Related Experiment Video
Updated: May 23, 2026

Façade-Level Monitoring of CO2 Variability under Urban Heat Island Conditions using Low-Cost Sensor Data Loggers
Published on: December 12, 2025
[Observation and study on atmospheric VOCs in Changsha city]
Quan Liu1, Yue-Si Wang, Fang-Kun Wu
1State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. lq@dq.cern.ac.cn
Abstract:
Volatile organic compounds (VOCs) are one of the key precursors of atmospheric ozone (O3), which also contribute to the production of SOA. During 2008, VOCs were measured near Changsha City. Weekly integrated canister samples were collected and analyzed in the morning and afternoon of each Tuesday. Simultaneously, concentration, potential ozone production and sources of VOCs in the atmosphere of Changsha were studied. The results indicated that the total VOCs species had higher concentrations in the morning (38.4 x 10(-9)), and lower in the afternoon (22.7 x 10(-9)), where the concentration of halo carbon was the highest, and alkanes, aromatics and alkenes came next. The m/p-xylene had the highest OH reactivity concentration (10.71 x 10(-9) C), 1,2,4-trimethylbenzene (6.04 x 10(-9) C) and 1,3,5-trimethylbenzene (2.23 x 10(-9) C) came next. Aromatics (66%) had the most significant contribution to the production of O3 in the atmospheric VOCs of Changsha, and alkenes (26%) and alkanes (8%) came next. The highest concentrations of propane and isopentane indicated vehicular exhaust and liquefied petroleum gas (LPG) appear to be the main source of VOCs in Changsha City. Benzene/toluene ratio was higher than 0.5 which was close to 0.8, showing solvent volatilization was also a main source of VOCs.
Related Concept Videos
Effects of Air-entrainment in Concrete
Variation of Atmospheric Pressure
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Naturalistic Observations
Volatilization
Measurement of Air Content in Concrete
The pressure method,...
Respiratory System Abnormal Finding I: Inspection and Percussion
Inspection Findings
During an inspection, several findings may suggest the presence of respiratory distress or disease. Pursed-lip breathing, where exhalation is slowed by...

