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Rainer Bleck

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Expertise: numerical modeling of atmospheric and oceanic circulations for weather and climate prediction. ---------- If you see my research interests described as "Space Plasma Physics United KingdomAgent Based Modeling and Simulation Agent-Based Computational EconomicsMagnetohydrodynamics", please ignore. Don't know who put it there. Haven't found a way to get rid of it.

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vittorio canuto

Columbia University

National Center for Atmospheric Research (NCAR)

Swiss Federal Institute of Technology (ETH)

Princeton University

Lawrence Livermore National Lab

M. Hadi Bordbar

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Papers by Rainer Bleck

North Atlantic simulations in Coordinated Ocean-ice Reference Experiments phase II (CORE-II). Part II: Inter-annual to decadal variability

Ocean Modelling, 2016

Please note that this is an author-produced PDF of an article accepted for publication following ... more

Subseasonal Forecasting with an Icosahedral, Vertically Quasi-Lagrangian Coupled Model. Part I: Model Overview and Evaluation of Systematic Errors

Monthly Weather Review, May 1, 2018

Subseasonal forecast skill of the global hydrostatic atmospheric Flow-Following Icosahedral Model... more Subseasonal forecast skill of the global hydrostatic atmospheric Flow-Following Icosahedral Model (FIM) coupled to an icosahedral-grid version of the Hybrid Coordinate Ocean Model (iHYCOM) is evaluated through 32-day predictions initialized weekly using a four-member time-lagged ensemble over the 16-yr period 1999-2014. Systematic biases in forecasts by the coupled system, referred to as FIM-iHYCOM, are described in a companion paper (Part I). This present study (Part II) assesses probabilistic and deterministic model skill for predictions of surface temperature, precipitation, and 500-hPa geopotential height in different seasons at different lead times ranging from 1 to 4 weeks. The coupled model appears to have reasonable agreement with reanalysis in terms of simulated weekly variability in sea surface temperatures, except in extratropical regions because the ocean model cannot explicitly resolve eddies there. This study also describes the ability of the model to simulate midlatitude tropospheric blocking frequency, Madden-Julian oscillation patterns, and sudden stratospheric warming events-all of which have been shown to be relevant on subseasonal time scales. The metrics used here indicate that the subseasonal forecast skill of the model is comparable to that of several operational models, including the National Oceanic and Atmospheric Administration's (NOAA's) operational Climate Forecast System version 2 and the European Centre for Medium-Range Weather Forecasts model. Therefore, FIM-iHYCOM-as a participant in NOAA's Subseasonal Experiment-is expected to add value to multimodel ensemble forecasts produced through this effort.

Observations of Aerosols Over Northeastern Colorado

Objective Analysis on Isentropic Surfaces

On the Use of Hybrid Vertical Coordinates in Ocean Circulation Modeling

Springer eBooks, Jul 7, 2006

The rationale for building hybrid-coordinate ocean circulation models is discussed in the context... more The rationale for building hybrid-coordinate ocean circulation models is discussed in the context of various approaches presently taken to improve mathematical and physical aspects of ocean models. Design choices made in formulating the vertical grid generator, the core component of hybrid models, are laid out. A new experimental approach toward minimizing numerical errors and inconsistencies during simultaneous advection of temperature, salinity and density is presented.

Ocean Prediction with the Hybrid Coordinate Ocean Model (HYCOM)

Springer eBooks, Jul 7, 2006

Numerical Forecasting Experiments Based on the Conservation of Potential Vorticity on Isentropic Surfaces

Journal of applied meteorology, Aug 1, 1973

ABSTRACT

Carbon cycle sensitivities in modeling the biological pump

AGU Fall Meeting Abstracts, Dec 1, 2012

Climate change simulations using the two NASA-GISS climate models coupled to ocean biogeochemistry

EGU General Assembly Conference Abstracts, Apr 1, 2012

ABSTRACT Results from twin control simulations of CO2 gas exchange between the ocean and the atmo... more ABSTRACT Results from twin control simulations of CO2 gas exchange between the ocean and the atmosphere are presented here using the two NASA-GISS climate models, in which the same atmospheric component (modelE) is coupled to two different ocean models, the Russell ocean model and HYCOM. Both climate models are also coupled to the same ocean biogeochemistry module (NBOM) which estimates prognostic distributions for biotic and abiotic fields that influence the air-sea flux of CO2. The two coupled models are spun-up to equilibrium first without ocean biogeochemistry and then with it. The model differences are mainly attributed to the different ocean model and in particular vertical processes such as mixing and vertical advection. The surface flux is shown to depend crucially in surface wind differences as well as the distributions of pCO2 in the two models. HYCOM takes longer to reach equilibrium despite the fact that vertical mixing is lower and therefore should be bringing the mixed layer depth faster into equilibrium. The global meridional overturning circulation can explain much of the differences in the biological pump in the two models together with the differences in mixed layer depth which are responsible for different SST distributions in the two models and consequently different atmospheric feedbacks (in the wind, net heat and freshwater fluxes into the ocean).

Evaluation of Subseasonal Errors and Skill in the FIM-iHYCOM Model

EGU General Assembly Conference Abstracts, Apr 1, 2018

a Numerical Technique for Calculating Dry-Adiabatic and Moist-Adiabatic Trajectories in the Atmosphere

PhDT, 1968

MICOM-Based Nowcast/Forecast for Coastal/Open Ocean Regions

To develop a nowcast/forecast system for coastal/open ocean regions with the hybrid version (HYbr... more To develop a nowcast/forecast system for coastal/open ocean regions with the hybrid version (HYbrid Coordinate Oceam Model HYCOM) of the Miami Isopycnic Coordinate Ocean Model (MICOM) (Bleck and Chassignet, 1994). OBJECTIVES a) To evaluate the model's performance in reproducing the oceanic circulation, with a special focus on the coastal regions b) To evaluate the model's forecast skills and usefulness in providing boundary conditions for ultra ne-mesh coastal models. APPROACH A series of numerical models of increasing complexity and resolution is used to (a) evaluate the model's forecast skills and (b) develop an understanding of the interaction between the ocean interior and the coastal regions. Same as Report (SAR)

Development and Evaluation of a Global Version of the Miami Isopycnic-Coordinate Ocean Model. Final report

Subseasonal Forecasting with an Icosahedral, Vertically Quasi-Lagrangian Coupled Model. Part II: Probabilistic and Deterministic Forecast Skill

Monthly Weather Review, May 1, 2018

Subseasonal forecast skill of the global hydrostatic atmospheric Flow-Following Icosahedral Model... more Subseasonal forecast skill of the global hydrostatic atmospheric Flow-Following Icosahedral Model (FIM) coupled to an icosahedral-grid version of the Hybrid Coordinate Ocean Model (iHYCOM) is evaluated through 32-day predictions initialized weekly using a four-member time-lagged ensemble over the 16-yr period 1999-2014. Systematic biases in forecasts by the coupled system, referred to as FIM-iHYCOM, are described in a companion paper (Part I). This present study (Part II) assesses probabilistic and deterministic model skill for predictions of surface temperature, precipitation, and 500-hPa geopotential height in different seasons at different lead times ranging from 1 to 4 weeks. The coupled model appears to have reasonable agreement with reanalysis in terms of simulated weekly variability in sea surface temperatures, except in extratropical regions because the ocean model cannot explicitly resolve eddies there. This study also describes the ability of the model to simulate midlatitude tropospheric blocking frequency, Madden-Julian oscillation patterns, and sudden stratospheric warming events-all of which have been shown to be relevant on subseasonal time scales. The metrics used here indicate that the subseasonal forecast skill of the model is comparable to that of several operational models, including the National Oceanic and Atmospheric Administration's (NOAA's) operational Climate Forecast System version 2 and the European Centre for Medium-Range Weather Forecasts model. Therefore, FIM-iHYCOM-as a participant in NOAA's Subseasonal Experiment-is expected to add value to multimodel ensemble forecasts produced through this effort.

Diagnostics of the oceanic thermohaline circulation in a coupled climate model

Global and Planetary Change, Feb 1, 2004

Two century-scale integrations of a global coupled model consisting of the GISS atmospheric model... more Two century-scale integrations of a global coupled model consisting of the GISS atmospheric model and the HYCOM ocean model are carried out: a control run assuming fixed atmospheric composition, and a perturbation run assuming gradual doubling of CO 2. The model does not use flux corrections at the air-sea interface, nor is the ocean ''spun up'' prior to coupling. When increasing CO 2 at the rate of 1% per year to twice its original level and keeping it constant thereafter, the model responds with a 2 jC increase in 200 years in the global mean surface air temperature and a virtually unchanged Atlantic meridional overturning circulation (MOC). Due to the predominantly isopycnic character of HYCOM, geographic details of the 3-D thermohaline circulation in potential density space can be extracted from the model output with relative ease. The analysis confirms that even regional details of the MOC in this experiment are rather insensitive to the climate change brought on by CO 2 doubling. Furthermore, the analysis reveals strong similarities between the simulated and the observed MOC.

On the conversion between mean and eddy components of potential and kinetic energy in isentropic and isopycnic coordinates

Dynamics of Atmospheres and Oceans, May 1, 1985

Bleck, R., 1985. On the conversion between mean and eddy components of potential and kinetic ener... more Bleck, R., 1985. On the conversion between mean and eddy components of potential and kinetic energy in isentropic and isopycnic coordinates. Dyn. Atmos. Oceans, 9: 17-37. Equations for the mean and eddy kinetic energy and for the mean and eddy potential energy in isopycnic and isentropic coordinates are derived, and conversion terms between the four energy forms are identified. Contrary to Lorenz' isobaric formulae, a conversion term between mean kinetic and eddy potential energy is found in the isopycnic/isentropic framework; furthermore, no term governing direct conversion between eddy and mean potential energy exists in isopycnic coordinates. The option of "re-routing" some energy conversion processes to eliminate the formal difference between the isopycnic/isentropic and the isobaric viewpoint is discussed. A numerical simulation of baroclinic instability in an isentropic coordinate model is used to illustrate the energy conversion processes.

Atlantic thermohaline circulation and its response to increasing CO2in a coupled atmosphere-ocean model

Geophysical Research Letters, Nov 15, 2001

We discuss aspects of the Atlantic thermohaline circulation (THC) and its response to increased g... more We discuss aspects of the Atlantic thermohaline circulation (THC) and its response to increased greenhouse gas concentration, using a coupled atmosphere-ocean general circulation model (AOGCM) whose oceanic component is a new hybrid-isopycnal model. Two 200-year model integrations are carried out-a control run assuming fixed atmospheric composition and a perturbation run assuming gradual doubling of CO2. We employ no flux corrections at the air-sea interface, nor do we spin up the ocean prior to coupling. The surface conditions in the control run stabilize after several decades. When doubling CO2 at the rate of 1% per year, the model responds with a 2 • C increase in global mean surface air temperature (SAT) after 200 years and a virtually unchanged Atlantic meridional overturning circulation. The latter is maintained by a salinity increase that counteracts the effect of global warming on the surface buoyancy.

Hail Growth by Stochastic Collection in a Cumulus Model

Journal of the Atmospheric Sciences, 1972

Techniques of Lagrangian Trajectory Analysis in Isentropic Coordinates

Monthly Weather Review, Mar 1, 1986

Regional Weather Prediction with a Model Combining Terrain-following and Isentropic Coordinates. Part I: Model Description

Monthly Weather Review, Jun 1, 1993

North Atlantic simulations in Coordinated Ocean-ice Reference Experiments phase II (CORE-II). Part II: Inter-annual to decadal variability

Ocean Modelling, 2016

Please note that this is an author-produced PDF of an article accepted for publication following ... more

Subseasonal Forecasting with an Icosahedral, Vertically Quasi-Lagrangian Coupled Model. Part I: Model Overview and Evaluation of Systematic Errors

Monthly Weather Review, May 1, 2018

Subseasonal forecast skill of the global hydrostatic atmospheric Flow-Following Icosahedral Model... more Subseasonal forecast skill of the global hydrostatic atmospheric Flow-Following Icosahedral Model (FIM) coupled to an icosahedral-grid version of the Hybrid Coordinate Ocean Model (iHYCOM) is evaluated through 32-day predictions initialized weekly using a four-member time-lagged ensemble over the 16-yr period 1999-2014. Systematic biases in forecasts by the coupled system, referred to as FIM-iHYCOM, are described in a companion paper (Part I). This present study (Part II) assesses probabilistic and deterministic model skill for predictions of surface temperature, precipitation, and 500-hPa geopotential height in different seasons at different lead times ranging from 1 to 4 weeks. The coupled model appears to have reasonable agreement with reanalysis in terms of simulated weekly variability in sea surface temperatures, except in extratropical regions because the ocean model cannot explicitly resolve eddies there. This study also describes the ability of the model to simulate midlatitude tropospheric blocking frequency, Madden-Julian oscillation patterns, and sudden stratospheric warming events-all of which have been shown to be relevant on subseasonal time scales. The metrics used here indicate that the subseasonal forecast skill of the model is comparable to that of several operational models, including the National Oceanic and Atmospheric Administration's (NOAA's) operational Climate Forecast System version 2 and the European Centre for Medium-Range Weather Forecasts model. Therefore, FIM-iHYCOM-as a participant in NOAA's Subseasonal Experiment-is expected to add value to multimodel ensemble forecasts produced through this effort.

Observations of Aerosols Over Northeastern Colorado

Objective Analysis on Isentropic Surfaces

On the Use of Hybrid Vertical Coordinates in Ocean Circulation Modeling

Springer eBooks, Jul 7, 2006

The rationale for building hybrid-coordinate ocean circulation models is discussed in the context... more The rationale for building hybrid-coordinate ocean circulation models is discussed in the context of various approaches presently taken to improve mathematical and physical aspects of ocean models. Design choices made in formulating the vertical grid generator, the core component of hybrid models, are laid out. A new experimental approach toward minimizing numerical errors and inconsistencies during simultaneous advection of temperature, salinity and density is presented.

Ocean Prediction with the Hybrid Coordinate Ocean Model (HYCOM)

Springer eBooks, Jul 7, 2006

Numerical Forecasting Experiments Based on the Conservation of Potential Vorticity on Isentropic Surfaces

Journal of applied meteorology, Aug 1, 1973

ABSTRACT

Carbon cycle sensitivities in modeling the biological pump

AGU Fall Meeting Abstracts, Dec 1, 2012

Climate change simulations using the two NASA-GISS climate models coupled to ocean biogeochemistry

EGU General Assembly Conference Abstracts, Apr 1, 2012

ABSTRACT Results from twin control simulations of CO2 gas exchange between the ocean and the atmo... more ABSTRACT Results from twin control simulations of CO2 gas exchange between the ocean and the atmosphere are presented here using the two NASA-GISS climate models, in which the same atmospheric component (modelE) is coupled to two different ocean models, the Russell ocean model and HYCOM. Both climate models are also coupled to the same ocean biogeochemistry module (NBOM) which estimates prognostic distributions for biotic and abiotic fields that influence the air-sea flux of CO2. The two coupled models are spun-up to equilibrium first without ocean biogeochemistry and then with it. The model differences are mainly attributed to the different ocean model and in particular vertical processes such as mixing and vertical advection. The surface flux is shown to depend crucially in surface wind differences as well as the distributions of pCO2 in the two models. HYCOM takes longer to reach equilibrium despite the fact that vertical mixing is lower and therefore should be bringing the mixed layer depth faster into equilibrium. The global meridional overturning circulation can explain much of the differences in the biological pump in the two models together with the differences in mixed layer depth which are responsible for different SST distributions in the two models and consequently different atmospheric feedbacks (in the wind, net heat and freshwater fluxes into the ocean).

Evaluation of Subseasonal Errors and Skill in the FIM-iHYCOM Model

EGU General Assembly Conference Abstracts, Apr 1, 2018

a Numerical Technique for Calculating Dry-Adiabatic and Moist-Adiabatic Trajectories in the Atmosphere

PhDT, 1968

MICOM-Based Nowcast/Forecast for Coastal/Open Ocean Regions

To develop a nowcast/forecast system for coastal/open ocean regions with the hybrid version (HYbr... more To develop a nowcast/forecast system for coastal/open ocean regions with the hybrid version (HYbrid Coordinate Oceam Model HYCOM) of the Miami Isopycnic Coordinate Ocean Model (MICOM) (Bleck and Chassignet, 1994). OBJECTIVES a) To evaluate the model's performance in reproducing the oceanic circulation, with a special focus on the coastal regions b) To evaluate the model's forecast skills and usefulness in providing boundary conditions for ultra ne-mesh coastal models. APPROACH A series of numerical models of increasing complexity and resolution is used to (a) evaluate the model's forecast skills and (b) develop an understanding of the interaction between the ocean interior and the coastal regions. Same as Report (SAR)

Development and Evaluation of a Global Version of the Miami Isopycnic-Coordinate Ocean Model. Final report

Subseasonal Forecasting with an Icosahedral, Vertically Quasi-Lagrangian Coupled Model. Part II: Probabilistic and Deterministic Forecast Skill

Monthly Weather Review, May 1, 2018

Subseasonal forecast skill of the global hydrostatic atmospheric Flow-Following Icosahedral Model... more Subseasonal forecast skill of the global hydrostatic atmospheric Flow-Following Icosahedral Model (FIM) coupled to an icosahedral-grid version of the Hybrid Coordinate Ocean Model (iHYCOM) is evaluated through 32-day predictions initialized weekly using a four-member time-lagged ensemble over the 16-yr period 1999-2014. Systematic biases in forecasts by the coupled system, referred to as FIM-iHYCOM, are described in a companion paper (Part I). This present study (Part II) assesses probabilistic and deterministic model skill for predictions of surface temperature, precipitation, and 500-hPa geopotential height in different seasons at different lead times ranging from 1 to 4 weeks. The coupled model appears to have reasonable agreement with reanalysis in terms of simulated weekly variability in sea surface temperatures, except in extratropical regions because the ocean model cannot explicitly resolve eddies there. This study also describes the ability of the model to simulate midlatitude tropospheric blocking frequency, Madden-Julian oscillation patterns, and sudden stratospheric warming events-all of which have been shown to be relevant on subseasonal time scales. The metrics used here indicate that the subseasonal forecast skill of the model is comparable to that of several operational models, including the National Oceanic and Atmospheric Administration's (NOAA's) operational Climate Forecast System version 2 and the European Centre for Medium-Range Weather Forecasts model. Therefore, FIM-iHYCOM-as a participant in NOAA's Subseasonal Experiment-is expected to add value to multimodel ensemble forecasts produced through this effort.

Diagnostics of the oceanic thermohaline circulation in a coupled climate model

Global and Planetary Change, Feb 1, 2004

Two century-scale integrations of a global coupled model consisting of the GISS atmospheric model... more Two century-scale integrations of a global coupled model consisting of the GISS atmospheric model and the HYCOM ocean model are carried out: a control run assuming fixed atmospheric composition, and a perturbation run assuming gradual doubling of CO 2. The model does not use flux corrections at the air-sea interface, nor is the ocean ''spun up'' prior to coupling. When increasing CO 2 at the rate of 1% per year to twice its original level and keeping it constant thereafter, the model responds with a 2 jC increase in 200 years in the global mean surface air temperature and a virtually unchanged Atlantic meridional overturning circulation (MOC). Due to the predominantly isopycnic character of HYCOM, geographic details of the 3-D thermohaline circulation in potential density space can be extracted from the model output with relative ease. The analysis confirms that even regional details of the MOC in this experiment are rather insensitive to the climate change brought on by CO 2 doubling. Furthermore, the analysis reveals strong similarities between the simulated and the observed MOC.

On the conversion between mean and eddy components of potential and kinetic energy in isentropic and isopycnic coordinates

Dynamics of Atmospheres and Oceans, May 1, 1985

Bleck, R., 1985. On the conversion between mean and eddy components of potential and kinetic ener... more Bleck, R., 1985. On the conversion between mean and eddy components of potential and kinetic energy in isentropic and isopycnic coordinates. Dyn. Atmos. Oceans, 9: 17-37. Equations for the mean and eddy kinetic energy and for the mean and eddy potential energy in isopycnic and isentropic coordinates are derived, and conversion terms between the four energy forms are identified. Contrary to Lorenz' isobaric formulae, a conversion term between mean kinetic and eddy potential energy is found in the isopycnic/isentropic framework; furthermore, no term governing direct conversion between eddy and mean potential energy exists in isopycnic coordinates. The option of "re-routing" some energy conversion processes to eliminate the formal difference between the isopycnic/isentropic and the isobaric viewpoint is discussed. A numerical simulation of baroclinic instability in an isentropic coordinate model is used to illustrate the energy conversion processes.

Atlantic thermohaline circulation and its response to increasing CO2in a coupled atmosphere-ocean model

Geophysical Research Letters, Nov 15, 2001

We discuss aspects of the Atlantic thermohaline circulation (THC) and its response to increased g... more We discuss aspects of the Atlantic thermohaline circulation (THC) and its response to increased greenhouse gas concentration, using a coupled atmosphere-ocean general circulation model (AOGCM) whose oceanic component is a new hybrid-isopycnal model. Two 200-year model integrations are carried out-a control run assuming fixed atmospheric composition and a perturbation run assuming gradual doubling of CO2. We employ no flux corrections at the air-sea interface, nor do we spin up the ocean prior to coupling. The surface conditions in the control run stabilize after several decades. When doubling CO2 at the rate of 1% per year, the model responds with a 2 • C increase in global mean surface air temperature (SAT) after 200 years and a virtually unchanged Atlantic meridional overturning circulation. The latter is maintained by a salinity increase that counteracts the effect of global warming on the surface buoyancy.

Hail Growth by Stochastic Collection in a Cumulus Model

Journal of the Atmospheric Sciences, 1972

Techniques of Lagrangian Trajectory Analysis in Isentropic Coordinates

Monthly Weather Review, Mar 1, 1986

Regional Weather Prediction with a Model Combining Terrain-following and Isentropic Coordinates. Part I: Model Description

Monthly Weather Review, Jun 1, 1993