Weather And Climate

• The sun supplies energy to Earth that is necessary for its survival
• The heat of the sun is too much to bear if not because of a blanket of air that surrounds the Earth we call the atmosphere
• The atmosphere


  • It contains the oxygen that we breathe
  • It allows us to communicate
  • It has the ozone layer that protects us from harmful solar radiation
• A lot is happening in the atmosphere such as the weather system and the atmospheric phenomena caused by the sun or solar energy
• It is necessary that one should be familiar with the structure and composition of the atmosphere
• One can give reasons for the weather events as well as global atmospheric phenomena like greenhouse effect and global warming that result from changes in the composition of the gases of the atmosphere brought by some human activities

  
• Earth's atmosphere absorbs and reflects incoming solar radiation
• The geosphere of the Earth is warmed by sunlight, and depending on the type of surface, reflects sunlight, for example ice reflects more sunlight than asphalt
• The sun is the main source of energy of the Earth
• The sun is composed mostly of hydrogen and helium
• The energy from the sun is either scattered, reflected or absorbed by the layers of the atmosphere
• Permanent gases in the atmosphere

  • Nitrogen (N2) - 78%
  • Oxygen (O2) - 21%
  • Argon (Ar) - <1%
• The relative percentages of the permanent gases remain constant up to 80-100 km high or approximately 60 miles
• Weather


  The condition of the atmosphere at any particular time and place

  
• Elements of weather


  • Air temperature
  • Air pressure
  • Humidity
  • Clouds
  • Precipitation
  • Visibility
  • Wind
• Climate


  The average weather of a particular region over a long period of time
• Climate represents the accumulation of daily and seasonal weather events (the average range of weather) over a long period of time

  
• Climate also includes the extremes of weather—the heat waves of summer and the cold spells of winter—that occur in a particular region
• The earth and its atmosphere are dynamic systems that are constantly changing
• While major transformations of the earth's surface are completed only after long spans of time, the state of the atmosphere can change in a matter of minutes
• Layers of the atmosphere

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere

  
• Troposphere


  Lower part of the atmosphere, where energy source is heating the earth's surface by the sun, temperature generally decreases with height, air circulations (weather, clouds, water vapour, precipitation) takes place mainly here
• Stratosphere


  Sun's ultraviolet light is absorbed by ozone, heating the air, temperature increases with height, ozone protects life on Earth from the Sun's ultraviolet (UV) radiation
• Mesosphere


  Above 50 km, very little ozone, so no solar heating, air continues to cool with height
• Thermosphere


  Above 90 km, residual atmospheric molecules absorb solar wind of nuclear particles, x-rays and gamma rays, absorbed energy causes an increase of temperature with height, where charged particles from the sun interact with air molecules to produce dazzling aurora displays
• Exosphere


  It is mainly composed of hydrogen and helium, no air pressure and high temperature, 600 miles above earth's surface, lighter, faster-moving molecules in the exosphere may escape Earth's gravitational pull, it represents the upper limit of Earth's atmosphere
• The troposphere and the stratosphere together account for more than 99% of the total mass of the atmosphere

  
• Ionosphere


  Located in the altitude range between 80 to 400 kilometers, N and O atoms are readily ionized as they absorb high energy, short-wavelength solar energy, has little impact upon daily weather, has an effect on AM radio reception
• The interactions of the energy from the sun with the different layers of the atmosphere are: Troposphere - some of the sun's heat is obtained by the Earth while others are radiated back and trapped into the air, Stratosphere - the ozone layer protects the Earth from the harmful UV rays, Mesosphere - the coldest layer that is not directly heated by the sun, Thermosphere - the radio waves emitted by the sun is reflected back to Earth from the atmosphere, Exosphere - everything in this layer is hot due to its direct heat from the sun
• Understanding the structure of the atmosphere is important for many purposes, as it improves our knowledge and management of different environmental, meteorological, and climatic events

  
• Reasons why studying the structure of the atmosphere is important

  • The atmosphere protects life on earth by shielding it from incoming ultraviolet (UV) radiation
  • Understanding how energy is transferred within the Earth's system and how it affects climate
  • Insulating the planet in order to keep it warm
  • Earth's atmosphere helps maintain liquid water on the surface
  • Atmosphere provide gaseous resources (Carbon Dioxide required for photosynthesis, Oxygen required for respiration)

  
• Troposphere


  Everything in this layer is hot due to its direct heat from the sun
• Layers of the atmosphere

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere

  
• Importance of studying the structure of the atmosphere

  • The atmosphere protects life on earth by shielding it from incoming ultraviolet (UV) radiation
  • Understanding how energy is transferred within the Earth's system and how it affects climate
  • Insulating the planet in order to keep it warm
  • Earth's atmosphere helps maintain liquid water on the surface
  • Atmosphere provide gaseous resources (Carbon Dioxide, Oxygen, Methane, Nitrogen, Argon)

  
• Sea breeze


  Wind blows from the water to the land during the day

  
• Land breeze


  Wind blows from the land to the sea at night

  
• Land breezes can occur at any time of year but are more prevalent during the fall and winter seasons when water temperatures are still fairly warm and nights are cool
• Monsoons


  Products of the annual variation of temperature over large land areas compared with neighboring ocean surfaces which then cause an excess of pressure over the continents
• Monsoons are characterized by a dramatic seasonal change in the direction of the prevailing winds over a large area
• Types of monsoons in the Philippines

  • Northeast monsoon (amihan)
  • Southwest monsoon (habagat)