Meteorology and Weatherby Sean Wang and Collin Westcott

Introduction

Have you ever wondered how weather is formed? Or maybe you're curious about how to predict what the weather will be like tomorrow. This can all be traced back to the Sun.

AtmosphereThe atmosphere consists of 5 layers. From lowest to highest: Troposphere, Stratosphere, Mesosphere, Thermosphere, and the Exosphere. It is composed of nitrogen, oxygen, argon, carbon dioxide, other noble gases, and water vapor.

Troposphere and StratosphereThe the Troposphere reaches up to 14 kilometers high.The Stratosphere, located just above the Troposphere, reaches up to 50 kilometers. The Ozone Layer is located inside the Stratosphere, and it acts as a shield from harmful sunlight.

Mesosphere and ThermosphereThe Mesosphere is located above the Stratosphere and reaches up to 90 kilometers.The Thermosphere reaches up to 500 kilometers. This is where most small meteorites burn up and also where the Aurora Borealis occurs.

Exosphere

The exosphere is the furthest layer from land in the atmosphere. It is 10,000 meters above sea level. It is composed of hydrogen, helium, and a little bit of other gases.

ConvectionConvection is the transfer of heat by movement of currents within a fluid. Hot air or fluid rises and is replaced by cold air or fluid going down, causing convection currents. The bottom is then heated and the top cools, continuing the cycle.

Wind Currents

Variety of winds- Local Winds (Land and Sea Breezes) and Global Winds (Doldrums, Trade Winds, Prevailing Westerlies, Polar Easterlies)

Local Winds

● Land Breeze- blows from the land to the ocean and occurs due to water retaining more heat than land during the night. The cold air above the land blows into the warm, less dense air above the water.

● Sea Breeze- blows from the sea to the land due to land warming faster than water, so the opposite of a land breeze occurs, blowing cold air onto land where the warm air is less dense.

Global Winds● Doldrums- surface winds at

the equator that are calm and weak

● Trade Winds (Horse Latitudes)- 30° lat from equator with calm winds and few clouds

● Prevailing Westerlies- located at 30°-60° lat and has a strong impact on US weather

● Polar Easterlies- near the poles and are cold and weak, but influences US weather

Ocean Currents● Surface- at a depth of several

hundred meters driven by winds and affects climates on the coast. Move in a clockwise direction in the north and counter-clockwise in the south.

● Deep- when cold, dense water sinks beneath less dense water deep in the ocean.

● Gulf Stream- is warm due to equator origination and is located in the North Atlantic Ocean.

Low and High Pressure (Cyclones/Anticyclones)

Low- An area with cold, dense air is a high pressure area, or anticyclone. Winds in this area spiral outwards in a clockwise direction in the northern hemisphere due to the Coriolis Effect. It is marked with an "H" on a weather map.High- This is an area where warm air at the center rises, decreasing the air pressure. Cooler air blows toward this area, spiraling inwards in a counter-clockwise direction in the northern hemisphere due to the Coriolis Effect. These areas have unstable weather conditions because of the fronts that branch out from it.

Cyclone/Anticyclone Diagram

Fronts● 4 types of fronts- Cold

Front, Warm Front, Occluded Front, Stationary Front

● Cold- when a mass of cold air slides under a mass of warm air, causing stormy weather abruptly

● Warm- when a mass of warm air slides over a mass of cold air, causing light rainfall

Fronts (cont.)

● Occluded- when a warm air mass is caught between two colder air masses (the warm air is cut off from the ground and the weather becomes cloudy and rainy)

● Stationary- when a warm and a cold air mass meet each other, but neither has enough force to move each other (can bring many days of clouds and precipitation)

HurricanesA hurricane begins over warm water as a low-pressure area. A hurricane gets its energy from the warm air at the ocean’s surface. As this air rises and forms clouds, more air is drawn into the system. The winds spiral inward to the areas of low pressure.

Tornadoes Tornadoes happen when a warm humid air mass meets a dry cold air mass.For example, a warm, humid air mass moves north from the Gulf of Mexico into the lower Great Plains. A cold, dry air mass moves south from Canada. When the air masses meet, the cold air moves under the warm air, which rises.

The Sun and Its Energy

collin

Weather Maps

collin

Weather Map

Isotherm and Isobar

collin

Types of PrecipitationThere are four main types of precipitation: rain, snow, sleet, and hail. Precipitation is formed when warm air rises and condenses. It then forms into clouds and precipitates when it is unable to hold any more liquid.If certain conditions are met (e.g. temperature), different forms of precipitation may appear.

Types of CloudsClouds are all formed through condensation of warm air into water droplets. The main types of clouds are Cirrus, Stratus, Cumulus, and Cumulonimbus. Cumululonimbus clouds are dense, tall clouds that cause unstable weather. Cumulus clouds have flat bottoms and clearly defined edges. They produce little or no precipitation, but can build up into a Cumulonimbus cloud. Stratus clouds are horizontal clouds that act like above ground fog, and may bring rain. Cirrus clouds are made of ice crystals, which cause them to be long and wispy. They produce falling ice crystals that evaporate before touching the ground, but indicate precipitation.

Types of Clouds Diagram

Dew Point

Dew point is the temperature at which condensation begins. If the dew point is below freezing then water can become ice crystals.

How Do Scientists Get Images?Scientists are able to predict what will happen in a certain area based on images from similar areas with similar occurrences. They acquire these images from a satellite orbiting the Earth that takes pictures and sends it back. The pictures are able to show changes over time in a certain area and provide important information to scientists.

Meteorological InstrumentsMeteorological instruments used by scientists include the thermometer, barometer, hygrometer, and anemometer. A thermometer measures temperature of the surrounding area. A barometer is used to measure air pressure. A hygrometer measures the relative humidity of the air. An anemometer is used to measure the speed of wind.

SeanSlide 2- IntroductionSlide 3- AtmosphereSlide 4- Troposphere and StratosphereSlide 5- Mesosphere and ThermosphereSlide 8- Wind CurrentsSlide 9- Local WindsSlide 10- Global WindsSlide 11- Ocean CurrentsSlide 12- Low and High PressureSlide 13- Cyclone/Anticyclone DiagramSlide 14- FrontsSlide 15- Fronts (cont.)Slide 20- Weather MapSlide 22- Types of PrecipitationSlide 23- Types of CloudsSlide 24- Types of Clouds DiagramSlide 26- How do...Images?Slide 27- Meteorological Insutrments

CollinSlide 1- Title SlideSlide 6- ExosphereSlide 7- ConvectionSlide 16- HurricanesSlide 17- TornadoesSlide 18- The Sun and Its EnergySlide 19- Weather MapsSlide 20- Isotherm and IsobarSlide 25- Dew Point