Trond Iversen
A5018755043- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Atmospheric and Environmental Gas Dynamics
- Climate variability and models
- Atmospheric Ozone and Climate
- Meteorological Phenomena and Simulations
- Air Quality and Health Impacts
- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Oceanographic and Atmospheric Processes
- Methane Hydrates and Related Phenomena
- Vehicle emissions and performance
- Climate change and permafrost
- Aeolian processes and effects
- Air Quality Monitoring and Forecasting
- Cancer, Hypoxia, and Metabolism
- Energy Load and Power Forecasting
- Geophysics and Gravity Measurements
- Climate Change Communication and Perception
- Cytokine Signaling Pathways and Interactions
- Science and Climate Studies
- Numerical methods for differential equations
- Hydrocarbon exploration and reservoir analysis
- Geology and Paleoclimatology Research
- Biological Research and Disease Studies
Norwegian Meteorological Institute
2015-2024
University of Oslo
2010-2023
CICERO Center for International Climate Research
2018
European Centre for Medium-Range Weather Forecasts
2010-2015
Universidad Metropolitana
2013
UiT The Arctic University of Norway
1989-2011
University of Reading
2011
University Hospital of North Norway
2011
NILU
1982-1989
Abstract. The core version of the Norwegian Climate Center's Earth System Model, named NorESM1-M, is presented. NorESM family models are based on Community Model 4 (CCSM4) University Corporation for Atmospheric Research, but differs from latter by, in particular, an isopycnic coordinate ocean model and advanced chemistry–aerosol–cloud–radiation interaction schemes. NorESM1-M has a horizontal resolution approximately 2° atmosphere land components 1° ice components. also available lower...
Abstract. We report on the AeroCom Phase II direct aerosol effect (DAE) experiment where 16 detailed global models have been used to simulate changes in distribution over industrial era. All estimated radiative forcing (RF) of anthropogenic DAE, and taken into account sulphate, black carbon (BC) organic aerosols (OA) from fossil fuel, biofuel, biomass burning emissions. In addition several simulated DAE nitrate influenced secondary (SOA). The model all-sky RF total has a range −0.58 −0.02...
Abstract. The AeroCom exercise diagnoses multi-component aerosol modules in global modeling. In an initial assessment simulated distributions for mass and mid-visible optical thickness (aot) were compared among 20 different modules. Model diversity was also explored the context of previous comparisons. For component combined aot general agreement has improved annual mean. At 0.11 to 0.14, values are at lower end averages suggested by remote sensing from ground (AERONET ca. 0.135) space...
Abstract. Nine different global models with detailed aerosol modules have independently produced instantaneous direct radiative forcing due to anthropogenic aerosols. The impact is derived from the difference of two model simulations prescribed emissions, one for present-day and pre-industrial conditions. in solar energy budget at top atmosphere (ToA) yields a new harmonized estimate (RF) under all-sky On annual basis RF −0.22 Wm−2, ranging +0.04 −0.41 standard deviation ±0.16 Wm−2....
Abstract. We evaluate black carbon (BC) model predictions from the AeroCom intercomparison project by considering diversity among year 2000 simulations and comparing with available measurements. These model-measurement intercomparisons include BC surface aircraft concentrations, aerosol absorption optical depth (AAOD) retrievals AERONET Ozone Monitoring Instrument (OMI) column estimations based on AERONET. In regions other than Asia, most models are biased high compared to concentration...
The second version of the coupled Norwegian Earth System Model (NorESM2) is presented and evaluated. NorESM2 based on Community (CESM2) shares with CESM2 computer code infrastructure many system model components. However, employs entirely different ocean biogeochemistry models. atmosphere component (CAM-Nor) includes a module for aerosol physics chemistry, including interactions cloud radiation; additionally, CAM-Nor improvements in formulation local dry moist energy conservation, global...
<strong class="journal-contentHeaderColor">Abstract.</strong> This paper evaluates the current status of global modeling organic aerosol (OA) in troposphere and analyzes differences between models as well observations. Thirty-one chemistry transport (CTMs) general circulation (GCMs) have participated this intercomparison, framework AeroCom phase II. The simulation OA varies greatly terms magnitude primary emissions, secondary (SOA) formation, number species used (2 to 62), complexity...
Abstract. Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within international AEROCOM initiative, representation aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus on stratiform liquid water clouds since GCMs do not include ice nucleation effects, and none model explicitly parameterises aerosol convective clouds. We...
Abstract. In this paper we describe and summarize the main achievements of European Aerosol Cloud Climate Air Quality Interactions project (EUCAARI). EUCAARI started on 1 January 2007 ended 31 December 2010 leaving a rich legacy including: (a) comprehensive database with year observations physical, chemical optical properties aerosol particles over Europe, (b) measurements in four developing countries, (c) airborne aerosols clouds Europe during May 2008, (d) modeling tools to study processes...
Using NASA's A‐Train satellite measurements, we evaluate the accuracy of cloud water content (CWC) and vapor mixing ratio (H 2 O) outputs from 19 climate models submitted to Phase 5 Coupled Model Intercomparison Project (CMIP5), assess improvements relative their counterparts for earlier CMIP3. We find more than half show CMIP3 CMIP5 in simulating column‐integrated amount, while changes simulation are insignificant. For models, model spreads differences observations larger upper troposphere...
Abstract. NorESM is a generic name of the Norwegian earth system model. The first version named NorESM1, and has been applied with medium spatial resolution to provide results for CMIP5 (http://cmip-pcmdi.llnl.gov/cmip5/index.html) without (NorESM1-M) (NorESM1-ME) interactive carbon-cycling. Together accompanying paper by Bentsen et al. (2012), this documents that core NorESM1-M valuable global climate model research providing complementary evaluation possible anthropogenic change. based on...
Abstract The polar regions have been attracting more and attention in recent years, fueled by the perceptible impacts of anthropogenic climate change. Polar change provides new opportunities, such as shorter shipping routes between Europe East Asia, but also risks potential for industrial accidents or emergencies ice-covered seas. Here, it is argued that environmental prediction systems are less developed than elsewhere. There many reasons this situation, including being (historically) lower...
The CALIOP (Cloud‐Aerosol Lidar with Orthogonal Polarization) layer product is used for a multimodel evaluation of the vertical distribution aerosols. Annual and seasonal aerosol extinction profiles are analyzed over 13 sub‐continental regions representative industrial, dust, biomass burning pollution, from 2007–2009 observations AeroCom (Aerosol Comparisons between Observations Models) 2000 simulations. An mean height diagnostic (Z α ) defined to quantitatively assess models' performance....
Abstract. The impact of black carbon (BC) aerosols on the global radiation balance is not well constrained. Here twelve aerosol models are used to show that at least 20% present uncertainty in modeled BC direct radiative forcing (RF) due diversity simulated vertical profile mass. Results from phases 1 and 2 model intercomparison project (AeroCom). Additionally, a significant fraction variability shown come high altitudes, as, globally, more than 40% total RF exerted above 5 km. emission...
Abstract. The Intergovernmental Panel on Climate Change (IPCC) has accepted the invitation from UNFCCC to provide a special report impacts of global warming 1.5 °C above pre-industrial levels and related greenhouse-gas emission pathways. Many current experiments in, for example, Coupled Model Inter-comparison Project (CMIP), are not specifically designed informing this report. Here, we document design half degree additional warming, projections, prognosis (HAPPI) experiment. HAPPI provides...
Abstract. The objective of this study is to document and evaluate recent changes updates the module for aerosols aerosol–cloud–radiation interactions in atmospheric CAM4-Oslo core version Norwegian Earth System Model (NorESM), NorESM1-M. Particular attention paid role natural organics, sea salt, mineral dust determining gross aerosol properties as well anthropogenic contribution these associated direct indirect radiative forcing. extended from earlier versions that have been published,...
Abstract. Atmospheric black carbon (BC) absorbs solar radiation, and exacerbates global warming through exerting positive radiative forcing (RF). However, the contribution of BC to ongoing changes in climate is under debate. Anthropogenic emissions, resulting distribution concentration, are highly uncertain. In particular, long-range transport processes affecting atmospheric lifetime poorly understood. Here we discuss whether recent assessments may have overestimated present-day remote...
Abstract We investigate the climate response to increased concentrations of black carbon (BC), as part Precipitation Driver Response Model Intercomparison Project (PDRMIP). A tenfold increase in BC is simulated by nine global coupled‐climate models, producing a model median effective radiative forcing 0.82 (ranging from 0.41 2.91) W m −2 , and warming 0.67 (0.16 1.66) K globally 1.24 (0.26 4.31) Arctic. strong positive instantaneous (median 2.10 based on five models) countered negative rapid...
As the global temperature increases with changing climate, precipitation rates and patterns are affected through a wide range of physical mechanisms. The globally averaged intensity extreme also changes more rapidly than rate. While some aspects regional variation in predicted by climate models appear robust, there is still large degree inter-model differences unaccounted for. Individual drivers change initially alter energy budget atmosphere leading to distinct rapid adjustments involving...
Abstract. The effects of unified aerosol sources on global fields simulated by different models are examined in this paper. We compare results from two AeroCom experiments, one with (ExpA) and emissions, injection heights, particle sizes at the source (ExpB). Surprisingly, harmonization has only a small impact inter-model diversity burden, consequently optical properties, as largely controlled model-specific transport, removal, chemistry (leading to formation secondary aerosols)...
Abstract The ability of 11 models in simulating the aerosol vertical distribution from regional to global scales, as part second phase AeroCom model intercomparison initiative (AeroCom II), is assessed and compared results first phase. evaluation performed using a monthly gridded data set extinction profiles built for this purpose CALIOP (Cloud‐Aerosol Lidar with Orthogonal Polarization) Layer Product 3.01. Results over 12 subcontinental regions show that five improved, whereas three...
Global aerosol‐climate models with prognostic treatment of cloud droplet number concentration (CDNC) often prescribe lower bounds for CDNC or aerosol concentrations. Here we demonstrate that this possibly unphysical constraint reduces the simulated indirect effect by up to 80%, caused extensively uniform CDNCs. In present‐day conditions, impact prescribed bound is mainly visible over oceans, while preindustrial emissions, large parts both land and ocean areas are influenced. We furthermore...
Atmospheric aerosols such as sulfate and black carbon (BC) generate inhomogeneous radiative forcing can affect precipitation in distinct ways compared to greenhouse gases (GHGs). Their regional effects on the atmospheric energy budget circulation be important for understanding predicting global changes, which act top of background GHG-induced hydrological changes. Under framework Precipitation Driver Response Model Inter-comparison Project (PDRMIP), multiple models were used first time...
Abstract. The core version of the Norwegian Climate Center's Earth System Model, named NorESM1-M, is presented. NorESM-family models are based on Community Model 4 (CCSM4) University Corporation for Atmospheric Research, but differs from latter by, in particular, an isopycnic coordinate ocean model and advanced chemistry-aerosol-cloud-radiation interaction schemes. NorESM1-M has a horizontal resolution approximately 2° atmosphere land components 1° ice components. NorESM also available lower...