Papers by Sven-erik Gryning
Atmospheric Environment, 1998
... The tracer, a perfluorocarbon (PFC), was released in Brittany, France, transported eastward o... more ... The tracer, a perfluorocarbon (PFC), was released in Brittany, France, transported eastward over Europe and could be followed for more than 2000 km. ... At the rear of the trailing front, from Brittany to northern France, convective rain developed. ...
13th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes
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22nd Conference on Climate Variability and Change, Jan 18, 2010
SUMMARY The paper presents evaluation of model simulations against data on the vertical profiles ... more SUMMARY The paper presents evaluation of model simulations against data on the vertical profiles of mean meteorological parameters and surface turbulent momentum and heat fluxes for Sofia, Bulgaria. The simulation of the vertical profiles is currently a weak point in mesoscale modeling, and needs investigations in view of numerous practical applications.
Boundary-Layer …, 1999
Abstract. The purpose of this paper is to test the ability of two quite different models to simul... more Abstract. The purpose of this paper is to test the ability of two quite different models to simulate the combined spatial and temporal variability of the internal boundary layer in an area of complex terrain and coastline during one day. The simple applied slab model of Gryning and ...
Agricultural and Forest Meteorology, 1999
The NOPEX two concentrated ®eld efforts (CFEs) (June 1994 and April±July 1995) provide high quali... more The NOPEX two concentrated ®eld efforts (CFEs) (June 1994 and April±July 1995) provide high quality data sets for the Boreal environment. The analysis of these data with traditional meteorological and hydrological approaches allow estimations of¯uxes of latent and sensible heat, but these¯ux estimates are not directly comparable due to differences in temporal and spatial scales. The challenge here has been to overcome these dif®culties so that the different estimates can be critically compared and evaluated in a systematical way. Five different approaches for the estimation of the regional¯ux of sensible and/or latent heat over the NOPEX area have been evaluated: (1) Direct aggregation Ð mixed layer evolution method, (2) Weighted averages of (a) aircraft measurements in the boundary layer and of (b) mast measurements, (3) Numerical models (a) ECOMAG Ð a distributed hydrological model and (b) MIUU Ð a mesoscale meteorological model.
Journal of Atmospheric & Ocean Science, 2005
Precipitation and evaporation budgets over the Baltic Sea were studied in a concerted project cal... more Precipitation and evaporation budgets over the Baltic Sea were studied in a concerted project called PEP in BALTEX (Pilot study of Evaporation and Precipitation in the Baltic Sea), combining extensive field measurements and modelling efforts. Eddy-correlation-measurements of turbulent heat flux were made on a semi-continuous basis for a 12 month period at four well-exposed coastal sites in the Baltic Proper (the main basin of the Baltic Sea). Precipitation was measured at land-based sites with standard gauges and on four merchant ships travelling between Germany and Finland with the aid of specially designed ship rain gauges (SRGs). The evaporation and precipitation regime of the Baltic Sea was modelled for a 12 month period by applying a wide range of numerical models: the operational atmospheric High Resolution Limited Area Model (HIRLAM, Swedish and Finnish versions), the German atmospheric REgionalscale MOdel, REMO, the operational German Europe Model (only precipitation), the oceanographic model PROBE-Baltic, and two models that use interpolation of ground-based data, the Swedish MESAN model of SMHI and a German model of IFM-GEOMAR Kiel. Modelled precipitation was compared with SRG measurements on board the ships. A reasonable correlation was obtained, but the regional-scale models and MESAN gave some 20% higher precipitation over the sea than is measured. Bulk parameterisation schemes for evaporation were evaluated against measurements. A constant value of C HN and C EN with wind speed, underestimated large fluxes of both sensible and latent heat flux. The limited area models do not resolve the influence of the height of the marine boundary layer in coastal zones and the entrainment (on the surface fluxes), which may explain the observed low correlations between modelled and measured latent heat fluxes. Estimates of evaporation, E, and precipitation, P, for the entire Baltic Proper were made with several models for a 12 month period. While the annual variation was well represented by all predictions, there are still important differences in the annual means. Evaporation ranges from 509 to 625 mm year À1 and precipitation between 624 and 805 mm year À1 for this particular 12 month period. Taking the results of model verification from *Corresponding author. the present study into account, the best estimate of P-E is about 100 AE 50 mm for this particular 12 month period. But the annual mean of P-E varies considerably from year to year. This is reflected in simulations with the PROBE-Baltic model for an 18 year period, which gave 95 mm year À1 for the 12 month period studied here and 32 mm year À1 as an average for 18 years.
Abstract. The purpose of this paper is to test the ability of two quite different models to simul... more Abstract. The purpose of this paper is to test the ability of two quite different models to simulate the combined spatial and temporal variability of the internal boundary layer in an area of complex terrain and coastline during one day. The simple applied slab model of Gryning and ...
Boundary-layer Meteorology, 2001
Measurements carried out in Northern Finland on radiation and turbulent fluxes over a sparse, sub... more Measurements carried out in Northern Finland on radiation and turbulent fluxes over a sparse, sub-arctic boreal forest with snow covered ground were analysed. The measurements represent late winter conditions characterised by low solar elevation angles. During the experiment (12–24 March 1997) day and night were about equally long. At low solar elevation angles the forest shades most of the snow
Boundary-layer Meteorology, 1994
A model is presented for the height of the mixed layer and the depth of the entrainment zone unde... more A model is presented for the height of the mixed layer and the depth of the entrainment zone under near-neutral and unstable atmospheric conditions. It is based on the zero-order mixed-layer height model of Batchvarova and Gryning (1991) and the parameterization of the entrainment zone depth proposed by Gryning and Batchvarova (1994). However, most zero-order slab type models of mixed-layer
Theoretical and Applied Climatology, 2005
Summary The Basel UrBan Boundary Layer Experiment (BUBBLE) was a year-long experimental effort to... more Summary The Basel UrBan Boundary Layer Experiment (BUBBLE) was a year-long experimental effort to investigate in detail the boundary layer structure in the City of Basel, Switzerland. At several sites over different surface types (urban, sub-urban and rural reference) towers up to at least twice the main obstacle height provided turbulence observations at many levels. In addition, a Wind Profiler
Theoretical and Applied Climatology, 2001
Summary A mesoscale numerical model, incorporating a land-surface scheme based on Deardorffs’ a... more Summary A mesoscale numerical model, incorporating a land-surface scheme based on Deardorffs’ approach, is used to study the diurnal variation of the boundary layer structure and surface fluxes during four consecutive days with air temperatures well below zero, snow covered ground and changing synoptic forcing. Model results are evaluated against in-situ measurements performed during the WINTEX field campaign held in Sodankyl�,
Boundary-Layer Meteorology, 1996
A model for the time and space variation of the internal boundary-layer height over a land area w... more A model for the time and space variation of the internal boundary-layer height over a land area with an irregular coastline is presented. It is based on the analytical model of the boundary-layer height proposed by Gryning and Batchvarova (1990) and Batchvarova and Gryning (199 1). The model accounts for the temperature jump and the mean vertical air motion at the top of the internal boundarylayer. Four cases from experiments in Nanticoke and Vancouver are used for model validation. The agreement between the calculated and measured internal boundary layer height at the observational sites is fairly good. The input information for the model consist of wind speed and direction, friction velocity and kinematic heat flux in time and space for the area, and the potential temperature gradient and the mean vertical air motion above the internal boundary layer. For the experiments used in the validation the effect of subsidence is relatively important in the afternoon under low wind speed high pressure conditions, lowering the height of the internal boundary layer by up to lo%, and it is negligible in the morning hours. The effect of the mixing height over the sea is found to be negligible.
Journal of Applied Meteorology, 1987
Wind and temperature data obtained on 5 June 1984 during the Øresund experiment are analyzed. The... more Wind and temperature data obtained on 5 June 1984 during the Øresund experiment are analyzed. The day was characterized by moderately strong winds blowing from a heated land area over a colder water surface and then over a second heated land area. To aid our interpretation of the data, the Colorado State University Hydrodynamic Mesoscale Model was used to simulate
Journal of Climate and Applied Meteorology, 1984
Atmospheric dispersion experiments were carried out in the Copenhagen area under neutral and unst... more Atmospheric dispersion experiments were carried out in the Copenhagen area under neutral and unstable conditions. The tracer sulphurhexafluoride was released without buoyancy from a tower at a height of 115 m and then collected at ground-level positions in up to three crosswind series of tracer sampling units, positioned 2-6 km from the point of release. The site was mainly residential having a roughness length of 0.6 m. The meteorological measurements performed during the experiments included the three-dimensional wind velocity fluctuations at the height of release.Dispersion parameters estimated from the measured tracer concentrations were compared with dispersion parameters calculated by various standard methods. These included methods based on the measured wind variances at the experiments and methods based on a stability classification of the atmospheric conditions. The wind variance-based methods are seen to be better than the stability-based methods in predicting the variation of y. In addition to being a function of downwind distance, the normalized lateral spread estimated from the measurements was found also to vary as a function of the wind speed as already demonstrated by Doran and others for low-level sources. The centerline ground-level concentrations were calculated by use of y and z derived according to the aforementioned methods and assuming the ordinary Gaussian concentration profile. These were compared with the corresponding measured concentrations; in this case also, the wind variance-based methods were seen to be better. In some of the experiments, the assumed Gaussian tracer concentration profile in the vertical direction was found to be inconsistent with the measured crosswind-integrated tracer concentrations.
Developments in Environmental Science, 2002
The height of the atmospheric boundary layer (ABL) or the mixing height (MH) is a fundamental par... more The height of the atmospheric boundary layer (ABL) or the mixing height (MH) is a fundamental parameter characterising the structure of the lower troposphere. Two basic possibilities for the practical determination of the MH are its derivation from profile data (measurements or numerical model output) and its parameterisation using simple equations or models (which only need a few measured input values). Different methods suggested in the literature are reviewed in this paper. The most important methods have been tested on data sets from three different sites in Europe (Cabauw—NL, Payerne—CH, Melpitz—D). Parcel and Richardson number methods applied to radiosonde profiles and the analysis of sodar and wind profiler data have been investigated. Modules for MH determination implemented in five currently used meteorological preprocessors for dispersion models have been tested, too. Parcel methods using a revised coefficient for the excess temperature and Richardson number methods using a surface excess temperature worked well under convective conditions. Under stable conditions, the inherent difficulties call for a combination of several methods (e.g., mast and sodar). All the tested parameterisation schemes showed deficiencies under certain conditions, thus requiring more flexible algorithms able to take into account changing and non-classical conditions. Recommendations are formulated regarding both the analysis of profile measurements and the use of parameterisations and simple models, and suggestions for the preprocessor development and for future research activities are presented.
Fate of Pesticides in the Atmosphere: Implications for Environmental Risk Assessment, 1999
... W. ADDO J. VAN PUL1*, TERRY F. BIDLEMAN2, EVA BRORSTROM-LUNDÉN3, PETER JH BUILTJES4, SERGEY D... more ... W. ADDO J. VAN PUL1*, TERRY F. BIDLEMAN2, EVA BRORSTROM-LUNDÉN3, PETER JH BUILTJES4, SERGEY DUTCHAK5, JAN H. DUYZER4 ... These have been mainly for non-polar pesticides such as DDT, HCHs and chiordane (Pankow and Bidleman, 1992; Lane et al ...
Boundary-layer Meteorology, 2000
Results from an experimental investigation of themixing height over inner Danish waters carriedou... more Results from an experimental investigation of themixing height over inner Danish waters carriedout from September 1990 to October 1992, are discussed.
Air Pollution Modeling and Its Application XVI, 2004
In this study first results from a low-level source urban tracer SF6 experiment are reported. The... more In this study first results from a low-level source urban tracer SF6 experiment are reported. The experiment was performed in the framework of the Basel UrBan Boundary Layer Experiment BUBBLE - in an area of the city of Basel (Switzerland) named Kleinbasel. Extensive ...
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Papers by Sven-erik Gryning