El-Nino And La-Nina Affect Climate Patterns

El-nino and La-nina had altered a large area of our tropical Pacific Ocean with warm and cool condition in various forms. The main location of moist, full of rising air is centred over the central or eastern pacific during El-nino, while during La-nina, it happens over Indonesia water bodies stretch to the western Pacific. This pattern will disturb the atmospheric circulation patterns that happen at the central and splitting to both of the poles. The atmospheric circulation connects the tropics with the middle latitudes, witch in return, the circulations will turn to mid-latitude jet streams. By modification, ENSO has the chance to give impact on the temperature and precipitation across the United States and related parts globally. The effect usually at it strongest effects during winter which is from January to March, but the effects can stand until early of the spring. According to NOAA (2016), During El-nino, the southern part of Alaska and U.S Pacific Northwest lean towards warmer conditions than the average, but the opposite of this region will be cooler and wetter than the average. During La-nina, the deviations from the average are reverse but not exactly as the El-nino.

In New Zealand, El-nino influence in its wind movement. According to the National Institute of Water and Atmospheric Research (NIWA) (2020), during El-nino event, New Zealand will have stronger and persistent winds blow from the west during summer season, which promotes dryness in the East area and more rain in the west. However, during Winter season, the wind will reversely blown from the south making the temperature colder in all region of the country. In spring and autumn, the most common type of wind is the south-westerly. Moving to La-nina in New Zealand, the north-easterly winds will likely become common type of wind. The event also bring along moist, rainy conditions to the northeast region at the North Island and the rain will eventually decrease approaching the western South Island. Besides, La-nina can potentially make the average air and sea temperature to be warmer around New Zealand.

Next, they also effect the global average temperature. Usually, during El-nino, the warmest year from several years will be recorded and during La-nina, the coldest temperature of the year also recorded. The average temperature are possible to be calculated due to the size of Pacific Ocean. The massive size of the ocean making the warming and cooling process due to these phenomena lift a footprint on the global average surface temperature. However, the surface warming and cooling process does not include any heat energy entering or releasing the climate system as a whole process from these phenomena. To put in the simplest words, the whole climate system generally is just shifting their heat energy back and forth without really cooling or heating. The changes of the temperature are aided by the trade winds the passing from east to west. If the trade winds happen to be blown harder during La-nina, the wind will push more surface water to the western part of the pacific water. The warm water in the basin will increase with the excess heat stored and allowing for colder, the deeper warm water will rise on the eastern part of Pacific Ocean.

In addition, the wind create a disturbance by making the ocean surface temperature dropped below normal. In some time, heat from the atmosphere will be absorb into the ocean making the cooler air temperatures over a region is large enough to decrease the global average temperature. During El-nino, sometimes the trade wind are no strong enough and tend to reverse themselves causing the amount of cold water travel upward will decrease. Warm water in the west part will moves to east resulting a large area where the ocean temperature is below than normal. Heat from the ocean will absorb to the atmosphere making the warmer air temperature across Pacific Ocean and alter the global air temperature. Again, these phenomena are not creating or reducing any energy resource. They work together with La-nina as the process that hind the existing heat energy from the Earth while El-nino reveals the energy form.

Apart from that, El-nino and La-nina also influence the hurricane and the storm at the Atlantic and Pacific Oceans. During El-nino, there are less hurricane forms in the African easterly waves but in contrast, La-nina produce more hurricane at the same region and have the potential to become major hurricane that will form a threat to the land near the region such as Caribbean Islands and U.S. In short, El-nino contributes to eastern and central pacific hurricanes and lees in the Atlantic contradict to the La-nina. Moving to the famous question which is what is the relationship between ENSO and tornado forming? According to Tippet and Lepore (2017), U.S has experience extreme weather season with the tornado, hail and winds increasing in average numbers. Most of the tornados reported begins at the southern of U.S. which is close to the warm water region at the Gulf of Mexico. However, some of the tornadoes ended up really far than it was supposed to be including 2 EF-1 tornadoes origin in Massachusetts.

The role of El-nino and La-nino in these massive events was they are responsible in shifting the atmospheric circulation, as mention above, mainly the jet stream in a way that cause significant effect to the winter temperature and precipitation rate. The changes occur in the spring are also like during the winter season, but due to several reasons, it appears to be weaker. Besides, the shift will also impact on the thunderstorm activity due to the changes influence by El-nino that tend to shift the jet stream away from the south of U.S. region, resulting the blockage of moisture from the nearby ocean witch is the Gulf of Mexico reducing the probability of thunderstorms event. In contrast, La-nina is linked to the extreme wavy and northward shifted jet stream, which have the tendency to promotes serious weather activities both in south and southeast. Several history of tornadoes outbreaks in 1974, 2008 and 2011 are all origin from the La-nina phenomenon.

Changes in the Climate Pattern Effect the Environment and the Livelihood of People in the Affected Area

Globally, there are some significance impact of El-nino and La-nina phenomena. Although they only effect the closest area to the equatorial Pacific, they still can bring damage due to the powerful forces that they emit because their process involves the temperature and precipitation rate pattern across the world. In most locations especially near or at the tropics, La-nina rarely give much impact on the climate change as much as the El-nino. An example provided by OCHA, again explained that certain parts of Australia and Indonesia including several neighbouring regions, are very effected by the El-nino, but during La-nina, the impact was not severe. During El-nino, there will be a serious drought, but it will not turning ice cold during the cold episodes. This is because each La-nina’s episode, the impact is never the same. It depends heavily on several factors which are the intensity of the phenomena occurs, the year of which it will develop and the time and the interconnection with other associate climate patterns.

Although La-nina is mainly associated by the cold temperature, in the eastern Australia and a couple of South East Asian countries like Indonesia, Malaysia, Singapore, Thailand and Philippines, La-nina is linked to the wet conditions due to heavy rainfall. The same situations also occur at the North Eastern Brazil, Columbia and other northern parts of South America which La-nina held the responsibility to the increase of rainfall. Along coastal Ecuador and North Western Peru, the condition will turn drier than the average same in the Uruguay and certain parts of Argentina. Beside rainfall, La-nina also cause a very wave-like looking of jet stream flow over the United States and Canada in the northern winter season, causing the weather to become colder with big storms over the average events across the North, but slowly becoming warmer and less stormy reaching the South. Lastly, La-nina impact the rain deficiency in the equatorial eastern of Africa specifically at the Somalia and eastern Kenya, making the region experienced drier land with not enough water.

The general concepts of El-nino and La-nina is always revolved around the idea that El-nino and its warm water will cause the drought, while La-nina is associated with the flooding, but this is not always the cause, because our world has a complex weather system. The climate pattern changes due to El-nino and La-nina also has affected the environment and the lifestyle of locals at the affected region. According Sivaramanan (2014), El-nino and La-nina events has affected in term of over-drought that eventually leads to the food shortage and famine. El-nino, has cause drought in various vulnerable region such as in Brazil, India and Papua New Guinea. In a series of El-nino, it is reported that about 8 million of India population has affected with food crisis and starvation. Another event in 1988, reported that the greatest event of El-nino has cause about more than quarter of Ethiopia people died out of extreme hunger.

This is due to the agricultural activities at the area are affected. The grain harvesting activities cannot be carried on because of insufficient of water resources that is very essential in crops development. This has mainly cause the food crisis in many regions even in Asia countries. On top of that, in 1982 until 1983 El-nino events has cause massive world food crisis and in 1992, the drought has caused 80% crop failure rate in some of the effected regions (Yip, 1997 and Kovats, Bouma & Haines, 1999 cited in Sivaramanan, 2014). Next, it also causes the forest fire. This is because both La-nina and El-nino had caused depletion of moisture in both vegetation and soil. The soil and the tree will become extremely dry and a little heat or fire can cause forest fires. The fire bring harm to both animals and human. It also will cause air pollution as the ash and the gasses will travel via air and spread in many areas. Sivaramanan also reported that in 2000 to 2006, an average number of 470 million tonnes of CO2 emit in Southeast Asia region due to the forest fire which one of the reasons was cause by El-nino.

With the food and water crisis, this situation will impact the health of the people at the affected region. According to United Nations Development Programme (UNDP) (2017), there are several cases from Africa and Arab States (Horn of Africa) that is affected by the El-nino and La-nina. For instance, in the Horn of Africa region, the extreme drought causes by El-nino had increase their food insecurity and malnutrition rates. The drought also effects their agricultural production and livelihoods. In June 206, 24 million locals were fronting serious food insecurities. In late 2015, and mid-2016 few parts in Somalia, Kenya, Ethiopia and Uganda has experienced rainy seasons resulting a massive flood that destroy their crops effecting nearly half million of people with the death of 271 people in those regions. Another case is at Burundi also due to extreme drought. As one of the poorest countries in the worlds, they had been effected by the climate with 2108 people died, 1000 families were displaced, damage of lands, 300,000 students had to stop their studies and 1562 cases of malnutrition with children dominating the number were recorded.

In addition, the most vulnerable country such as the underdeveloped countries where the poverty rate and population rate are high. Moreover, their livelihood is highly depended on the natural resources that can be found around them, thus their main activities in ensuring their sustainability is highly related to agricultural activities. in order to survive such extreme climate caused by ENSO, they always took their measurement to the extreme due to insufficient resources such as access to the healthcare, safe drinking water and proper housing. This also contribute the health risk in the affected countries, the health issue can be originate from increasing of the dry conditions such as drought and wildfires also can be originate from increased of the rainfall which causes floods and storms cyclones. According to WHO (2015), there are many consequences that these people had to face, such as vector-borne and waterborne diseases, wildfire smoke exposure and flood or drought related health also nutritional impacts.

For the vector-borne diseases, the most known disease are malaria and dengue. The vectors, mainly mosquitoes held the responsibility in transferring the disease within human. The disease became easily infected due to its characteristics of sensitive to the changes in temperature, rainfall and humidity. WHO also give evidence to associate El-nino and malaria has been found mainly in the Southern Africa, South Asia and South America. This is because the effect of ENSO had change the rainfall and temperature changes. Besides, it also causes waterborne disease such as cholera. In a research, the link between waterborne diseases mostly focused on the bacteria cholera. The study suggested that the increasing sea surface temperature on marine reservoirs of the cholera pathogens has caused the waterborne disease by El-nino in Bangladesh. In separate report by WHO (2016) on the 2016 and 2017 ENSO events, there are nearly 1.5 million in Papua New Guinea, are affected by floods due to above average rainfall. As result, many diseases such as malaria, dengue, chikungunya and Zika virus was fast spread during the disaster.

Natural disaster is also one of the consequences from El-nino and La-nina. For example, floods are the result due to La-nina that has alter the rainfall pattern also exert powerful and widespread influences on both flood and hazards risk. The risk can be bigger with the limited access to food, clean water and sanitation. Floods can damage food supplies and also waterborne disease. The abnormal precipitations events during ENSO had aiding to the increases in the floods risk in basins involving nearly half of the Earth’s land area, especially in Southern Africa, part of the Sahel and more. Thus, it is proven that El-nino and La-nina has the relation in affecting the environment and the livelihood of the people on it.


In conclusion, there are a lot of things that influence our global climate and El-nino and La-nina is one of the factors influencing them. It is also notice that El-nino occurs frequently more than La-nina but the effect from La-nina can be very dangerous and not all La-nina events affect the weather in the same pattern. Same goes to the El-nino event, it is unpredictable whether it can happened exact on the calculated and predicted year. Although these events only happened in the gap of three to seven years, the impact of this phenomena can be fatal to some region and to human being. Hence, we must get ready to face the climate challenge that will come. It is also important for us to calculate the possible damage caused by the El-nino and La-nina in order to sustain for lives and livelihood, economics and environment.

Apart from that, we also learned what is the normal weather patterns and how it develops. We also getting to know that how El-nino and La-nina affect or influence these normal weather pattern by effecting the atmospheric circulations, the wind patterns until the process evolve to become extreme weather such as thunderstorm, tornadoes and more. It also effects the global average temperature because the events cover a large region which is at the Pacific Ocean. Thus, we need to appreciate our natural phenomenon because not all of them bring fatality to the environment and human beings. In Al-Quran, Allah stated in surah Al-Nahl (27:88) “… (Such is) the artistry of Allah, Who disposes of all things in perfect order...' meaning that Allah has created all of His creature with their own function and He also put all the things that happened in such perfect order where it can always benefits us if we look on the bright sight.

07 July 2022
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