El Niño

El Niño is the name given to a change in the flow of water currents in the Pacific Ocean near the equator. El Niño in Spanish means the child. It was given that name because if often occurs around Christmas. Although El Niño takes place in a small portion of the Pacific, it can affect the weather in large parts of Asia, Africa, Indonesia, and North and South America.

The rotation of Earth and the exchange of heat between the atmosphere and the oceans create wind and ocean currents. At the equator, trade winds blow westward over the Pacific, pushing surface water away from South America toward Australia and Indonesia. These strong trade winds bring life giving monsoons to eastern Asia. As warm surface water moves west, cold water from the deep in the ocean rises to replace it.

Every three to five years, the trade winds slacken or reverse direction allowing winds from the west to push warm surface water eastward toward South America. This change is called the Southern Oscillation and is caused by a shifting pattern of air pressure between the eastern and western ends of the Pacific Ocean. The warm, moist air that slams into South America coast brings heavy rains and storms. At the same time, countries on the western Pacific, such as Australia, Indonesia, and the Philippines, have dry weather.

Another type of weather that follows El Niño is La Niña which in Spanish means the girl. La Niña and El Niño are opposite. El Niño is a warming trend that raises the water temperature as much as 5.6 degrees Celsius above normal and La Niña is a cooling of the waters that drops the temperature of the water as much as 8 degrees Celsius below normal.

http://www.scienceclarified.com/El-Ex/El-Ni-o.html

What is a Thunderstorm?

     A thunderstorm is millions of droplets of water vapor in the atmosphere that produce lightning, rainfall, winds, hail, and thunder. Thunderstorms form when instability in the atmosphere cause cumulonimbus clouds to form. Towards the tops of the thunderstorm water droplets become supercooled and is a region know as the anvil. This is where the thunderstorm can’t go any higher because the stratosphere is stable. The cloud starts to spread out along the bottom of the stratosphere. Dust is sucked into the cloud when growing so the supercooled water droplets come in contact with it and turn into to ice.

     If enough ice particles collide and clump together, a small hailstone will form. Forced by gravity, the hailstone falls toward the earth. If the updrafts are strong enough, the hailstone will be sucked back to the top of the storm and get bigger. This process continues until the hailstone is too large and the updraft can’t support it anymore. This causes it to fall to the earth.

     Lightning occurs when the ice particles in the cloud rub each other and cause friction which in turn charges the water droplets. Once enough charge builds between the ice particles rubbing against each other and the ground, the stage is set for lightning. A single lightning can heat the air around it to 30,000 degrees Celsius. This intense heating occurs so rapidly that air density cannot respond. The rapid rise in air temperature is accompanied by an increase in air pressure that generates a shock wave. The shock wave goes outward and produces thunder. This explains why it’s called thunderstorm.

http://michael.bsch.au.com/whatisstorm.html

Cumulus Congestus Clouds

Cumulus congestus clouds are thick fluffy clouds. Basically, water vapor starts condensing at a particular altitude, and as it rises further, it tends to drift upwards in the Earth's atmosphere. These factors play a significant role in giving the clouds its fluffy appearance. A congestus cloud has the ability to cover a significant vertical distance, which gives it a gigantic appearance. Cumulus congestus clouds are characteristics of areas of the atmosphere that are undergoing convection. They are often characterized by sharp outlines and great vertical development. Because cumulus congestus is produced by strong updrafts, it is typically taller than it is wide, and don’t reach higher than the lower troposphere.

It is the largest of the four possible species of Cumulus. Congestus can develop from the smaller humilis and mediocris species when the atmospheric conditions are unstable. This means that the way the air temperature changes with latitude tends to encourage the rising column of warm, moist air at the centre of the cloud to keep lifting higher and higher. Such convection makes the cloud swell to dreadful proportions.

Cumulus congestus clouds are also called towering cumulus. The tops of them look like cauliflower and sometimes light rain can fall from them. Congestus clouds are in the last stage of development. This stage of Cumulus is when it is at the point of maturing into a Cumulonimbus cloud. Once the top of the cloud begins to glaciate, its droplets freezing into ice crystals, the crisp edges of it soften and become more blurred. This is the point at which the cloud has officially turned into a Cumulonimbus cloud and thunderstorms with rain, hail, thunder and lightning can occur.

http://amsglossary.allenpress.com/glossary/search?id=cumulus-congestus1

The Great Tri-State Tornado

On March 18 1925, the U.S. was hit with its worst tornado. The Great Tri-State tornado started out from the Ozarks in southeastern Missouri, headed eastward through southern Illinois, and then lifted in southwestern Indiana after a duration of three and a half hours. The tornado was rated as a F5 on the Fujita scale. It traveled at an average speed of 62mph which is approximately double the speed of an average tornado. The wind speeds of the funnel were 261 to 318 mph. Strong frame houses were swept away by the tornado. Automobiles looked like missiles flying through the air which were thrown in excess of 109 yards.

In total, there were 652 deaths and over 2000 people injured. The number of deaths was double the number of the second worst tornado in U.S. history.The tornado traveled the distance of 219 miles which is the longest recorded in history. It destroyed 15,000 homes and damaged more than 164 square miles. Due to the tornado about $16.5 million in damage was caused. Today it would be about almost $2 billion in damage as a result of today’s prices.

The tornado was the worst because it had longest path in history and destroyed 50% more than an average tornado. In that era, there were no warning systems within towns. There were also ineffective communications with other towns because phone and telegraph services were immediately cut off by the tornado. People didn’t even realize a tornado was in its way until it was right in front of them.

http://www.suite101.com/content/worst-tornado-in-us-history-a37716

Katrina

Hurricane Katrina is one of deadliest storms to hit the U.S Coast. It ripped through the Gulf Coast in 2005 and became the largest hurricane to hit the United States. Major damage was done to Louisiana, Mississippi, and Alabama. Due to the hurricane, 1836 lives were lost and more than $89.6 billion in damage was caused. The oil and forest industries suffered a major blow with interruption in oil supply and loss to the forest industry amounting to $5 billion. Katrina is the costliest hurricane of U.S. history.

Due to a tropical wave and the remains of a Tropical Depression 10, Katrina formed over the Bahamas on August 23, 2005. It then upgraded to a tropical storm on the 24^th, from where it moved to Florida as category 1. After weakening over land, it gained intensity as it moved to the Gulf of Mexico. On the 28^th it grew from a category 3 to a category 5 hurricane with winds up to 160 mph which caused severe damage along the Gulf Coast. The pressure measurement recorded Katrina as the fourth most intense hurricane.  On the early hours of August 29^th the storm weakened and was classified as a category 4 storm. Moving slowly at 12 mph with wind blowing at 155 mph, Katrina caused far greater damage than a fast moving storm would have done.

The main reason for the great loss of life and property in New Orleans was the failure of its levee system due to the system design flaws and lack of maintenance. Nearly every levee in New Orleans was broken or ruptured which caused the flooding of 80% of the city.

http://www.buzzle.com/articles/hurricane-katrina-facts-and-information.html

Earthquake Triggers Tsunami

     On March 28, 1964, an earthquake of a magnitude of 9.2 hit Prince William Sound, Alaska. It is the largest earthquake to hit the United States. The earthquake and a following tsunami took 128 lives and caused about $311 million in damage. The tsunami took 113 lives and the earthquake took 15. Effects were severe in many towns such as Anchorage, Chitina, Glennallen, Homer, Hope, Kasilof, Kenai, Kodiak, Moose Pass, and others. Anchorage held the most severe damage to property. About 30 blocks of homes and commercial buildings were damaged or destroyed in the downtown area. Many schools and stores were damaged beyond repair. Duration of the shock was about 3 minutes.

     Landslides in Anchorage caused heavy damage too. The largest landslide occurred at Turnagain Heights. An area of about 130 acres was demolished by displacements that broke the ground into many deranged blocks that were collapsed and tilted at all angles. This slide destroyed about 75 private houses. Water mains and gas, sewer, telephone, and electrical systems were disrupted throughout the area. Due to the earthquake vertical displacement took place which caused a tsunami. There was no time for warning and within minutes huge tsunami waves destroyed local towns and fishing villages. The tsunami destroyed many towns along the Gulf of Alaska. It left serious damage at Alberni, Canada, along the West Coast of the United States, and in Hawaii. The maximum wave height recorded was 67 meters at Valdez Inlet.


     In my opinion, I believe the earthquake didn’t cause as much damage compared to others even though it triggered a tsunami. I would think that with the magnitude of 9.2, the earthquake would have caused much more damage and the cost would be much greater to repair.

 

http://earthquake.usgs.gov/earthquakes/states/events/1964_03_28.php

Hurricane Andrew

     Hurricane Andrew is part of a group of hurricanes that have been the most destructive in the United States. On August 14, 1992, it started as a tropical wave that moved from the west coast to Africa. Three days later, August 17, it became a tropical storm now known as Hurricane Andrew. As it moved west-northwestward, the development of Andrew was slow. By August 21, it was between Bermuda and Puerto Rico turning west into a better atmosphere. It rapidly started strengthening reaching hurricane strength of Category 4 on the 23. When Andrew passed through the Bahamas it weakened but shortly after regained its Category 4 strength. A day later, it burst straight towards Florida and continued west toward the Gulf of Mexico where it then made a northern turn. This movement led Andrew to Louisiana as a Category 3 hurricane and then it made a northeastward turn to the Mid-Atlantic states where it diminished.


     Andrew is the third most intense hurricane that has hit the United States in record. From the reports of the barometer they have established that Andrew’s central pressure was 27.23 inches. An automated station at Fowey Rocks reported 142 mph sustained winds with gusts to 169 mph. Andrew produced a 17 ft. near the landfall point Florida and tides of 8 ft in the Louisiana coast. It also created a tornado in southern Louisiana.

     Due to the hurricane’s disaster, 23 life’s were lost and $26.5 billion in damage which $1 billion was accounted to Louisiana and the rest to Florida. The damage in the Bahamas was estimated to be $250 million.

     I was amazed by how much damage the hurricane caused. $26.5 billion is a lot of money lost. I would have expected a higher death rate but thankfully it wasn’t.