AMBIENT AIR MONITORING with different parameter

1. AMBIENT AIR
MONITORING
- Wind Speed, Direction, Temperature And Other Meteorological Parameters
BY,
SANTHIYA C
22ENVA16

2. INTRODUCTION
• If the air is calm and pollutants cannot disperse , then the concentration of these
pollutants will build up
• On the other hand , when strong, turbulent winds blow , the pollutants disperse
quickly , resulting in lower pollutant concentrations
• When studying air quality , it is important to measure the following factors as
they can help us understand the chemical reactions that occur in the atmosphere:
 Wind speed and direction
 Temperature
 Humidity
 Pollutants
 Rainfall
 Solar radiation

3. WIND SPEED
• In meteorology, wind speed is a fundamental atmospheric quantity caused by air
moving from high to low pressure, usually due to changes in temperature.
• Wind speed is commonly measured by anemometer
• Wind speed affects weather forecasting, aviation and maritime operations,
construction projects, growth and metabolism rate of many plant species and has
countless other implication
• Meters per second (m/s) is the SI unit for velocity.
• Wind speed is affected by a number of factors and situation including pressure
gradient , jet streams and local weather conditions

4. WIND DIRECTION
• Wind direction is generally reported by the direction from which the wind
originates
• Wind direction is usually reported in cardinal (or compass) direction or in
degrees
• A variety of instruments can be used to measure wind direction, such as the
anemoscope, windsock and wind vane
• Modern instruments used to measure wind speed and direction are called
anemometers
• Weather forecasts typically give the direction of the wind along with its speed,
for example, northernly wind at 15 km/h

5. TEMPERATURE
• Air temperature is a measure of hot or cold the air is. It is most commonly
measured weather parameter
• More specifically, temperature describes the kinetic energy or energy of motion
of the gases that make up air
• As gas molecules move more quickly , air temperature increases.
• It also affects nearly all other weather parameters. For instance, air temperature
affects:
 The rate of evaporation
 Relative humidity
 Wind speed and direction
 Precipitation patterns and types, such as whether it will rain, snow or sleet

6. HUMIDITY
• Humidity is the concentration of water vapor present in the air
• Humidity indicates the likelihood for precipitation , dew or fog to be present
• Humidity depends on the temperature and pressure of the system of interest
• If attached to the particles suspended in the air, they can significantly increase the
amount of light scattered by the particles
• Measuring humidity uses the absorption properties of a polymer film
• The film either absorbs or loses water vapor as the relative humidity of the
ambient air changes
• A sensor measures these changes and converts them into a humidity reading

7. POLLUTANTS
• Under National Air Quality Monitoring Programme (NAMP) , 12 air pollutants
viz., Sulphur Oxides, Oxides Of Nitrogen, PM10, PM2.5, Ozone, Lead, Carbon
Monoxide, Ammonia, Benzene, Benzo-pyrene, Arsenic, Nickel has been
identified for regular monitoring
• Among all these parameters, particulate matter is the most important pollutant
present in the atmosphere.
• National Ambient Air Quality Standards (NAAQS), states that it should be 8 hrs
or 24 hrs as per requirement.
• Particulate matter levels are lower during the monsoon months due to removal by
wet deposition.

8. RAINFALL
• Rain has a ‘scavenging’ effect when it washes particulate matter out of the
atmosphere and dissolves gaseous pollutants
• Where there is frequent high rainfall, air quality is generally better
• If the rain dissolves gaseous pollutants, such as sulfur dioxide, it can form acid
rain resulting in potential damage to materials or vegetation
• A common method to measure rainfall is to use a tipping bucket rain gauge.

9. SOLAR RADIATION
• It is important to monitor solar radiation for use in modelling photochemical
smog events, as intensity of sunlight has an important influence on the rate of
chemical reactions that produce the smog
• The cloudiness of the sky, time of day and geographical location all affect
sunlight intensity
• An instrument called pyranometer measures solar radiation from the output of a
type of silicon cell sensor

10. THANK YOU