Mr. Fetch's Earth Science Class Ch 17.1: The Atmosphere Meteorology Mr. Fetch's Earth Science Class A+

17.1 Atmosphere Characteristics Composition of the Atmosphere 17.1 Atmosphere Characteristics Weather is the condition of the atmosphere measured over a short period of time Is constantly changing Climate is based on observations of weather that have been collected over many years. Climate helps describe a place or region.

What is measured regularly? Temperature Humidity Cloudiness Precipitation Air Pressure Wind speed and direction Weather Bug

Mr. Fetch's Earth Science Class The Atmosphere A layer of gas that surrounds Earth. Created long ago by volcanic eruptions. Held around Earth by gravity. Regulates Earth’s temperature. Gravity hold air around Earth A+ Mr. Fetch's Earth Science Class Mr. Fetch’s Earth Science Classroom

Mr. Fetch's Earth Science Class The Early Atmosphere Much different than our atmosphere today. Not suitable for life: No Oxygen to breathe and no Ozone to protect from sun’s rays. Lots of Carbon Dioxide Very little Oxygen Early Atmosphere Lots of Oxygen More suitable for Current Atmosphere Mr. Fetch's Earth Science Class Mr. Fetch’s Earth Science Classroom

Mr. Fetch's Earth Science Class Eventually, organisms called Cyanobacteria started making Oxygen photosynthetically. That oxygen was used to create Ozone. Ozone blocked harmful rays from the sun allowing plants to survive on Earth’s surface. Plants produce Oxygen allowing you and I to live and breathe on Earth. The Process Mr. Fetch's Earth Science Class Mr. Fetch’s Earth Science Classroom

Mr. Fetch's Earth Science Class Composition of the Atmosphere Components of the atmosphere The most abundant gasses in our atmosphere are: Nitrogen Oxygen Argon Carbon Dioxide The atmosphere also contains some solids and liquids: Dust Acids Ash Salt Water Vapor Mr. Fetch's Earth Science Class Mr. Fetch’s Earth Science Classroom

Mr. Fetch's Earth Science Class Layers of the Atmosphere Atmosphere is divided into different layers based on temperature. Temperature changes as you go up. Sometimes it INCREASES Sometimes it DECREASES Sometimes it STAYS THE SAME There are 5 layers to our atmosphere, each with different characteristics: 1. Troposphere 2. Stratosphere 3. Mesosphere 4. Thermosphere 5. Exosphere Mr. Fetch's Earth Science Class Mr. Fetch’s Earth Science Classroom

Mr. Fetch's Earth Science Class Layers of the Atmosphere Thermosphere Temperature INCREASES High temperatures Thin air. Feels cold. Mesosphere Temperature DECREASES Stratosphere Temperature INCREASES Contains ozone O3 absorbs bad rays Absorption = Warm Troposphere Temperature DECREASES. Weather occurs here. ATMOSPHERE Mr. Fetch's Earth Science Class Mr. Fetch’s Earth Science Classroom

Mr. Fetch's Earth Science Class Air Pressure Air pressure is the weight of air pushing down from above. As you go up, pressure DECREASES. Air pressure makes air near Earth’s surface DENSE. Mr. Fetch's Earth Science Class Mr. Fetch’s Earth Science Classroom

17.1 How do Humans influence our Atmosphere? Composition of the Atmosphere 17.1 How do Humans influence our Atmosphere?  Human Influence Human depletion of ozone by use of chloroflorocarbons (CFCs) Emissions from transportation vehicles account for nearly half the primary pollutants by weight.

Primary Pollutants Makes no sense without caption in book

17.1 Earth-Sun Relationships What are two major motions of Earth? Rotation – Spinning on axis Revolution – Moving around the sun Click on Globe!

Tilt of Earth’s Axis What creates the Earth’s seasons? The Earth’s tilt relative to the position to the sun. This also changes the length of daylight. Makes no sense without caption in book

17.1 Atmosphere Characteristics Earth-Sun Relationships 17.1 Atmosphere Characteristics  Solstices • The summer solstice is the solstice that occurs on June 21 or 22 in the Northern Hemisphere and is the “official” first day of summer. The winter solstice is the solstice that occurs on December 21 or 22 in the Northern Hemisphere and is the “official” first day of winter.  Equinoxes The autumnal equinox is the equinox that occurs on September 22 or 23 in the Northern Hemisphere. The spring equinox is the equinox that occurs on March 21 or 22 in the Northern Hemisphere.

Solstices and Equinoxes Makes no sense without caption in book