6 CLIMATE
Local hydro-meteorological variables (temperature, humidity, sunshine, atmospheric pressure, wind velocity, precipitation, etc.), and hence water availability, are influenced by the climate. Climate (or climatological normal) is a measure of the average pattern of the meteorological variables over a particular region and over a time period, usually 30-years. Discussions on the climate, in the context of water availability, include climate variability and climate change (or global warming). Climate variability pertains to the way the climate fluctuates around the long-term mean, while climate change refers to the long-term continuous change to a long-term statistically significant variation in either the mean state of the climate, or in its variability.
6.1 CLIMATE VARIABILITY
The common drivers of climate variability are large-scale circulation patterns, sunspots, and volcanic eruptions. The former, however, is the most important one and it can dramatically alter the climate, weather and hydro-meteorological variables around the world. The time period of the resultant change can be in terms of months, years, or even decades.
6.1.1 El Niño-Southern Oscillation
There are a number of climate variability patterns that influences local hydro-meteorological conditions. The most important one is the El Niño-Southern Oscillation (ENSO). ENSO is a coupled ocean-atmosphere phenomenon related to sea surface temperature (SST) anomalies in the central and eastern equatorial Pacific and the associated sea-level pressure difference, the Southern Oscillation (SO) (Rasmusson and Carpenter, 1982). The Southern Oscillation is the fluctuation in air pressure between Tahiti and Darwin, Australia. Negative (positive) pressure is accompanied ...
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... of the most common ones include: the Pacific Decadal Oscillation (PDO), the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation, the Quasi Biennial Oscillation, the El Niño Modoki, etc.
In the US, for example, it has been found that PDO may modulate the effect of ENSO; El Niño (La Niña) during the positive (negative) phase of the PDO, and lead to stronger climate responses, than when they are evolving in opposite phases (Gershunov and Barnett, 1998b). There is, however, a possibility that stronger El Niño and La Niña events result from random decadal variation of ENSO and may even be responsible for the PDO (McPhaden et al., 2006; Rodgers et al., 2004). Irrespective, knowledge of all the climate variability patterns that influence local climate conditions is important and can help forecasting precipitation and other climate variables that affect
A climate model is a mathematical representation of the climate system based on physical, biological and chemical principles. The equations derived from these laws are so complex that they must be solved numerically. As a consequence, climate models provide a solution, which is discrete in space and time, meaning that the results obtained represent averages over regions, whose size depends on model resolution and for specific times (Goosse).
In the statistical distribution of weather condition and its perfect pattern in an amount of time ranging from decades to centuries to millions of years, a substantial, long-lasting and drastic change is largely known as Climate change. It may be a change in more or fewer extreme weather events or in the distribution of weather more or less the average conditions or in average weather conditions. With the usage of theoretical models and observations methods, scientists, experts and specialists in this particular field actively works in order to perfectly understand past and future climate under certain situation and circumstances.
El Nino is both an atmospheric and oceanic phenomenon affecting weather patterns all around the world. It is complemented by La Nina in a cycle that occurs approximately every 4 years, varying as much as every two years to every six years (Wang 1999, 3331). La Nina has almost the opposite effect, however differs in its strength and duration randomly, as does El Nino (Fedorov 2000, 1998). The cycle is often paraphrased as ENSO, standing for El Nino-Southern Oscillation (Flugel 1997, 3230). It is called this because the El Nino phenomenon is especially strong in the Southern Hemisphere, and has greater effects in areas of the pacific near the equator. Although ENSO is prominent in certain areas, it alters weather patterns all around the world. The El Nino pattern can be quite random with and approximate range of 2 to 6 years per cycle, and is a loaded gun believed to be triggered by western winds (Fedorov 2000, 1997). Many scientists are now looking to the past for answers, so the El Nino cycle can be predicted for the years to come. New discoveries have recently been made on El Nino's history, and possible future.
Scientists have determined that weather systems are changeable. Over a large amount of time, the earths tilt changes, causing the axis’s to tilt more one way then it used to, and thus changing the weather. Greenhouse gasses may also change the weather, making our climate either much hotter or much cooler. Ice caps and deserts have one thing in common, one small change in the weather can change them- and they will change the world.
Scientists are currently having a great debate; are the arctic storms at lower latitudes normal weather patterns? Or are they happening due to human activity? The effects of climate change are reshaping weather patterns all over the g...
Climate change refers to shifts in the mean state of the climate or in its variability, persisting for an extended period of decades or longer (Ziervogel and Zermoglio, 2009). It is the change in average atmospheric behavior, and change in the patterns of variation around this behavior (Rumbach and Kudva, 2011). The Intergovernmental Panel on Climate Change (IPCC) declared that climate change is unequivocal as evidenced by observed changes in several global and regional climatic indicators (IPCC, 2007). At the country level, climate change refers to observable changes and permutations (undefined geographic variations) of temperature, rainfall and extreme climate events and their single or collective impacts on various agricultural production (Lasco, et al., 2009).
The two graphs illustrate the relationship between the changes in atmospheric/global temperature with time (in years) when various natural and anthropogenic climatic factors are in existence. Both graphs show sharp, but fluctuating, observed temperature records in every span of five years, between 1900 and 1920. The observed temperature anomaly is recorded as -0.3oC after every five years for the entire 20 years. The observed temperature variance is seen to have a rising trend from 1920 up to 1945 after which there is a slight decrease in temperature up to 1960. The recorded temperature anomaly then continues to rise until it reaches a peak of 0.95oC. On the other hand, the line graphs of the climatic temperature models are smooth and depict a steady rise in temperature anomaly from 1900 up to 1960. In the first graph, which depicts natural and anthropogenic forcing, there is a sudden decrease in temperature anomaly of the models followed by a cumulative increase until the point where it reaches a peak value of 0.74oC. However, in the second graph, which involves natural climate for...
Evidence shows that, we had lots of unusual weather over the past years, and because of global warming, weather patterns are changing. Also according to “Minute Earth,” “https://www.youtube.com/watch?v=nEQghbA3pLM” they explain that the Earth is experiencing more powerful storms due to increased temperature on the Earth’s oceans. On the other hand, a lot of hot or cold air pressure has changed a lot, do to global warming. Finally, just like previously mentioned, CO2 in the air is another factor to why the Earth has climate changes, with factories, and other man-made things causing the problem, we can actually see what is
El Niño is a weak and warm current off the Western Coast of South America (Ecuador and Peru).
5) Volcanic eruptions – Effects of a volcanic eruption affects the climate for a long period of time even if the volcanic activity itself lasts only a few hours.
Climate change is evidenced through shifts in the weather patterns such as winds, humidity and temperatures over certain durations. Natural climate changes occur less frequently and they are triggered by factors related geographical aspects as well as solar radiation. The earth’s movement on the orbit triggers changes in climate causing some areas to have higher temperatures than usual while others are significantly cold depending on the position of the earth on the orbit. The heat form the sun causes changes on the stratospheric ozone and it increases the amount of greenhouse gases. Heat from the oceanic crust also contributes to warming as a result of episodic hydrothermal venting (Liao & Sandeberg, 2012). Volcanic activity also causes a release of certain elements that may block the sun and also contribute to increase greenhouse gases in the atmosphere.
As defined by the Oxford dictionary, climate change is, “a change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels.” (Oxford Dictionaries) Moreover, evidence of climate change can be found all over the world, and in many different forms, but is especially prevalent in certain regions. For instance, in Southeast Asia, specifically the nation of the Philippines, signs of climate change can be observed frequently, if not regularly. One major ...
Climate change is the long-term shift in weather patterns in a specific region or globally. Climate change refers to changes in a regions overall weather patterns. These include temperature changes, precipitation and cloud cover (www.ecolife.com).
Normal weather patterns are when low atmospheric pressure is over northern Australia and Indonesia, and when high atmospheric pressure is over the Pacific Ocean. Winds move east to west over the Pacific. The east flows of the trade winds carries the warm surface waters to the west, and bring rainstorms to Indonesia and northern Australia. To the coast of Ecuador and Peru, warm surface water is pulled west, and the cold water beneath pulls up to replace it. This is called an upwelling.
According to the Canada’s Action on Climate Change, Climate change is a long-term shift in weather conditions identified by changes in temperature, precipitation, winds, and other indicators. Climate change can involve both changes in average conditions and changes in variability, including, for example, extreme events. Climate change is one of the biggest crisis in the earth. It will cause a huge damage to the eco-system and human. We are the victims of the climate change. However, we are the one who cause the climate change.