Manipulating Clouds

                  Manipulating Clouds

   People have trying to control the weather and the impact that the weather has on us all for a very long time. The earliest known measures known to have taken place in the forms of prayers and ceremonies. The most commonly known forms of ceremonies are by the Native Americans who preformed a ritual called a "rain dance".All over the world similar rituals have taken place.

  

   During the 20th century our understanding in cloud physics has advanced. Scientists started to bring to intentionally seed clouds meaning that they can stimulate the cloud to bring precipitation, clear fog, and reduce hailstone sizes.The U.S government had a project called "Project Storm Fury", which was intended to weaken the strength of a hurricane by disrupting the structure of the hurricane. During the 1962-1971 all hurricanes were seeded with a chemical called " Silver Iodine, but this experiment gave no great success. One thing this experiment did accomplish was it gave meteorologist more knowledge on hurricanes.

   Clouds are made up of water droplets and ice crystals growing on a nuclei. Cloud seeding is when scientist create more water droplets and ice crystals by introducing an artificial nuclei into the part of the cloud saturated with water vapor. This causes a greater chance of precipitation. 

  Cloud seeding advanced when the American scientist Vincent Schaefer discovered that seeding a cloud with small crystals made up of dry ice can serve the same purpose as the artificial nuclei does. This is because the extreme low temperatures of around -109F of the dry ice crystals attracts the water droplets rapidly, building up until they grow large enough to fall from the cloud as rain.

   Later the scientist Bernard Vonnegut discovered that the silver iodine crystals is another ideal substitute for a nuclei.Using silver iodine crystals along with dry ice crystals for seeding clouds, making it even more quicker results. These methods have been used since 1946.

  Cloud seeding air crafts hold tanks of propane that contain silver iodine.The silver iodine is released by the tanks burning off the propane. This releases the silver iodine into the atmosphere where is freezes into ice crystals. Sometimes called "chem-trails" or "chemical trails".  

   

     

Dew and Frost

                               Dew and Frost

    On cold, clear nights the ground is cooled causing the ground to radiate into the atmosphere. If the temperature of the ground reaches the dew point, and also causing the water vapor to form on surfaces near the ground. When the temperature is above freezing , dew is created; and when the temperature is below freezing, the water vapor condenses to form frost.
    Dew is formed when water molecules in the atmosphere slow down as the temperature cools, When the temperature reached the dew point, the molecules start to bundle together on any cold surface. Some water molecules evaporate back into the atmosphere, more molecules replace them.

 
      Frost forms when the dew point is below freezing, causing water molecules to transform directly from vapor to solid ice crystals. Some water molecules may evaporate back into the air, while other molecules replace them.
    Frost damage to crops can become severe. The water in a plant cells can freeze and expand, their cell will be damaged and they can die. Frost damages can also ruin grape harvests.

   

Humidity

                          Humidity

     Humidity to the amount of water vapor in the atmosphere. the quantity of water that the air mass can hold gradually increases over time with the temperature. Saturated air is air mass that is incapable of holding more water vapor. The temperature where saturation is made is known as the dew point (Dew point is the term that most meteorologists use to describe the amount of moisture in the air).

     In hot weather conditions, your body's vital strategies are to sweat, which keeps your body cool. However, with high humidity it makes it much more difficult. In hot weather, your heart pumps blood from the body's core to the skin. When the air is dry, your sweat evaporates easily, this takes some of the body's heat with it. The water vapor in the humid air slows the evaporation process, decreasing the cooling effect.

Sleet

                      SLEET

   

    Sleet is made up of a translucent ball of frozen raindrops. Sleet forms when the layer of subfreezing air ( colder than the temperature at which water freezes) in the atmosphere deep enough to freeze.

     

    The difference between freezing rain and sleet is very minimal. When sleet hits the ground (or any surface), it bounces off unlike freezing rain which covers a surface with a sheet of ice. Instead sleet covers a flat surface with millions of tiny ice pellets.

    Both snow and sleet can fall at any temperature below 32 F and when the air beneath the cloud is dry. If this happens, the rain partly evaporates as it falls. Then the evaporation cools the particles enough to keep them frozen all the way to the ground. Sleet is particularly resilient against melting.

Freezing Rain

              FREEZING RAIN

   Freezing Rain forms when snow falls into a band of warmer air, the snow melts to form raindrops. If the air is below freezing, the raindrops cool along with the temperature (below freezing), but they will not freeze until they reach the ground.
   Freezing Rain coats everything in a sheet of ice, causing plants to die or be damaged and roads dangerous.
   

   During an intense freezing rain storm, trees can be painted with a thick coat of ice. The extra weight can sometimes be to much for the branches to bare, damaging the tree badly. 

   Freezing rain is the most common in the North East, the Upper Mid-West, the Columbia River Valley, and along the Mid Atlantic foothills of the Appalachians. The reason for freezing rain to here is because these are areas were cold air sinks or can be trapped at the surface. Meaning, warmer air moves above the cold arir to form the warm layer the snow passes through.

Percipitation

                                         RAIN

      Like snow and hail, rain falls when they grow  to be to heavy to carried by the cloud. From the top of the cloud the start to fall, collecting smaller water droplets on the way down until they reach the cloud base (the bottom of the cloud). Then the rain falls. Smaller rain drops, called drizzle, comes from stratus clouds.
     Smaller raindrops are shaped like a sphere. While larger raindrops make a more spheroid shape, a sphere with a dent at the bottom. The sent is caused by the wind resistance. If they grow larger they open up like a parachute before bursting into smaller raindrops.

    

   If the temperature remains above 32 degrees, precipitation particles melts into liquid drops bigger than 0.5 mm., called "rain".

Snow

                                        Snow

    Snow, like rain drops falls when they grow to heavy for their cloud. Snow forms if the cloud height is below a height of 1000 ft. high so that the ice crystals (snow) do no t melt by the time they reach the ground. 

   Wilson A. Bentley (was a farmer of Vermont, U.S.A), is known for taking the first detailed photograph of a snowflake in 1885. His book 'Snow Crystals' has become a classic and the phrase 'No two snowflakes are alike' came from him. The shape of a snowflake is established by the temperature and the humidity level of the atmosphere. The different forms snowflakes come in are shown below:

    1888 was not a good year for weather, for two famous and tragic blizzards occured in this year.

• The Children's Blizzard (or also known as the 'Schoolhouse Blizzard'). Hit the U.S planes states on January, 12, 1888. The blizzard came unexpectedly on a warm day, causing many people to go unaware of the great blizzard. Especially the children in the one room schoolhouse, giving this blizzard its name, for most of the 235 causalities were children. This storm started on January 12, and ended on January 13.
  
  
  
  
  
  
• 'The Great Blizzard Of 1888' going through March 11, and March 14, 1888. Also known as 'The Great White Hurricane' was one of the worst blizzards in recorded in the U.S.A. Hitting the East Coast from the Chesapeake Bay to Maine as well as th eAtlantic province of Canada. Snowfall was recorded to get as deep as 20-60 inches, and held winds more than 45 miles per hours fast.

 

   Even though it can never be to cold to snow, it can become less likely in below freezing temperatures. This is because cold air carries less water vapor, and heavy and dense making it less likely to expand to condense. 

Hail

                                           Hail

    Hailstorms tend to be most damaging and frequent where thunderstorms most commonly occur and where the topography (the arrangement of the natural and artificial physical features of an area) is elevated. Severe thunderstorms generate wild, gusty winds and can sometimes produce hailstones. Hailstorms are most common in mid latitudes, particularly in spring and summer.
    Hail is formed inside the cumulonimbus cloud. As you know the cumulonimbus have thermals (updrafts), raindrops can get caught in the thermals carrying them up. As they go up in the cloud again the mold with other raindrops, and because its so cold inside the cloud they freeze up together. Growing every time they go up until they become hailstones, this procces keeps happening until the hailstones become grow to be to heavy for the cumulonimbus cloud. they larger the hailstone the faster they fall.
    While most hailstone grow up to the size of peas, some can form as large as golf

balls or even grapefruits. Lobes and asymmetric shaped can occur in rare, extremely large hailstones. The largest hailstone in recorded history fell in Aura Nebraska, U.S.A, it fell on June, 22, 2003. It measured 18.75 in. in circumference.
    The strongest hailstorm in recorded history occurred on November,3,2007, this storm fell over Bogata, Columbia. The storm blanketed the city with ice. Rain followed by hail and cold temperatures buried dozens of cars in up to 59 in. of ice and freezing rain.