1. Weather & the Ocean
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2. The Atmosphere
The Earth is covered by a thin shell of mixed gases that extends 90km above it – this is our atmosphere.
The atmosphere and the ocean are in contact for over 71% of the Earth’s surface.
The atmosphere has four layers:
The troposphere – 0 to 12km, heat and water constantly are exchanged here
The stratosphere – 12km to 50km, built mainly of ozone
The mesosphere – 50km to 90km
The thermosphere – 90km to outer space

3. Temperature in the Atmosphere
Solar radiation from the sun heats the outer layers of the atmosphere.
About 31% of solar radiation bounces back out into space
About 17.5% is absorbed in the atmosphere
About 47.5% is absorbed at the Earth’s surface
Of the heat that is absorbed at Earth’s surface, 42% of it gets transferred to the atmosphere by evaporation as water vapor
About 4% bounces back from Earth’s surface into space

4. Pressure in the Atmosphere
Atmospheric pressure is the force with which a column of overlying air presses on an area of Earth’s surface.
Low pressure systems happen when less dense, warmer air rises.
High pressure systems happen when more dense, cooler air sinks.

5. Wind Bands in the Atmosphere
Winds are named for the direction they come from, not the direction they are blowing towards (so a wind moving from north to south is a “north wind”)
Around the world, there are consistent flows of surface air.
Between 0 degrees and 30 degrees N and 30 degrees S are the trade winds.
Between 30 degrees N and 60 degrees N, and 30 degrees S and 60 degrees S are the westerlies
Between 60 degrees N and 90 degrees N, and 60 degrees S and 90 degrees S are the polar easterlies

6. Seasonal Changes to Winds
Differences in temperature throughout the season can cause small changes to global wind patterns.
For example, rising air can be replaced by warm, moist air during the summer months, causing heavy rainfall.
Locally this also causes our onshore and offshore winds that occur during the summertime, bringing our afternoon thunderstorms off the Gulf of Mexico
During the winter months, the polar jet stream flows more rapidly and creates waves of strong high pressure systems or cold fronts that move south
This is what is happening today and tomorrow – a cold front!

7. Hurricanes, Cyclones, & Typhoons…oh my!
Hurricanes (also called cyclones or typhoons in the Pacific Ocean) are caused by pressure disturbances over tropical oceans.
As atmospheric pressure decreases, a low pressure system is formed.
If the evaporation rate over this system increases due to high temperatures, it can form a tropical depression.
Winds circle around the depression, helping it build in strength and creating an eye wall (an area where the wind is constantly rising).
Hurricanes are ranked on the Saffir- Simpson scale based on their pressure and wind speed.

8. Storm Surge
A storm surge is a period of excessive high water along a coast associated with a change in atmospheric pressure and the wind’s action on the sea surface.
Under the low-pressure of a hurricane, the sea surface builds up into a dome.
The elevated dome travels under the center of the storm, pulling water from around it as it builds.
When the storm makes landfall, the water moving toward the shore piles up and increases the overall height of the sea surface. This produced the storm surge.
Along a shallow shore, such as Tampa Bay, the water extends beyond the sea and there is little pressure for the water to return seaward.

9. Worst Case Scenarios and Creating a Hurricane Plan!
Welcome: Grab a Laptop!
Worst Case Scenarios and Creating a Hurricane Plan!

10. Hurricanes & the Tampa Bay area
The last major hurricane to directly hit Tampa Bay was in 1921 (called the Tarpon Springs Hurricane)
Since then, we have had many close calls including 2017’s Hurricane Irma.
Many residents tend to get complacent because so many of the close calls have veered away at the last second (such as 2017 Irma or 2005 Charlie).
But what would happen if a Category 5 hurricane were to directly hit Tampa Bay?
In 2014, meteorologists partnered with Pinellas County and the National Weather Service for Project Phoenix, a worst case scenario of how our area would be impacted by a large storm:
(12 min)

11. Creating a Hurricane Plan
Obviously, we hope that nothing like Hurricane Phoenix never ever happens – but it is better to be prepared.
2017’s Hurricane Irma was a scary situation, with gas, food, and water shortages in the days leading up to the storm.
Today and tonight, you will work on creating a hurricane plan for the 2018 season for your family so that you are better prepared in the event of another busy hurricane season.
Complete Part 1 today in class, Part 2 tonight at home with your family.

12. Creating a Hurricane Plan
Obviously, we hope that nothing like Hurricane Phoenix never ever happens – but it is better to be prepared.
2017’s Hurricane Irma was a scary situation, with gas, food, and water shortages in the days leading up to the storm.
Today and tonight, you will work on creating a hurricane plan for the 2018 season for your family so that you are better prepared in the event of another busy hurricane season.
Complete Part 1 today in class, Part 2 tonight at home with your family.