Climate Change Impacts and Mitigation

Over the next century all of Africa is very likely to become dryer and warmer than the global annual mean warming. Due to shift in the rain belt there will be changes in the amount of rainfall, resulting in a decrease of rainfall in northern Sahara and Mediterranean Africa. However, the annual mean rainfall in East Africa is predicted to increase. The average temperature increase is 3-4 degrees Celsius, which is around 1.5 times the global mean. Smaller increases of around 3 degrees Celsius are projected to be found in equatorial and coastal areas while a higher increase of around 4 degrees Celsius will be found in the Western Sahara region.



http://www.grida.no/graphicslib/detail/freshwater-stress-and-scarcity-in-africa-by-2025_4036#

Studies show that Africa is one of the most vulnerable continents to climate change and variability. With the decrease in precipitation, by the year 2020, around 75 million and 250 million people are going to be exposed to increase water stress. As you can see from the picture to the left, the northern and eastern African countries will feel either water stress or have a scarcity of water by the year 2025. This also means that agriculture production will suffer; the area ideal for agriculture, and the length of growing seasons will decrease. Overall, this will negatively affect malnutrition in Africa and affect food security. To make things worse, towards the end of the 21^st century there is an expected sea-level rise, which will affect low lying coastal areas.

African farmers have started to develop adaption options to cope with future climate variability; however it may not be sufficient for this upcoming climate change. African countries already tackle arid conditions making agriculture difficult. By 2020, crop yield in some countries will have a decrease of as much as 50% and by 2100 crop yield will have a decrease of around 90%. Currently around 25% of Africa’s population experience high water stress with an increase of between 75-250 million and 350-600 million people by the 2020s and 2050s. Even without climate change, several countries in northern Africa will exceed the limits of their usable water resources before 2025.



http://www.grida.no/publications/vg/africa/page/3116.aspx

There are many threats resulting from climate change in Africa. It was a toss-up between the decrease of agricultural production/food yield and increase stress of water supply, however the threat that interests me the most is the overall decrease of water supply. As you can see from the image to the right, more than half of the countries in Africa will feel the increase of stress of water supply in 2025, This was the most interesting threat to me because dehydration kills people faster than starvation. Decrease of water ultimately has the biggest impact because without water agriculture will rapidly dwindle down. It affects so many other aspects other than dehydration. Plus, a portion of Africa struggles with their current water supply. When this problem increase resulting from climate change, it will be the biggest problem Africa faces.

 

Severe Weather in Egypt

 

Today I am going to share with you some of the ins and outs of cyclones and hurricanes. How does a tornado even occur? Wherever there is a thunderstorm, there is a chance of a tornado. After all, tornadoes are formed by severe thunderstorms. Generally, there are three steps for tornado development. First tornadoes need vertical wind shear. This is when wind increasingly blows faster as height increases. This vertical wind shear helps wind topple over causing a spinning, rotating body of air at the surface called a vortex tube. In the second step, an updraft from a thunderstorm lifts the vortex tube off the ground which is pulled into a thunderstorm. Once the vortex tube is vertical, it is called a mesocyclone. The mesocyclone intensifies as its walls contract, which makes wind speeds increase. A tornado occurs once the mesocyclone reaches the ground.  

In the United States tornadoes travel from west to east, with a counter-clockwise rotation. Since tornadoes travel where ever the wind takes them, it is just natural that tornadoes in the US will move in this direction resulting from the Westerlies. As you may have guessed it, if tornadoes travel from west to east, one will first spot the signs of a tornado in the western skies. According to the Storm Prediction Center, there are 1,300 plus or minus a few hundred tornadoes observed in the US per year (The Online Tornado FAQ, NOAA). Unlike the US, Egypt has an average of zero tornadoes per year (WikiAnswers).
 

http://www.windows2universe.org/earth/Atmosphere/tornado/agri_map.html

The picture to the right shows a global map of tornado occurrences. The red dots are the location of previous tornadoes and the green shaded area are agricultural areas. When I first saw this picture I noticed that the red dots and the green area are mostly in the same place. This is because both, tornadoes and agriculture need moisture. Tornadoes do happen in Egypt, however it is very rare. If there is ever a tornado in Egypt it will result with minor damages and there will NEVER be a tornado in Cairo. If you look at the Global map, Egypt is not close to any of the tornado "hot spots."

Over time, tornado occurrences have appeared to increase. I don't think tornado occurrences have increased, just more of the tornadoes are being observed. This is probably due to rapid technological advancements. It is now easier to observe and measure tornadoes and other weather related phenomenon's. Even today there are tornadoes that come and go with out anyone being able to record the data. This is due to tornadoes touching down on areas that are uninhabited.

 

http://web.mit.edu/12.000/www/m2010/finalwebsite/background/hurricanes/hurricanewhatis.html

As you can see in the picture above, hurricanes are born in the tropics. The tropics is ideal for hurricane formation because it comprises of the three main requirements that hurricanes need to form. The three main requirements for hurricane formation are warm ocean temperatures for evaporation, deep warm ocean layer of at least 200 meters in depth and Coriolis. The ideal ocean temperature needs to be above 80 degrees Fahrenheit, which only happens equator-ward of 20 degrees North or South. Not only does the surface ocean temperature have to be warm but the deep layers as well because when the wind churns up the water it is still has to be warm in order to produce a hurricane. This also only happens equator-ward of 20 degrees North and South. The confusing thing is that the term for hurricane depends on the region it is occurs. In the Atlantic and East Pacific it is called a hurricane while hurricanes in the Indian Ocean near Australia are called Cyclones and off the coast of China and Indonesia they are called Typhoons.



 

http://www.wunderground.com/blog/JeffMasters/remainder-of-july-hurricane-outlook

Generally in the United States, hurricanes travel in a "C" path. The picture above shows the paths of different hurricanes near or over the United States. You can notice that most of the hurricanes are traveling on this "C" path. This is the dominant path that hurricanes travel in the US due to multiple reasons. First of all since we have a warm gulf stream the Hurricane will more likely follow that path up. Secondly, hurricanes need water! So once a hurricane reaches land, there isn't any water to fuel this gigantic storm. On land there is also friction. Terrain cuts off the hurricanes circulation and steals the storms moisture. The storm will eventually travel back over cold water where it will decay. According to the Hurricane Research Division, the average number of hurricanes that hit the US per year is 1.7 (NOAA).
 

Hurricanes do not happen in Egypt. The average number of hurricanes that hit Egypt annually is zero (Wikianswers). 

Daily Weather in Cairo

 Today I am going to be writing about the five-day forecast in Egypt’s capital city, Cairo. My five-day forecast will be covering Monday thru Friday: March 17, 18, 19, 20 and 21. Monday, March 17, Cairo’s high is forecasted to be 82 degrees Fahrenheit and the low is forecasted to be 58 degrees Fahrenheit, with absolutely 0% chance of precipitation. On Tuesday, March 18, the high is expected to be 74 degrees Fahrenheit while the low is expected to be 55 degrees Fahrenheit. There is a 20% chance of precipitation. Wednesday, March 19, Cairo has an expected high of 77 degrees Fahrenheit with the low expected to be 55 degrees Fahrenheit. The chance of precipitation is very slim with just a 10% chance.Thursday, March 20, Cairo’s forecasted high is 80 degrees Fahrenheit the forecasted low is 54 degrees Fahrenheit, with a 10 % percent chance of precipitation. Cairo’s Friday forecast has a high of 79 degrees Fahrenheit a low of 59 degrees Fahrenheit with also a 10% chance of precipitation.

The map above is a satellite image of Cairo. As you can see there are only a few clouds around Cairo, with a huge cloud just off Egypts coast over the Mediterranean Sea. There must be a low pressure system there. In this image blue clouds are indicated to be high, cold clouds, while gray clouds are lower, warmer clouds. There are a mix of both these clouds around this area of Egypt. From this satellite image you can also see where the dry desert is located compared to the lush green area of the Nile Valley.

 

Above is a Global Surface Analysis image of Africa. This map shows current frontal high and low pressures. A high pressure is indicated with the blue "H", while the low pressure system is indicated with the red "L". There are two high pressure systems and one low pressure system, around the northern part of Africa. There seems to be stronger winds around the high pressure system on the left because the isobars are closer together. If you don't know what isobars are, they are lines of constant pressure. Therefore the closer they are to each other, the stronger the winds will be. Although there are stronger winds in the north western part of Africa, you can tell that the winds are weak in central and Southern Africa from the spacing of the isobars. Due to numerous factors like, pressure gradient force, coriolis and friction, winds from a high pressure will blow in a clockwise swirling motion out toward the low pressure system causing clouds and rainy weather. As you look to the bottom right hand corner of this image you will see a blue and red line with blue triangles and a red semi circle. This line is called a stationary front. A stationary front occurs when two air masses push together, but neither one is powerful enough to move the other. Winds blow parallel to the front, helping it stay in place.

 

Here is the same Global Surface Analysis image, however it is zoomed so we see just the Middle East instead of all of Africa. In the top right corner we can see a cold front moving east and since the isobars are so close to each other, the winds are blowing fast. If you are not too sure, a cold front is indicated by the blue line. The blue triangles on the line indicate the direction that the front is traveling. If the line was red with red semi-circles, it would indicate a warm front. Similar to the cold front, the red semi-circles point to which direction the front is traveling. Now if we look at Egypt we can see that the isobars are very far apart, indicating slow wind speeds. 

 

Well that does it for this weeks blog post. See ya next week.

Global and Local Winds in Egypt

Egypt's latitude and longitude coordinates extend from around 32 degrees N to 22 degrees N latitude and from 25 degrees E to 35 degrees E longitude, making Egypt located in the Ferrel Cell. Since my country is located in the Ferrel Cell the wind belt that Egypt resides in is the Westerlies, which makes the wind blow from West to East. If you look at a map of Egypt, most of the populated cities are along the coast of the Nile. The Nile is on the right side of Egypt, so as the winds blow from west to east it will pick up much sand and dust and fly it straight into populated cities like Cairo. Plus if this wind blows over extremely hot land, the wind gets hotter and hotter. This does not sound pleasant at all. Thinking about Egypt's climate makes me so thankful that I live in Hawaii. Anyway, enough with the little tangents, lets get back on topic. Egypt is located near a high pressure belt because it lies very close to the boarder of the Hadley Cell and Ferrel Cell. At around 30 degrees N (S) latitude there is a special area called the Horse Latitude. This occurs from subsiding air associated from the Hadley Cell. In this special area you will find most of the land covered in deserts and barely any winds. That is exactly how Egypt's climate is. Egypt is very hot and dry which is a result from this geographic location of the Horse Latitude. Though Egypt is a mostly a vast desert it is bordering two bodies of water. Thanks to differential heating, land cools and heats faster than water, which makes for land and sea breezes.

Egypt does have a large grouping of mountains in the Southern Peninsula. However most of the Country is a dry desert with a lot of moving desert sand and dust. There are different breezes and winds associated with mountains. Five in particular are mountain breeze, valley breeze, Katabatic wind, Chinook Wind and Santa Ana Wind. Egypt does not experience the Katabatic, Chinook or Santa Ana winds because those winds reside in specific locations. On the other hand, Egypt does experience mountain breezes and valley breezes because the wind has to go up or down the mountain depending on where the high and low pressures are. 

Temperature Controls in the city of Cairo in Egypt

The most populated city is Egypt is Cairo, which is also the countries capital. Cairo has the latitude and longitude positions of 29º52 North and 30º21 East. The warmest months in Cairo are July and August, both with an average monthly temperature of 84.2 degrees Fahrenheit. The coldest month in Cairo is January with an average month temperature of 57.2 degrees Fahrenheit (World Weather Online). The annual range of temperature for Cairo is 70.7 degrees Fahrenheit.

In class, we learned about different temperature controls. Those being: ocean currents, altitude, differential heating, geographic location, cloud coverage and albedo. Egypt is one of the hottest and driest countries in the world due to its geographic location. Cairo is more toward the right side of Egypt, while on the left of the Nile is a vast, and scoring hot desert. Since the winds blow across this hot desert, it blows hot air right in to Cairo and many other cities. Plus when this wind blows over the desert, it carries large quantities of sand and dust, which may also cause temperatures to rise.

I think all of the temperature controls learned in class impact Cairo's hot and dry climate in some way. I think altitude, geographic location and cloud albedo make Cairo hotter, while ocean currents and differential heating make Cairo cooler than shall I say, Al Harrah. Al Harrah is closer to the center of Egypt, with a much hotter temperature than Cairo. This city is not close to any open water, making for no cool wind from these oceans/ seas.

As sea level rises I believe Cairo's temperature will slowly decrease. When sea level rises Cairo will get closer and closer to open water. Thanks to differential heating, water does not change temperatures as fast as land. Winds over the water and the surrounding areas will be cooler.