Weather and Hurricanes Mrs. gomez Weather and Hurricanes

-Matthew Murray-father of oceanography “Our planet is invested with two great oceans; one visible, the other invisible; one underfoot, the other overhead; one entirely envelopes it, the other covers nearly two thirds of its surface” -Matthew Murray-father of oceanography

Key concepts and Vocabulary Text Key concepts and Vocabulary Weather vs. Climate Convection Low and high pressures in the atmosphere Hurricane formations Classifications of hurricanes

Weather is… movement of water through the water cycle Weather vs. Climate Weather is… movement of water through the water cycle varies with seasons and location refers to short-term atmospheric and hydrological conditions while climate refers to long term weather patterns.

in other words Weather is the air temperature, cloud cover, precipitation, wind, moisture content, and air pressure at any particular place. Reflects the prevailing conditions of the air masses overlying the land and seas over the entire globe.

In other words climate is… the overall picture of weather during periods of seasons or years. Historical records (including geological and recorded history) show us how the climate of the Earth has changed throughout its history.

Hurricanes Convection The transfer of heat by actual movement of the heated material ANY substance that flows is considered a fluid this includes the less obvious- gases and air The continual cycling of a fluid is called a convection current. Convection motions are responsible for the redistribution of heat from warm equatorial regions to higher latitudes and from the surface upward.

Basically convection is… Hurricanes Basically convection is… Heat goes up, cold goes down Hot air rises, cold air sinks Hot things go up, cold things go down

Trade wind: wind blowing steadily toward the equator from the NE in the northern hemisphere or the SE in the southern hemisphere especially at sea. Easterlies: winds blowing from the east Westerlies: winds blowing from the west

The largest and strongest storms on the planet! What are they? The largest and strongest storms on the planet! Hurricanes

How Do They Form? First…understand how convection works Hurricanes How Do They Form? First…understand how convection works Second…know about high pressure and low pressure in the atmosphere Then we can tackle how they form

Hurricanes How do they form? These storms can be called typhoons or cyclones depending on where they occur. The scientific term for these storms is tropical cyclone Only tropical cyclones that form over the Atlantic Ocean or eastern Pacific Ocean are called “hurricanes”

Air Pressure Air pressure is all around us…but why don't we feel it??? Hurricanes Air Pressure Air pressure is all around us…but why don't we feel it???

BArometers Air pressure is measured in mb or mmHg Original barometers used Hg-the air pressure was calculated based off of how much Hg the air could hold up

Air pressure BArometers Modern barometers use an enclosed cell that expands or contracts and moves a lever.

air pressure low and high pressure Air will always try to move from an area of high concentration to an area of low concentration

How does a low pressure system form? Air Pressure How does a low pressure system form? CONVECTION!!!!! As the air is heated, it rises leaving a “hole” Air will then be pulled back in to replace the hole.

Air Pressure As warm humid air rises, it cools and the water vapor eventually will condense back into water to form a cloud and eventually rain RELEASING LOTS OF ENERGY AS IT DOES

low pressure sucks, high pressure blows hurricanes low pressure sucks, high pressure blows If hot air rising creates a “low” pressure, then cold air dropping creates a “high” pressure.

Hurricanes How do they form? Tropical Cyclones (hurricanes) are like giant engines that use warm moist air as fuel This is why they only form over warm ocean waters near the equator. The warm moist air near the ocean surface will rise upward and away from the surface This causes there to be less air near the surface of the ocean In other words…warm air rises causing an area of low air pressure below

How do they form? in short… Hurricanes How do they form? in short… Air from surrounding areas with higher air pressure pushes in to the low pressure area. Then that "new" air becomes warm and moist and rises, too. As the warm air continues to rise, the surrounding air swirls in to take its place. As the warmed, moist air rises and cools off, the water in the air forms clouds. The whole system of clouds and wind spins and grows, fed by the ocean's heat and water evaporating from the surface.

Hurricanes Pop Quiz!

Take out a paper and do not talk! do not use your notes! Hurricanes pop quiz Take out a paper and do not talk! do not use your notes! What is convection and how does it tie in with hurricanes? Tropical cyclones are the scientific term for these massive storms; however, where do these storms need to form in order to be called/considered a hurricane? In a hurricane, hot air rising causes a _________ pressure while cold air dropping creates _______ pressure. The _______ pressure causes a sucking of air pressure on the surface of the ocean leading to the eye of the hurricane while the ________ pressure causes the massive winds associated with a hurricane. Where do tropical cyclones, typhoons, and cyclones form? What do they need in order to be “fueled”?

Hurricane Coriolis Effect Coriolis Effect is simple…yet very VERY confusing We are on a spinning ball, even something going straight will curve over a long distance The effect gets magnified by everything else turning (no, this has nothing to do with toilet water spinning and no toilets don’t spin the other way in the southern hemisphere)

South-Left; North-Right Hurricanes Coriolis Effect South-Left; North-Right

Ingredients for a Hurricane Hurricanes Ingredients for a Hurricane Ocean is very warm and the warm is deep (80 degrees down to 150ft) Everything is calm (low winds), so air heats up Air rises quickly and creates a “super low” pressure area HOT, humid, water carrying air zooms into the “super low” pressure carrying crazy amounts of water and heat energy into the storm As it spirals up the eye it looses all it moisture and we get massive condensation (rain clouds)!

Storm-Surge!! The most deadly part of a hurricane!!! Hurricanes Storm-Surge!! The most deadly part of a hurricane!!! The “LOW” pressure sucks in more than just air. It actually pulls the ocean surface up! Add this to the huge waves caused by wind…

Severity Hurricanes Catagories Pressure (normally above 1000) Winds mph Storm surge ft Can …. Tropical storm >993 <74 1-2 Flood large areas H1 74-95 4-5 Take out trees H2 979-965 96-110 6-8 Rip roof off H3 964-945 111-130 9-12 Knock small building down H4 944-920 131-155 13-18 Destroy even large buildings H5 <920 155+ 19+ bad…. just bad