Category: Weather

LIGHTINING AND THUNDERSTORM

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By Amon Samwel – Art in Tanzania internship

Lightning is the brilliant electric spark discharge in the atmosphere occurring within a thunderstorm, between the clouds. The flashing of light produced by a discharge of atmospheric electricity and a flashing of light is the result of discharge of atmosphere electricity within a thunderstorm cloud way up into the sky. Many small bits of ice frozen raindrop bump into each other as they move around in the air. All of these collisions create an electric charge and usually occurs to the areas that are mostly concentrated with metals.

Lightning can occur during anytime of the year but lightning casualties are highest during summer. July is generally the month with the most lightning and the strikes mostly occur in the afternoon. In fact, two thirds of all lightning casualties occur between noon and 6pm.

Examples of places or countries that are affected with lightning are the all regions of USA, Alabama, Colorado, Florida, Georgia, Missouri and North Carolina. Florida is considered as the lightning capital of the country with more than 2000 lightning injuries over the past 50 years.

According to the U.S department of health and human services, they have reported some categories which are:

  • Males are, five times more, likely than females to be struck by lightning. Around 85% of lightning fatalities are men
  • People aged 15-34 years account for almost half of all lightning strike victims (41%). The majority (89%) of lightning deaths occurs among Caucasians.
  • About one third (32%) of lightning injuries occur indoors.

Lightning is the results of thunderstorm from a charge in the normal electrical field between the surface and the atmosphere, in fair weather the surface is negatively charged, and atmosphere is positively charged. Owning to intense friction of air within the Cumulonimbus cloud, higher charges are built up with positive charges in upper portion and negative charge in lower portion. When the potential difference becomes more pronounced, discharges [lighting] occur from the cloud to the ground, from cloud to cloud or within the same cloud.

The occurrence of lighting involves different process as explained bellow;

  • The sky is filled with electric charge. In calm skies they are positive + and negative[-]charged
  • Inside a thunderstorm the electric charge is spread out differently.
  • A thunderstorm is made up of ice crystal and hailstone.
  • The ice crystal have positive charge (+) and the hailstone have a negative charge (-).
  • The hailstone is pushed to the bottom of the thunderstorms by its downdraft.
  • During the thunderstorm the Earth surface has a positive charge. Because the positive charge attract the negative charge at the bottom of the thunder clouds wants to link up with the positive charge of the earth surface.
  • Once the negative charge at the bottom of the cloud gets the large enough, a flow of negative charge rushes towards the earth surface. This is Known as the “stepped leader,”
  • The positive charge of the earth surface is attracted to this stepped leader so as a flow of positive charge moves into the air. When the stepped leader and the positive charge from the earth meet a storm.

THUNDERSTORM

Refers to violent convective storm accompanied by thunder and lightning usually localized and lived. Vertical air motion, considerable humidity, and instability combine to create towering cumulonimbus clouds. Frequently occur in conjunction with other kinds of storms like hurricanes, tornadoes, fronts especially cold fronts in mid latitude cyclones and orographic lifting

Types of Thunderstorm

  • Orographic thunderstorms – caused by air that is forced up by a mountain or hillside.  
  • Air mass thunderstorms – is the result of localized convection in an unstable air mass.
  • Frontal thunderstorms – occur along the boundaries of weather fronts (e.g. cold front).

 Characteristics of thunderstorms

  • Thunderstorm last for a short duration, seldom two hours
  • It consist of down and updraft of air with electric charges and thunder.
  • It is associated with heavy precipitation or hail.
  • It is usually destructive in nature as, it can kill people, animals, and destroy property.

Condition leading to the formation of thunderstorms

  • There should be prevalence of atmospheric instability such that air updraft can set off.
  • There should be availability of ample supply of atmosphere moisture for condensation to take place and maintain a storm.
  • There should be some agent to start convection as uplift over a hill or mountain.

STAGES OF THUNDERSTORM

The thunderstorm has three main stages which are cumulus stage, the mature stage, and dissipating stage.

The cumulus stage; this is the first stage of the thunderstorm .its dominated by updrafts that create the cloud formations which are cumulonimbus cloud necessary. The continuous strong updrafts prevent precipitation from falling .This occur where super cooled water droplets and ice crystal coalesce, then fall initiated a downdraft.

The mature stage; this once the storm has developed it will enter the mature stage. This stage is dominated by both updrafts and downdrafts and is the most dangerous stage. Falling precipitation is indicator that the storm has reached the mature stage. Lighting severe turbulence and hail can all be encountered during this time. It is also most active at this time.

The dissipating stage; this is the last stage once the updrafts begin to die out the storm is dominated by downdrafts and enters the dissipating stage. This signals that the thunderstorm is dying out. In this stage it is where downdrafts dominate and turbulence cease.

          THUNDERSTORM FORMATION

The action of warm air rising and cool air sinking plays a key role in the formation of severe thunderstorm, if the warm surface air is forced to rise because is less dense than the surrounding air. This occur when the cold air and warm air meet each other whereby the warm air is forced to rise due to be that it is less denser and the cold air sinks, so the warm air in the atmosphere will settle and condense slowly. 

Two of the most important ingredients for thunderstorm formation is instability and moisture Normally in the atmosphere, there is unstable air that causes the disturbance in the atmosphere and also the moisture that is caused by the cooling of warm air in the atmosphere might result to the occurrence of precipitation, even the presence of moisture and unstable air results to the thunderstorm formation

Thunderstorms are formed by uplifting of warm and humid air, the air that is formed is forced to move upwards due to it being denser normally it becomes cooler and mixes humid air clouds and water droplets that lead to precipitation or rain.

When humid air is lifted , it will be cooled and the moisture in the air will condense to form cloud. So, after the warm air rises upward to the atmosphere, it normally meets the moist air or moisture that forces it to cool and become humid, this situation leads to the formation of the clouds known as cumulonimbus. Normally these clouds are formed after the cooking of warm air containing the cloud within positive charges and negative charges and negative charges that once come into contact leads to the occurrence of thunderstorm.

Upon further uplifting, the clouds will extend higher water droplets in the clouds continue to grow in size as the clouds extends further upwards ice crystals may form because of low temperature. This means that due to the denser air rising upwards higher in the atmosphere forces and causes the clouds known as cumulonimbus to be formed higher away in the atmosphere and also due to the cool temperature in the higher atmosphere forced the water droplets became pieces of ice crystals so this becomes very essential for the clouds formation.

Finally thunderstorms are produced by the cumulonimbus cloud normally the cumulonimbus clouds contain two different charges that is positive charge known as crystal and the negative known as hail so once these come across they produce a steeper light known as lightning that comes with a heavy and huge sound known as thunderstorm.

What should we do during lightning and thunderstorm period?

In summary;

HOW CLIMATE CHANGE AFFECTS AGRICULTURE IN TANZANIA

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By Faraja Ntilulagomba – Art in Tanzania Internship

‘Climate Change’ denotes to long-term change in the statistical distribution of weather patterns (e.g., temperature, precipitation etc.) over decades to millions of years of time. Climate on earth has changed over millions of years since the beginning long before human activity could have played a role in its transformation.

But the United Nation of Framework Conservation on Climate Change (UNFCCC), defined Climate Change as “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods”. However, the Intergovernmental Panel on Climate Change’s (IPCC) definition of climate change includes changes due to natural variability alongside human activity. Australian Government’s DCCEE, on its website described Climate Change- ‘our climate is changing, largely due to the observed increases in human produced greenhouse gases. Greenhouse gases absorb heat from the sun in the atmosphere and reduce the amount of heat escaping into space. This extra heat has been found to be the primary cause of observed changes in the climate system over the 20th century’.

Thus, in the environmental discourse different stakeholders have characterized Climate Change as mainly the change in modern climate augmented by human activities. The adverse human activities for example are burning of fossil fuel or deforestation, which are considered likely to bring change in some climatic  aspects.

Climate change is the global phenomenon of climate transformation characterized by the changes in the usual climate of the planet (regarding temperature, precipitation, and wind) that are especially caused by human activities or climate change is “a broad range of global phenomena created predominantly by burning fossil fuels, which add heat-trapping gases to Earth’s atmosphere. Some aspects or examples of climate changes include increase in temperature (which is global warming), drought, floods, ozone layer depletion, shrinking ice sheets, rise in sea level, ocean acidification, greenhouse gases etc. Some causes of climate change are Industrial activities, meteorite impacts, quantity of greenhouse gases in the atmosphere, burning of  fossil fuel, deforestation etc. According to Rahman M.I(2012) said that Climate Change, the most uttered environmental term of present time has been used to refer to the change in modern climate brought predominantly by human beings.

European Research on Climate change funded by Seventh Framework Programme said that Climate change is arguably among the most pressing societal challenges of our times, and now certainly the most well-known amongst the public. From initial observations of global warming and proposed ideas about the root causes, a steady consensus has built up that climate change is one of the most serious threats facing the world in the near future. It is very clearly stated in the recently released 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) on the physical science basis, that global warming is mostly caused by human activities.

Agriculture can be defined as the science or practice of farming, including cultivation of the soil for the growing of crops and the rearing of animals to provide food, wool, and other

products. It involves crop cultivation and animal keeping. Agriculture is a critical economic sector, representing 29.1 percent of Tanzania’s Gross Domestic Product (GDP) and almost three quarters of the productive workforce. Moreover, it is the main source of food, industrial raw materials, and foreign exchange earnings. Since Tanzania is endowed with a diversity of climatic and geographical zones, farmers grow a wide variety of annual and permanent crops. This includes food and cash crops as well as fruits, vegetables, and spices. Major agricultural exports include tea, coffee, tobacco, cotton, and cashew nuts. In addition, some farmers raise livestock including cattle, goats, sheep, pigs, and chicken as well as small numbers of turkeys, ducks, rabbits, donkeys, and horses.

In Tanzania climate change affects agricultural activities. The following are negative impacts of Climate change on agriculture in Tanzania.

Reduction of Productivity in agriculture; for example, increase in temperature, drought, and floods can decrease the rate of production in agricultural sectors. Increase in temperature lead the dry of crops like maize and beans hence results low in production to farmers.

Reduction of water availability; for example, drought can result in loss of water in the agricultural sector. Water is the primary medium through which we will feel the effects of climate change. Also, water availability is becoming less predictable in many places, and increased incidences of flooding threaten to destroy water points and sanitation facilities and contaminate water sources. Higher temperatures and more extreme, less predictable, weather conditions are projected to affect availability and distribution of rainfall, snowmelt, river flows, and groundwater, further deteriorating water quality and insufficient supply of water. Due to these irrigation activities in the agricultural sectors, plant growth may fail due to lack of moisture in the soil.

Destruction of plants and decrease in number of animals; for example, Global warming affects plants and animals, some of which may die. Most plants and animals live in areas with very specific climate conditions, such as temperature and rainfall patterns, that enable them to thrive. Any change in the climate of an area can affect the plants and animals living there, as well as the makeup of the entire ecosystem. Some species are already responding to a warmer climate by moving to cooler locations. For example, some animals and plants in Tanzania are moving farther in other place or to higher elevations to find suitable places to live. Climate change also alters the life cycles of plants and animals. For example, as temperatures get warmer, many plants are starting to grow and bloom earlier in the spring and survive longer into the fall. Some animals are waking from hibernation sooner or migrating at different times, too.

Increase of evapo-transpiration; for example, increase in temperature result loss of water from water bodies by evaporation and loss of water from plants by transpiration. So excessive loss of water from plants results the decrease or loss of water in other soil, so crops or plants my fail to grow due to lack of moisture in the soil.

Decrease of income to farmers; This because climate change like global warming, ozone layer depletion, drought, and floods result low in production in agricultural sector hence income decreases because farmer have a low crop yield

Soil erosion: Increasing in available moisture, also called effective precipitation, would tend to promote both runoff and soil erosion on the one hand, and vegetation cover on the other. Since vegetation reduces erosion, we have another case of the result hinging on the net effects of “competing” processes. Effective precipitation result floods so hence lead soil erosion, this results the loss of nutrients hence bringing less growth of crops in agricultural sector.

Destruction of agricultural infrastructures, for example high rainfall and increase in temperature result the loss of vegetations. Also, floods may cause land degradation. So, climate change result destruction of agricultural infrastructure.

Delay of plant or crop growth, for example, when there are seasonal rainfall plants or crops my lack water for growth. When there are no rainfall crops may fail to grow and develop but if there is minimum rainfall crops mat develop and grow.

Reducing crop quality, due to the reduced growth period following high levels of temperature rise; reduced sugar content, bad coloration, and reduced storage stability in fruits; increase of weeds, blights, and harmful insects in agricultural crops.

Reducing land fertility; Due to the accelerated decomposition of organic substances; and increased soil erosion due the increased rainfall.

Therefore, Climate change is a rapidly growing concern for the Government of Tanzania and development partners alike. Policy and strategy processes related to climate change must be undertaken in some sectors in order to reduce climate change aspects, Climate change is a cross cutting issue affecting a number of sectors including forestry, agriculture, water, lands, energy, infrastructure, and others. So, we need to take action on climate change action (mitigation and adaptation) in order to reduce the effects of climate change on agricultural sector in Tanzania.

REFFERENCES

_on_Agriculture_and_Health_Sectors_in_Tanzania_A_review

WHAT IS CLIMATE CHANGE AND WHAT ARE ITS EFFECT ON OUR PLANET? PART 3

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By Gabriel Andre – Art in Tanzania internship

THE IMPACT OF CLIMATE CHANGE IN TANZANIA

1. What can be expected

Tanzania is a coastal country in East Africa which shares the Victoria Lake border with Kenya and Uganda. Given that the vast majority of the population’s livelihoods are dependent on the agriculture sector (80 % of the population) which is highly sensitive to climate change, Tanzania is considered to be particularly vulnerable to climate change. Climate change impacts are already taking a significant toll on the livelihoods and wellbeing of Tanzanians, including:

Rising of severe droughts frequency and its associated water scarcity issues, slow down in the food production chain, economics and poverty reductions gains, reduced quantity and quality of the water in Victoria Lake, including an increase in contaminants which impact the purity of the water and have the potential to harm health,  reduced surface water flows and aquifer (see diagrams below) that recharge during drought periods, as well as groundwater depletion through aquifer over extraction.  

Furthermore, we can anticipate the intrusion of saline into aquifers (diagram) in low-lying coastal areas, as well as on a more global scale, impacts from coastal flooding.  Climate projections for Tanzania include increased periods of prolonged drought, more erratic rainfall patterns (leading to extreme flooding) and a rise of sea-levels, all of which may exacerbate the mentioned pressures on water resources in this already water stressed country. If Tanzania’s low capacity for climate resilience is not addressed, this will likely have a profound impact on public health, stifling future development in urban and rural settings alike.

2. Projections from today to 2100

In this section, I’m going to illustrate what transformation we can expect in different sectors in Tanzania such as energy, agriculture, water, and health. 

Before going into technical information, it’s important to understand how those sectors will be impacted. In most of the diagrams, there will be two baselines: RCP 2.6 and RCP 8.5

The Representative Concentration Pathways (RCP) is a greenhouse gas concentration

(Not emission) trajectory adopted by the Intergovernmental Panel on Climate change (IPCC). They described different climate futures depending on the volume of GHG’s emitted in the years to come. Founded by the World Meteorological Organization (WMO) and the United Nations Environmental program (UNEP), IPCC’s role is to provide objective with scientific information to understand the risk of human induced climate change and drafted recommendations to act in consequence. 

IPCC has foreseen many different scenarios such as RCP 1.9, RCP 2.6, RCP 3.4, RCP 4.5, RCP 6, RCP 7 and RCP 8.5. In the following analysis of Tanzania climate change future, we are going to focus only on RCP 2.6 and RCP 8.5. 

RCP 2.6 requires that CO2 will start decreasing by 2020 and go to zero by 2100. Methane emissions (CH4) are going half the CH4 level of 2020 and Sulphur dioxide declined to approximately 10% of those of 1980-1990. In simple words we will be able to respect Paris Agreement and likely to keep global temperature warming rise under the 2*C by 2100. We will have to face new environmental conditions, that are still close to the actuals one’s, but our daily life will remain comfortable.

RCP 8.5 as you can imagine is another story. It’s the worst climate change scenario with a very high baseline emissions scenario. Experts see it as the “business as usual” scenario.

RCP 8.5 scenario assumes that by 2100 there will be between 9.6 billion and 12.3 billion people. Assuming that the collapse of fertility will occur in the entire world without considering Africa. For example, Nigeria’s population will rise from 175 million nowadays to 1.5 billion by 2100. Almost all the fossil energies will be consumed, and we can expect that southern Europe will be the new Sahara. Most of the people on the planet will be leaving in extreme conditions. A scenario where giving birth in 2100 would be condemning your children to a hopeless life.  

Let’s then focus on the impact of those scenarios on Tanzania through those sectors. Most of the following diagrams in this section are being taken from the Climate Change Knowledge Portal of the World Bank group. https://climateknowledgeportal.worldbank.org/country/tanzania-unitedrepublic/climate-data-projections

Þ Agriculture and Energy sector 

Precipitation: extreme events  

As warmer air has a higher capacity to carry moisture in form of water vapor, future climate raises the likelihood of strong rainfall events, towards the extremes. In many

places around the world, the maximum expected amount of rainfall in a 10-year period is projected to increase, which can lead to flooding. 

Nowadays, Tanzania is issued to this seasonal temperature and climate variation. Rainfall period starts in December and ends at the beginning of April. Then, the easter season arrives with comfortable temperatures, consequently causing the arrival of millions of tourists. 

What would be the projection of this monthly precipitation in RCP 2.6 and 8.5 scenarios?

RCP 2.6

Compared to historical data, between 2080-2099, Tanzania will face variation around 75mm maximum (January, November) of its precipitation which will reinforce floods in coastal regions and in the Victoria Lake region. In other terms, the rainfall season will be each year more intense, but Tanzania will have time to adapt to those new conditions. New innovations will engender better management in the agricultural and the energy sectors. On the left, monthly precipitation projections for 2020-2039. On the right, monthly precipitation projections for 2080-2099. In the case of RCP 2.6 scenario, the difference in 50-80 years is not considerable. 

RCP 8.5

In the case of RCP 8.5, monthly precipitation will drastically increase leading to a maximum precipitation level difference of around 150mm in January. On the left monthly precipitation projections for 2020-2039. On the right, monthly precipitation projections for 2080-2099. In the RCP 8.5 scenario. 

In both cases, precipitation concentration will increase, which will intensify future floods, yet not with the same intensity. Indeed, in the diagram above, RCP 8.5 scenario demonstrates the impact of “business as usual” attitude towards Tanzanian climate. It is clear that if we were to find ourselves in the situation of the diagram on the right, business will not be as usual. Power production will be largely affected. For example, the transportation lines for fuel could be interrupted by local flood for days or even weeks, or the networks distribution could be disturbed by excessive rainfall and flooding. Agriculture will be hit critically with farm crops always swept by floods which will drive Tanzania into a deeper poverty. 

Drought: extreme events 

Both power demand and production are tied to water availability. Obviously, this is most directly the case in hydropower systems. Although, dry conditions might also come along with higher temperatures, thus heightened cooling needs and an increase in demand for water pumping, particularly in regions of intense agriculture. 

On the production side, water is required for cooling the power plants. If there is not enough water, then cooling is restricted, thus production might need to be slowed down. In some places, there are regulations preventing power plants from causing an increase in the temperature of returned water above specific thresholds, which are dangerous for local fish and plants. These thresholds are more quickly reached if stream flows are low during dry conditions. In a few regions, too much moisture can also be an issue as water might need to be removed.

RCP 2.6

Concerning agriculture, drought can disrupt its demand and production because the exposition of soils to high temperatures and the scarcity of water can result in the infertility of soil. 

In the RCP 2.6 scenario, temperature will rise for 2.5 degrees with extreme variation. Normally it will stay around the 1 degree rising prediction. The temperature will still promote comfortable living. Both energy and agricultural sectors will remain possible thanks to technical innovation. 

RCP 8.5

In the RCP 8.5 scenario, temperature will rise from 3 degrees to maximum 6 degrees! It will drastically change Tanzanians habits in terms of energy supply. Disruption of operation and distribution will become a major problem because of the rising demand of growing population and evolving power needs. In the same case, demand for agriculture will rise but production will decrease because of soil infertility. With 80% of the population living on agriculture, feeding Tanzania’s population will be a huge challenge. Moreover, the breeding of goats and cows will face a lack of grasslands and associated difficulties sustaining livestock. 

To sum up, in the case of the RCP 2.6 scenario, environmental conditions will increase progressively, leaving time to find innovations and new management methods to keep demand and production at a sustainable level. That also means, that the Tanzanian society will have to take a responsible pathway for its environment by focusing on green energies and avoiding fossils energies.  

In the case of the RCP 8.5 scenario, environmental conditions will increase drastically without leaving time for the farmers and energy companies to adapt their methods. Both sectors will be submerged by those changes. Agriculture will face long drought periods making soils incapable of growing any crops, and then will follow long term rainfall causing incessant floods where here also, the farmers will not have the time for transition and crops will be drown and washed away. Electricity will face high demand for cooling, hence conditions for living workers in both extreme periods will be inhumane. Finally, supply, production and distribution in flood periods will be difficult because of poor road conditions. 

Þ Water sector: Lake Victoria case

Africa’s Victoria Lake is the largest tropical lake and source of the Nile River. Climate changes will affect Lake Victoria’s levels of evaporation, temperature, rainfall, and solar energy. According to Emily Beverly, assistant professor of sedimentary geology at Baylor University, the Lake Victoria “could have no outlet to the White Nile in at least ten years”. Which means that every major port will be land closed and Kenya could lose access to the lake in a maximum of 400 years. More than 40 million people are living on the Lake Victoria basin and this result will badly affect their economy. Tanzania depends on the lake’s freshwater because it provides 1 million tons of fish annually. Tanzania’s fishing industry will decrease highly, and all northern regions would be directly affected by this shortage. 

Even with an increase of the precipitations in Tanzania (monthly precipitation diagram 2080-2099), in the RCP 8.5 scenario, temperatures will be so high that the lake will dry out too quickly for it to fill up. 

The diagram shows the drought impact in the Victoria Lake where more than half of the Tanzanian lake area will be affected. 

Moreover, with the rise of temperature, the demand for drinkable water will equally rise.

Global warming will cause the ice on Kilimanjaro and Mount Meru to melt irreversibly.

Neither of these sources will be able to provide drinking water to the districts around

Mount Meru (Arumeru, Arusha, Karatu, Monduli, Ngorongoro) and those around the Kilimanjaro (Hai, Moshi rural, Moshi urban, Mwanga, Rombo, Same) who are completely dependent on them, representing more than 3 million people. 

Finally, the rise of sea levels will constrain a majority of Zanzibar’s population to immigrate to the mainland. 

Þ Health sector 

Most economic sectors will be affected by climate change (agriculture, energy, fishing, etc.) and the impact on those sectors will result in many adverse effects on the human health of the Tanzanian population. With 80% of the population living on local agriculture, most of them won’t be able to feed themself and starvation will be become through years, common.  Because of this malnutrition, many will be inclined to face communicable or non-communicable diseases. According to the World Bank data, 54% cause of death in Tanzania were by communicable diseases, maternal, prenatal and nutrition conditions. 

Malaria is still also a major issue in Tanzania. In 2018, the incidence of Malaria was 124 per 1000 which represents 7.4 million people at risk. The rise of tropical temperature and floods will increase the mosquito’s population and therefore the risks of obtaining yellow fever, malaria, Zika virus, chikungunya and many others. 

Finally, according to the RCP 8.5 scenario, poverty will increase consequently, and the population won’t be able to face massive floods. 49% of the population living under the 1.90$ per day, with houses on the ground and only a sheet of metal as roof, we can easily imagine the catastrophe. 

In conclusion, if Tanzania takes the pathway of green energy which means avoiding both coal and oil, the two major used fossils energies, and if a massive environmental sensibilization campaign is implemented by the government, then Tanzania could likely be faces the RCP 2.6 scenario. As always, the biggest drivers of gas emissions are the public and private sector and there are the ones who have to give the example. Otherwise, the country will face, in the worst-case, the RCP 8.5 scenario. As seen before, these scenarios will be a disaster for a country in development such as Tanzania which faces extreme events and unbearable conditions of life.