What factors affect different types of weather (the whole lesson)
- 1. The Water Cycle •To understand the processes involved in the water cycle
- 2. What is Evaporation? •It is the process of a liquid heating to form a gas
- 3. What is Condensation? •It is the process of a gas cooling to form a liquid
- 4. The Water Cycle Water is constantly moving between sea, air and land The sun shines and the sea is heated heat
- 5. The Water Cycle Water is constantly moving between sea, air and land Evaporation The water evaporates and forms clouds
- 6. The Water Cycle Water is constantly moving between sea, air and land Condensation As air rises it cools and condenses. It reaches the ground as rain, snow, sleet or hail.
- 7. The Water Cycle Water is constantly moving between sea, air and land The snow melts and flows Lakes form Snow forms
- 8. The Water Cycle is complete
- 10. Humidity It is the amount of water vapor in the air . The higher the temperature the more water vapor it can hold Warm air can absorb much more water vapor than cold air
- 11. Relative Humidity The amount of water vapor in the air compared to the total amount that air can hold at that temperature . When water can’t hold water vapor anymore the relative humidity is 100%
- 12. • When the air is saturated or filled with water vapor ,any additional water vapor will condenses in to a liquid ….This temperature is called “Dew point “
- 13. Types of Clouds 1)Stratus Blanket Like
- 14. 2)Cumulus • Billowy puffy clouds that seem to rise from flat bottoms
- 15. 3)Cirrus • They are wispy feather like .
- 16. Naming clouds • we can call the clouds according to their altitude by adding prefix or suffix. Example: Prefix “Cirro “ Clouds formed at high altitude “Alto “ Middle altitude “Nimbo” They are clouds bringing thunder storm Suffix Nimbus They are clouds bringing thunder storm
- 17. Alto stratus Prefix Cumulo nimbus Suffix Examples
- 18. Cloud Cover
- 19. Types of cloud
- 20. Types of precipitation 1)Rain It falls when the temperature is warm .
- 21. 2) Sleet • Forms when raindrops freeze and turn into pellets of ice before falling to earth’s surface.
- 22. Snow • It falls when the air becomes cold that water vapor becomes solid rather than condensing into droplets
- 23. Hail stones • As wind pushes raindrops high into the atmosphere where they turn into ice.
- 24. • The process repeat as water freezes in layers and the hail stone grow.
- 25. Clouds and weather •Puffy cumulus cloud They often appear in fair weather .
- 26. •Wispy cirrus cloud Change in weather is happening
- 28. Large Cumulus Clouds • Heavy rain or snow showers which ends quickly.
- 29. Stratus cloud • Long lasting precipitation with smaller raindrops and snow flakes
- 30. Measuring amount of rainfall • People have measured rainfall for thousands of years. • It is especially important for farmers to know how much rain will fall this year. • The instrument used to measure rain fall is called “Rain Gauge”
- 31. Thunderstorm • It begins when intense heat causes air to rise quickly (low dense air ) • This heated air ,or updraft, then cools and forms clouds.
- 32. • Updrafts hold water droplets and ice crystals in the cloud. • When they grow too heavy for the updrafts to support , they fall as rain or hail.
- 33. • As the precipitation falls many of the raindrops and ice crystals collide (hit each other) . • Downdrafts in the cloud also cause falling air to brush against rising air . • This results in the formation of electric charge at the bottom of the cloud . • (Negative electric charges build up in the bottom of the cloud.)
- 34. • When enough of a charge builds up ,it produces a huge spark ,which is called “lightning “ . • Lightning superheats the air around it ,where air expands suddenly (spread out ) then contracts as it cools. • This rapid movement of air produces sound waves that are heard as “thunder “
- 35. Tornado • It is a violently rotating column of air that extends downward from thunderclouds and touches the ground.
- 36. • A tornado starts when moist hot air mixes with cold dry air . • On hot days ,rising air (low density) causes powerful updrafts . • The air begins to spin in the cloud ,if the updraft is strong air rushes with high speed decreasing the pressure at the center. • As more air rushes in ,the air pressure at the center decreases more and more ,increasing the spinning speed . • Soon a funnel forms that may reach the ground
- 38. • The swirling funnel starts to descend. • The wind speed in the tornado can reach 500km/hr or more.
- 39. • The force of the tornado ‘s winds destroy houses , cars and anything in its path.
- 40. Hurricane It is a large ,rotating tropical storm system with wind speeds of at least 119km/hr
- 41. What is a hurricane? A hurricane is a very destructive and dangerous storm. It forms in stages. The hurricanes are filled with rain, strong winds, lightning, thunder, hail and tornadoes. Stages of the hurricane : 1)Tropical depression 2)Tropical storm 3)Hurricane (wind speed 120km/hr)
- 43. • It starts as thunderstorm over the ocean near the equator . • The heat causes air above the ocean to be warm with low pressure ,and evaporation of the water (area of tropical depression) • As the water vapor rises up , the temperature decreases causing it condensation and release of energy causing the warming of air that causes the decrease in density more and more. • AS the air pressure falls ,the wind grow stronger when winds near the center reach 120km/hr the storm is considered hurricane . • Hurricanes produce huge amount of rain .
- 44. What is eye of a hurricane? While some hurricanes, are small, others can be quite large. Hurricanes are mighty storms. In the center of a hurricane is an eye. Ironically, the eye is actually a calm area in a hurricane.