Biomaterial Database

Atmospheric concentrations of the Cl atom, ClO radical, and HO radical in the coastal marine boundary layer. 2004

Chang-Tang Chang, and Tsun-Hsien Liu, and Fu-Tien Jeng

Department of Environmental Engineering, National I-Lan Institute of Technology, No. 1, Sheen-Long Road, I-Lan City 260, Taiwan. ctchang@ilantech.edu.tw

Atmospheric concentrations of chlorine atom (Cl*), chlorine monoxide radical (ClO*), and hydroxyl radical (HO*) in the coastal marine boundary layer are estimated in this study. A steady-state approach to their concentrations in equilibrium with other atmospheric chemical species is used. Measurements of atmospheric trace species, HCl, Cl2, HCHO, H2O2, CH3OOH, CH4, CO, SO2, NO, NO2, and O3, were performed at four sites in Taiwan during the spring of 1999. The results indicate that the concentrations of the Cl* atom and the ClO* and HO* radicals decrease significantly with cloud cover. The calculated average daytime concentrations of Cl*, ClO*, and HO* are 3 x 10(5), 1 x 10(7), and 6 x 10(5) molecules/cm3, respectively. Due to the high reactivity of Cl* with hydrocarbons and its concentration level competitive to that of HO*, Cl* should be a significant sink for hydrocarbons in these cases.

UI	MeSH Term	Description	Entries
D002713	Chlorine	An element with atomic symbol Cl, atomic number 17, and atomic weight 35, and member of the halogen family.	Chlorine Gas,Chlorine-35,Cl2 Gas,Chlorine 35,Gas, Chlorine,Gas, Cl2
D004781	Environmental Exposure	The exposure to potentially harmful chemical, physical, or biological agents in the environment or to environmental factors that may include ionizing radiation, pathogenic organisms, or toxic chemicals.	Exposure, Environmental,Environmental Exposures,Exposures, Environmental
D004784	Environmental Monitoring	The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.	Monitoring, Environmental,Environmental Surveillance,Surveillance, Environmental
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000393	Air Pollutants	Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or materials. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.	Air Pollutant,Air Pollutants, Environmental,Environmental Air Pollutants,Environmental Pollutants, Air,Air Environmental Pollutants,Pollutant, Air,Pollutants, Air,Pollutants, Air Environmental,Pollutants, Environmental Air
D012621	Seasons	Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Seasonal Variation,Season,Seasonal Variations,Variation, Seasonal,Variations, Seasonal
D012623	Seawater	The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.	Sea Water,Sea Waters,Seawaters,Water, Sea,Waters, Sea
D013624	Taiwan	Country in eastern Asia, islands bordering the East China Sea, Philippine Sea, South China Sea, and Taiwan Strait, north of the Philippines, off the southeastern coast of China. The capital is Taipei. The alternate country name is Republic of China.	Formosa,Republic of China
D017606	Chlorine Compounds	Inorganic compounds that contain chlorine as an integral part of the molecule.	Chlorine Compounds, Inorganic,Compounds, Chlorine,Compounds, Inorganic Chlorine,Inorganic Chlorine Compounds
D017665	Hydroxyl Radical	The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.