The Norwegian Earth System Model, NorESM2 – Evaluation of theCMIP6 DECK and historical simulations

Abstract. The second version of the fully coupled Norwegian Earth System Model (NorESM2) is presented and evaluated. NorESM2 is based on the second version of the Community Earth System Model (CESM2), but has entirely different ocean and ocean biogeochemistry models; a new module for aerosols in the atmosphere model along with aerosol-radiation-cloud interactions and changes related to the moist energy formulation, deep convection scheme and angular momentum conservation; modified albedo and air-sea turbulent flux calculations; and minor changes to land and sea ice models. We show results from low (∼2°) and medium (∼1°) atmosphere-land resolution versions of NorESM2 that have both been used to carry out simulations for the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The stability of the pre-industrial climate and the sensitivity of the model to abrupt and gradual quadrupling of CO2 is assessed, along with the ability of the model to simulate the historical climate under the CMIP6 forcings. As compared to observations and reanalyses, NorESM2 represents an improvement over previous versions of NorESM in most aspects. NorESM2 is less sensitive to greenhouse gas forcing than its predecessors, with an equilibrium climate sensitivity of 2.5 K in both resolutions on a 150 year frame. We also consider the model response to future scenarios as defined by selected shared socioeconomic pathways (SSP) from the Scenario Model Intercomparison Project defined under CMIP6. Under the four scenarios SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5, the warming in the period 2090–2099 compared to 1850–1879 reaches 1.3, 2.2, 3.0, and 3.9 K in NorESM2-LM, and 1.3, 2.1, 3.1, and 3.9 K in NorESM–MM, robustly similar in both resolutions. NorESM2-LM shows a rather satisfactorily evolution of recent sea ice area. In NorESM2-LM an ice free Arctic Ocean is only avoided in the SSP1-2.6 scenario.

[1]  K. Swanson,et al.  Storm Track Dynamics , 2002, The Global Circulation of the Atmosphere.

[2]  W. G. Strand,et al.  The Community Earth System Model Version 2 (CESM2) , 2020, Journal of Advances in Modeling Earth Systems.

[3]  G. Danabasoglu,et al.  Evaluation of global ocean–sea-ice model simulations based on the experimental protocols of the Ocean Model Intercomparison Project phase 2 (OMIP-2) , 2020, Geoscientific Model Development.

[4]  C. Heinze,et al.  Ocean biogeochemistry in the Norwegian Earth System Model version 2 (NorESM2) , 2020, Geoscientific Model Development.

[5]  Pierre Friedlingstein,et al.  Carbon–concentration and carbon–climate feedbacks in CMIP6 models and their comparison to CMIP5 models , 2019, Biogeosciences.

[6]  A. Kirkevåg,et al.  Arctic amplification under global warming of 1.5 and 2 °C in NorESM1-Happi , 2019, Earth System Dynamics.

[7]  Matthieu Lengaigne,et al.  Ocean Climate Observing Requirements in Support of Climate Research and Climate Information , 2019, Front. Mar. Sci..

[8]  M. Mills,et al.  High Climate Sensitivity in the Community Earth System Model Version 2 (CESM2) , 2019, Geophysical Research Letters.

[9]  T. Berntsen,et al.  BVOC–aerosol–climate feedbacks investigated using NorESM , 2019, Atmospheric Chemistry and Physics.

[10]  N. McFarlane,et al.  Sensitivity of Climate Simulations to the Parameterization of Cumulus Convection in the Canadian Climate Centre General Circulation Model , 1995, Data, Models and Analysis.

[11]  K. Calvin,et al.  Global emissions pathways under different socioeconomic scenarios for use in CMIP6: a dataset of harmonized emissions trajectories through the end of the century , 2018, Geoscientific Model Development.

[12]  S. Ghan,et al.  Low‐Cloud Feedback in CAM5‐CLUBB: Physical Mechanisms and Parameter Sensitivity Analysis , 2018, Journal of Advances in Modeling Earth Systems.

[13]  G. Danabasoglu,et al.  JRA-55 based surface dataset for driving ocean–sea-ice models (JRA55-do) , 2018, Ocean Modelling.

[14]  Estimating the Transient Climate Response from Observed Warming , 2018, Journal of Climate.

[15]  Sergey Danilov,et al.  Sensitivity of deep ocean biases to horizontal resolution in prototype CMIP6 simulations with AWI-CM1.0 , 2018, Geoscientific Model Development.

[16]  Andrew R. Bennett,et al.  Description and evaluation of the Community Ice Sheet Model (CISM) v2.1 , 2018, Geoscientific Model Development.

[17]  S. Kern,et al.  Version 2 of the EUMETSAT OSI SAF and ESA CCI sea-ice concentration climate data records , 2018, The Cryosphere.

[18]  A. Kirkevåg,et al.  A production-tagged aerosol module for Earth system models, OsloAero5.3 – extensions and updates for CAM5.3-Oslo , 2018, Geoscientific Model Development.

[19]  E. Guilyardi,et al.  Identifying causes of Western Pacific ITCZ drift in ECMWF System 4 hindcasts , 2018, Climate Dynamics.

[20]  Johannes W. Kaiser,et al.  Historic global biomass burning emissions for CMIP6 (BB4CMIP) based on merging satellite observations with proxies and fire models (1750-2015) , 2017 .

[21]  C. Heinze,et al.  Amplification of global warming through pH dependence of DMS production simulated with a fully coupled Earth system model , 2017 .

[22]  C. Hannay,et al.  The path to CAM6: coupled simulations with CAM5.4 and CAM5.5 , 2017 .

[23]  Meng Li,et al.  Historical (1750–2014) anthropogenic emissions of reactive gases and aerosols from the Community Emissions Data System (CEDS) , 2017 .

[24]  Zhao Xu.  CHALLENGES AND PROSPECTS FOR REDUCING COUPLED CLIMATE MODEL SST BIASES IN THE EASTERN TROPICAL ATLANTIC AND PACIFIC OCEANS , 2016 .

[25]  Stefan Reimann,et al.  Historical greenhouse gas concentrations for climate modelling (CMIP6) , 2016 .

[26]  Brian C. O'Neill,et al.  The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6 , 2016 .

[27]  Patrick Heimbach,et al.  OMIP contribution to CMIP6: experimental and diagnostic protocol for the physical component of the Ocean Model Intercomparison Project , 2016 .

[28]  Sylvain Watelet,et al.  A new global interior ocean mapped climatology: the 1° × 1° GLODAP version 2 , 2016 .

[29]  K. Assmann,et al.  Evaluation of NorESM-OC (versions 1 and 1.2), the ocean carbon-cycle stand-alone configuration of the Norwegian Earth System Model (NorESM1) , 2016 .

[30]  Scott C. Doney,et al.  Biogeochemical protocols and diagnostics for the CMIP6 Ocean Model Intercomparison Project (OMIP) , 2016 .

[31]  G. Rickard,et al.  Southern Ocean deep convection in global climate models: A driver for variability of subpolar gyres and Drake Passage transport on decadal timescales , 2016 .

[32]  Gabriel A. Vecchi,et al.  Enhanced warming of the Northwest Atlantic Ocean under climate change , 2016 .

[33]  Veronika Eyring,et al.  Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) experimental design and organization , 2015 .

[34]  J. A. Navarro,et al.  An empirically derived inorganic sea spray source function incorporating sea surface temperature , 2015 .

[35]  E. Hunke,et al.  Impacts of a mushy-layer thermodynamic approach in global sea-ice simulations using the CICE sea-ice model , 2015 .

[36]  C. Mechoso,et al.  A global perspective on CMIP5 climate model biases , 2014 .

[37]  E. Hunke,et al.  Level-ice melt ponds in the Los Alamos sea ice model, CICE , 2013 .

[38]  Myles R. Allen,et al.  Constraining the Ratio of Global Warming to Cumulative CO2 Emissions Using CMIP5 Simulations , 2013 .

[39]  T. Fichefet,et al.  On the formulation of snow thermal conductivity in large‐scale sea ice models , 2013 .

[40]  Yinghai Ke,et al.  A Physically Based Runoff Routing Model for Land Surface and Earth System Models , 2013 .

[41]  T. Andrews,et al.  Evaluating adjusted forcing and model spread for historical and future scenarios in the CMIP5 generation of climate models , 2013 .

[42]  Christoph Heinze,et al.  Evaluation of the carbon cycle components in the Norwegian Earth System Model (NorESM) , 2012 .

[43]  Ivar A. Seierstad,et al.  The Norwegian Earth System Model, NorESM1-M – Part 2: Climate response and scenario projections , 2012 .

[44]  P. Jones,et al.  Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 data set , 2012 .

[45]  Karl E. Taylor,et al.  An overview of CMIP5 and the experiment design , 2012 .

[46]  J. LaCasce,et al.  Changes in the Extratropical Storm Tracks in Response to Changes in SST in an AGCM , 2012 .

[47]  David R. Doelling,et al.  Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty , 2012 .

[48]  M. Mcphaden,et al.  TropFlux: air-sea fluxes for the global tropical oceans—description and evaluation , 2012, Climate Dynamics.

[49]  J. Thepaut,et al.  The ERA‐Interim reanalysis: configuration and performance of the data assimilation system , 2011 .

[50]  Stephen G. Yeager,et al.  The global climatology of an interannually varying air–sea flux data set , 2009 .

[51]  Gilles Larnicol,et al.  On the Use of Satellite Altimeter Data in Argo Quality Control , 2009 .

[52]  Carsten Eden,et al.  Effects of different closures for thickness diffusivity , 2009 .

[53]  Christophe Cassou,et al.  Intraseasonal interaction between the Madden–Julian Oscillation and the North Atlantic Oscillation , 2008, Nature.

[54]  Paul W. Stackhouse,et al.  Impact of clouds on atmospheric heating based on the R04 CloudSat fluxes and heating rates data set , 2008 .

[55]  Christopher W. O'Dell,et al.  Cloud Liquid Water Path from Satellite-Based Passive Microwave Observations: A New Climatology over the Global Oceans , 2008 .

[56]  Robert A. Weller,et al.  Multidecade Global Flux Datasets from the Objectively Analyzed Air-sea Fluxes (OAFlux) Project: Latent and Sensible Heat Fluxes, Ocean Evaporation, and Related Surface Meteorological Variables , 2008 .

[57]  S. Kobayashi,et al.  The JRA-25 Reanalysis , 2007 .

[58]  Robert A. Weller,et al.  Objectively Analyzed Air–Sea Heat Fluxes for the Global Ice-Free Oceans (1981–2005) , 2007 .

[59]  Andrew G. Dickson,et al.  Guide to best practices for ocean CO2 measurements , 2007 .

[60]  Frank O. Bryan,et al.  Resolution convergence and sensitivity studies with North Atlantic circulation models. Part I: The western boundary current system , 2007 .

[61]  C. Schwierz,et al.  Surface Cyclones in the ERA-40 Dataset (1958–2001). Part I: Novel Identification Method and Global Climatology , 2006 .

[62]  Tami C. Bond,et al.  Emissions of primary aerosol and precursor gases in the years 2000 and 1750 prescribed data-sets for AeroCom , 2006 .

[63]  W. Collins,et al.  The Formulation and Atmospheric Simulation of the Community Atmosphere Model Version 3 (CAM3) , 2006 .

[64]  Harry H. Hendon,et al.  Seasonal Dependence of the MJO-ENSO Relationship , 2006 .

[65]  Walter H. F. Smith,et al.  An Evaluation of Publicly Available Global Bathymetry Grids , 2006 .

[66]  A. Sterl,et al.  The ERA‐40 re‐analysis , 2005 .

[67]  Axel Lauer,et al.  © Author(s) 2006. This work is licensed under a Creative Commons License. Atmospheric Chemistry and Physics Analysis and quantification of the diversities of aerosol life cycles , 2022 .

[68]  Hans Burchard,et al.  Second-order turbulence closure models for geophysical boundary layers. A review of recent work , 2005 .

[69]  W. Rossow,et al.  The International Satellite Cloud Climatology Project (ISCCP) Web Site An Online Resource for Research , 2004 .

[70]  Jonathan M. Gregory,et al.  A new method for diagnosing radiative forcing and climate sensitivity , 2004 .

[71]  Stephen G. Yeager,et al.  Diurnal to decadal global forcing for ocean and sea-ice models: The data sets and flux climatologies , 2004 .

[72]  J. Janowiak,et al.  The Version 2 Global Precipitation Climatology Project (GPCP) Monthly Precipitation Analysis (1979-Present) , 2003 .

[73]  Elizabeth C. Kent,et al.  Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century , 2003 .

[74]  E. F. Bradley,et al.  Bulk Parameterization of Air–Sea Fluxes: Updates and Verification for the COARE Algorithm , 2003 .

[75]  D. F. Young,et al.  Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth's Radiant Energy System Instrument on the Tropical Rainfall Measuring Mission Satellite. Part II; Validation , 2003 .

[76]  Timothy P. Boyer,et al.  World ocean atlas 2013. Volume 2, Salinity , 2002 .

[77]  H. Annamalai,et al.  Active / break cycles: diagnosis of the intraseasonal variability of the Asian Summer Monsoon , 2001 .

[78]  Michael Steele,et al.  PHC: A Global Ocean Hydrography with a High-Quality Arctic Ocean , 2001 .

[79]  W. Rossow,et al.  Advances in understanding clouds from ISCCP , 1999 .

[80]  P. Xie,et al.  Global Precipitation: A 17-Year Monthly Analysis Based on Gauge Observations, Satellite Estimates, and Numerical Model Outputs , 1997 .

[81]  Shian-Jiann Lin,et al.  An explicit flux‐form semi‐lagrangian shallow‐water model on the sphere , 1997 .

[82]  K. Trenberth,et al.  Earth's annual global mean energy budget , 1997 .

[83]  Katharina D. Six,et al.  Effects of plankton dynamics on seasonal carbon fluxes in an ocean general circulation model , 1996 .

[84]  W. Large,et al.  Oceanic vertical mixing: a review and a model with a nonlocal boundary layer parameterization , 1994 .

[85]  B. Barkstrom,et al.  Seasonal variation of cloud radiative forcing derived from the Earth Radiation Budget Experiment , 1990 .

[86]  Franco Molteni,et al.  On the operational predictability of blocking , 1990 .

[87]  P. Gent,et al.  Isopycnal mixing in ocean circulation models , 1990 .

[88]  Liu Xinwu.  This is How the Discussion Started , 1981 .

[89]  J. Wallace,et al.  An Observational Study of the Northern Hemisphere Wintertime Circulation , 1977 .

[90]  M. Blackmon,et al.  A Climatological Spectral Study of the 500 mb Geopotential Height of the Northern Hemisphere. , 1976 .

[91]  P. R. Julian,et al.  Detection of a 40–50 Day Oscillation in the Zonal Wind in the Tropical Pacific , 1971 .

[92]  Andrew Assur,et al.  Composition of sea ice and its tensile strength , 1960 .