Die Messung der Zunahme der Meeresspiegels Exkurs: Salz-Verklappung auf hoher See Dr. Ingo Sasgen Alfred-Wegener-Institut (AWI), Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven 13. Juni 2019, 14:30 Uhr, Bayerischer Hof, München

Alfred-Wegener-Institute 3 Antarctic stations 2 Arctic stations 2 polar aircrafts 109 Mio. € Annual Budget (2013) 90% Federal Ministry of Education and Research (BMBF) 8% Bremen 1% Brandenburg und Schleswig-Holstein 20 Mio. € Third-party funding ca. 1100 employees 5 research vessels Slide 1

Processes causing sea-level rise Controlled by complex ice-sheet dynamic processes Land Melting of continental ice Addition of water ~ 2/3 Ocean mass Sea-level rise Global warming +ΔT Volume expansion Warming of ocean Ocean volume ~ 1/3 Direct effect Slide 2

Satellite measurements of sea-level rise Mass on continents and in ocean GRACE/GRACE-FO Satellite observations Land Height of the sea surface Addition of water Ocean mass Ocean altimetry Satellite observations *2002 Temperature and salinity of ocean * 1992 Argo Floats In situ network Volume expansion Ocean volume * 2005 * Start of data availability Slide 3

Components of sea-level rise Time period:2005 to 2017 Source: WCRP Global Sea Level Budget Group https://doi.org/10.5194/essd-10-1551-2018 cm / decade Total (Altimetry) Total over ocean (GRACE+Argo) Sum of sources (main) 3.5 Terrestrial Terrestrial Volume expansion Antarctica Antarctica cm / decade Greenland Greenland Addition of water Glaciers Glaciers Expansion Slide 4

Long-term trends of sea-level rise Time (years) Long-term trends of sea-level rise Paleo data Tide-gauge measurements since 1880 Projections Width of possible scenarios (state 2013, RCP8.5) Method 1: Coupled climate models: based on physics Method 2: Probabilistic projection: based on data correlations Method 3: Expert elicitation: Accounts for high end probabilities and limited knowledge Satellite measurements since 1992 Year Slide 5 Source: IPCC 2013 Figure 13.27, S. 1204

Probabilistic sea-level projection (year 2100) Scenario: RCP8.5 “business as usual” Partial collapse? Cuxhaven, Northern Germany Method 2 Limited Underest. Sea-level change wrt. 2005 (cm) ~CO2 ??? Source: Jevrejeva et al. 2016, Doi: 10.1073/pnas.1605312113 Slide 6

Projections beyond the year 2100 Sea-level change (m) 2100 2200 2300 2400 2500 Year Slide 7 Source: IPCC 2013 Figure 13.13, S. 1188

Excursion: Salt disposal at open sea Deep water formation Ocean water: ca. 35 kg salt per ton of water Ideal place of salt disposal? Melting in Greenland  Freshwater inflow  Weakening of thermohaline circulation (e.g gulf stream) Deep water formation Source: https://www.pik-potsdam.de/institut/querverbindungen/hochschulen/images/thc-world-ocean-review.jpg/image_view_fullscreen Slide 8

Dr. Ingo Sasgen Alfred-Wegener-Institut (AWI), Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven

Backup slides

Deutlicher Anstieg des Meeresspiegels während der letzten 15 Jahre! hier auch erwähnen: Beschleunigung des Anstiegs!! Deutlicher Anstieg des Meeresspiegels während der letzten 15 Jahre! [http://climateadaptation.hawaii.gov/sea-level-rise/]

Components of sea-level rise Slide 3 Tapley et al. 2019, accepted, Section Global Mean Sea-level Data: Don Chambers, Univ. Florida

Source: https://diercke. westermann