Climate Change is Now

Climate is measured by classifying the distribution of precipitation and temperature over long periods of time. These patterns vary over Earth surface and time: while having lasting effects on the geography and inhabitants of any one place on Earth. Many say we  could soon see another climate change as the average temperature of Earth continues to rise.  

Subtropical highs create severe dry climate patterns in the Northern part of Africa known as the Sahara Desert. It is here where some of the driest climates exist and  the natural resource of water is beyond scarce and becoming less accessible as climate changes and temperatures rise.

 The Northern interior of Africa is classified as a BWh and BWk climate. Characteristics of this climate type include BWh very hot summers, or  BWk very cold. Both climate types have precipitation which stays  between 2-10” a year. These subtropical High areas tend to be located between 25 and 30 degrees latitude. 

 Subtropical Highs are susceptible to dryer more arid conditions because it lies outside the wetter regions of the equator where the ITCZ drives convection resulting in rains that occurs daily. As rain falls near the equator the air is dried and pushed north creating the climates we see in the interior North Africa. 

Climate change is occurring. Kenya and Ethiopia are already exibiting warmer weather and dryer season causing a lack of water and vegetation. Lake Turkana has been shrinking for 40 years, decreasing water supplies to its hundreds of thousands of recipiants. The lakes shores use to reach into Ethiopia but now reside in Kenya leaving people hungry and thirsty, fighting for their lives.These people rely on it for farming, pastralization and    survival. 

When The Water Ends: Africa’s Climate Conflicts

The spike in temperatures is resulting from trapped heat in the environment from green house gases that prevent short wave length of radiation to escape back into the atmosphere. Thus we are getting more energy input than we are exerting back out.

Unfortunately many do not realize the effects of changing climate. Thousands of people rely on Lake Turkana as a survival source. In the video, “ When the Water Ends,” a time lapse illustrates how serious this 2 degree increase is. Lake Turkana is evaporating at an incredible rate drying lands and turning tropical zones into more arid unproductive land, a process known as desertification, and resulting from climate change that is not predicted for the future but is happening NOW. 

Http://www1.american.edu/ted/ice/turkana-merille.htm

Http://www.unccd.int/publicingo/factsheets/showFS.php?number=11

http://e360.yale.edu/feature/when_the_water_ends_climate_conflicts/2331

Hurricane turns Tropical Storm.

As most hurrincans this season Rina originated in the Atlantic basin. As the storm grew stregnth it headed toward Mexico's east coastline, disrupting many vacations in the destination hot spot.  Rina became this seasons eighteenth depression which ultimatly resulted in a huricanne threatening coastline in the Caribbean Sea.

Hurricanes develope from pre-existing tropical disturbance. Rina formed from a tropical disturbance that was situated between Nicaragua and Jamaica. As the graph below shows this area was experiencing high cloud heights, heavy rain and strong convection. Convection was stimulated by a low pressure center that forced the warm air high into the atmosphere.

Cloud height and Rainfall measurements.

As the pressure dropped the tropical disturbance was intensified and began to form a tropical storm. As the storm churned in the Caribean Sea it made its way toward Mexico's Yucatan  peninsula.  While it migrated it picked up the speed and momentum from the warm, moist air coditions provided by the Caribbean ocean surface. These are the conditions that fuel hurricanes and allow for stronger faster convection currents and lower pressure cells.  The graph below illustrates how much the storm intesified when compared with the previouse graph.

Cloud Height/Rainfall

By October 25th the tropical storm had become a category 2 hurricane. Warm air was forced higher into the atmosphere causing more unstable conditions and violent thunderstorms that surrounded the eye of the storm. Enormous Thunderheads grew high into the atmosphere from the intensifying uplifts of warm air that began to circulate in a counterclockwise rotation from the coriolis effect.

Infrared image of Hurricane Irene

Purple are stong thunder storms surrounding the center of the Hurricane.

Hurricanes thrive in warm moist conditions.  Unstable air is associated with low pressure cells because it has a tendency to rise. As warm air rises it condenses. If it rises high enough it can reach its point of saturation. In the case of Hurricane Rina, the air rose so quickly that it cause large cumulonimbus clouds towering high in the troposphere, causing extreme thunderstorms and an ideal condition for a hurricane to form.

Fortunately by the time she made it to Mexico's eastcoast, the Category 2 hurricane had been downgraded back to a tropical storm. Wind shear, changing direction of the wind, slowed the momentum of her circulation. Once it came into contact with the peninsula the storm continued to weaken. When Rina began to move over the land mass it experienced drag and lack of moisture that the ocean provided and the fuel Rina needed to survive. 

Unfortunately many out of towners vacations were cut short and cruise ships were re-routed to the east to avoid Rina. Although the hurricane weakend to a tropical storm by the time it hit Mexico it still brought with it extreme winds, high rain fall,  high tides, and storm surges that caused flooding and damage to the peninsula.