Toward a Fully Lagrangian Atmospheric Modeling System

Abstract An improved treatment of advection is essential for atmospheric transport and chemistry models. Eulerian treatments are generally plagued with instabilities, unrealistic negative constituent values, diffusion, and dispersion errors. A higher-order Eulerian model improves one error at significant cost but magnifies another error. The cost of semi-Lagrangian models is too high for many applications. Furthermore, traditional trajectory “Lagrangian” models do not solve both the dynamical and tracer equations simultaneously in the Lagrangian frame. A fully Lagrangian numerical model is, therefore, presented for calculating atmospheric flows. The model employs a Lagrangian mesh of particles to approximate the nonlinear advection processes for all dependent variables simultaneously. Verification results for simulating sea-breeze circulations in a dry atmosphere are presented. Comparison with Defant’s analytical solution for the sea-breeze system enabled quantitative assessment of the model’s convergence and stability. An average of 20 particles in each cell of an 11 × 20 staggered grid system are required to predict the two-dimensional sea-breeze circulation, which accounts for a total of about 4400 particles in the Lagrangian mesh. Comparison with Eulerian and semi-Lagrangian models shows that the proposed fully Lagrangian model is more accurate for the sea-breeze circulation problem. Furthermore, the Lagrangian model is about 20 times as fast as the semi-Lagrangian model and about 2 times as fast as the Eulerian model. These results point toward the value of constructing an atmospheric model based on the fully Lagrangian approach.

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The effect of coastal upwelling on the sea-breeze circulation at Cabo Frio, Brazil: a numerical experiment

Annales Geophysicae ◽

10.1007/s00585-998-0866-3 ◽

1998 ◽

Vol 16 (7) ◽

pp. 866-871 ◽

Cited By ~ 34

Author(s):

S. H. Franchito ◽

V. B. Rao ◽

J. L. Stech ◽

J. A. Lorenzzetti

Keyword(s):

Coastal Upwelling ◽

Surface Wind ◽

Three Dimensional ◽

Sea Breeze ◽

Atmospheric Model ◽

Ocean Model ◽

Breeze Circulation ◽

Mesoscale Meteorology ◽

Forcing Function ◽

Cabo Frio

Abstract. The effect of coastal upwelling on sea-breeze circulation in Cabo Frio (Brazil) and the feedback of sea-breeze on the upwelling signal in this region are investigated. In order to study the effect of coastal upwelling on sea-breeze a non-linear, three-dimensional, primitive equation atmospheric model is employed. The model considers only dry air and employs boundary layer formulation. The surface temperature is determined by a forcing function applied to the Earth's surface. In order to investigate the seasonal variations of the circulation, numerical experiments considering three-month means are conducted: January-February-March (JFM), April-May-June (AMJ), July-August-September (JAS) and October-November-December (OND). The model results show that the sea-breeze is most intense near the coast at all the seasons. The sea-breeze is stronger in OND and JFM, when the upwelling occurs, and weaker in AMJ and JAS, when there is no upwelling. Numerical simulations also show that when the upwelling occurs the sea-breeze develops and attains maximum intensity earlier than when it does not occur. Observations show a similar behavior. In order to verify the effect of the sea-breeze surface wind on the upwelling, a two-layer finite element ocean model is also implemented. The results of simulations using this model, forced by the wind generated in the sea-breeze model, show that the sea-breeze effectively enhances the upwelling signal.Key words. Meteorology and atmospheric dynamics (mesoscale meteorology; ocean-atmosphere interactions) · Oceanography (numerical modeling)

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The co-influence of the sea breeze and the coastal upwelling at Cabo Frio: a numerical investigation using coupled models

Brazilian Journal of Oceanography ◽

10.1590/s1679-87592011000200002 ◽

2011 ◽

Vol 59 (2) ◽

pp. 131-144 ◽

Cited By ~ 5

Author(s):

Flávia Noronha Dutra Ribeiro ◽

Jacyra Soares ◽

Amauri Pereira de Oliveira

Keyword(s):

Positive Feedback ◽

Coastal Upwelling ◽

Coupled Model ◽

Sea Breeze ◽

Atmospheric Model ◽

Breeze Circulation ◽

Coupled Models ◽

Initial Field ◽

Oceanic Model ◽

Cabo Frio

A coupled atmospheric-oceanic model was used to investigate whether there is a positive feedback between the coastal upwelling and the sea breeze at Cabo Frio - RJ (Brazil). Two experiments were performed to ascertain the influence of the sea breeze on the coastal upwelling: the first one used the coupled model forced with synoptic NE winds of 8 m s-1 and the sign of the sea breeze circulation was set by the atmospheric model; the second experiment used only the oceanic model with constant 8 m s-1 NE winds. Then, to study the influence of the coastal upwelling on the sea breeze, two more experiments were performed: one using a coastal upwelling representative SST initial field and the other one using a constant and homogeneous SST field of 26°C. Finally, two more experiments were conducted to verify the influence of the topography and the spatial distribution of the sea surface temperature on the previous results. The results showed that the sea breeze can intensify the coastal upwelling, but the coastal upwelling does not intensify the sea breeze circulation, suggesting that there is no positive feedback between these two phenomena at Cabo Frio.

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The Application of an Evolutionary Algorithm to the Optimization of a Mesoscale Meteorological Model

Journal of Applied Meteorology and Climatology ◽

10.1175/2008jamc1967.1 ◽

2009 ◽

Vol 48 (2) ◽

pp. 317-329 ◽

Cited By ~ 8

Author(s):

Lance O’Steen ◽

David Werth

Keyword(s):

Cost Function ◽

Evolutionary Algorithm ◽

Synthetic Data ◽

Atmospheric Model ◽

Atmospheric Modeling ◽

Model Parameters ◽

Meteorological Model ◽

Rms Error ◽

Mesoscale Atmospheric Model ◽

The Cost

Abstract It is shown that a simple evolutionary algorithm can optimize a set of mesoscale atmospheric model parameters with respect to agreement between the mesoscale simulation and a limited set of synthetic observations. This is illustrated using the Regional Atmospheric Modeling System (RAMS). A set of 23 RAMS parameters is optimized by minimizing a cost function based on the root-mean-square (rms) error between the RAMS simulation and synthetic data (observations derived from a separate RAMS simulation). It is found that the optimization can be done with relatively modest computer resources; therefore, operational implementation is possible. The overall number of simulations needed to obtain a specific reduction of the cost function is found to depend strongly on the procedure used to perturb the “child” parameters relative to their “parents” within the evolutionary algorithm. In addition, the choice of meteorological variables that are included in the rms error and their relative weighting are also found to be important factors in the optimization.

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Intercomparison and evaluation of atmospheric transport in a Lagrangian model (STOCHEM), and an Eulerian model (UM), using222Rn as a short-lived tracer

Quarterly Journal of the Royal Meteorological Society ◽

10.1002/qj.49712455115 ◽

1998 ◽

Vol 124 (551) ◽

pp. 2477-2491 ◽

Cited By ~ 5

Author(s):

D. S. Stevenson ◽

W. J. Collins ◽

C. E. Johnson ◽

R. G. Derwent

Keyword(s):

Atmospheric Transport ◽

Lagrangian Model ◽

Eulerian Model

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Intercomparison and evaluation of atmospheric transport in a Lagrangian model (STOCHEM), and an Eulerian model (UM), using 222Rn as a short lived tracer.

Quarterly Journal of the Royal Meteorological Society ◽

10.1256/smsqj.55114 ◽

1998 ◽

Vol 124 (551) ◽

pp. 2477-2491 ◽

Cited By ~ 10

Author(s):

DS STEVENSON ◽

WJ COLLINS ◽

CE JOHNSON ◽

RG DERWENT

Keyword(s):

Atmospheric Transport ◽

Lagrangian Model ◽

Eulerian Model

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A complete sea-breeze circulation cell derived from aircraft observations

Boundary-Layer Meteorology ◽

10.1007/bf00711261 ◽

1995 ◽

Vol 73 (3) ◽

pp. 299-317 ◽

Cited By ~ 50

Author(s):

Klara Finkele ◽

J�rg M. Hacker ◽

Helmut Kraus ◽

Roland A. D. Byron-Scott

Keyword(s):

Sea Breeze ◽

Breeze Circulation ◽

Aircraft Observations ◽

Circulation Cell

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EMEP Eulerian model for atmospheric transport and deposition of nitrogen species over Europe

Nitrogen, the Confer-N-s ◽

10.1016/b978-0-08-043201-4.50044-7 ◽

1998 ◽

pp. 289-298

Author(s):

J.E. Jonson ◽

J. Bartnicki ◽

K. Olendrzynski ◽

H.A. Jakobsen ◽

E. Berge

Keyword(s):

Atmospheric Transport ◽

Nitrogen Species ◽

Eulerian Model

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Transport of short-lived halocarbons to the stratosphere over the Pacific Ocean

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-1163-2020 ◽

2020 ◽

Vol 20 (2) ◽

pp. 1163-1181

Author(s):

Michal T. Filus ◽

Elliot L. Atlas ◽

Maria A. Navarro ◽

Elena Meneguz ◽

David Thomson ◽

...

Keyword(s):

Boundary Layer ◽

Lower Stratosphere ◽

Atmospheric Transport ◽

Convective Transport ◽

Transport Processes ◽

Lagrangian Model ◽

Convection Scheme ◽

Model Calculations ◽

Upper Troposphere ◽

Tropical Troposphere

Abstract. The effectiveness of transport of short-lived halocarbons to the upper troposphere and lower stratosphere remains an important uncertainty in quantifying the supply of ozone-depleting substances to the stratosphere. In early 2014, a major field campaign in Guam in the western Pacific, involving UK and US research aircraft, sampled the tropical troposphere and lower stratosphere. The resulting measurements of CH3I, CHBr3 and CH2Br2 are compared here with calculations from a Lagrangian model. This methodology benefits from an updated convection scheme that improves simulation of the effect of deep convective motions on particle distribution within the tropical troposphere. We find that the observed CH3I, CHBr3 and CH2Br2 mixing ratios in the tropical tropopause layer (TTL) are consistent with those in the boundary layer when the new convection scheme is used to account for convective transport. More specifically, comparisons between modelled estimates and observations of short-lived CH3I indicate that the updated convection scheme is realistic up to the lower TTL but is less good at reproducing the small number of extreme convective events in the upper TTL. This study consolidates our understanding of the transport of short-lived halocarbons to the upper troposphere and lower stratosphere by using improved model calculations to confirm consistency between observations in the boundary layer, observations in the TTL and atmospheric transport processes. Our results support recent estimates of the contribution of short-lived bromocarbons to the stratospheric bromine budget.

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Impact of Vertical Wind Shear on Gravity Wave Propagation in the Land–Sea-Breeze Circulation at the Equator

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-19-0069.1 ◽

2019 ◽

Vol 76 (10) ◽

pp. 3247-3265

Author(s):

Yu Du ◽

Richard Rotunno ◽

Fuqing Zhang

Keyword(s):

Gravity Wave ◽

Gravity Waves ◽

Wind Shear ◽

Vertical Wind Shear ◽

Sea Breeze ◽

Vertical Wind ◽

Background Wind ◽

Breeze Circulation ◽

Attenuation Level ◽

Ray Path

Abstract The impact of vertical wind shear on the land–sea-breeze circulation at the equator is explored using idealized 2D numerical simulations and a simple 2D linear analytical model. Both the idealized and linear analytical models indicate Doppler shifting and attenuation effects coexist under the effect of vertical wind shear for the propagation of gravity waves that characterize the land–sea-breeze circulation. Without a background wind, the idealized sea breeze has two ray paths of gravity waves that extend outward and upward from the coast. A uniform background wind causes a tilting of the two ray paths due to Doppler shifting. With vertical shear in the background wind, the downstream ray path of wave propagation can be rapidly attenuated near a certain level, whereas the upstream ray path is not attenuated and the amplitudes even increase with height. The downstream attenuation level is found to descend with increasing linear wind shear. The present analytical model establishes that the attenuation level corresponds to the critical level where the background wind is equal to the horizontal gravity wave phase speed. The upstream gravity wave ray path can propagate upward without attenuation as there is no critical level there.

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