EAS mod3

Vertical pressure gradient in the atmosphere

Atmospheric pressure decreases exponentially with altitude

What is the weather in high vs low pressure

• High pressures

  • Cooler

  • Sunnier

• Low pressure

  • Warmer

  • Rainier

Coriolis effect

• Northern hemisphere: objects are deflected towards the right relative to starting position

• Southern hemisphere: objects are deflected towards the left

  • This is because parcels of air near the equator are moving faster than near the poles

Geostrophic wind

Pressure gradient acceleration apg and the coriolis accelerate are balanced and equal, causing winds to blow parallel to isobars (constant lines of pressure) = frequent

Hurricanes & storms

The storm is a strong low pressure system that draws air in, pushes i tup unstably, and condenses rain. Coriolis system causes it to rotate

Hadley cell

Solar radiation strikes at the equator, causing air to warm and rise. It then condenses into rain. As it expands, it cools and moves toward the poles, descending on +30 and -30 latitudes.

Where is atmosphere thicker/thinner

Thicker at equator, thinner at poles. This is because warmer at equator = less dense

Air stability - 3 types

• Unstable

  • Temperature of air parcel > surroundings; air moves up

• Stable

  • Temperature of air parcel < surroundings; air moves down

• Netural

  • Temperatures are same

What determines atmospheric stability?

When an air parcel is forced to rise, the rate at which it cools is dependent on the initial Relative Humidity of the air parcel

Relative humidity

Measure of how much water vapor is in a parcel of air relative to how much vapor it could hold

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explain saturation vapor pressure of water vapor

The maximum pressure exerted by water vapor when the air parcel is saturated, meaning i tholds the max allow number of water vapor molecules

Temperature lapse rates

The rate at which an air parcel’s temperate changes with height, if the parcel were forced to sink or rise

For an air parcel forced to rise, what makes it stable vs unstable?

For an air parcel forced to sink, what makes it stable vs unstable?

• Air forced to rise

  • warmer than surroundings = unstable; will keep rising

  • cooler than surroundings = stable; will sink

• Air forced to sink

  • warmer than surroundings = stable, will rise back to height

  • cooler than surroundings = unstable, will sink

Adiabatic warming/cooling

Temperature change without its heat changing

Katabatic winds

High density air (cool air in high pressure) travels down slope into a low pressure system —> adiabatically warms as it sinks (just like how it could cool if it rises) winds can achieve very high speeds & has very low relative humidity —> can start fires

Boundary layer and gradient

If a fluid is moving past an object or surface, the object generates forces that affect how fast the fluid moves

Fluid can be either laminar (parallel layers) or turbulent (chaotically)

Closer to earth = wind is slower due to friction

Further from earth = wind is faster

Viscosity relationship to temperature

• Temperature increase —> viscosity decreases

• Temperature decrease —> viscosity increases

What causes the intertropical convergence zone?

Equatorial air is very moist, and when it is heated by the sun, it rises and condenses to clouds, causing rain.

What causes deserts?

Dry air that has already risen, cooled off, and lost all of its water vapor as rain drops back to the surface.

What causes a thunderstorm to form

Thunderstorms form because of a positive feedback between warm moist air rising unstably, cooling as it rises, condensing water vapor into rain and releasing latent heat. The latent heat creates further instability and causes the air to continue rising, continue cooling, and continue condensing water vapor, generating further instability.

What causes air to rise during thunderstorm formation?

1. heating from the sun

2. Mountains

3. Cold front

Orographic precipitation

rain shadow effect - moist rising air and condenses on windward side, then dry descending air as it warms on leeward side

Capacity factor of wind turbine

The amount of electricity generated by the farm divided by the total electricity that could be generated given its nameplate capacity

Turbine issues

Can explode, malfunction

Can interfere with other turbines

Can kill birds

Can appear on radar