Description: Das Projekt "Anthropogenic carbon and heat uptake by the Southern Ocean" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Biogeochemie und Schadstoffdynamik durchgeführt. Heat and carbon dioxide exchange between the atmosphere and ocean is a major control on Earths climate and increasing atmospheric carbon dioxide (CO2) and concomitant global warming stimulate uptake of both heat and CO2 by the ocean. The Southern Ocean south of 30 S, occupying just over 1/4 of the surface ocean area, accounts for a disproportionate share of the vertical exchange of properties between the deep and surface waters of the ocean and between the surface ocean and the atmosphere. On average, the Southern Ocean absorbs 70Prozent of anthropogenic heat and 42Prozent of anthropogenic carbon in a new set of climate model simulations. This region thus plays a central role in determining the rate of climate change. However, the exact processes governing the magnitude and regional distribution of heat and carbon uptake remain poorly understood with models showing the largest disagreement in Southern Ocean anthropogenic air-sea heat and CO2 fluxes due to their widely divergent representation of physical circulation and atmosphere-ocean interactions. Indeed, the fraction of the simulated uptake within the Southern Ocean ranges between 30 to 160Prozent for excess heat and between 38 to 47Prozent for anthropogenic carbon. Natural unforced variability in models and observations further complicates the detection and attribution of changes. We will investigate anthropogenic ocean heat and carbon uptake with our main objectives being: (i) intercomparing ocean heat and carbon uptake in Earth System Model (ESM) simulations conducted for the Coupled Model Intercomparison Project Phase 5 (CMIP5), (ii) assessing the contribution of internal variability to model-model and model-data differences in anthropogenic heat and carbon uptake, and (iii) quantifying the contribution of differences in basic atmospheric forcing, model parameterizations, sea ice representation and model resolution to differences in heat and carbon uptake and distribution, and disagreements between models. This will be achieved through a series of process-perturbation experiments and ensemble simulations with an Earth System Model configured for transient climate change that help in attributing variations over the Southern Ocean. We will also contribute to the broader community goal in interpreting projections of IPCC AR5 coupled climate models. Ultimately, the project leads to a better understanding of Southern Ocean biogeochemical processes, thereby pinning down one of the greatest sources of uncertainty in predictions of the fate of anthropogenic carbon and of the climate.
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Main ? Biogeochemie ? Zürich ? Buchhaltung ? Kohlenstoff ? Meereswärme ? Meereis ? Kohlendioxid ? Prognose ? Luft ? Globale Erwärmung ? Gelöster organischer Kohlenstoff ? Datenmodell ? Globales Klima ? Bewässerung ? Hochrechnung ? Klimamodell ? Kohlenstoffkreislauf ? Modellversuch ? Oberflächengewässer ? Simulation ? Meeresgewässer ? Wasser ? Modellierung ? Salztonebene ? Anthropogener Einfluss ? Atmosphäre ? Heizung ? Klima ? Klimawandel ? Regionale Verteilung ? Zirkulation ? Gebiet ? Globale Aspekte ? Änderung ? Südlicher Ozean ? Mittelwert ? Erdsystem ? GEKOPPELT ? KONTROLLE ? OBERFLAECHE ? Buchgrundstück ? BETRACHTUNG ? PROJEKT ? REGIONAL ? SUEDLICH ? Climate Science ? VERBLEIB ? VERTEILUNG ? AUSTAUSCHEN ? BEWERTEN ? EIN ? EXAKT ? EXPERIMENT ? FRAKTION ? BEITRAG ? GEMEINSCHAFT ? BIOGEOCHEMISCH ? VERTRETUNG ? HILF ? Vermehrung ? NACHWEIS ? NEU ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2013-05-01 - 2016-04-30
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