Das Projekt "Partikelsedimentation etc. im Suedchinesischen Meer - Teilvorhaben 2: Rekolonisation der Pinatubo-Tephra im Suedchinesischen Meer - Teilvorhaben 3: Spaetquartaere Stoffluesse und Sedimentation am Vietnam-Schelf" wird vom Umweltbundesamt gefördert und von Christian-Albrechts-Universität zu Kiel, Sektion Geowissenschaften, Institut für Geowissenschaften durchgeführt. Zur raeumlich zeitlichen Rekonstruktion der postglazialen Transgression im Suedchinesischen Meer werden Untersuchungen im Bereich des Mekong-Deltas und des noerdlich anschliessenden vietnamesischen Schelfs durchgefuehrt. Die Auswirkungen meeresspiegelkontrollierter Aenderungen terrigener Fluesse und klimainduzierter Zirkulationsaenderungen auf das pelagische System eines relativ kleinen Ozeanrandbeckens sollen mit der geologischen Geschichte des Sedimenteintrags aus dem Mekongdelta sowie des Kuestenauftriebs vor der vietnamesischen Ostkueste bis ins Pleistozaen zurueckverfolgt werden. Die Wiederbeprobung von Sedimentstationen im proximalen, medialen und distalen Bereich sowie ausserhalb des Mt. Pinatubo-Aschenfaechers von 1991 verfolgt den Fortschritt des Rekolonisationsgeschehens durch benthische Foraminiferen sowie der Bioturbation durch Makrofauna. Zusaetzlich wird der Einfluss saisonaler bzw. interannueller Schwankungen im Kohlenstofffluss auf die Faunenzusammensetzung und Rekolonisation untersucht.
Das Projekt "Impact of Artificial Stratospheric Sulfate Aerosols investigated with a coupled aerosol-chemistry climate model (IASSA)" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Atmosphäre und Klima durchgeführt. BACKGROUND In its report 'Geoengineering the Climate - Science, Governance and Uncertainty' (1 September 2009) the Royal Society states that 'no geoengineering method can provide an easy or readily acceptable solution to the problem of climate change', yet that 'geoengineering methods could potentially be useful in future to augment continuing efforts to mitigate climate change by reducing emissions'. Geoengineering might serve as an 'emergency action' to cool the planet on short time scale, but should not distract from the primary goal of reducing greenhouse gas emissions. Detailed research and analysis will be required before geoengineering methods could become an option, if at all, and this research should not wait until the emergency is unavoidable. The report ranks the increase of Earth's albedo by injection of sulfur containing gases into the stratosphere as promising method. GOAL Substantial improvements in understanding will be required to reduce uncertainties in current modeling approaches to geoengineering. In response to this challenge, we aim here at an accurate assessment of stratospheric aerosol-based geoengineering using a spectral stratospheric aerosol model coupled to an atmosphere-ocean-chemistry-climate model (Aero-AOCCM). By means of results from long-term multiple ensemble runs the following questions will be addressed: -What would be the optimum total mass, altitude, meridional distribution and time sequence of the sulfur containing gas injections? -How do the responses of climate and ozone to the eruption of Mt. Pinatubo compare as natural analog to geoengineering? -What is the importance of the interactive dynamic ocean for the simulations of the climate and ozone response? -Finally, what is the expected efficiency and safety of geoengineering by injection of sulfur containing gases? METHOD To achieve these goals we will apply a novel AOCCM which is coupled to a spectral aerosol model with explicit simulation of sulfate aerosol nucleation, coagulation, growth/evaporaton, sedimentation and removal. Thus, the model applied for this project takes into account the main components of the climate system (atmosphere, clouds, land surface, ocean, sea ice, chemical species, sulfate aerosol) and their interaction. RELEVANCE The application of this advanced model is expected to provide a much improved, objective scientific basis from which the geoengineering scenarios can be assessed. The project results are expected to impact the upcoming IPCC climate change and WMO/UNEP ozone assessments.
Das Projekt "STEP/ESMOS/ALPS: Europaeische Stratosphaerenueberwachungsstationen in den Alpen: Ein europaeischer Beitrag zum Netzwerk fuer den Nachweis von Veraenderungen der Stratosphaere (NDSC)" wird vom Umweltbundesamt gefördert und von Universität Bern, Institut für Angewandte Physik durchgeführt. This proposal is based on ground-based observations performed at mid-latitude in Europe, in order to study the chemical and physical processes determining the stratospheric composition and its variations and changes. The measurements are made by means of number spectroscopic methods: Lidar (ozone, temperature, aerosols); Microwave radiometry (ozone, NO2); IR high resolution spectroscopy (HC1, HF, HNO3, C1ONO2, NO2, NO, N2O, CH4). This study relies on the 'Alpine Station' selected for the Network for the Detection of Stratosphere Change (NDSC) as the mid-latitude, Northern hemisphere site. The objectives are to make intensive coordinated ground-based observations to provide climatological measurements of ozone total amounts and vertical profiles, aerosol vertical distributions, C1O vertical profiles, NO2, NO reservoirs and long-lived tracers total amounts; to provide validated ground-based measurements at mid-latitudes to meet the SESAME scientific objectives in 1994 and 1995; to study the seasonal and interannual variability of the measured trace species; to study the aeronomic processes involved in atmospheric composition changes at mid-latitude; to study the role of volcanic aerosols on ozone and NO2 reduction observed after the Mt Pinatubo eruption, by expanding the observations during the decay of volcanic aerosols during the next two years and by the development of aerosol modelling; to provide measurement to test and improve stratospheric models including heterogeneous processes and to validate the current and planned satellite observations of the stratosphere (eg UARS and ERS2/GOME). The validated data will be archived in the data center of NILU.