caa a22 4500 477061281 CHVBK 20180405111401.0 cr unu---uuuuu 170330e19960301xx s 000 0 eng 10.1007/BF00055156 doi (NATIONALLICENCE)springer-10.1007/BF00055156 Flux between soil and atmosphere, vertical concentration profiles in soil, and turnover of nitric oxide: 1. Measurements on a model soil core [Elektronische Daten] [Jutta Rudolph, Franz Rothfuss, Ralf Conrad] A stainless steel soil corer which was filled with homogenized soil was used to measure the flux (J) of NO between soil and atmosphere and the vertical profile of the NO mixing ratios (m) in the soil atmosphere, both as function of the NO mixing ratio (mm a ) in the atmosphere of the headspace. The NO emission flux decreased linearly with increasing NO mixing ratio and turned into a deposition flux after passage of the compensation point (m c) at about 400 ppbv NO. Almost the same compensation point was obtained when the turnover of NO was measured in flask-incubated soil samples as function of the NO mixing ratio. The flux (J) of NO at the soil-atmosphere interface was calculated from the production rate (P) of NO and the NO uptake rate constant (k) that were measured in these flask-incubated soil samples using the diffusion model of Galbally and Johansson (1989). The calculated fluxes agreed within <15% with those actually measured. The vertical profiles of NO were fitted to an exponential function and analyzed by Fick's first law of diffusion. The shape of the profiles indicated a net production of NO in the upper 10 cm soil layer when the atmospheric NO mixing ratio was below the compensation point and in a net consumption of NO when the atmospheric NO mixing ratio was above the compensation point. In soil layers below 10 cm depth, the turnover of NO resulted in compensation of production and consumption rates. Measurement of the actual diffusion coefficient using SF6 showed that gas transport in the soil core was not only due to molecular diffusion but in addition due to a bidirectional gas flow. The experimentally determined diffusion coefficient was smaller than that computed from soil porosities, but resulted together with the additional transport term in NO fluxes that were close (< ±15%) to those measured. This is the first comprehensive study of NO concentration profiles and turnover rates in soil providing a theoretical basis for modelling NO fluxes at the soil-atmosphere interface. Kluwer Academic Publishers, 1996 NO emission nationallicence NO production nationallicence NO consumption nationallicence NO vertical profile nationallicence NO compensation concentration nationallicence relaxation depth nationallicence soil atmosphere nationallicence diffusion model nationallicence diffusion coefficient nationallicence gas flow nationallicence Rudolph Jutta Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str., D-35043, Marburg, Germany aut Rothfuss Franz Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str., D-35043, Marburg, Germany aut Conrad Ralf Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str., D-35043, Marburg, Germany aut Journal of Atmospheric Chemistry Kluwer Academic Publishers; gopher://gopher.wkap.nl 23/3(1996-03-01), 253-273 0167-7764 23:3<253 1996 23 10874 https://doi.org/10.1007/BF00055156 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00055156 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rudolph Jutta Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str., D-35043, Marburg, Germany aut NATIONALLICENCE 700 1- Rothfuss Franz Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str., D-35043, Marburg, Germany aut NATIONALLICENCE 700 1- Conrad Ralf Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str., D-35043, Marburg, Germany aut NATIONALLICENCE 773 0- Journal of Atmospheric Chemistry Kluwer Academic Publishers; gopher://gopher.wkap.nl/ 23/3(1996-03-01), 253-273 0167-7764 23:3<253 1996 23 10874 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 477061265 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer