Evaluation of the rate of uptake of nitrogen dioxide by atmospheric and surface liquid water

Abstract

The rate of uptake of NO2 by liquid water according to (R1), 2NO2(g) + H2O(1) → 2H+ + NO3− + NO2−, is shown to be unaffected by O2 (0.2 atm). Hence the rate constant and Henry's law solubility constant of NO2 previously obtained may be employed to evaluate the rates of aqueous phase reactions of NO2 in the ambient atmosphere. Reactions (R1) and (R2), NO2(g) + NO(g) + H2O(1) → 2H+ + 2NO2−, are quite slow at representative atmospheric partial pressures and cloud liquid water content; the characteristic times range upward from 103–104 hours at 10−7 atm, increasing with decreasing partial pressures of the gases. Direct acidification of cloud liquid water by (R1) or (R2) is also unimportant. Catalytic enhancement of (R1) is potentially important for catalyst concentrations of order 10−7 M, assuming sufficiently fast rate constants (∼108 M−l s−1). Iron‐catalyzed reaction in particular, however, is found to be unimportant. Reaction of NO2 with dissolved S(IV) is potentially mportant, based upon an assumed upper limit rate constant of 2.5×107 M−1 s−1. Deposition of NO2 to surface (ocean or lake) water is shown to be controlled by aqueous phase mass transport and/or reaction and is much slower than heretofore assumed.

On the role of nitrogen dioxide in the absorption of solar radiation

“…NO 2 can be converted to HNO 3 via reaction with OH, but this process takes place on a timescale of the order of days or weeks in the free troposphere, so that the bulk of the reactive nitrogen produced by the lightning stroke both within and outside the cloud can persist in the forms of NO and NO 2 for several days. Neither gas is sufficiently soluble in water for significant removal within cloud droplets [Tuck, 1976;Lee and Schwartz, 1981]. Some authors have argued that ohmic heating of the air may also be a significant source capable of producing higher local NO concentrations than the shock wave model [Hill et at., 1980].…”

UV shielding of NH3and O2by organic hazes in the Archean atmosphere

“…At the lower boundary, soluble species with no surface source were assumed to flow downward with constant deposition velocities between 0 and 1 cm s -• following the approach of Slinn et al [1978] and Lee and Schwartz [1981]. Volcanic outgassing of SO2 and H2 was included; the surface fluxes were set equal to 3.5 x 109 and 2.5 x 10 •ø cm -2 s -• respectively [Kasting, 1990].…”

Conversion of gaseous nitrogen dioxide to nitrate and nitrite on aqueous surfactants

“…, such as those of b-bonds in free radicals), 21,22 (B) the bimolecular disproportionation of NO 2 on wet surfaces (R1). 23 The large and lingering discrepancies (up to four orders of magnitude) 10,18,[23][24][25][26][27][28][29][30][31][32][33] among laboratory measurements of NO 2 uptake coefficients ''on water'', g water , has turned attention to airborne particles that could support pathway (A), such as soot and dust. 12,16,20,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] Since HONO emissions from soot exposed to NO 2 decay rapidly in the dark 51 and cease immediately after illumination, 34,52 significant HONO production at nighttime still calls for a thermal process of type (B) that would operate throughout the day.…”

“…Schwartz et al, at variance with previously held assumptions, on pure water follows second-order kinetics in [NO 2 (g)], has therefore a very low probability (about one in ten million NO 2 /water collisions) and would not contribute significantly to HONO production on cloud or aerosol droplets under atmospheric conditions. 26,53 ''Catalysis'' by reactive species, such as transition metal ions, various types of natural organic matter and iodide, was considered, 32 but found to have minimal impact on (R1). 26 Subsequent measurements of NO 2 (g) uptake by NaCl-seeded droplets in a cloud chamber led to much larger (up to 10 4 times) (R1) reaction probabilities.…”