science

• Seasons

  Different periods of the year that are distinguished by special weather and climate conditions
• Seasons


  • Spring
  • Summer
  • Autumn
  • Winter
• Seasons


  • Different amount of light received from the sun
  • Different temperatures
  • Different weather conditions that repeat
• Axis


  An imaginary line passing through the center of the earth that goes through both the north pole and the south pole
• Rotation

  The spinning motion of earth around its axis
• Revolution

  The movement of the earth around the sun
• It takes 24 hours or one day for the earth to completely rotate around on its axis
• It takes 365 and 1/4 days or one year for the earth to move around the sun
• Tilt of the earth's axis

  • Tilted at an angle of 23.5 degrees
  • Reason behind the occurrence of seasons
• Solstice


  When the axis of the earth points forward or away from the sun
• The first day of summer is marked by the summer solstice which occurred during June 21 or June 22
• The first day of winter is marked by the winter solstice which occurred during December 21 or 22
• When the north pole is tilted toward the sun in June

  The northern hemisphere receives more direct rays from the sun and experiences longer daytime than nighttime
• When the south pole is tilted toward the sun in December

  The southern hemisphere receives more direct rays from the sun and experiences summer
• Equinox


  When the axis of the earth does not point either toward or away from the sun, resulting in equal day and night
• The first day of spring is marked by the vernal equinox which happens on March 21 or 22
• The first day of the autumn season is marked by the autumnal equinox which happens on September 21 or 22
• Wet and dry seasons

  The two main seasons experienced in the Philippines due to its location near the equator
• The rainy season in the Philippines is from June to November, and the dry season is from December to May
• The dry season in the Philippines can be subdivided into cold dry season and hot dry season
• Seasonal change is caused by the tilt of the earth's axis, the revolution of the earth around the sun, the direct rays of the sun, and the length of daytime
• There are a number of unique combinations of atmospheric phenomena experienced by people in all parts of the world
• Common atmospheric phenomena


  • Breezes
  • Monsoons
  • Intertropical Convergence Zone
• How air behaves when heated

  1. Air molecules move faster and spread out

  2. Makes the air less dense or light

  3. Warm air rises
• Warm air rises


  Surrounding air moves toward it to replace the rising warm air
• Wind


  Air that is moving horizontally
• Land surface heats up faster than bodies of water during the day, but loses heat faster at night
• Breezes

  • Localized winds near bodies of water
  • Experienced by those living in coastal areas
• Sea breeze

  1. Land warms up faster than bodies of water during the day

  2. Warm air on land rises

  3. Cooler air above the sea moves toward the land and replaces the warm air
• Land breeze


  1. Land cools faster than the sea at night

  2. Warm air over the sea rises

  3. Cooler air from the land moves toward the sea
• Monsoons

  • Wind systems that involve bigger masses of air moving horizontally
  • Bring abundant rainfall
• Types of monsoons

  • East monsoon
  • Southwest monsoon
• How monsoons occur

  1. Air moves toward the place where warm air is rising (low pressure area)

  2. Air sinks in the high pressure area

  3. Wind moves from high pressure to low pressure area
• Northeast monsoon


  • High pressure in China and Siberia, low pressure in South Indian Ocean/Australia
  • Brings dry, cold wind
• Southwest monsoon


  • High pressure in South Indian Ocean/Australia, low pressure in China and Siberia
  • Brings warm, moist wind
• Intertropical Convergence Zone (ITCZ)


  • Place where trade winds from Northern and Southern hemispheres meet at the equator
  • Warm, humid air masses form, resulting in heavy precipitation and thunderstorms
  • Breeding zone of low pressure areas
• There are a number of unique combinations of atmospheric phenomena experienced by people in all parts of the world
• Common atmospheric phenomena


  • Breezes
  • Monsoons
  • Intertropical Convergence Zone
• How air behaves when heated

  1. Air molecules move faster and spread out

  2. Makes the air less dense or light

  3. Warm air rises
• Warm air rises


  Surrounding air moves toward it to replace the rising warm air