Research Paper: Contrails and There Affect on Climate

Pages: 5 (1732 words)  ·  Bibliography Sources: 5  ·  Level: College Junior  ·  Topic: Weather  ·  Buy This Paper

Contrails and Their Affect on Climate

Contrails, which is the short form of condensation trails also known as vapor trails, are known as the artificial clouds that are formed from the exhaust of the aircraft and are visible from the earth surface (Dictionary.com LLC, 2011). The contrails are formed when the exhaust of the aircraft engines is condensed rapidly into water vapor.

The rapid condensation results into formation of tiny ice particles in the air that is visible hence white trail after planes. The white color of the trails is reflected from the large number of ice particles bundled together in a continuous trail.

The contrails may vary in the duration that they remain in the sky and visible from the earth's surface before they disperse and disappear. The contrails may be visible from the earth's surface for a few seconds, or at time persists for a few minutes and to some situations it can persist for a number of hours that at times run into days, and this is the type that affects the atmospheric balance and the weather in general.

Looking at the scientific angle to the formation of contrails, we find that the main by-product of the combustion of the hydrocarbon fuel that plane engines combust in order to produce the power to propel the plane is the carbon dioxide and water vapor. Since the planes fly at high altitudes where it is extremely cold and there is water vapor, the water vapor from the combustion of the plane engine, which is relatively warmer than that which is in the atmosphere at high altitudes, is exposed to the very cold surrounding and this increase in the water vapor automatically pushes the water content of the surrounding air beyond the saturation point.

The water vapor emitted by the engine then condenses into very small droplets of water or at times they turn into tiny ice crystals. When the droplets or ice crystals are gathered in millions then they form a visible contrail. It is worth noting that the vapor in the air at times just requires a trigger for it to condense into ice particles and the exhaust water from the plane engines comes in handy to act as the catalyst and hence triggering the condensation.

It is estimated that these contrails are usually formed at altitudes of 30,000 and the temperature that is conductive for the formation is ?40F to facilitate the condensation of the water vapor emitted from the engines of the planes (Peter Tyson, 2006). However, the altitude and the temperature are not universal and unchanging since there have been several occurrences of contrails identified at altitudes of as low as 12,000 to 15,000 in New Mexico and Coastal Texas

The cover that the contrails can have on the atmosphere is significant enough to alter the climatic conditions in a given area for a significant duration though not as long as the natural clouds can affect. According to Wynne Parry (2011), there could be contrails that can cover 10% of the European skies and 6% of the entire North American East coast if the skies could be cleared of any other clouds. This is true taking into account that these regions are heavy plane traffic host with numerous planes lying across each minute.

The above percentages were calculated by the various meteorological departments during the 9/11 grounding of all planes. The study of the atmosphere showed a significant 6% missing cloud cover from the 11th to 14th the period when the planes were grounded due to security reasons. Such amounts of clouds introduced into the atmosphere are bound to have some effects on the atmospheric conditions.

Just like the natural clouds, the contribution of the contrails to the atmospheric conditions is quite contradictory and debatable especially on matters to do with the earth's surface temperature. The air transport has been criticized wide and far for its possible depletion of the atmosphere and its contribution to the climatic change. Apart from the potential harm they expose the atmosphere to in terms of the exhaust they emit from their engines, now there is a new menace of the contrails that have been observed to alter the earth's atmosphere.

The process is simple, the thin lines of contrails at last evolves into the "contrail cirrus" clouds that spread out and lose their linear shape and spreads out so that it is not distinguishable from the real clouds. It has been a renown scientific fact that the low altitude clouds have a positive effect of cooling the surface of the earth by reflecting the sunlight; unfortunately the high altitude clouds have the very opposite effect and even more disastrous effect of helping in the warming of the earth's surface.

The ice crystals act to reflect back the solar light hence decreasing the amount of heat and light from the sun that reaches the earth's surface but at the very same time the crystals and the condensed cloud trap the infrared and other long wave radiations coming from the earth hence hindering it from escaping into the space once it has been reflected from the ground. This process when repeated over a period of time heats the surface of the earth since the radiations have no room for escape and keep rotating within the same area with a contrail cloud blanket hence forming a kind of oven with no ventilation, this inevitably forms a warm zone below the contrails altering the climatic condition significantly.

There are various factors that can affect how much of the heat is trapped on the surface of the earth. One of the most prominent causes is the thickness of these contrails otherwise known as the optical depth. Though most of the contrails are too thin to be seen through the human eye or even the satellite, there is a very negligible contribution to the warming that is experienced due to their presence.

The size and the shape of the contrail also have a lot to do with the amount of heat trapped on the earth's surface. The larger ice particles in the contrails will facilitate a longer duration that the contrail will last and consequently the duration that the insulation the contrail will provide to the surface of the earth. It is however worth noting that the fact that at times one cannot see the contrails with naked eyes does not necessarily mean that they are not in the skies. It has been noted that the contrails can grow so thin that they can no longer be seen from the earth's surface. The contrails also have a characteristic of spreading out in the skies till they are similar to other natural cloud hence one cannot pick them out clearly but their effects on the climate remain.

The other explanation behind the manner in which the contrails affect the climatic condition is in their formation process. During their formation, contrails use up the water found in the atmosphere that was supposed to be used in the formation of the natural clouds. This then makes the water or the atmospheric vapor around the region where the contrails are formed to be used up in the contrail cirrus cloud formation hence altering the atmospheric humidity of the region. However, some contrails as noted before could be low altitude clouds hence can be beneficial to the earth.

The alteration of the climatic conditions have been studied by John Timmer (2011) who observes that the above discussed factors that accompany the contrails can increase the earth's temperature to the tune of 40 milliwatts per square meter (this is in adverse contrast to the solar cycle results which poses changes of about a full watt/m2).

The opportunity to verify and prove that the effects of the contrails were real and wide was during the grounding of the planes after the 9/11 terrorists attack. At this time, the meteorological departments reported an increase in the daily temperature range. During the three days grounding of planes, there was an anomalous climb in the diurnal temperature range. The diurnal range is the difference that is observed between the night time minimum temperatures and the daytime maximum temperatures experienced in a given area.

For the above conclusion to be drawn, there were 4,0000 weather stations results and daily recordings that were studied from 1971 to 2000 and the result tabulated and compared against the three days when the planes were grounded after the terrorists attack. It was found out that there was a recorded difference of 1.8°C in temperature between these three days of minimal plane flights and the days prior to the three day of minimal flights.

The increase in the earth's temperature is feared that would rise further by the year 2050 as the contrail cover is forecasted to increase from the current estimated 6% cover to some much higher figures due to the increase in planes introduced into the atmosphere each day which will spiral into a temperature increase at the end… [END OF PREVIEW]

Environmental Engineering -- Contrails Are an Exhaust Case Study


Effects of Air Traveling on Our Environment Term Paper


Marpol Annex (VI) Requirements on Sulfur Content Term Paper


Effects of Aircraft Engine Fuel on Our Ozone Thesis


European Union's New Emmissions Proposal on U Term Paper


View 7 other related papers  >>

Cite This Research Paper:

APA Format

Contrails and There Affect on Climate.  (2011, May 13).  Retrieved November 13, 2019, from https://www.essaytown.com/subjects/paper/contrails-affect-climate/39502

MLA Format

"Contrails and There Affect on Climate."  13 May 2011.  Web.  13 November 2019. <https://www.essaytown.com/subjects/paper/contrails-affect-climate/39502>.

Chicago Format

"Contrails and There Affect on Climate."  Essaytown.com.  May 13, 2011.  Accessed November 13, 2019.
https://www.essaytown.com/subjects/paper/contrails-affect-climate/39502.