Feedback Loop of Plant Earth

The Hydrosphere not only supports life on this planet but depending on its concentrations and locations can have lasting effects on our climate. The Hydrocycle is an example of a natural feedback loop that occurs on this planet.  Clouds accumulating creates rain that is absorbed by the ground and sucked up by the plants who then return the water to the atmosphere. This happens through transevaporation in the form of water vapor which condenses in the atmosphere and creates another rain cloud. This is an example of a feedback loop, and when these loops are interrupted by humans and other occurances on Earth the loop can be broken and have lasting effects on the environment, climate and ecological habitats.

Oceans  are the main source of evaporation and percipitation in the hydrologic cycle. At the current trend oceans are becoming more acidic as a result of the large amounts of CO2 it is absorbing. Too much CO2 can cause other disturbances like acid rain which kill fauna. When plants die there is less evapotranspiration re-admitted into the atmosphere. As the land becomes barren of plants it also absorbs more of the sun’s rays drying the soil which can result in deforestation. 

Deforestation is also decreasing the amount of water vapor released by plants through evapotranspiratition. As humans eliminate large areas of vegetated land we are seeing effects to our climate and environment that could be irreversible. Plants in the Amazon rainforest store large amounts of carbon dioxide. When these forests are torn down the stored carbon is released increasing the already high carbon dioxide that stores and captures heat in the atmosphere. The heat then warms the barren land to higher temperatures creating a climate change.

                           

Water divergence or damming is causing the few natural lakes we have on Earth to dry up. Damming water increases the surface area of water thereby increasing the evaporation rate of the once flowing water source. Downstream environments loose their nutrients, dry up, and die altering the landscape. The Aral Sea has shrunk in the last decade. An irrigation project to feed water to cotton plantations has diminished the water table from the fourth largest lake to less than 10% of its natural size. Human activities like these are altering the environment unconditionally. The area is now seeing  a decrease in precipitation and increase in temperature range.

                                                

    

The Aral Sea story

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These three human driving forces are interrupting the Earth’s natural feedback loops while changing and warming our climates, and destroying and depreciating our water supply.  Without water there can not be life. Humans around the globe are already feeling the effects of the disruptance of the hydrological cycle and there are many more challenges ahead to be faced.

http://www.effects-of-deforestation.com/amazon-rainforest-deforestation.php

http://www.fao.org/ag/magazine/9809/spot2.htm

http://www.youtube.com/watch?feature=fvwp&v=Z0Pi61SyVSM&NR=1

http://www.globalchange.umich.edu/globalchange2/current/lectures/deforest/deforest.html

Earthquakes in California

Earthquakes are a bizare phenomenon that can be explained but predicting when they occur is still a puzzling concept.  The Earth is made up of differents layers. The layer which humans and earth processes have modified is the thin outer crust made up of rock materials. This crust is put together like a puzzle and the pieces are called plate tectonics. These plates are always and have always been continuously moving. 

When these puzzle pieces converge, diverge and slide past one another we experience the dreaded earthquake.

Underneath the crust is the mantle this is the second layer of Earth. The mantle has different layers to it but the one closest to the lithosphere, or crust, is the Asthenosphere a bendable molten mixture that the tectonic plates float on. The Asthenosphere is the driving force of the movement of the plates. Where these puzzle pieces meet are ridges that have new molten material that pushes up through the crust through convection and spreads out, called sea floor spreadin. When new material is added to the crust pressure builds along the edges of these puzzles pieces(tectonic plates) until the pressure is too much to take and energy is released in the form of an earthquake. 

           

One of the well known, earthquake prone areas of the United States is the San Andres Fault located in California. Fault lines are associated with plate boundaries. In the case of the San Andres Fault we see a Transfom boundary of the Pacific and North American plates. There are several types of boundries between plates with different characteristics and movement.  Transform Boundries are charaterized by their 

horizontal movement past one another and lateral displacement of Earth’s crust. The two plates slip past one another when the pressure is too intense for the Earth’s crust and therefore the Earth under our feet shifts in a violent movement and jolt.

                                                                                                                                                                                                                 Areal view of the San Andreas Fault

Earthquakes origin of movement is relatively shallow. The pressure is released at the focus point, and or the center of the fault’s motion. This focus sends shock waves further below the origin and above. The area directly above the focus on the Earth’s crust is the epicenter. It is here that the wave of released energy in the earths surface is felt.

http://pubs.usgs.gov/gip/earthq1/how.html 

http://latimesblogs.latimes.com/lanow/earthquakes/

http://geology.com/san-andreas-fault/ 

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.