Climate, climate and atmosphere both directly and indirectly influence the Earth and impact all human life and all other aspects of our world. Airline traffic is one of those things which is badly affected by environment, climate and atmosphere change.
Most people rely on reliable and qualitative weather, climatic and atmospheric forecasts to prepare for energy and natural resources including solar and wind and bio-fuels and also to make plans if there is any impending danger. One such important area is its impact on airline traffic. Therefore, the importance of knowing about the different climatic conditions, the surfaces of both land and sea, the chemical properties that affect atmosphere and the condition of the space environment is both vital and indispensable.
It is not enough if we know about all the various phenomena present before us in our environment, but how we observe them, understand them and implement these strategies that are most useful to us is what is most important. The increasing global reliance on weather information gives NASA and the rest of the Earth science community greater responsibility to make more changes.
Introduction
The ambient composition, density and structure of the air around us make up the study of meteorology that is of primary importance, especially in the aviation field. Meteorology is a concept used to describe a science involving the atmospheric phenomena that affect us, specifically the atmosphere and weather conditions. Several different disciplines belong to both meteorology and climatology – the first has its origins in physics while the latter has its roots in physical geography. These disciplines have become interwoven with each other over the decades and have taken the form of a single discipline called atmospheric sciences, which is devoted to analysing and understanding the evolution of the planetary atmosphere and all the other phenomena that occur along with it.
Atmospheric physics or Physical meteorology is another complimentary field that has the capacity to alter the physical and chemical compositions of air while moving through the atmosphere. Some of the sub – fields linked with atmospheric physics includes cloud physics that is essentially concerned with the growth and the chemical and optical properties of droplets present in the clouds and radiative transfer that involves radiation by aerosols and trace gases that are radiatively active in the planetary atmosphere.
Weather and Climate
The primary difference between weather and climate is a volume of time.
Weather depicts the condition of the atmosphere over a short period of time, whereas Climate shows the condition of the atmosphere over a much longer period of time. When we speak of the weather conditions we are referring to the hour to hour or the day – to – day condition of the atmosphere. But when we speak of climate we are speaking of the weather or atmospheric conditions spread over a few months or years.
Basically, we think and react to weather in terms of rain, sun, clouds, wind, sleet and snow, hail, thunderstorms, blizzards and floods. Weather is quick to change within minutes, hours, days and also seasons. On the other hand, climate does not bring about a rapid change but changes slowly over many months and years. While climate is known as spreading the average weather conditions over time and space. Climate is also defined as the long-term weather conditions which prevail in a particular area.
To measure the climatic conditions of a given region, scientists calculate the averages of temperature, humidity, rainfall and sunshine, wind speed and other such phenomena as frost, fog, floods and thunderstorms. This average estimate is measured and generally agreed over a long period of 30 years for a specific field.
Studying about the weather or climatic conditions of different regions is very important because they affect people’s lives in every possible way. For example a rise in global temperatures would mean that there would be a rise in sea levels resulting in a change in the region’s climatic conditions. The change in climate would in turn affect the forests, growth of crops and yields and the supply of water. Climatic changes also affect human life, health, the different ecosystems and all the flora and fauna that go with it. If the climate of a region is extremely dry for years together then it could make deserts expand and even affect and alter our National Parks and forests.
A leading scientific body in the US called The National Academy of Sciences denoted an increase in the temperature of the Earth’s surface by about 1 degree Fahrenheit in the last century and the global warming seems to be on the increase. I has been currently proved that this global warming is the result of all human activity that has taken place over the past 50 years and which has contributed to the altering of chemical compositions of the air around us. The constant build up of green house gases such as carbon – di – oxide, nitrous oxide and methane that possesses the heat trapping property is one of the main causes that contribute to global warming.
Urban Development and Climate
A comprehensive stand has been taken by urban planning researchers is that the key factor that contributes to climate change is urban development and at the same time the primary factor that also contributes greatly in combating this effect is also urban development. Key changes involving patterns of growth in land development would importantly help to remove the green house effect by significantly reducing vehicular smoke and gas emissions.
One of the major criteria that contributes to this problem is the relationship shared between urban development and the emission of CO2 by vehicles on the road. Urban development has increased in leaps and bounds but it also has a flip side to it. For example people living in sprawling urban dwellings find it difficult traveling to work, shopping and other entertainment areas because everything is situated so far away. So when they travel these long distances much more carbon – di – oxide is mixed into the air that contributes greatly to Global warming.
Urban development researchers have come up with what is called “compact development” which means building areas having most of the amenities close at hand- such as home, job centers, shopping areas and the linking or connecting of different streets etc. which would not only make life more easy but it would essentially lessen the carbon – di – oxide and carbon monoxide in the air. Compact development would drastically reduce a person’s driving time and fuel costs and at the same time it would increase many other health and fiscal benefits.
The present Scientific consensus has proved that the “greenhouse gas accumulations due to human activities are contributing to global warming with potentially catastrophic consequences.” (IPCC) When comparing between the world’s greenhouse CO2 contributors, the United States ranks first as the largest transmitter.
There is a major concern across all sections of people to reduce the amount of carbon – di – oxide by producing vehicles that are much more efficient and at the same time lowering the use of carbon – di – oxide fuel like bio-diesel fuel and also cutting short the length of driving miles per vehicle. Therefore the only way to minimize the vehicular emissions is to stop burning so much of gasoline and diesel.
Urban development is the primary factor that forces us to drive to far off distances because they have built homes, shopping centers, schools and other entertainment centers so far off from each other. Urban development is also responsible for reducing the forests that are responsible in absorbing CO2.
Global Warming
Our Earth seems to be getting warmer day by day and year by year this is because of Global warming which is affecting all categories of human life. In order to determine whether a certain region is either warming or cooling, the highest and lowest temperature is calculated each day and the average gives us the temperature of the day.
The scientists calculate the average of all these days for a whole year and arrive at the temperature of different regions. So over a long period of time we could come to know if a particular region is warm or cool. The temperatures are not only taken of the land but also of the oceans. The temperature for land surfaces are procured from the weather stations and the temperature for the oceans are got from the satellites. All this data gets computed and calculated by NASA resulting in the Global temperature.
Makiko Sato of NASA’s Goddard Institute for Space Studies (GISS) New York, collects all the data and converts it into matter that is readable about global temperature which gives us the information of how much the Earth has warmed or cooled. According to the statistics on climate there has been a strong upward warming pattern over the last thirty years and this is mainly because of the presence of greenhouse gases in the atmosphere. Globally speaking, the year 1998 is recorded as the warmest year with 2002 and 2003 in the second and third places respectively.
Other factors that contribute to the changing climate are volcanic eruptions that spurt out sulphuric acid into the stratosphere (upper layer of atmosphere), natural occurring events such as El Ninos (the spreading of warm water over most part of the Pacific Ocean and the like. In fact the 1998 shoot up in global temperature was due to one of the most strongest El Nino’s of the recent centuries and the exceptionally high global temperatures in 2002 and 2003 was due to a weak El Nino which contributed to it. The year 2005 seemed to supersede all the above years as it is proved to be the hottest year of this century.
Though the El Ninos greatly affect the global temperatures around the world, yet many different pollutants made by humans is also a major contributing factor. Great scientists like Hansen have been rigorously working hard to find ways and means as to how the human impact on Global Warming could be minimized and change the trend for the future.
In 1970, Dr. Hansen a scientist defined the basic temperature analysis scheme (GISS) to estimate the global temperature. The first results showed that “contrary to impressions from Northern Latitudes, global cooling after 1940 was small, and there was net global warming of about 0.4 degrees C between 1880s – 1970s.” (Hansen et al. 1981)
Current analysis of global temperature and climate is being carried out by institutions such as the Global Historical Climatology Network (Peterson and Vose, 1997, 1998), United States Historical Climatology Network (USHCN), and SCAR (Antarctic Research Scientific Committee) Hansen et al (1996) describes the global temperature Index which is procured by “combining the meteorological station measurements with sea surface temperatures based on satellite measurements’.
The green house effect has resulted in raising the global temperatures to 15 degrees C instead of it being -18 degrees C. Three of the most important greenhouse gases are C02, CH4 and N2O. Anthropogenic emissions of certain greenhouse gases such as SO2 together with other particles of matter are capable of bringing about changes in the atmospheric composition of air. It is difficult to speculate the amount of global warming because of human activity, but nevertheless, “the evidence that most of the global warming that has been observed in the last 50 years is anthropogenic has become stronger (IPCC 2001). Some of the other factors that contribute to global warming are the chemical processes in factories and industries, decomposition of different biological wastes, manure and also the production and utilization of fertilizers.
The Stratosphere houses the atmospheric ozone layer which is about 10 to 40 km above the Earth’s surface and is very useful in preventing harmful UV rays (ultra violet rays) from reaching the surface of the Earth. According to observations made in the Antarctica, it was found that the ozone layer in the middle and northern latitudes have dangerously fallen.
This depletion of the ozone layers reflects the amount of dangerous emissions of gases like CFCs. HCFCs, halons and many others which contribute to breaking down of the ozone layer when reacting with sunlight. The depleted ozone layers allows more UV radiation to reach the Earth which in turn increases the dangers of skin cancer, diseases of the eye and may also cause damage to the immune system of our body.
If there is a continuous rise in greenhouse emissions then it would have an adverse impact on the climate because of the retention of thermal radiation of the Earth’s surface which results in the rise of the global mean temperature which reflects a climatic change. Such a phenomenon is termed as the “anthropogenic greenhouse effect”. The Global warming potential or GWP is calculated by the cumulative impact the greenhouse effect has of 1 tonne of the gas compared with that of 1 tonne of CO2 over a specified period of time.
Weather’s Affect on Air Traffic
Weather is considered to be one of the primary dangers in the modern age aerospace system. The Federal Aviation Administration (FAA) has stated that 405 0f the aircraft accidents are mainly due to bad weather. Also 65% of delays of more than 15 minutes is attributed to the cause of poor weather. According to the FAA around 60% of the accidents incurred by inclement weather accidents lead to fatalities.
Therefore there is no doubt that weather plays a major role where the safety of air traffic is concerned. It is therefore imperative that the air traffic control specialist maintains a constant and accurate mental model of the 3D configuration of the weather and its changing conditions. This particular requirement is very necessary in the terminal area because there would be uncertainty in maneuvering an aircraft in the given space because of the higher traffic density. This particular difficulty is much more evident when required to hold patterns during hazardous weather conditions.
Further it becomes all the more stressful and difficult as the two very critical aspects i.e traffic and weather which has to be mentally calculated and integrated by the ATCS would be physically separated. Research involving the aspect of flight deck information “has pointed to the advantage of physically integrating information if it must also be mentally integrated.” (Wickens and Carswell et al. 1993, 1994)
According to many of the research studies carried out, aviation is considered to be one of the detrimental contributing factors because of the chemical changes brought about in the atmosphere. (especially the ozone content) and possibly some modifications in the climate. Assessments are carried out by various institutions in this subject but the most reliable and widely accepted assessments are those that are undertaken by the United Nations Scientific Organizations. Monitoring is carried out by the United Nations Environment Program (UNEP) and also the World Meteorological Organization. (VMO)
Cloud Formation
Around the globe, the concentration of both air traffic and contrails differ from place to place. Contrails are formed at very high altitudes and are essentially human induced. They are very much concentrated in sections of Europe and the United States of America where the local warming rises to 0.7watts per sq. meter or approximately 35 times more than the global average. These contrails follow the airplanes and rockets across the sky and essentially contribute to an increase in global warming.
According to the scientists working at NASA’s Langley Research Center, Hampton, VA, the contrails most often change into cirrus clouds which are nothing but wispy clouds of ice crystals. These clouds are found at high altitudes of over 20,000 feet (6,000 meters) The ice crystals in the cirrus clouds form due to the freezing of water droplets present in the air. However some clouds contribute to cooling the globe and removing the bad effects of global warming but the cirrus clouds are not to be included in this category as they are heat trappers that hold much more heat than the amount they reflect into space.
Weather Forecasting and Air Traffic
Safety of human life and property is one of the main concerns of our government and as such safety involving traveling in air is one of the aspects. The AMO or Meteorological Airport Office is located at the Traffic Control Tower and has the responsibility to predict the weather around the clock . The AMO has the responsibility of giving out warnings whenever the weather is hazardous which may in turn affect the safety of aircraft operations within a designated area or region. Personnel working at the AMO like aviation forecasters and observers work continuously to record weather observations and pass weather forecasts to warn airport authorities and aircraft crew of any impending dangers in the air due to inclement weather.
Some of the observations recorded by them are bad weather involving rain, snow, wind, storms or squalls, visibility, and air turbulence. They also give warning of cloud precipitation especially where cirrus clouds and contrails are concerned as this could prove dangerous to any aircraft. When the weather is adverse, the AMO announces aerodrome warnings to avoid stationed aircraft and aerodrome services and facilities from being disrupted.
Some of these aerodrome warnings are – Thunderstorms, Hail, Frost, Squalls, cyclones and strong winds and high peaks.
Using weather sensors, they automatically send alerts for possible turbulence and low- level windshear that is updated every minute to the aircraft in the form of a graphical display for aviation forecasters and control supervisors of air traffic. The Automatic Terminal Information Services (ATIS) send automated alerts to the pilots regarding cloud formation, turbulence and windshear. Modern techniques of alerting facilities have contributed to the successful detection of the different elements and this has helped to decrease the rate of false alarm.
An aviation special report by METAR or SPECI issue a special hourly or half – hourly weather report about either the deterioration or improvement of weather conditions such as visibility, clouds or strong winds. Sometimes when the weather conditions are very severe flights may be cancelled or redirected via another route that is not dangerous to avoid accidents and loss of life and property. According to the Journal of Air Traffic Control (April, 2005) suggested to change or divert routes especially when convective weather was forecasted.
Therefore it can be understood how important it is keep abreast of the weather forecasts especially when flying because without these forecasts there could be immeasurable damage to both life and property. Research in this area is an on-going process that is trying its best to improve the different segments in the field of aviation.
Conclusion
Atmosphere, weather and climate play vital roles in the field of aviation. Most of us depend greatly on he forecasting of the weather and climatic conditions of various regions for our safety and the protection of life and property. Global warming is on the rise and in lieu of this important aspect, steps are being taken by our government to decrease vehicular traffic, acidification due to the burning of fossils and growing more trees to prevent deforestation because of the high rise buildings that are eating up our space. Moreover, trees supply us with more oxygen that would prevent harmful radiation from the Ozone layer.
Researchers are trying to find ways to put an end to global warming which in turn affects the climatic changes that prove harmful to Air traffic. Scientists are also striving to bring about improvements in the existing equipment that is used in forecasting the weather to base and air personnel in order to ensure better safety to their customers. The meteorology department is also making great progress in educating us about all the atmospheric phenomena which would help to give us a clear picture of all that is prevalent in the atmosphere and how it directly and indirectly has an impact on the field of aviation.
Makiko Sato of NASA’s Goddard Institute for Space Studies (GISS), Makiko Sato of NASA’s Goddard Institute Studies (GISS).
References
- EMEP/MSC-W (2005): Transboundary air pollution by main pollutants (S, N, O3) and Norway MSC-W Data Note 1/2005, Norwegian Meteorological Institute. https://www.emep.int/publ/reports/2005/Country_Reports/report_NO.pdf
- Hansen, J.E., and S. Lebedeff, 1987: Global Trends of Measured Surface Air Temperature. J. Geophys. Res., 92, 13345-13372.
- Hansen, J., M. Sato, J. Glascoe and R. Ruedy, 1998: A common-sense climate index: Is climate changing noticeably? Proc. Natl. Acad. Sci. 95, 4113-4120.
- Hansen, J., R. Ruedy, J. Glascoe, and M. Sato, 1999: GISS analysis of surface temperature change. J. Geophys. Res. 104, 30997-31022.
- Hansen, J., R. Ruedy, M. Sato, M. Imhoff, W. Lawrence, D. Easterling, T. Peterson, and T. Karl, 2001: A closer look at United States and global surface temperature change. J. Geophys. Res. 106, 23947-23963
- Joseph Hollenberg,Mark Huberdeau and Mike Klinker The Mitre Corporation Center for Advanced Aviation System Development {CAASD} McLean,Virginia
- NASA – What’s the Difference between Weather and Climate? www.nasa.gov/mission_pages/noaa-n/climate/climate_weather.html
- National Academies Press. (2007) Earth science and Applications from Space: National Imperatives for the Next Decade and beyond. Weather Science and Applications. (2007) Space Studies Board (SSB) National Research Council.
- Norwegian Institute for Air Research (2006b): Monitoring of the atmospheric ozone layer and natural ultraviolet radiation. Annual report 2005. Rapport 965/2006, OR 67/2006, TA-2197/2006.
- Peterson, T.C., and R.S. Vose 1997. An overview of the Global Historical Climatology Network temperature database. Bull. Amer. Meteorol. Soc. 78, 2837-2849.
- Peterson, T.C., R.S. Vose, R. Schmoyer, and V. Razuvaev, 1998: Global historical climatology network (GHCN) quality control of monthly temperature data. Int. J. Climatol. 18, 1169-1179.
- Rob Gutro (2005) Earth Gets a Warm Feeling All Over. Goddard Space Flight Center. New York NY.
- Weather Displays for Air Traffic Control www.aviation.uiuc.edu/institute/research/arl/…/weather.html
- Wickens, C.D., & Carswell, C.M. (in press). The proximity compatibility principle: Its psychological foundations and its relevance to display design. Human Factors.
- Wickens, C.D., & May, P. (1994). Terrain representation for air traffic control: A comparison of perspective with plan view displays. University of Illinois Institute of Aviation Technical Report (ARL-94-10/FAA-94-2). Savoy, IL: Aviation Res. Lab.