High Surface winds in the S hem.

Move counter-clockwise and inward . The Coriolis force makes this opposite as the N. Hem.

### Surface Winds

Friction Layer winds. Friction reduces wind speed which reduces the coriolis force; the weaker c. force no longer balance the pgf and the wind blows across the isobars toward lower pressure.

### Surface Divergence

Air sinks causing us to have clear skies. *

### low level Surface convergence

Air piles up and you have rising motion, cooling the air and producing rainy or cloudy weather.

### Mid Lat westerlies

Blow from S to W. 30-60 degrees.

Blow from NE to SW 30-0 degrees

SE winds 0-30 degrees

### Thermal Circulations

Circulations resulting from changes in the air temp in which warm, less dense, air rises and cold, more dense, air sinks.

### Polar Highs

Air blows clockwise with Easterly winds in the poles.

### ITCZ

At the equator trade winds from each hemisphere come together and converge into a low. Air rises, ans hits the top of the troposhere, a portion spreads n and s and then sinks. This air creates high pressure at 30 degrees n and s, making bad weather.

### Land Sea breeze

winds that come from ocean breeze. Cool breeze coming from ocean in the morning. Evening breeze much warmer coming from land. The pressure gradient force helps create this wind because the land/ water temp differences.

### Monsoons

Regional wind systems that change direction seasonally. India and SE Asia get effected. The water is warmer than the land in the in the winter, so the pressure is low over water, and high on land. In the summer, the pressure is high over the water, causing monsoons all summer.

### Mountain and valley breezes

Warm, less dense, air rises upslope during the day. Cool dense air sinks down the mountain at night.

### Katabatic Winds

large scale winds. (Santa Ana) . Warm winds move down mountain slopes. The base of the mountain gets sinking wind that is warmer.

### Air mass

a huge volume of air - uniform in its temperature and humidity characteristics

movement of an air mass (and thus its properties of temp & moisture) in the horizontal from one location to another

very cold & dry

cold & dry

hot & dry

cool & moist

warm & moist

### Orographic Lifting

Air being forced up a mountain.

### Convection

A cooler & moist air mass moves over a warmer land area -heating from the land causes the air to rise - if the atmosphere is unstable it continues to rise

### Fronts

a transition zone between two air masses having different densities (temperatures)
* fronts typically separate air masses with different temperatures and humidities
* since air masses have both a vertical and horizontal extent, a front also extends upward in the vertical - the "frontal surface" (frontal zone)