A note on MOST and HOST for turbulence parametrization

2020 ◽  
Vol 146 (729) ◽  
pp. 1991-1997
Author(s):  
Branko Grisogono ◽  
Jielun Sun ◽  
Danijel Belušić
Keyword(s):  
Turbulence Parametrization

Evaluation of the turbulence parametrization in the MOLOCH meteorological model

2019 ◽  
Vol 146 (726) ◽  
pp. 124-140 ◽  
Author(s):  
Silvia Trini Castelli ◽  
Andrea Bisignano ◽  
Antonio Donateo ◽  
Tony C. Landi ◽  
Paolo Martano ◽  
...  
Keyword(s):  
Meteorological Model ◽  
Turbulence Parametrization

scholarly journals Sensitivity of the ocean circulation model to the k–omega vertical turbulence parametrization

2019 ◽  
Vol 55 (5) ◽  
pp. 103-113
Author(s):  
V. B. Zalesny ◽  
S. N. Moshonkin
Keyword(s):  
Ocean Circulation ◽  
General Circulation ◽  
Splitting Method ◽  
Three Dimensional ◽  
Numerical Algorithms ◽  
Circulation Model ◽  
Ocean General Circulation Model ◽  
Turbulence Parametrization ◽  
Vertical Turbulence ◽  
Model Equations

Ocean general circulation model (OGCM) of the INM RAS with embedded k turbulent model is developed. The solution of the k model equations depends on the frequencies of buoyancy and velocity shift which are generated by the OGCM. The coefficients of vertical turbulence in OGCM depend on k and omega. The numerical algorithms of both models are based on the splitting method for physical processes. The model equations are split into two stages, describing the three-dimensional transport-diffusion of the kinetic energy of turbulence and frequency and their local generation-dissipation. The system of ordinary differential equations arising at the second stage is solved analytically, which ensures the efficiency of the algorithm. Analytical solution also written for the vertical turbulence coefficient equation. The model is used to study the sensitivity of the model circulation of the North AtlanticArctic Ocean to variations in the parameters of vertical turbulence. Experiments show that varying the coefficients of the analytical model solution can improve the adequacy of the simulation.

Wind effect in turbulence parametrization

2005 ◽  
Vol 28 (9) ◽  
pp. 939-949 ◽  
Author(s):  
M. Colombini ◽  
A. Stocchino
Keyword(s):  
Wind Effect ◽  
Turbulence Parametrization

scholarly journals Verification of the regional atmospheric model CCLM v5.0 with conventional data and Lidar measurements in Antarctica

2019 ◽  
Author(s):  
Rolf Zentek ◽  
Günther Heinemann
Keyword(s):  
Wind Speed ◽  
Sea Ice ◽  
Climate Model ◽  
Regional Climate ◽  
Weddell Sea ◽  
Good Representation ◽  
Near Surface ◽  
Turbulence Parametrization ◽  
Lidar Measurements ◽  
The Antarctic

Abstract. The non-hydrostatic regional climate model CCLM was used for a long-term hindcast run (2002–2016) for the Weddell Sea region with resolutions of 15 and 5 km and two different turbulence parametrizations. CCLM was nested in ERA-Interim data. We prescribed sea-ice concentration from satellite data, and used a thermodynamic sea-ice model. The performance of the model was evaluated in terms of temperature and wind using data from Antarctic stations, AWS over land and sea ice, operational forecast model and reanalyses data, and lidar wind profiles. For the reference run we found a warm bias for the near-surface temperature over the Antarctic plateau. This bias was removed in the second run by adjusting the turbulence parametrization, which results in a more realistic representation of the surface inversion over the plateau. Differences in other regions were small. A comparison with measurements over the sea ice of the Weddell Sea by three AWS buoys for one year showed small biases for temperature around 1 K and for wind speed of 1 m s−1. Comparisons of radio soundings showed a model bias around zero and a RMSE of 1–2 K for temperature and of 3–4 m s−1 for wind speed. The comparison of CCLM simulations at resolutions down to 1 km with wind data from Doppler Lidar measurements during December 2015 and January 2016 yielded almost no bias in wind speed and RMSE of ca. 2 m s−1. Overall CCLM shows a good representation of temperature and wind for the Weddell Sea region. These results encourage for further studies using CCLM data for the regional climate in the Antarctic at high resolutions and the study of atmosphere-ice-ocean interactions processes.

scholarly journals Coupling a new turbulence parametrization to RegCM adds realistic stratocumulus clouds

2011 ◽  
Vol 4 (4) ◽  
pp. 3437-3484
Author(s):  
T. A. O'Brien ◽  
P. Y. Chuang ◽  
L. C. Sloan ◽  
I. C. Faloona ◽  
D. L. Rossiter
Keyword(s):  
Marine Boundary Layer ◽  
Climate Model ◽  
Regional Climate ◽  
Liquid Water Content ◽  
Theoretical Physics ◽  
Cold Bias ◽  
In Situ Data ◽  
Turbulence Parametrization ◽  
Fractional Cloud ◽  
Stratocumulus Clouds

Abstract. To model stratocumulus clouds in the regional climate model, RegCM4.1, the University of Washington (UW) turbulence parametrization has been coupled to RegCM. We describe improvements in RegCM's coastal and near-coastal climatology, including improvements in the representation of stratiform clouds. By comparing output from a 27-yr (1982–2009) simulation of the climate of Western North America to a wide variety of observational data (station data, satellite data, and aircraft in situ data), we show the following: (1) RegCM-UW is appropriate for use in general regional climate studies, and (2) the UW model distinctly improves the representation of the marine boundary layer in RegCM. These model-data comparisons also show that RegCM-UW has slight cold bias, a (wet) precipitation bias, a systematic low bias in the vertically-integrated liquid water content near the coast, and a high bias in the fractional cloud coverage. The model represents well the diurnal, monthly, and interannual variability in low clouds. These results show RegCM-UW as a nascent mesoscale stratocumulus model that is appropriate for stratocumulus investigations at scales ranging from hourly to decadal. The source code for RegCM-UW is publicly available, under the GNU license, through the International Centre for Theoretical Physics.

scholarly journals Coupling a new turbulence parametrization to RegCM adds realistic stratocumulus clouds

2012 ◽  
Vol 5 (4) ◽  
pp. 989-1008 ◽  
Author(s):  
T. A. O'Brien ◽  
P. Y. Chuang ◽  
L. C. Sloan ◽  
I. C. Faloona ◽  
D. L. Rossiter
Keyword(s):  
Marine Boundary Layer ◽  
Climate Model ◽  
Regional Climate ◽  
Liquid Water Content ◽  
Theoretical Physics ◽  
Cold Bias ◽  
In Situ Data ◽  
Turbulence Parametrization ◽  
Fractional Cloud ◽  
Stratocumulus Clouds

Abstract. To model stratocumulus clouds in the regional climate model, RegCM4.1, the University of Washington (UW) turbulence parametrization has been coupled to RegCM. We describe improvements in RegCM's coastal and near-coastal climatology, including improvements in the representation of stratiform clouds. By comparing output from a 27-yr (1982–2009) simulation of the climate of western North America to a wide variety of observational data (station data, satellite data, and aircraft in situ data), we show the following: (1) RegCM-UW is appropriate for use in general regional climate studies, and (2) the UW model distinctly improves the representation of the marine boundary layer in RegCM. These model–data comparisons also show that RegCM-UW has a slight cold bias, a (wet) precipitation bias, a systematic low bias in the vertically-integrated liquid water content near the coast, and a high bias in the fractional cloud coverage. The model represents well the diurnal, monthly, and interannual variability in low clouds. These results show RegCM-UW as a nascent mesoscale stratocumulus model that is appropriate for stratocumulus investigations at scales ranging from hourly to decadal. The source code for RegCM-UW is publicly available, under the GNU license, through the International Centre for Theoretical Physics.

scholarly journals Verification of the regional atmospheric model CCLM v5.0 with conventional data and lidar measurements in Antarctica

2020 ◽  
Vol 13 (4) ◽  
pp. 1809-1825 ◽  
Author(s):  
Rolf Zentek ◽  
Günther Heinemann
Keyword(s):  
Wind Speed ◽  
Sea Ice ◽  
Climate Model ◽  
Regional Climate ◽  
Weddell Sea ◽  
Good Representation ◽  
Near Surface ◽  
Turbulence Parametrization ◽  
Lidar Measurements ◽  
The Antarctic

Abstract. The nonhydrostatic regional climate model CCLM was used for a long-term hindcast run (2002–2016) for the Weddell Sea region with resolutions of 15 and 5 km and two different turbulence parametrizations. CCLM was nested in ERA-Interim data and used in forecast mode (suite of consecutive 30 h long simulations with 6 h spin-up). We prescribed the sea ice concentration from satellite data and used a thermodynamic sea ice model. The performance of the model was evaluated in terms of temperature and wind using data from Antarctic stations, automatic weather stations (AWSs), an operational forecast model and reanalyses data, and lidar wind profiles. For the reference run we found a warm bias for the near-surface temperature over the Antarctic Plateau. This bias was removed in the second run by adjusting the turbulence parametrization, which results in a more realistic representation of the surface inversion over the plateau but resulted in a negative bias for some coastal regions. A comparison with measurements over the sea ice of the Weddell Sea by three AWS buoys for 1 year showed small biases for temperature around ±1 K and for wind speed of 1 m s−1. Comparisons of radio soundings showed a model bias around 0 and a RMSE of 1–2 K for temperature and 3–4 m s−1 for wind speed. The comparison of CCLM simulations at resolutions down to 1 km with wind data from Doppler lidar measurements during December 2015 and January 2016 yielded almost no bias in wind speed and a RMSE of ca. 2 m s−1. Overall CCLM shows a good representation of temperature and wind for the Weddell Sea region. Based on these encouraging results, CCLM at high resolution will be used for the investigation of the regional climate in the Antarctic and atmosphere–ice–ocean interactions processes in a forthcoming study.

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