Name: ReeNa Khushwaha Roll No: 29 Class: 9 ‘B’ thteaCheRs Name: Namita mam sChool: J.N.V. BaRsooR
Climate Definitions• Climate – “Climate is the sum of all weather events in an area over a long period of time. We have different climates in different parts of the world.”
Major Climate Zone• Tropical Zone: The area lying between the tropic of cancer and tropic of Capricorn on both sides of the equator receives direct rays of the sun..• Frigid Zone: The region between the artic circle and the north pole and between the antartic circle and south pole is called the frizid zone
• Temperature Zone:• These areas lying between the torrid zones and the frizzed zones and the frigid zones are called the temperature zones.
Factors of Climate Change• Climate change happens gradually over years. It is caused by a number of natural factors as well as artificial ones.• Natural Factors• Some famous examples of atmospheric change caused by external factors are: an increased amount of aerosol in the stratosphere from volcanic eruptions, changes in solar activity and changes in relative solar-terrestrial positions.• Without external factors, climate systems change naturally because of five primary factors(atmosphere, hydrosphere, cryosphere, lithosphere, and biosphere). These factors constantly interact with each other.
• Artificial Factors• Since the beginning of the industrial revolution of the mid 18th century, human activity has effected earths climate enormously. Especially, the combustion of fossil fuels, (chemical and organic) changed the solar radiation and the optical properties of clouds in the atmosphere which led to an increase in the greenhouse effect and the production levels of aerosol. Moreover, the radiation of CFCs, a fluorine chemical combination, and bromine compounds, decreased the stratospheres ozone layer, (a barrier which protects the Earth from the suns harmful rays). Also, the changes in the utilization pattern of land saw: increases in urban communities, over development of land, and razed forests. These all resulted in significant changes in the physical and biological properties of the Earths surface.
High Pressure• Higher pressure than what is normal for that altitude.• What do you notice about the air in this region?• Brings clear skies and fair weather. – The sinking cold air warms as it does so and becomes stable.
Low Pressure• A low pressure region (depression or cyclone) is caused by rising air.• Clouds, rain, and very strong winds occur.• Why do you think that is?
Creating a Cloud• Watch the cloud demonstration:• What were the key ingredients in creating the cloud?• How is this representative of what might take place in the atmosphere?
Temperature & Humidity• Temperature - Air higher in pressure is usually cooler air and air lower in pressure is usually warmer air.• What happens when the two meet?• Humidity - How much water is in the air over how much water could fit in the air (right before the water begins to condense out of the air).• Dew point - Temperature at which the moisture saturates the air is the dew point.
Wind• Caused by the earth’s surface being heated unevenly by the sun.• Why would the earth’s surface heat unevenly?• How do you think this causes the wind?
Thunderstorms• What type of cloud causes these?• Consists of gusty winds, heavy rain and hail.• Can result in a tornado
Lightning• What did you observe in all the lightning demonstrations? How does this suggest lightning occurs?• Interesting Fact: More people are killed by lightning per year than in tornadoes!!!
Atmosphere• Troposphere - Most of the weather occurs.• Stratosphere - 19% of the atmosphere’s gases are here; ozone layer is here• Mesosphere - Most meteorites burn up here.• Thermosphere - High energy rays from the sun are absorbed; hottest layer.• Exosphere - Molecules from atmosphere escape into space; satellites orbit here.
Greenhouse Gases• Greenhouse gases - carbon dioxide, methane, water vapor, nitrous oxide, and fluorocarbons.• Are they all bad? We will find out through the lab.• Retain the heat through a process called the Greenhouse effect.