Truls Johannessen
A5067755608- Atmospheric and Environmental Gas Dynamics
- Ocean Acidification Effects and Responses
- Arctic and Antarctic ice dynamics
- Marine and coastal ecosystems
- Maritime Navigation and Safety
- Maritime Transport Emissions and Efficiency
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Geology and Paleoclimatology Research
- Offshore Engineering and Technologies
- Marine Biology and Ecology Research
- Geological Studies and Exploration
- Climate variability and models
- Atmospheric chemistry and aerosols
- Reservoir Engineering and Simulation Methods
- Oil Spill Detection and Mitigation
- Isotope Analysis in Ecology
- Cryospheric studies and observations
- Coral and Marine Ecosystems Studies
- Atmospheric Ozone and Climate
- Scientific Research and Discoveries
- CO2 Sequestration and Geologic Interactions
- Underwater Vehicles and Communication Systems
- Water Quality Monitoring and Analysis
- Hydrocarbon exploration and reservoir analysis
Bjerknes Centre for Climate Research
2014-2025
University of Bergen
2014-2025
Integrated Carbon Observation System
2020
Uni Research (Norway)
2009-2017
Earth Science Institute of the Slovak Academy of Sciences
2007-2017
Geological Institute
1995
Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, terrestrial biosphere – “global budget” is important to better understand global cycle, support development climate policies, project future change. Here we describe data sets methodology quantify five major components budget uncertainties. Fossil CO2 (EFF) are based on energy statistics cement production data, while from land use land-use change (ELUC), mainly...
Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, terrestrial biosphere is important to better understand global cycle, support development climate policies, project future change. Here we describe data sets a methodology quantify all major components budget, including uncertainties, based on combination range data, algorithms, statistics, model estimates interpretation by broad scientific community. We discuss...
Abstract. The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 SOCAT has 14.7 million from 3646 data sets covering years 1957 to 2014. This latest version an additional 4.6 relative 2 extends record 2011 also significantly increases availability 2005 2013. average approximately 1.2 water per year 2006 2012. Quality documentation improved. A new feature set...
Abstract. A well-documented, publicly available, global data set of surface ocean carbon dioxide (CO2) parameters has been called for by international groups nearly two decades. The Surface Ocean CO2 Atlas (SOCAT) project was initiated the marine science community in 2007 with aim providing a comprehensive, regularly updated, CO2, which had subject to quality control (QC). Many additional data, not yet made public via Carbon Dioxide Information Analysis Center (CDIAC), were retrieved from...
Eight time slices of surface‐water paleoceanography were reconstructed from stable isotope and paleotemperature data to evaluate late Quaternary changes in density, current directions, sea‐ice cover the Nordic Seas NE Atlantic. We used isotopic records 110 deep‐sea cores, 20 which are accelerator mass spectrometry (AMS)‐ 14 C dated 30 have high (>8 cm /kyr) sedimentation rates, enabling a resolution about 120 years. Paleotemperature estimates based on species counts planktonic...
A Happy Marriage The fluxes of CO 2 between the atmosphere and ocean are large variable, understanding why concentration atmospheric changes as it does, depends on accurately determining details those fluxes. One major obstacles in way quantifying this exchange is that there too few measurements available, both temporally geographically. Watson et al. (p. 1391 ) report results from a happy marriage science commerce—data collected by instruments fitted onto commercial ships plying waters...
Abstract. The Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO2 (fugacity dioxide) products for surface oceans. Version 2 SOCAT is update previous release (version 1) with more data (increased from 6.3 million 10.1 water values) extended coverage (from 1968–2007 1968–2011). quality control criteria, while identical in both versions, have been applied strictly version than 1. website...
Abstract. As a response to public demand for well-documented, quality controlled, publically available, global surface ocean carbon dioxide (CO2) data set, the international marine science community developed Surface Ocean CO2 Atlas (SOCAT). The first SOCAT product is collection of 6.3 million controlled from oceans and coastal seas, spanning four decades (1968–2007). gridded presented here second come project. Recognizing that some groups may have trouble working with millions measurements,...
Abstract. Here we present monthly, basin-wide maps of the partial pressure carbon dioxide (pCO2) for North Atlantic on a 1° latitude by longitude grid years 2004 through 2006 inclusive. The have been computed using neural network technique which reconstructs non-linear relationships between three biogeochemical parameters and marine pCO2. A self organizing map (SOM) has trained 389 000 triplets SeaWiFS-MODIS chlorophyll-a concentration, NCEP/NCAR reanalysis sea surface temperature, FOAM...
Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, terrestrial biosphere is important to better understand global cycle, support development climate policies, project future change. Here we describe datasets a methodology quantify all major components budget, including uncertainties, based on combination range data, algorithms, statistics model estimates interpretation by broad scientific community. We discuss...
Abstract We present a global ocean climatology of dissolved inorganic carbon δ 13 C (‰) corrected for the C‐Suess effect, preindustrial C. This was constructed by first using Olsen and Ninnemann's (2010) back‐calculation method on data from 25 World Ocean Circulation Experiment cruises to reconstruct sections spanning all major oceans. Next, we developed five multilinear regression equations, one each basin, which were applied Atlas construct climatology. reveals natural distribution in...
We produced 204 monthly maps of the air–sea CO2 flux in Arctic north 60°N, including Ocean and its adjacent seas, from January 1997 to December 2013 by using a self-organizing map technique. The partial pressure (pCO2) surface water data were obtained shipboard underway measurements or calculated alkalinity total inorganic carbon samples. Subsequently, we investigated basin-wide distribution seasonal interannual variability fluxes. 17-year annual mean shows that all areas seas net sinks....
Abstract. Changes to seawater inorganic carbon and nutrient concentrations in response the deliberate CO2 perturbation of natural plankton assemblages were studied during 2005 Pelagic Ecosystem Enrichment (PeECE III) experiment. Inverse analysis temporal dioxide system variations was used determine net community stoichiometric uptake characteristics a pelagic ecosystem perturbed over range pCO2 scenarios (350, 700 1050 μatm). Nutrient showed no sensitivity treatment. There enhanced...
Recent studies based on ocean and atmospheric carbon dioxide (CO 2 ) observations, suggesting that the uptake has been reduced, may help explain increase in fraction of anthropogenic CO emissions remain atmosphere. Is it a response to climate change or signal natural variability both? Regional process analyses are needed follow enable better attributions observed changes. Here, we describe evolution surface fugacity ( f oc over period 1993–2008 North Atlantic subpolar gyre (NASPG). This...
Abstract. Due to low calcium carbonate saturation states, and winter mixing that brings anthropogenic carbon the deep ocean, Nordic Seas their cold-water corals are vulnerable ocean acidification. Here, we present a detailed investigation of changes in pH aragonite from preindustrial times 2100, by using situ observations, gridded climatological data, projections for three different future scenarios with Norwegian Earth System Model (NorESM1-ME). During period regular biogeochemistry...
Global ocean carbon models and available syntheses of the oceanic CO 2 flux suggest that North Atlantic subpolar gyre (50°N–70°N, 80°W–10°W) is a region increasing uptake from atmosphere, with partial pressure (pCO ) more slowly than atmospheric over time. Our analysis data shows that, on contrary, seawater pCO has increased faster atmosphere in recent decades, especially summer, resulting decrease atmosphere. A biological productivity may be underlying cause this trend. From observed trend...
This study evaluates the anthropogenic changes of CO 2 (ΔC ant ) and δ 13 C (Δ in Nordic seas, northern limb Atlantic Meridional Overturning Circulation, that took place between 1981 2002/2003. The have been determined by comparing data obtained during Transient Tracers Ocean, North Study (TTO‐NAS) with seas surveys R/V Knorr 2002 G.O. Sars 2003 using an extended multilinear regression approach. estimated Δ ΔC their relationship to each other water mass distribution suggest Polar Water...
Abstract. We present the first year-long subpolar trans-Atlantic set of surface seawater CO2 fugacity (fCO2sw) data. The data were obtained aboard MV Nuka Arctica in 2005 and provide a quasi-continuous picture fCO2sw variability between Denmark Greenland. Complementary real-time high-resolution chlorophyll-a (chl-a) concentrations mixed layer depth (MLD) estimates have been collocated with Off-shelf exhibit pronounced seasonal cycle. In winter, waters are saturated to slightly supersaturated...
The Ocean Weather Station M (OWSM) is situated at a fixed position in the Norwegian Sea, one of major basins Nordic Seas, which represents an important area for uptake atmospheric CO2 as well deep water formation. At OWSM, inorganic carbon cycle has been regularly monitored since 2001, and significant interannual changes carbonate system have determined. Data collected this site 1990s included, over 28 last years surface fugacity (fCO2) increased by 2.92 ± 0.37 μatm yr−1, while pH aragonite...