The vertical structure of OH-HO2-RO2chemistry in the nocturnal boundary layer: A one-dimensional model study

Abstract. Sudden depletions of tropospheric ozone during spring were reported from the Arctic and also from Antarctic coastal sites. Field studies showed that those depletion events are caused by reactive halogen species, especially bromine compounds. However the source and seasonal variation of reactive halogen species is still not completely understood. There are several indications that the halogen mobilisation from the sea ice surface of the polar oceans may be the most important source for the necessary halogens. Here we present a one dimensional model study aimed at determining the primary source of reactive halogens. The model includes gas phase and heterogeneous bromine and chlorine chemistry as well as vertical transport between the surface and the top of the boundary layer. The autocatalytic Br release by photochemical processes (bromine explosion) and subsequent rapid bromine catalysed ozone depletion is well reproduced in the model and the major source of reactive bromine appears to be the sea ice surface. The sea salt aerosol alone is not sufficient to yield the high levels of reactive bromine in the gas phase necessary for fast ozone depletion. However, the aerosol efficiently "recycles" less reactive bromine species (e.g. HBr) and feeds them back into the ozone destruction cycle. Isolation of the boundary layer air from the free troposphere by a strong temperature inversion was found to be critical for boundary layer ozone depletion to happen. The combination of strong surface inversions and presence of sunlight occurs only during polar spring.

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One-dimensional Model for Studying Seasonal Changes of Vertical Structure of Salt Lake Uchum

Journal of Siberian Federal University Mathematics & Physics ◽

10.17516/1997-1397-2019-12-1-100-108 ◽

2019 ◽

Vol 12 (1) ◽

pp. 100-108

Author(s):

Belolipetskii Victor M. ◽

◽

Genova Svetlana N. ◽

Degermendzhy Andrey G. ◽

Zykov Vladimir V. ◽

...

Keyword(s):

Seasonal Changes ◽

Vertical Structure ◽

Salt Lake ◽

Dimensional Model ◽

One Dimensional

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A simple calculation method for estimating the flow velocity on the roof of a train running through a tunnel using an unsteady incompressible flow model

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1177/0954409719864738 ◽

2019 ◽

Vol 234 (7) ◽

pp. 734-748

Author(s):

Katsuhiro Kikuchi ◽

Satoru Ozawa ◽

Yuhei Noguchi ◽

Shinya Mashimo ◽

Takanobu Igawa

Keyword(s):

Boundary Layer ◽

Flow Velocity ◽

Calculation Method ◽

Model Experiment ◽

Flow Model ◽

Simple Calculation ◽

Dimensional Model ◽

One Dimensional ◽

Calculation Results ◽

Tunnel System

Predicting the aerodynamic phenomena in a train-tunnel system is important for increasing the speed of railway trains. Among these phenomena, many studies have focused on the effects of pressure; however, only a few studies have examined the effects of flow velocity. When designing train roof equipment such as a pantograph and an aerodynamic braking unit, it is necessary to estimate the flow velocity while considering the influence of the boundary layer developed on the train roof. Until now, numerical simulations using a one-dimensional model have been utilized to predict the flow velocity around a train traveling through a tunnel; however, the influence of the boundary layer cannot be taken into consideration in these simulations. For this purpose, the authors have previously proposed a simple calculation method based on a steady incompressible tunnel flow model that can take into account the influence of the boundary layer, but this method could not incorporate the unsteadiness of the flow velocity. Therefore, in this study, the authors extend the previous simple calculation method such that it can be used for an unsteady incompressible tunnel flow. The authors compare the calculation results obtained from the extended method with the results of a model experiment and a field test to confirm its effectiveness.

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A one-dimensional model for bed-boundary layer particle exchange

Journal of Marine Systems ◽

10.1016/s0924-7963(96)00127-3 ◽

1997 ◽

Vol 11 (3-4) ◽

pp. 279-303 ◽

Cited By ~ 31

Author(s):

B.P. Boudreau

Keyword(s):

Boundary Layer ◽

Dimensional Model ◽

One Dimensional ◽

Particle Exchange

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A one-dimensional model of the planetary boundary layer for monsoon studies

Monsoon Dynamics ◽

10.1017/cbo9780511897580.047 ◽

1981 ◽

pp. 615-626

Author(s):

Savita Varma

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Dimensional Model ◽

One Dimensional

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A One-Dimensional Viscous-Inviscid Strong Interaction Model for Flow in Indented Channels With Separation and Reattachment

Journal of Biomechanical Engineering ◽

10.1115/1.1580524 ◽

2003 ◽

Vol 125 (3) ◽

pp. 355-362 ◽

Cited By ~ 7

Author(s):

S. G. C. Kalse ◽

H. Bijl ◽

B. W. van Oudheusden

Keyword(s):

Boundary Layer ◽

Boundary Layers ◽

Present Model ◽

Interaction Model ◽

Dimensional Model ◽

One Dimensional ◽

Flow Models ◽

Flow Through ◽

Layer Flow ◽

Semi Empirical

A new one-dimensional model is presented for the calculation of steady and unsteady flow through an indented two-dimensional channel with separation and reattachment. It is based on an interactive boundary layer approach, where the equations for the boundary layer flow near the channel walls and for an inviscid core flow are solved simultaneously. This approach requires no semi-empirical inputs, such as the location of separation and reattachment, which is an advantage over other existing one-dimensional models. Because of the need of an inviscid core alongside the boundary layers, the type of inflow as well as the length of the channel and the value of the Reynolds number poses some limitations on the use of the new model. Results have been obtained for steady flow through the indented channel of Ikeda and Matsuzaki. In further perspective, it is discussed how the present model, in contrast to other one-dimensional flow models, can be extended to calculate the flow in nonsymmetrical channels, by considering different boundary layers on each of the walls.

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