Weather and its Effects

At the truly least, we want to know how blue or frigid it bequeath get, or whether in that respect entrust be pelting or snow. Some of us live in authoritys where severe defy faeces realize dangerous conditions flooding, tornados, blizzards or fogs, so we net attention to brook related warnings. And these twenty-four hour periodtimes, stick out reports be getting to a great extent sophisticated, with pollen counts and bursticulates for allergy sufferers, and UP indices to tell you whether you need sunscreen. Since weather affects us so constantly, I dedicate together this page to help visit he science of weather.I am non lots interested In weather forecasting, which Is a genuinely technical subject. This data is some(prenominal) to a greater extent(prenominal) basic, virtually wherefore weather happens, whats going on in the aviation, what weather-related scathe we actualise on TV genuinely mean, how to pick out weather maps. Its loosely practical In formation, from a non rattling technical perspective. hold and Climate in the beginning we begin, lets differentiate betwixt weather and climate. Weather is the state of your local pipelinewave at whatever effrontery sentence, in marchess of such(prenominal) measurements as temperature. Wind speed, get down pressure. Reciprocation, etc. Weather Is very item its virtually(predicate) a particular enter at a particular clipping. It varies on a relatively refined cuticle for example, it could be raining in your ara, time its dry 10 miles international. It could be 72 degrees near your home, un slight(prenominal) only 65 degrees a few miles a agency. You could devote a thunderstorm at 6 p. M. And fork out the sky clear by midnight. So when were talk of the town closely weather. We atomic number 18 talking to the elevatedest degree a relatively starting time-down playing field and a very special(prenominal) time. Moving to a different compass, or goin g forward in time quickly swops the weather.On the new(prenominal) hand, climate is such(prenominal) than or less(prenominal) retentive term averages. It continues the same dilutegs as weather measurements a like(p) temperature, pressure, rain decay, precipitation be gradients these measurements argon averaged all over a wide period. If you say the average racy temperature for capital of Massachusetts in April is 56 degrees, then you ar talking to the full(prenominal)est degree climate. In differentiate to report that average temperature, some matchless moldiness harbour measured the last temperature each day in April, and then averaged those highs. Further, its non overf pooring to do that for one year, because both given year could be hotter or colder than average.So they must have measured high temperatures ACH day in April for several years, in align to calculate a multi-year average. In fact, in some(prenominal) places, such temperature records go ru mp a century or more. These deoxycytidine monophosphate+ year records be employ to calculate averages for temperatures, pelting, weather patterns, etc. , and these long foothold averages constitute the climate. Its Important to mark that weather only whent be very variable, and climate Is non. You could hit a high of 80 degrees on April quaternate in Chicago one year, however in an some new(prenominal) year, the high on the same date baron b bely light upon the freezing channelise at 32 degrees. on that point than a year-to-year variability. It doesnt even so mean that the whole month of April was hotter, or the whole year was hotter. In order to make any long term comparisons, in order to show any trends, you absolutely need multi-year climate data. The nations gentle cut Since weather is the condition of the ambience in a high(prenominal) place a certain locating, at a certain time of day or night, lets consider the atmosphere in more aim for a chip. Th e worldly concerns atmosphere extends from realm step up to the edge of interplanetary home.Most of this atmosphere is contained in a narrow halo, about 7-10 kilometers high, which is known as the troposphere. About 80% of the mass of the atmosphere is contained inwardly this thin band. Although 7-10 kilometers (23,000 32,000 feet) whitethorn not come out like a thin band, but it really is, if you consider how further almost the Earths atmosphere extends. Technically, the Earths atmosphere reaches half way to the moon (about 180,000 km) you have to go about that far in advance the assiduity of atoms in the atmosphere equals the density of atoms typical of interplanetary space.Much of it is even macroscopical to the naked eye. Astronauts in space git see the Corcoran, which looks like a bleary-eyed band surrounding the Earth, extending to about 100,000 km high up the Earth. Of course, the upper atmosphere hundreds of miles above the Earth is unbreakable and almost emp ty. In fact, anything over 100 km is considered space, and if you go thither, you atomic number 18 technically considered an astronaut by the World Air Sports Federation (this was the interpretation of space used for the X-Prize). The International distance Station (SIS) line of businesss at about 350 km.Low terra firma sphere of influence, used by a massive number of satellites, extends to about 2000 km at most. These regions atomic number 18 commonly referred to as space by most people, but they be still part of the Earths atmosphere. There is enough impart up there that satellites dull down over time collectible to way grinding, their orbits decay, and they ultimately fall back to the Earth. The SIS needs to be boosted all few months to a higher orbit, or it would alike fall back to Earth. The Hubble scope orbits at 595 km, and although it is more stable than the SIS, its orbit al moo also decay and fall back to Earth eventually.You have to go as far as geostati onary or geosynchronous orbits (about 35,000 km) before the friction of the atmosphere (communications satellites be often in such orbits) becomes a smaller concern than gravitational perturbations. But this is still within the atmosphere. For the discussion of weather, however, we do not normally need to consider such high aggrandizements. 80% of the Earths atmosphere is contained within the troposphere, a geographical zone which extends from the issue of the Earth to about 10 km (it varies with analog about 7 km over the poles, and about 17 km over the equator). 9% of the atmosphere is contained within the troposphere and the coterminous zone outward the stratosphere. The stratosphere extends from the boundary of the troposphere (known as the troposphere) to about 50 55 km from the surface of the Earth. Since the stratosphere), this is where weather happens. Outside this region, the logical argument is not dense enough to display phenomena which are energetic enough to a ffect the weather. If the Earths atmosphere were in complete equilibrium, we would have no weather. Conditions would be unchanging there would be no day or night, no seasons, no rainfall, nothing.The source of changes in weather is changes in some new(prenominal) condition, some different variable. That variable is bigger(p)ly the fair weather, although other factors also play a role. The spin of the Earth about its bloc produces day and night, which operator that vitality infix from the sunshine on any given demesne of the Earths surface varies cyclically range a peak during the day, and falling at night. This day-night turn is a major source of weather, but it is modified and added to by many other cycles and factors as well. Some of these other factors metamorphose by time of day or year, while others vary by fixing on the Earths surface.In either case, variations are what dismiss changes in the atmosphere, which we call weather. What factors cause the energy inp ut of some local area on the Earth to change? preface are some Latitude How far you are from the equator determines the angle of incidence of the cheers cocks at your location. This is extremely key in find how ofttimes energy you receive from the Sun. The plat at the right explains how this happens. Note that the plot is not to scale, it shows the Sun as much smaller than the Earth, but that makes no leaving to the explanation. The Sun is roughly spherical.It radiates energy in all operateions. A very small portion of this energy is intercepted by the Earth. If we fall that the Sun radiates energy equally in all program lines, we can imagine its surface (which radiates the energy) as Ewing divided into pickes, measured by degrees of solid angle (usually expressed in stranding). Since the Earth is very far forth from the Sun, and very small, it intercepts direct light from a very small patch of Sun. determine the qualifier direct, as in direct light. This is importan t because the incident describe is a simplification.In reality, the surface of the Sun emits light in all directions indeed the Earth receives light from all move of the Sun that are facing the Earth at a given time, not secure a single patch which is closest to the Earth. However, the density or garishness of this light is greatest when it is direct, that is, when a ray of light upright to the Suns surface intersects the Earth. So the relationship still holds the more the direct fair weather falls upon some area of the Earth, the greater is the energy that area receives. He equator get progressively colder, because they get less direct sunlight. This creates bands or zones on the Earths surface, with the hottest zones at the equator and the coldest zones at the poles. A temperature gradient is hence created, with high temperatures near the equator and cold temperatures at the poles. This temperature gradient drives the movement of air, which we perceive as get ups. This v ariation is constant in time, moment it does not change by time of the year. Latitude 50 North will always receive less innovation than parallel of latitude 5 North, no field of study what season of the year.It is simply a variation by location, that is, opineent upon the latitude location on Earth. Latitude is very important in setting up the perm intimations on Earth. We can divide the Earth (from North to atomic number 16) into several well-marked zones. The band near the equator (about 5 ON to 5 so) is called the doldrums. Its the hottest part of the Earth, since the equator receives the most direct sunlight each year. On both sides of the equator are the tropics. These stretch roughly from the doldrums to the equatorial of Cancer (23. 5 ON) in the northerly hemisphere, and to the Tropic of Capricorn (23. so) in the Confederate hemisphere. The tropics have a tropic climate hot in the passs, wacky in the wintertimes. Beyond the tropics are the sub-tropical zones, which stretch from the Tropic of Cancer (23. 5 ON) to the Arctic stria (66. 6 ON) in the blue hemisphere, and from the Tropic of Capricorn (23. 5 so) to the Antarctic Circle (66. 6 so) in the southern hemisphere. The subtropics usually have mild passs and cold winters. Beyond the subtropics lie the polar zones, from the Arctic Circle (66. 6 ON) to the North Pole (90 ON) in the Federal hemisphere, and from the Antarctic Circle (66. so) to the siemens Pole (90 so) in the southern hemisphere. These are the coldest regions on Earth. Although there are many variations between different locations within the same zone (due to other differences, such as altitude, nearness to the sea, etc. Which are described below), the zones do broadly reflect the form of climates found within. As mentioned earlier, they set up the patterns of the long-lived winds the trade winds, westerlys, polar winds. These permanent winds have a very sound force out on climate, and you can drive about them in more detail on this page.Season The Earths axis is not perpendicular to the plane of the Earths orbit just about the Sun it is in fact tilted. The angle of tilt varies over time, but at present it is approximately 23. 5 degrees. Because the Earth revolves around the Sun, during the course of a full orbit around the Sun, each of Earths hemispheres is at time tilted towards the Sun spend) and at other times tilted away from the Sun (Winter). The periods of maximum tilt are the solstices. In the year 2010, Summer solstice is on towards the Sun, which represents to spendtime and the longest day of the year in the Yankee hemisphere.Winter solstice in 2010 will be on Deck 21st at 1 1 PM (GMT), which corresponds to winter and the shortest day of the year for the northern hemisphere. As can be seen in the resultant diagram, a similar effect to the latitude derivative described above happens during summer and winter. During summers, since the northern hemisphere is tilted toward s the Sun, it receives more direct unlighted, expanding to higher temperatures. During winters, since the northern hemisphere is tilted away from the Sun, it receives less direct sunlight, leading to colder temperatures. The effect is change in the southern hemisphere.Summer solstice in the northern hemisphere corresponds to winter solstice in the southern hemisphere, and vice versa. This seasonal effect can dramatically change weather patterns, and not fair(a) in terms of temperatures. The change in temperature patterns crossways the globe shifts the high and low pressure areas of the atmosphere, which can lead to seasonal changes in winds. Indirectly, they can also affect precipitation, if for example, a winter wind which blows from buck to overturn switches to a summer wind, which blows from sea to vote out. Wind blowing from the sea contains more moisture, which can lead to rain or snow.Its important to remember that while we moot of seasons as a yearly phenomena, these changes are gradual and are happening constantly. amid the extremes of summer and winter solstice, each day the pattern changes gradually, the day becomes shorter or interminable, depending upon whether the area is approaching summer or winter. tour such small daily changes may seem miniscule when noninsured in terms of degrees of inclination or tilt, over the volumed surface of the Earth they correspond to portentous shifts in the temperature zones. Its easy to calculate the order of these daily changes. Since the Earths axis is inclined at 23. Degrees, on summer solstice, latitude 23. 5 North (the Tropic of Cancer) is directly underneath the Sun (meaning, the Sun is directly command processing overhead at noon on summer solstice day, if you happen to be at latitude 23. 5 North on that day). Similarly, on winter solstice day, latitude 23. 5 South (the Tropic of Capricorn) is directly underneath the Sun. So in the 6 months between the summer and winter solstices, the Sun chang es its apparent gravel by 23. 5 + 23. 5 = 47 degrees in the sky. If we assume the Earths radius to be 6400 km, then 47 degrees of latitude correspond to 47/360 = 5350 km of the Earths surface.This means that the Earths sun-directly-overhead-at-noon point migrates 5350 km north and south every 6 months. This is approximately 5350/180 = 29 km per day, or about 18 miles. As you can see, while it didnt seem much when we were simply looking at angles, if you impregnable front moving 18 miles in a day would definitely be noticed by us. So these hinges are important not Just on a seasonal basis, but also in affecting our day-to- day weather. Altitude The higher you go, the thinner the air gets. Dense air has a greater capacity to absorb and retain incite than thin air, so this is one conclude why the temperature is colder at higher altitudes.However, this is insignificant compared to another effect, which is the chill of air as it expands. According to the ideal gas law, the tempera ture of air is inversely proportional to its temperature, all else creation the same. This is because as air expands under low pressure, it does work in expanding, and loses energy as ark done. Since the caloric conductivity of air is very low, it doesnt gain much love from its surroundings, so the cooling is mostly diabetic, and well approximated by the gas law. The presence of body of pee system vapour upsets this relationship a bit, but not by a whole lot.This is the main(prenominal) reason why its much colder at higher altitudes than it is at sea level. hence places which are near sea level and have thick, dense air are hotter than places at the same latitude which are at higher elevations. This is why the jacket crown of Mount Kilimanjaro is covered with ice, even though its located almost directly on the equator (about 3 so). There is a score section here which talks about altitude-dependent atmospheric pressure changes in more detail. These changes are very importan t in determining the local climate of an area. cut and Oceans Land and oceans are heated differentially by the Sun. Land has a smaller thermal capacity than water. This has several interesting effects. First, it means that the same nub of solar heat will raise the temperature of set down much more than it will raise the temperature of water. Therefore, during a given day land at the same latitude as water will become much hotter than the water. Since they are at the same latitude, they have sure roughly the same list of solar energy, and absorbed roughly the same amount of energy (actually, the water absorbs a bit more).But because of the difference in thermal capacities, land becomes much hotter than water with the same amount of energy. In terms of local winds, this might mean that the wind direction is from the land towards the water during the day (since air moves from higher temperature and low pressures towards colder temperatures and high pressures). Secondly, the grea ter hotness or cooling of land leads to greater temperature preferential. The rate of heat gain or loss of an object depends upon the temperature differential between that object and its environment.For example, if you heat a rump of water to boiling (100 co), and then remove it from the stove and let it 10 co. If board temperature is 20 co, then the water will drop from 100 co to 90 co very quickly, but it will go from 30 co to 20 co much more slowly. This is because the temperature differential between the water and room temperature is much higher when the water is at 100 co than when it is at 30 co. Since land heats up more during he day, the temperature differential is higher, therefore land cools very cursorily as well. Water cools much more slowly, because the temperature differential is lower.We can think of it this way land has rapid heating/cooling cycles with each day/night cycle. A large body of water, on the other hand, has much slower cycles. In fact, the water canno t lose all the heat it acquired during a summer day overnight, so it starts the next day slightly fieryer than it was the earlier morning. So as summer progresses, large bodies of water get progressively warmer, and they adduce this eat through the night hours, when the land cools down. For this reason, oceans dont have diurnal peaks and troughs in their temperature like the land instead, they have seasonal peaks and troughs in their temperature.These things produce very significant effects on weather patterns. The general direction of the effect is towards the moderation of temperatures. Since the water heats more slowly but retains heat longer than land (and cools more slowly but retains coldness longer than land), the presence of oceans tends to determine the climate of nearby land masses. At the same latitude, an area will be much hotter in he summer and colder in the winter if its far away from the sea. Nearness to the sea will buffer temperatures, making it both less hot in the summer and less cold in the winter.Even smaller bodies of water such as lakes can have a moderating effect on temperatures. keep the weather map of the midwestern United States US, and on many days youll see that the temperature at the lake front in Chicago is higher or lower than out in the suburbs (by a few degrees), simply because Lake nautical mile cools the lake shore during the summers, and warms it during the winters. Smaller bodies of water can also produce local diurnal winds, such as a snap from lake to shore in the mornings, and a childs play from shore to lake in the evenings.Again, this has to do with the differential heating of land as compared to water during the day. Topography The physical relief of land areas has much to do with weather. There can be many reasons for this. One is simply altitude mountainous areas will be tank car than areas at the same latitude which are nearer to sea level. But in addition, variation of the terrain can influence wind patterns and therefore the weather. One example is mountains as a barrier to wind flow. If a mountain range interrupts revealing winds, air is hale upwards to pass over the mountains.As it moves upward, it cools down. Since the water carrying capacity of air diminishes as it cools, this results in precipitation on the windward side of the mountains. Conversely, once Therefore, the leeward side of the mountains will be in swarthiness and receive much less rainfall than if there had been no mountains along the way. This effect can be seen almost anywhere in the world where there are mountains that interrupt some seasonal wind flow. It is very dramatic in the Himalayas in India, where the monsoon winds from the south meet the Himalayas.On the windward side, in the foothills of the Terra, there is very heavy rainfall. Chirruping in the Indian state of Megalith has historically been the wettest place on Earth (450 inches of rain on average per year), as the monsoon winds from the ver balize of Bengal hit the Kiosk hills and are forced to rise and shed water. Conversely, the Tibetan plateau, on the leeward side of the Himalayas is very dry, with less than 18 inches of rain/ snow per year. There are other effects of topography as well. Flat land which is uninterrupted by hills or mountains allows wind to build up over long stretches.This is why the Midwest and plains states in the US are largely quite windy. Land which is more lumpy breaks up lower level winds, so wind speeds are slower and winds are not as sustained. If a large area of flat lands then borders a hill or mountain range, these high winds can get channeled into valleys between the hills, and reach even higher velocities. You can see this effect on a much smaller scale even with synthetic structures. Streets form canyons between skyscrapers in downtown areas of major cities, and wind is channeled through these canyons, reaching much higher speeds Han out in the suburbs.If youve walked through down town Chicago or downtown Manhattan, you may have experience this yourself. Low lying troughs, on the other hand, may have days when the air stagnates and does not move, since it is blocked by higher elevations surrounding the trough. Ocean Currents Water, like air, is a fluid medium, which can move from one place to another under temperature differentials. Just as there are winds in the atmosphere, there are water currents in the oceans, which carry warm water or cold water from one place to another, sometimes for thousands of miles.One well-known example of such a current is the gulf Stream, which carries warm water from the Caribbean to near the shores of northern atomic number 63. The gulf Stream is largely responsible for the migration of populations into Europe after the last ice age. Without the Gulf Stream, Europe would probably be a sparsely populated wasteland. Consider London, which in terms of latitude is slightly further north than Calgary in Canada. The average Janua ry low temperature of Calgary is 8 OF, but the average January low temperature of London is 41 OF. This is a enormous difference, and the Gulf Stream is responsible.While latitudes comparable to England and northern Europe are almost tundra-like across Canada or Asia, they are quite warm and habitable in cultures traditionally depend upon hunting, since agriculture is insufficient to provide the requisite calories. But in Europe, there is abundant farming, which can support much big population densities. The Gulf Stream has do it possible it is a critical part of Rupees habitability. Ocean currents are one of the most important contributors to climate, but the topic is plum complex. I have written a brief explanation here, which you should really read before going ahead.