Statistical Analyses of Climatological Data Related to Faisalabad Environment

By Muhammad Attique Khan Shahid¹, K. Hussain² and Rukshana Milk³
November 2006

Authors Designation:

  1. Professor at the Department of Physics, Chairman Supervisory Committee and Internships, Incharge Academic Research and Master Level Programmes with GC University, in Faisalabad - Pakistan
  2. Department of Physics, Punjab University, Lahore
  3. Department of Physics, GC University, FSD
The study of climatology is based on analysis and interpretation of metrological data collected over many years. To analyze data, an awareness of basic statistical methods is needed, and anyone seriously concerned with extensive use of climatic data should have a basic knowledge of statistical techniques.
This research report offers an overview of some of the statistical methods used in climatology. The coverage is not intended to be comprehensive and uses simple examples of commonly used methods that do not require sophisticated data manipulation. The concern is with descriptive statistics of data series, distribution of values and relationships between variables. Simple statistical parameter is included suffice it to say that climatological applications often require substantial amounts of data and the only manner by which to rationally manage them is through statistical analysis. Note too that in this research report examples using data from department of crop physiology, university of agriculture Faisalabad. Sources retain the centigrade scale. Climatic data of Faisalabad environment shows the average temperature of Faisalabad is increasing due to the discharge of green house gasses from transportation and industrial units .


Climate and weather have always had a significant, often a fundamental influence on quality of life. Human cultures and civilizations flourished following the last ice age, which retreated 14000 ears ago when warmer period made it possible to practice agriculture in a big way. Similarly small scale, climatic changes can seriously effect the very survival of life in a particular region or a period. For instance little ice age, between 1375 and 1850 AD. Most probably triggered by a large no of volcanic eruptions in SO2 resulted in complete destruction of Viking colonies in North America and Iceland.

In 1861 due most probably to the injection of volcanic sourced SO2 aerosols the weather become so cold that snow fell in summer, forest died and crops failed in large areas of North America. During little ice age the mean global temperature dropped by only 0.5°C. but the drop in temperature was uneven.

Even a single large SO2 rich volcanic eruption like Pinatubo in the Philippines during the summer of 1991 was responsible for a drop in mean global temperature by 0.5°C. On the other hand from 1860 to the present the mean increase in global temperature is 0.5°C. So catastrophic events can upset the weather. Recent rapid global warming has been attributed mainly to anthropogenic activity of burning fossil fuels and deforestation. These activities introduce 5.6 and 1.7 billion tones of CO2 respectively to the atmosphere of the total 7.3 billion tones of CO2 released annually in to the air only half’s accounted for since it is overloading the atmosphere. The other half goes into various sinks, which are little understood at present. Each year CO2 level in the air is increasing by 1.5ppm causing global warming. The missing CO2 may be diffusing into oceans where it may cause global (phytoplankton) blooms and increased biomass on land. This can now be documented by remote sensing using special satellites. Algal blooms (phytoplankton) and greater organic productivity (forests) in the North America may be fixing CO2.

In addition human activity like cattle farming, and increase rice paddies and leakages from gas field and gas pipe lines contribute substantial quantities of methane, which is a very potent green house gas and contributes to the extent of 15% to the global warming.

Other anthropogenic gases, which contributes to the global warming are CFCs (15%) N2O (8%) and O3 (12%).

So human activity over the past 50 years is producing rapid global warming. The effects of continued global warming are and will be diverse and multi furious. They can be summed up as follows

Climate changes in Pakistan have been studied by post graduate centre for earth sciences, university of the Punjab for last three years. A general lowering of temperature in pars of Punjab and a general increase in temperature in Balochistan was indicated. More recently Husain and Akhter (2002) of the post graduate centre for the earth sciences carried out a systematic study of climate change in Pakistan using available climatological data regarding surface area temperature and rain fall for the period 1931-2000.

They reported an average rise of temperature to the extent of 0.5°C and 1.0°C for north western part of North Western Frontier Province and province of Balochistan respectively. The southern plain areas of NWFP, Punjab and north eastern part of Sindh showed a cooling trend with average fall of temperature to the tune of -1.3°C. the rain fall data showed an increase of precipitation in Punjab to the extent of 28%, in the southern Sindh the rain fall increase was recorded as +34%. The northern parts of NWFP and southern Balochistan showed a decrease of rain fall to the extent of 18% and 23%.

The reason for drop in temperature in plain areas of NWFP, Punjab and northern Sindh are

  1. Substantial increase in industry in these areas where none existed in 1931 and in adjoining parts of India where coal is being used in a big way. The aerosols in atmosphere cut out parts of incoming solar radiation, especially in visible range.
  2. Since 1931 intensive and extensive irrigation in Indus plain and extensive use of ground water (to the extent of 27-30 MAF / annum) in Punjab has most probably resulted an increase precipitation.

In northern parts of NWFP and large parts of Balochistan increase in temperature and decrease in precipitation may be due to 1) extensive deforestation and damage to range lands. These findings are very significant when we consider that since 1860 the global average temperature has increased by only 0.5°C and that the global mean temperature rise (contrary to previous prediction, which indicate an expected rise in temperature of 4-8°C) by 2050 will be no more 0.5% and by 2100 about 1°C. Some scientists suggest that an increase of global temperature by 3°C by 2100.

If the above trends continue in Pakistan, the agricultural practices and cropping patterns may have to be changed radically.

Materials and Methods

The data of the meteorological parameters of Faisalabad District for the period 1992 -2004 was collected from the office of Crop Physiology, in Agriculture University of Faisalabad.The data of daily average temperature for the period of 13-years was obtained and for temperature the unit chosen was centigrade.

The day weather data was converted into monthly data. Then tabulation was made for each month throughout the period of 13-years. By taking the standard deviation (S.D) coefficient of variance (C.V), probability error (P.E) and relative probability error (R.P.E), statistical analysis was made. But it gave no authentic information about the climatic change in Faisalabad District. Then statistical analysis of climatic data was dealt by

  1. Measure of central tendency.
  2. Running mean.

Tabulated data are difficult to read meaningfully, and a constructed graph aids in visual interpretation of the climate over time. The general impression is that there appears to be in incline in average January temperature. There are a number of ways the data can be treated to clarify the observation. One method uses semi-average data. These are derived by finding the mean value for the first half of the period, (1992-1998) and that for the second half (1998-2004). The two values are plotted on the graph and joined by a line. This semi-average line again seems to indicate an increasing trend in temperature except in January.

Running Mean

A frequently used method to depict trends is running mean. When all is frequently difficult to see any patterns. Use of running means helps smooth the data series. „This method involve the calculation of a number of successive mean and grouping them to find the group mean” for a 5-year running mean (using the Faisalabad data), the following method is used.

Table 2K1   Running Mean of Average Temperature in January
Year R. Mean Temp (°C)
1994 15.4
1995 15.2
1996 13.5
1997 13.4
1998 12.9
1999 12.4
2000 12.5
2001 12.3
2002 12.6
Fig 1
Table 2K2   Running Mean of Average Temperature in February
Year R. Mean Temp (°C)
1994 16
1995 16
1996 15.6
1997 15.9
1998 15.4
1999 15.5
2000 15.4
2001 15.6
2002 15.9
Fig 2
Table 2K3   Running Mean of Average Temperature in March
Year R. Mean Temp (°C)
1994 20.2
1995 20.3
1996 20.4
1997 20.2
1998 20.3
1999 20.4
2000 20.6
2001 20.9
2002 21.7
Fig 3
Table 2K4   Running Mean of Average Temperature in April
Year R. Mean Temp (°C)
1994 25.4
1995 25.3
1996 23.8
1997 24.6
1998 25.6
1999 25.5
2000 26.4
2001 28.3
2002 28.6
Fig 4
Table 2K5   Running Mean of Average Temperature in May
Year R. Mean Temp (°C)
1994 32
1995 31.8
1996 31.4
1997 31.4
1998 31.3
1999 32.1
2000 33.0
2001 32.9
2002 33
Fig 5
Table 2K6   Running Mean of Average Temperature in June
Year R. Mean Temp (°C)
1994 34.3
1995 33.9
1996 33.9
1997 33.6
1998 33.4
1999 33.5
2000 33.9
2001 34.1
2002 34.2
Fig 6
Table 2K7   Running Mean of Average Temperature in July
Year R. Mean Temp (°C)
1994 32.4
1995 32.4
1996 32.9
1997 33
1998 32.8
1999 32.6
2000 33.1
2001 32.9
2002 32.6
Fig 7
Table 2K8   Running Mean of Average Temperature in August
Year R. Mean Temp (°C)
1994 31.9
1995 31.6
1996 31.4
1997 31.6
1998 31.9
1999 32.3
2000 33
2001 32.9
2002 32.8
Fig 8
Table 2K9   Running Mean of Average Temperature in September
Year R. Mean Temp (°C)
1994 29.9
1995 30.1
1996 30.2
1997 30.7
1998 30.7
1999 31
2000 30.8
2001 31.1
2002 31
Fig 9
Table 2K10   Running Mean of Average Temperature in October
Year R. Mean Temp (°C)
1994 26.1
1995 25.4
1996 25.5
1997 25.9
1998 25.9
1999 26.4
2000 27.9
2001 27.8
2002 27.4
Fig 10
Table 2K11   Running Mean of Average Temperature in November
Year R. Mean Temp (°C)
1994 20.3
1995 20.0
1996 19.9
1997 19.9
1998 19.8
1999 20.2
2000 20.8
2001 20.8
2002 20.9
Fig 11
Table 2K12   Running Mean of Average Temperature in December
Year R. Mean Temp (°C)
1994 15.2
1995 14.5
1996 14.3
1997 14.5
1998 14.4
1999 14.8
2000 15.6
2001 16
2002 16.1
Fig 12
Table 2K13   Years wise Temperature Percentage Relative Humidity
Month T°C / % R. H.
January 13.8 / 81.3
February 15.9 / 72.10
March 20.7 / 57.71
April 26.97 / 49.97
May 32.3 / 38.45
June 34.10 / 47.9
July 32.86 / 63.91
August 32.30 / 68.08
September 30.5 / 64.45
October 26.9 / 59.57
November 20.4 / 67.22
December 15.7 / 68.09
Table 2K14   Years wise Percentage Relative Humidity (Future Prediction)
Year %age R. H.
2005 48.26
2006 46.39
2007 44.50
2008 46.61
2009 40.72
2010 38.83
2011 36.94
2012 36.05
2013 33.16
2014 31.27

Ten Year span decreasing span (2005-2014)

January to June (Increase in temperature, decrease in % relative humidity)
July to December (Converse) 14 year time span (1990 - 2004).

Table 2K15   Years wise Visibility Reduction
(Smoke density)
Year Smoke % Visibility Reduction
2001 23.48
2002 36.67
2003 38.93
2004 43.32
2005 (continued) 50.38
Table 2K16   Years wise Accident Density
Year T / F / R.F.
2001 263 / 236 / 225.9
2002 235 / 203 / 202.8
2003 292 / 245 / 244.98
2004 279 / 241 / 240.9
2005 (continued) 64 / 44 / 64.94

Five Year span approximate increasing order trend

Five Year span increasing order trend

Results and Discussions

These graphs show that the average Temperature of Faisalabad is increasing. This increase is due to increase of different gases such as CO, SO2, and H2S are continually released into the atmosphere through the natural activities e.g. volcanic activity vegetation decay and forest fires and tiny particles. Solid liquid droplets are distributed throughout the air by wind, volcanic explosions and other similar natural pollutants, and man-made pollutants-gases, mists and particulates, aerosols resulting from the chemical and biological processes used by man. The latter are present in relatively high concentrations compared to the background values in air pollutants are present in atmosphere in concentration that distribute the dynamic equilibrium in the atmosphere and therefore affect man and his environment. There are five primary pollutants, which together contribute more than 90% of the global warming. These are

Table 2K24   Primary Pollutant Sources of Global Warming
Pollutant Source Weight of Pollutant Products Parts Total weight of pollutant produced by each source
Transportation 69.7 10.1 10.8 0.5 1.2 1.0 93.6
Fuel Combustion (stationary source) 1.2 11.8 1.2 21.6 4.5 1.3 42.2
Industrial Processes 7.8 0.7 9.2 4.1 5.3 2.7 31.0
Solid Waste Disposal 7.8 0.6 1.5 0.3 2.1 - 11.2
Miscellaneous 8.5 0.4 6.3 0.5 1.3 - 16.6
Total weight of each pollutant produced 95.0 23.6 29.5 27.0 19.5 194.6

Carbon monoxide is the major individual pollutant with a tonnage matching that of all other pollutants together.

Carbon monoxide

It is a colorless, odorless and tasteless gas. The basic chemical reactions yielding CO are

  1. Incomplete combustion of fuel or carbon containing compounds.

    2C+O2 → 2CO

  2. Reaction between CO2 and carbon containing materials at elevated temperature in industrial processes e.g. in blast furnaces.

    CO2+C → 2CO

  3. Dissociation of CO2 at high temperature.

    CO2 ↔ CO+O

Sources and Sinks of CO Pollution

Natural processes e.g. volcanic action, natural gas emission, electrical discharge during storm, seed germination, marsh gas production, etc. Contribute in a small measure to CO in the atmosphere. The significant contribution is from human activities. The annual emission on global scale 275 and 350 million tons (human source 275 and natural 75 million tons)

  1. Transportation contributes about 69% of CO motor vehicles, 59.2%, aircrafts 2.4%, and railroads 0.1%.
  2. Next in magnitude is miscellaneous source, 10.9% the main components are tree fires,7.2% and agricultural burning, 8.3% agricultural burning implies controlled burning of tree debris, crop residues brush, weeds and other vegetation.
  3. Industrial processes mainly iron, petroleum and paper industries; contribute the third largest contributor of CO (9.6%) to the air.

The annual input of CO into the atmosphere by human activities is expected to double its concentration in the ambient atmosphere every year.

Nitrogen oxides, NOx represents composite atmospheric gases, nitric oxide, NO and nitrogen dioxide which are primarily involved in air pollution. NO is a colorless, odorless gas, but NO2 has a reddish brown color and pungent suffocating odor.

The basic reaction leading to the formation of NO and NO2

N2+O2 ↔ 2NO
2NO+O2 ↔ 2NO2

the formation of NO is favored at high temperature normally attained during many contribution processes involving air.

The second reaction (formation of NO2) is also due to high temperature. NO2 is also formed by photolytic reaction. The presence of hydrocarbons disrupts this photolytic cycle and gives rise to photochemical smog, which will be discussed later.

The distribution of NOx from natural sources is more or less uniform on a global basis, but that from man made sources varies depending on urban\rural areas. In urban atmosphere, NOx is 10-100 times greater than in rural areas. The major man made source is combustion of coal, oil, natural gas and gasoline. The average residence time of NO is about 4days and NO2 3-days in the atmosphere. There residence time imply that natural processes, including photochemical reactions, take care of NOx the end product is HNO3 which is precipitate as nitrate salts in either rainfall or as dust. A possible mechanism for the formation of HNO3 is shown below, in which O3 plays important role.

O3+NO2 → NO3+O2
NO3+NO2 → N2O5
N2O5+H2O → 2 HNO3

This proposed mechanism is open to question. The end product of NOx, however, HNO3
Which rapidly react to form various particulate nitrates.
In urban areas, ambient NOx levels follow a regular pattern depending on sunlight and traffic density.

  1. Before daylight, NO and NO2 levels remain fairly stable at concentrations lightly higher than the daily minimum.
  2. As the traffic rush begins and increases (6-8 AM) the level of NO increase and becomes maximum.
  3. At mid morning, with increase in Uv. Light the NO2 level increases (0-10 AM) due to convention of NO into NO2.
  4. In the evening (5-8 AM) the NO level again goes up during the evening traffic rush.

Natural sources, particularly trees, emerges quantities of hydrocarbons in the atmosphere.CH4 is the major namely causing hydrocarbons emitted into the atmosphere. It is produced as considerable quantities in water by bacteria in the anaerobic decomposition of organic matter in water, sediments and soil:

2{CH3O} bacteria → CH2-CH2

Hydrocarbons from human activities are generally found in areas of high population density where the maximum damage to human beings and plants can occurs.
The majority of the harmful effects of hydrocarbons pollution are not due to the hydrocarbons themselves, but the products of photochemical reactions in which they are involved. Hydrocarbons do not react with sunlight, but they are reactive towards other substances produced photo chemically. An important characteristics of atmosphere which are loaded with large quantities of automobile exhaust, trapped by an inversion layer (stagnant air masses) and at same time exposed to intensive sunlight, is the formation of photochemical oxidants in the atmosphere. This gives rise to the phenomena of photochemical smog. It may be mentioned that ‘smog’ originally means an odd combination of smoke and fog. This is, however chemically reducing with high levels of SO2 and is called reducing smog, where as photochemical smog is an oxidizing smog having a high concentration of oxidants.
SO2 is colorless gas with a pungent odor. It is produced from combustion of any sulphur bearing material. SO2 is always accompanied by a little SO3.

S+O2 ↔ SO2
2SO2+O2 ↔ 2SO3

Under normal humid conditions of the atmosphere, SO3 invariability reacts with water vapor to form droplets of H2SO4:

SO3+H2O → H2SO4

It gives rise to the phenomenon of acid rain which will be discussed later. Natural processes e.g. volcanoes, provides 67% of the SOx pollution which is evenly distributed all over the globe. Man made sources contribute 33% SOx pollution which is, however localized in some urban areas. Among man made sources, fuel combustion, stationary sources, industries, and transportation accounts for total SOx emission.
Much of the NOx and SOx entering the atmosphere are converted into HNO3 and H2SO4 respectively. The detailed photochemical reactions in the atmosphere are summarized:

NO+O3 → NO2+O2
NO2+O3 → NO3+O2
NO2+NO3 → N2O5
N2O5+H2O → 2HNO3
SO2+1\2 O2+H2O → (HC.NOx) → H2SO4

The presence of hydrocarbons and NOx step-up the oxidation rate of the reaction. HNO3 and H2SO4 combine with HCl from HCl emission (both by natural anthropogenic sources) to generate acidic precipitation which is widely known as acid rain. Acid rain is now a major pollution in some areas.

Particulates are small, solid particles and liquid droplets present in atmosphere in fairly large number and some times pose a serious air pollution problem.
The particulates are injected into atmosphere by volcanic eruption, blowing of dust and soil by the wind, spray of salt. The combustions from man made activities are fly ash from power plant, melters and mining operations, smoke from the incomplete combustion processes, fuel combustion from stationary sources (coal, fuel oil, natural gas, wood), industrial processes and miscellaneous sources (tree fires, structural fires, coal refuse burning and agricultural burning).

CO is a very poisonous gas when breathed, as it combines with the haemoglobin of the blood to form bright red carboxyhaemoglobin. This is chemically stable and thus the haemoglobin is no longer available to carry oxygen. Thus death may occur.

NOx produces HNO3 and this cause’s acid rain fall which can produce carcinogenic in human body.

Hydrocarbons react with different body molecules and produced different effects e.g. when methane react with water molecule produces carbon dioxide and hydrogen gas. Thus the proportion of carbon dioxide in body increases which produces breathing problems.

CH4+2H2O → CO2+4H2

Photochemical smog is characterized by brown, hazy fumes which irritate the eyes and lungs, lead to the creating of rubber an extensive damage of plant life.

Sulphate aerosolsin urban air generally smaller 2µ so they can easily penetrate the inner most passages of the lungs (pulmonary regions) of human and cause sever respiratory troubles, particularly among older people (70+ years of age).

Acid rain damage leaves of tree and plants and retard the growth of trees, (major sources of production of wood pulp, paper and board).

In particulates airborne asbestos and toxic melts, have caused much concern as they are all carcinogenic. Asbestos workers in construction jobs for high rise office buildings suffer from lung disorders. Asbestos is fibrous silicate mineral which may persist for long periods of time in the environment. The fine particles (<3µ) are the worst causes of lung damage due to there ability to penetrate to the deep air passages. Larger particles (> 3µ) are trapped in the nose and throat from which they are easily eliminated, but finer particles can stay intact for years in the inner most region of the lungs lodged particles in the lungs can cause severe breathing problem by physical blockage and irritation of the lung capillaries, coal miner’s black – lung disease, asbestos workers pulmonary fibrosis, and emphysema or urban people are all associated with the accumulation of such all particles.

CO must be controlled by

  1. Modification of internal combustion engines to reduce the amounts of pollutants formed during fuel combustion must be developed.
  2. Exhaust system reactor which can complete the combustion processes and change potential pollutants in to more acceptable materials must be developed.
  3. Substitute fuels for gasoline must be introduced which can yield low concentrations of pollutants upon combustion.
  4. Pollution- free power sources like CNG (compressed natural gas) and LNG (liquefied natural gas) must use in the place of the internal combustion engines.

NOx must be controlled by using catalytic converters in the first stage as power plants emit about 50-1000ppm of NOx. Such emission of NOx can be reduced by 90% by using two – stage combustion process.

Hydrocarbons can be removed from the atmosphere by several chemical and photochemical reactions. They are thermodynamically unstable toward oxidation and tend to be oxidized through a series of steps.

SOx can be controlled by four possible approaches:

  1. Removal of SOx from fuel gases.
  2. Removal of sulphur from fuel burning.
  3. Use of low sulphur fuels.
  4. Substitution of other energy sources for fuel combustion.

Particulates can be removed to control air pollution by:

  1. Gravity settling chamber.
  2. Cyclone collector.
  3. Wet scrubber.
  4. Electrostatic precipitators.

These green house gases (CO, CO2, NOx, SOx) cause rise in temperature specially CO2and water vapors strongly absorb infrared radiation and effectively block a large fraction of the earth’s emitted radiation. The radiation thus absorbed by CO2 and H2O vapor is partly re-emitted to the earth surface. The net result is that the earth surface gets heated (global warming) up by a phenomenon called the green house effect.

The temperature effects of CO2 and water vapors combine together to have a long range impact on the global climate. As the surface temperature increases with increase in level of CO2, the evaporation of surface water increases, thereby raising the temperature further. It has been estimated that this combined effect will bring about a 3°C rise in surface temperature for a doubling of the CO2 concentration. It may be noted that a slight increase in surface temperature, say 1°C, can adversely effect the food production.

Thus CO2, which constitutes a fraction of the atmospheric gases, 0.03% of the total, plays an important role in changing the global climate. Without carbon dioxide the earth would be as cold as the moon. By trapping the heat radiating from the earth’s surface, CO2 regulates global temperature to life – sustaining 15 °C. But if its quantity increases too much, the earth may share the fate of its neighboring planet Venus with surface temperature of 450°C.

Ozone O3, which is the important species in the atmosphere acting as a protective radiation shield for living organisms on earth. O3 strongly absorbs Uv light in the region 220- 330nm and thereby protects life on earth from severe radiations damage. Only a small fraction of the Uv light reaches the lower atmosphere on the earth.
Ozone layer is depleting by reaction with atomic oxygen, reactive hydroxyl radicals and mainly by nitric oxides.

  1. O3+O → O2+O2

  2. O3+HO° → O2+HOO°
    HOO°+O → HO°+O2

  3. O3+NO → NO2+O2
    NO2+O → NO+O2

NO is produced in the atmosphere, below 30 km, by the reaction of N2O with exited oxygen atoms, and above 30km by ionizing radiation as nitrogen.

N2O+O° → 2NO
N2+hv → N+N
O2+N → NO+O

Ozone layer is depleting due to which percentage of harmful radiations emitted by the sun and reaching to earth is increasing and global warming is increasing.


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