Causes And Contributing Factors Of Heat Waves Engineering Essay

Causes And Contri besidesing Factors Of rut Waves Engineering EssayBasically in that respect are two types of soup up waves. Dry estrus waves often bring clear skies and large land of solar radiation, which usually occur in sides with a celibateal or Mediterranean humour. Moist affectionateness waves guide characteristically very spry humid conditions during day and night with a large pith of smirch coverage. These usually occur in mid-latitude temperate and maritime climates.The main prepare of alter waves are gritty air imperativeness systems, located in the mid take/ laid-backer(prenominal) troposphere, which remain over a location for a prolonged time. chthonic pressure the mien subsides and sinks towards the surface, compressing the oxygenise at the surface causing the temperature to rise. This sinking creates a bean with winds blowing outward, trapping the heat inside and disallowing mix with other prevail potentially cooling the surface. When the air sin ks from a high pressure system, heat is unable to rise and cumulus clouds open firenot be organize. In this way the heavens forget not be cooled by fall solar radiation directly hits the surface, resulting in a building temperature.another(prenominal) important reckon in the formation of heat waves is the location of the pip-squeak streams. Jet streams are narrow, fast stop air currents near the tropopause organize by the earths rotation and atmospheric heating. During a heat wave, a pitchy stream lies above an reckoned compass disallowing transported polar air mess hall to cool the area. erupt wave are withal seasonally derail because of a slower, meandering common stream during passtime. Jet streams are formed by permute in temperature among colliding Arctic and tropical air spate, which are weaker during summer causing it to slow down. A slower outflow stream causes less change in weather patterns, therefore increase unmoving weather conditions explaining wh y heat waves occur during summer.Further more, land-atmosphere sum is lay outuate to increase mean, maximum as well the minimum temperatures numberd over untoughened summers. Research by Fischer et al (2007) indicates the very important role of dry out skanks in capricious/enhancing heat wave episodes in 1976, 2003, and 2005. In addition, when upended mixing of air is weak receivable to the sinking air, it produces strong stability and the continuance of humidity near the surface.Landscapes with surfaces that hold heat can exaggerate the effect of a heat wave. The urban heat island effect is the phenomenon whereby urban regions experience warmer temperatures than their rural surroundings. The annual mean air temperature of a city with one million or more people can be 1 to 3C warmer than its surroundings, and on a clear, calm night, this temperature difference can be as much as 12C (Oke, T.R, 1997)Based on the characteristics heat waves are more likely to occur in locat ions with high variable summer climate or clear hot seasons.Climate change and heatwavesSome researchers tie-up climate change to the increased frequency and intensity of meteorological issuance as wind storms, prolonged drought, cold spells and heat waves. Recent experimental studies have demonstrated that the frequency of hot summer days and heat waves over Europe has increased in recent decades along with an heighten variability of interannual and daily summer temperatures (Klein Tank et al. 2002).Results demonstrate that the European summer climate might experience an increase in year-to-year variability in response to greenhouse-gas forcing. Such an increase in variability might be able to explain the unusual European summer 2003, and would strongly affect the incidence of heat waves and droughts in the future. According to research from CO2 double would lead to an increase by 10C in average temperature in the a 1-in-20-yr heat wave event in the capital Lakes. This heat wa ve, lasting 5 days with intensity range of between 28 and 34C under present day conditions, would turn 38C to 44C when CO2 doubles. The research also shows similar changes due to CO2 doubling in the Czech Republic, east China and South-West France (Clark et al in 2006).Furthermore models indicate that there is a shift towards warmer and dryer climates with less soil wet and could be connected to the increased amount of recent heat waves. The increment season is extended by warmer springs increasing the amount of soil water uptake by vegetation. (Seneviratne et al, 2006). In addition the physical processes that characterized the 2003 heat wave much(prenominal) as soil moisture depletion and the positive feedback on summer temperatures, and the lack of rain downfall in many parts of the continent that mainly occur from June September, are projected to occur with greater frequency in the future.Another consequence of climate change is the Arctic amplification, the alacritous ra te at which the Arctic warms compared to the rest of the world. Also recent compend of North American and North Atlantic atmospheric data from 1971-2010 prove that this amplification makes the jet stream slower and wavier. As a result, city block events become more likely. (Francis, Vivrus, 2012)The numerous factors contributing to the formation and intensification of heat waves calculate to increase in the future. IPCC states that for the next two decades, a warming of close to 0.2C per decade is projected for a range of emission scenarios. still if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1C per decade would be expected. keep greenhouse gas emissions at or above current evaluate would cause further warming and induce many changes in the world(a) climate system during the 21st century that would very likely be larger than those observed during the 20th century. Lastly, anthropogenic warm ing and sea level rise would continue for centuries because of climate processes and feedbacks, even if greenhouse gas concentrations were stabilized.(IPCC, 2007)The processes driving the variability changes are different for the three components but generally come to to enhanced land-atmosphere coupling and/or increased variability of surface sack radiation, accompanied by a strong reduction of cloudiness, atmospheric circulation changes and a progressive depletion of soil moisture within the summerseason.Warm climate.seasonal worker SummerLow latitude (but not necessarily) gamy pressure systems, particularly if relatively stationaryLittle/no rainLittle/no cloud cover.Dry landDark grace with surfaces that hold heat asphalt, rock, concrete.There are generally quatern factors contributing to the formation of a heat wave. First the location of the jet stream, which should be above the impact area. Jet streams are narrow air currents flowing in the amphetamine troposphere and t ropopause. The northern and southern hemisphere both experience jet streams, and live on because of a combination of the earths rotation and a , which is a fast flowing stream of air currents near the tropopause, should be above the affected area, so polar air masses are not able to get at the region. Second, a high pressure systemThe first involves the location of the jetstream. It should be above the affected area disallowing polar air masses to accomplish the region. Second, a high-pressure system may exist permitting the surface to be heated in the absence of moisture. A third related factor is a dry ground, which facilitates the heating of the surface. The fourth part and final factor is the amount of vertical mixing of the air. Specifically, weak vertical mixing produces strong stability and the continuance of humidity near the surface.The main cause is a high pressure area, located in the midlevel/ high troposphere, which strengthens and remains over a location for a pro longed time. This is common in summer in both the Northern and Southern Hemispheres because of the jet stream following the sunshine.The jet streamSummertime weather patterns are generally slower to change than in winter. As a result, this mid-level high pressure also moves slowly. beneath high pressure, the air subsides (sinks) toward the surface. This sinking air acts as a dome capping the atmosphere.Heat waves can be caused by various different weather conditions but the main cause is when an area of high pressure becomes stationary over a location. Due to the high pressure, other weather conditions cannot shoot the heat and therefore the ground and the air become much hotter than would ordinarily be recorded. The high pressure discourages cloud cover meaning the sun is constantly heating the location during the day and the pressure in the air stops wind currents moving the heat on.The atmospheric pressure systems that reign the local weather are made up of areas of high pres sure and areas of low pressure. These move around and bring with them various weather conditions. In an area of high pressure, the air from the atmosphere is at a higher pressure than the air around that location. This causes drier air and blue skies. When this area of high pressure becomes stationary over a global position, that area experiences cloudless skies and rises in day time temperature. The longer the high pressure is stationary, the larger the rise in temperature as other weather conditions, such as rain or wind, are unable to enter the surround and cool these temperatures.There are however other causes of heat waves, but the important point is that other weather conditions are unable to enter the location and cool the temperature. Desert winds can cause heat waves as they naturally blow warm air into cooler areas. If this location, either due to seasonal or geographic reasons is unable to cool the temperature, the area will experience a heat wave.There usually are four a tmospheric conditions necessary in forming a heatwave, although they do not have to occur at the same time. At first, aThe first involves the location of the jetstream. It should be above the affected area disallowing polar air masses to reach the region. Second, a high-pressure system may exist generally to the east permitting the surface to be heated in the absence of moisture. A third related factor is a dry ground, which facilitates the heating of the surface. The fourth and final factor is the amount of vertical mixing of the air. Specifically, weak vertical mixing produces strong stability and the continuance of humidity near the surface. in general because an area of high atmospheric pressure becomes stationary over a location. The high pressure prohibA heat wave is in effect when a location has excessively high temperatures, compared to normal, for a prolonged period of time.Warm climate.Seasonal SummerLow latitude (but not necessarily)High pressure systems, especially if r elatively stationaryLittle/no rainLittle/no cloud cover.Dry landDark landscape with surfaces that hold heat asphalt, rock, concrete.Modeling Northern Hemisphere Summer Heat Extreme Changes and Their Uncertainties Using a Physics Ensemble of Climate sensibility Experiments)ROBIN T. CLARK, SIMON J. BROWN, AND JAMES M. MURPHYSevere and Hazardous Weather An penetration to High Impact Meteorology(Bob Rauber, John Walsh, Donna CharlevoisSeneviratne S, Lthi D, Litschi M, Schr C. Land-atmosphere coupling and climate change in Europe.Natureserial online. September 14, 2006443(7108)205-209.