Heterogeneous chemistry and tropospheric ozone

نویسنده

  • Daniel J. Jacob
چکیده

Ozone is produced in the troposphere by gas-phase oxidation of hydrocarbons and CO catalyzed by hydrogen oxide radicals (HO x ,OH#H#peroxy radicals) and nitrogen oxide radicals (NO x ,NO#NO 2 ). Heterogeneous chemistry involving reactions in aerosol particles and cloud droplets may a!ect O 3 concentrations in a number of ways including production and loss of HO x and NO x , direct loss of O 3 , and production of halogen radicals. Current knowledge and hypotheses regarding these processes are reviewed. It is recommended that standard O 3 models include in their chemical mechanisms the following reaction probability parameterizations for reactive uptake of gases by aqueous aerosols and clouds: c HO2 "0.2 (range 0.1}1) for HO 2 P0.5 H 2 O 2 , c NO2 "10~4 (10~6}10~3) for NO 2 P 0.5 HONO#0.5 HNO 3 , c NO3 "10~3 (2]10~4}10~2) for NO 3 PHNO 3 , and c N2O5 "0.1 (0.01}1) for N 2 O 5 P2 HNO 3 . Current knowledge does not appear to warrant a more detailed approach. Hypotheses regarding fast O 3 loss on soot or in clouds, fast reduction of HNO 3 to NO x in aerosols, or heterogeneous loss of CH 2 O are not supported by evidence. Halogen radical chemistry could possibly be signi"cant in the marine boundary layer but more evidence is needed. Recommendations for future research are presented. They include among others (1) improved characterization of the phase and composition of atmospheric aerosols, in particular the organic component; (2) aircraft and ship studies of marine boundary layer chemistry; (3) measurements of HONO vertical pro"les in urban boundary layers, and of the resulting HO x source at sunrise; (4) laboratory studies of the mechanisms for reactions of peroxy radicals, NO 2 , and HNO 3 on surfaces representative of atmospheric aerosol; and (4) laboratory studies of O 3 reactivity on organic aerosols and mineral dust. ( 2000 Elsevier Science Ltd. All rights reserved.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

1 Heterogeneous Chemistry and Tropospheric Ozone

Ozone is produced in the troposphere by gas-phase oxidation of hydrocarbons and CO catalyzed by hydrogen oxide radicals (HOx ≡ OH + peroxy radicals) and nitrogen oxide radicals (NOx ≡ NO+NO2). Heterogeneous chemistry involving reactions in aerosol particles and cloud droplets can perturb O3 concentrations in a number of ways including production and loss of HOx and NOx, direct loss of O3, and p...

متن کامل

Ozone Destruction in Continental Stratus Clouds: Experimental Evidence for Heterogeneous Chemistry

There is considerable interest in studying tropospheric ozone because of its role as a greenhouse gas and as a key element in tropospheric chemistry. Heterogeneous chemistry involving reactions with aerosols and cloud droplets can affect O3 in a number of ways. The results of model studies show that aqueous phase chemistry is shown to decrease ozone concentrations significantly in the troposphe...

متن کامل

Study of tropospheric ozone concentration trend of Kermanshah by meteorological parameter and ozone precursor and OMI images

Abstract: Clean air is a necessity for human well-being and health. Air pollution is a major threat to humans and other organisms and is considered as one of the environmental challenges. Today, with the increase in air pollution, the need to know more about the causes of its occurrence has been raised. The various consequences of air pollution have made air quality monitoring and control inev...

متن کامل

Global radiative forcing of coupled tropospheric ozone and aerosols in a unified general circulation model

[1] Global simulations of sea salt and mineral dust aerosols are integrated into a previously developed unified general circulation model (GCM), the Goddard Institute for Space Studies (GISS) GCM II0, that simulates coupled tropospheric ozone-NOxhydrocarbon chemistry and sulfate, nitrate, ammonium, black carbon, primary organic carbon, and secondary organic carbon aerosols. The fully coupled ga...

متن کامل

Heterogeneous impact of dust on tropospheric ozone: Sensitivity to season, species, and uptake rates

Heterogeneous chemistry on mineral dust particles causes significant reductions in important tropospheric trace gases such as O3, OH, and HNO3 in dust-dominated regions such as the North African Tropical Atlantic region. We analyze the spatial and temporal modes of dust-induced heterogeneous ozone removal (∆HO3) using empirical orthogonal functions (EOFs) and principal components analysis. We u...

متن کامل

Heterogeneous Chemistry and Tropospheric Ozone

Ozone is produced in the troposphere by gas-phase oxidation of hydrocarbons and CO catalyzed by hydrogen oxide radicals (HOx ≡ OH + H + peroxy radicals) and nitrogen oxide radicals (NOx ≡ NO+NO2). Heterogeneous chemistry involving reactions in aerosol particles and cloud droplets may affect O3 concentrations in a number of ways including production and loss of HOx and NOx, direct loss of O3, an...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2000