MET1010 CHAPTER 7

Macroscale (planetary)

-Months to Years

-3,000-24,000 miles

-Examples Include: El Nino, Jet Stream, Trade Winds

Macroscale (synoptic)

-Days to week

-100-1000 miles

-Examples:Fronts, High and lows,Hurricanes

Mesoscale

-Minutes to Hours

-1/2-100 Miles

-Examples:Thunderstorms,Waterspouts,Tornadoes, Local Winds(sea breeze)

Microscale

-Second to minutes

-<1/2 miles

-Examples:Lightning , Downburst, turbulence,Dust Devil

What are the local winds?

-Sea Breeze

-Land Breeze

-Valley breeze

-Mountain breeze

-Chinook Wind

Sea breeze

Onshore flow (from the water to land) best developed in later afternoon during summer

Land Breeze

-Offshore flow (from land to water), nighttime reversal of sea breeze during summer

Valley Breeze

-Flow from the valley to the side of the mountain in the late afternoon

-Sinking=Stable=Good Weather

Mountain Breeze

-Downslope flow from the mountain to the valley at night time

-Rising=Unstable=Clouds and Precip

Chinook Winds or Santa Ana Winds

-Hot and dry downslope winds

George Hadley Theory

-1735

-One circulation cell in each hemisphere

-Based on temperature difference

There are _ circulation cells in each hemisphere

three

At 0 degrees

-Doldrums-hot,humid with light winds

-ITCZ- Intertripical convergence zone

-Trade winds convergence A

At 30 degrees

-Horse Latitudes

-Calm conditions

At 60 degrees

-Latitude separating bitterly cold air from warmer air

What are all the pressure patterns?

-0 degrees - equatorial lows- wet latitude belt

-30 degrees- subtropical high -dry latitude belt

-60 degrees- subpolar lows- wet latitude belt

-90 degrees- polar highs- dry latitude belt

Jet streams

Rapidly moving current of air in the upper levels

Polar jet streams

-Originates at around 60 degrees north and 30,000 feet

-Cold air advection

-Steers weather systems

Subtropical jet streams

-40000 feet

-Warm air advection

-Steers weather systems

What are two example of weather circulation systems?

El niño, ENSO (El Niño/ Southern Isolation)

El Nino

-Begins december and ends in november

-Warming of Sea Surface Temperatures in Pacific Ocean

Southern Isolation

-Seesaw Reversal of Pressure

ENSO ( El Nino Southern Osolotaion)

-Sea Saw reversal of pressure pattern in pacific

-Occurs every 3-7 years

What are the two types of El Nino

-Major Episodes (2-3 degrees farenheight) ( increase )

-Minor Episodes (1-2 degrees farenheight) (increase)

What are the effects of ENSO?

-Increases Subtropical Jet Stream

-Increases Rainfall-Southeastern coast

-Causes mudslides and landslides in places like California

-In Places like Peru they will loose about $2 billion in fishing and farming

-Severe drought in some areas: Indonesia, Australia, South Africa

-As far as the Atlantic hurricane season : fewer hurricanes than normal

-2 year rebound