Boundary Layer Ozone ConcentrationsDownwind of NYC

Anfal Boussayoud

AbstractTo determine why ozone concentrations may differ between Summer and Fall. I will focus on concentrations in the boundary layer, from ground level to about 10 km. The variables that are being tested for their affect on ozone concentration are temperature, pressure, relative humidity, wind speed, and direction. The urban heat island effect is also said to have a substantial impact on these factors, so research was done in that area as well. There are several factors for variability, such as the vegetation nearby, which displaces heat and reduces the formation of NOx and VOCs, and the weather during the days the data was collected, as inclement weather could scramble it.

What is ozone?Ozone is a highly reactive gas made up of three Oxygen molecules. • It is formed when Oxygen molecules (O2) are polarized by the

ultraviolet radiation from the sun, causing them to break apart. Those free oxygen atoms then react with the diatomic oxygen molecules and create O3, ozone.

• Ozone is present both at ground level and in the upper layers of the atmosphere.

Remember: Good up high, bad nearby.• Ground level and boundary layer ozone is created by chemical

reactions between NOx (Nitrogen oxide) and VOC (Volatile Organic Compounds), which are created from high temperature combustion processes

Background

http://www.atlantaregional.com/environment/air/ozone

MethodologyRadiosonde:An instrument that transmits radio signals. It contains a sensor that measures wind speed, temperature, pressure, humidity and wind direction. There is also a GPS onboard.

Temperature Sensor

Air Pump Motor

Styrofoam Box

Ozonesonde Compartment

Teflon Tube

Temperature Sensor

Humidity Sensor

Connector to Ozonesonde

Antenna

Frequency Switch

Payload

Parachute

Balloon (1200 g)

Transceiver

Modem

Antenna

Receiving Groundstation

Ozonesonde:Instruments that transmit information on ozone concentrations in the atmosphere.

Other Materials/Instruments:Weather Balloon, helium, parachute, transceiver and modem, antenna and laptop.

Both instruments are connected together and their data is transmitted via a Ground-tracking computer via an antenna using a radio frequency of 403 MHz (illustrated below)

Urban Heat Island Effect• Named for the effect that occurs when an urban environment

is substantially warmer than it's surrounding areas, during both summer and winter.

• Urban built environments are powerhouses for the creation of NOx and VOCs because of the abundant sunlight and high air temperature in the area.

• There is also an impervious surface to the landscape that reduces it's ability to shed excessive heat by latent heat exchange, increasing radiation.

Results

Conclusion

Acknowledgements

• Ozone concentration is affected by weather conditions.• Based on the observations, we can see a correlation between

the ozone concentrations and the impact of atmospheric variables such as temperature, pressure, and relative humidity, wind speed and direction, some way an influence on the concentration of ozone in NYC.

• Dr. Shermane Austin (MEC)• Dr. Leon Johnson (MEC)• Rita Barley (CCNY/MEC)• Special Thanks to Dr. Christopher Boxe (MEC)