TY - JOUR A1 - Saltikoff, Elena A1 - Friedrich, Katja A1 - Soderholm, Joshua A1 - Lengfeld, Katharina A1 - Nelson, Brian A1 - Becker, Andreas A1 - Hollmann, Rainer A1 - Urban, Bernard A1 - Heistermann, Maik A1 - Tassone, Caterina T1 - An Overview of Using Weather Radar for Climatological Studies: Successes, Challenges, and Potential JF - Bulletin of the American Meteorological Society N2 - Weather radars have been widely used to detect and quantify precipitation and nowcast severe weather for more than 50 years. Operational weather radars generate huge three-dimensional datasets that can accumulate to terabytes per day. So it is essential to review what can be done with existing vast amounts of data, and how we should manage the present datasets for the future climatologists. All weather radars provide the reflectivity factor, and this is the main parameter to be archived. Saving reflectivity as volumetric data in the original spherical coordinates allows for studies of the three-dimensional structure of precipitation, which can be applied to understand a number of processes, for example, analyzing hail or thunderstorm modes. Doppler velocity and polarimetric moments also have numerous applications for climate studies, for example, quality improvement of reflectivity and rain rate retrievals, and for interrogating microphysical and dynamical processes. However, observational data alone are not useful if they are not accompanied by sufficient metadata. Since the lifetime of a radar ranges between 10 and 20 years, instruments are typically replaced or upgraded during climatologically relevant time periods. As a result, present metadata often do not apply to past data. This paper outlines the work of the Radar Task Team set by the Atmospheric Observation Panel for Climate (AOPC) and summarizes results from a recent survey on the existence and availability of long time series. We also provide recommendations for archiving current and future data and examples of climatological studies in which radar data have already been used. Y1 - 2019 U6 - https://doi.org/10.1175/BAMS-D-18-0166.1 SN - 0003-0007 SN - 1520-0477 VL - 100 IS - 9 SP - 1739 EP - 1751 PB - American Meteorological Soc. CY - Boston ER - TY - THES A1 - Friedrich, Katja T1 - Selbstständig(er) durch Selbst- und Fremdeinschätzung? : Möglichkeiten und Grenzen der Förderung von Metakognitionsstrategien bei Schülerinnen und Schülern durch "Ich-kann"-Checklisten ; Ergebnisse einer gezielten Intervention im Fach Deutsch in der 7. gymnasialen Jahrgangsstufe T1 - Self-reliance through self-assessment and third-party assessment? : the potential and the limits of fostering the use of "Can do" checklists as a meta-cognitive strategy ; findings of a targeted intervention following 13 and 14 year old German class Gymnasium students N2 - Neben der Frage nach der leistungssteigernden Wirkung von sogenannten "Ich-kann"-Checklisten auf die Metakognitionsstrategien der Schülerinnen und Schüler, geht die Arbeit auch den Fragen nach, welche Schülerinnen und Schüler "Ich-kann"-Checklisten nutzen, in welcher Form und unter welchen Kontextmerkmalen sie am wirksamsten sind. Dabei handelt es sich um Listen mit festgelegten, fachlichen und überfachlichen Kompetenzen einer bzw. mehrerer Unterrichtseinheiten, die in Form von „Ich-kann“-Formulierungen für Schüler geschrieben sind und die Aufforderung einer Selbst- und Fremdeinschätzung beinhalten. Blickt man in die Veröffentlichungen der letzten Jahre zu diesem Thema und in die schulische Praxis, so ist eine deutliche Hinwendung zur Entwicklung und Arbeit mit „Ich-kann“-Checklisten und Kompetenzrastern zu erkennen. Umso erstaunlicher ist es, dass diesbezüglich so gut wie keine empirischen Untersuchungen vorliegen (vgl. Bastian & Merziger, 2007; Merziger, 2007). Basierend auf einer quantitativen Erhebung von 197 Gymnasialschülerinnen und -schülern in der 7. Jahrgangsstufe im Fach Deutsch wurde über einen Zeitraum von zwei Jahren diesen übergeordneten Fragen nachgegangen. Die Ergebnisse lassen die Aussagen zu, dass "Ich-kann"-Checklisten insbesondere für Jungen ein wirksames pädagogisches Instrument der Selbstregulation darstellen. So fördert die Arbeit mit "Ich-kann"-Checklisten nicht nur die Steuerung eigener Lernprozesse, sondern auch die Anstrengungsbereitschaft der Schülerinnen und Schüler, mehr für das Fach tun zu wollen. Eine während der Intervention erfolgte Selbsteinschätzung über den Leistungsstand mittels der "Ich-kann"-Checklisten fördert dabei den freiwilligen außerunterrichtlichen Gebrauch. N2 - This paper examines the performance enhancing effect of so called “Can Do” checklists on the metacognitive strategies of 13 to 14 year old Gymnasium students. This study analyzes which students actually use “Can Do” checklists, in what form they apply them, and the specific circumstances in which they appear to be most effective. These checklists define fundamental, subject-specific, and interdisciplinary competencies that are formulated into written “Can Do” lessons that require both self-assessment and third-party assessment. The increasing development and application of “Can Do” checklists and performance metrics is clearly seen both in the recent scholarly papers that address this issue and in classroom practice. The fact that this trend is emerging despite the lack of empirical studies is particularly surprising (e.g. Bastian & Merzinger, 2007; Merzinger, 2007). These salient questions were examined through analysis of a two-year quantitative survey that monitored two consecutive classes of 197 Gymnasium students in their German class during their 7th academic year. The results of this study indicate that “Can Do” checklists are an effective pedagogical tool for self-evaluation especially for boys. Applying this methodology both fosters self management of the learning process and motivates the student to invest more effort into the subject. The benefits of continuous performance self-assessment using “Can Do” checklists also transfer voluntarily beyond the classroom. KW - Metakognitionsstrategien KW - „Ich-kann“-Checklisten KW - Selbstregulation KW - Selbst- und Fremdeinschätzung KW - Schul- und Unterrichtsentwicklung KW - Metacognitive strategies KW - “Can do”-checklists KW - self-regulation KW - self-assessment and third-party assessment KW - curriculum and lesson plan develop Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-66411 ER - TY - JOUR A1 - Schleussner, Carl-Friedrich A1 - Lissner, Tabea K. A1 - Fischer, Erich M. A1 - Wohland, Jan A1 - Perrette, Mahe A1 - Golly, Antonius A1 - Rogelj, Joeri A1 - Childers, Katelin A1 - Schewe, Jacob A1 - Frieler, Katja A1 - Mengel, Matthias A1 - Hare, William A1 - Schaeffer, Michiel T1 - Differential climate impacts for policy-relevant limits to global warming: the case of 1.5 degrees C and 2 degrees C JF - Earth system dynamics N2 - Robust appraisals of climate impacts at different levels of global-mean temperature increase are vital to guide assessments of dangerous anthropogenic interference with the climate system. The 2015 Paris Agreement includes a two-headed temperature goal: "holding the increase in the global average temperature to well below 2 degrees C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 degrees C". Despite the prominence of these two temperature limits, a comprehensive overview of the differences in climate impacts at these levels is still missing. Here we provide an assessment of key impacts of climate change at warming levels of 1.5 degrees C and 2 degrees C, including extreme weather events, water availability, agricultural yields, sea-level rise and risk of coral reef loss. Our results reveal substantial differences in impacts between a 1.5 degrees C and 2 degrees C warming that are highly relevant for the assessment of dangerous anthropogenic interference with the climate system. For heat-related extremes, the additional 0.5 degrees C increase in global-mean temperature marks the difference between events at the upper limit of present-day natural variability and a new climate regime, particularly in tropical regions. Similarly, this warming difference is likely to be decisive for the future of tropical coral reefs. In a scenario with an end-of-century warming of 2 degrees C, virtually all tropical coral reefs are projected to be at risk of severe degradation due to temperature-induced bleaching from 2050 onwards. This fraction is reduced to about 90% in 2050 and projected to decline to 70% by 2100 for a 1.5 degrees C scenario. Analyses of precipitation-related impacts reveal distinct regional differences and hot-spots of change emerge. Regional reduction in median water availability for the Mediterranean is found to nearly double from 9% to 17% between 1.5 degrees C and 2 degrees C, and the projected lengthening of regional dry spells increases from 7 to 11%. Projections for agricultural yields differ between crop types as well as world regions. While some (in particular high-latitude) regions may benefit, tropical regions like West Africa, South-East Asia, as well as Central and northern South America are projected to face substantial local yield reductions, particularly for wheat and maize. Best estimate sea-level rise projections based on two illustrative scenarios indicate a 50cm rise by 2100 relative to year 2000-levels for a 2 degrees C scenario, and about 10 cm lower levels for a 1.5 degrees C scenario. In a 1.5 degrees C scenario, the rate of sea-level rise in 2100 would be reduced by about 30% compared to a 2 degrees C scenario. Our findings highlight the importance of regional differentiation to assess both future climate risks and different vulnerabilities to incremental increases in global-mean temperature. The article provides a consistent and comprehensive assessment of existing projections and a good basis for future work on refining our understanding of the difference between impacts at 1.5 degrees C and 2 degrees C warming. Y1 - 2016 U6 - https://doi.org/10.5194/esd-7-327-2016 SN - 2190-4979 SN - 2190-4987 VL - 7 SP - 327 EP - 351 PB - Copernicus CY - Göttingen ER - TY - GEN A1 - Schleussner, Carl-Friedrich A1 - Lissner, Tabea Katharina A1 - Fischer, Erich M. A1 - Wohland, Jan A1 - Perrette, Mahé A1 - Golly, Antonius A1 - Rogelj, Joeri A1 - Childers, Katelin A1 - Schewe, Jacob A1 - Frieler, Katja A1 - Mengel, Matthias A1 - Hare, William A1 - Schaeffer, Michiel T1 - Differential climate impacts for policy-relevant limits to global warming BT - the case of 1.5 °C and 2 °C T2 - Earth System Dynamics N2 - Robust appraisals of climate impacts at different levels of global-mean temperature increase are vital to guide assessments of dangerous anthropogenic interference with the climate system. The 2015 Paris Agreement includes a two-headed temperature goal: "holding the increase in the global average temperature to well below 2 degrees C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 degrees C". Despite the prominence of these two temperature limits, a comprehensive overview of the differences in climate impacts at these levels is still missing. Here we provide an assessment of key impacts of climate change at warming levels of 1.5 degrees C and 2 degrees C, including extreme weather events, water availability, agricultural yields, sea-level rise and risk of coral reef loss. Our results reveal substantial differences in impacts between a 1.5 degrees C and 2 degrees C warming that are highly relevant for the assessment of dangerous anthropogenic interference with the climate system. For heat-related extremes, the additional 0.5 degrees C increase in global-mean temperature marks the difference between events at the upper limit of present-day natural variability and a new climate regime, particularly in tropical regions. Similarly, this warming difference is likely to be decisive for the future of tropical coral reefs. In a scenario with an end-of-century warming of 2 degrees C, virtually all tropical coral reefs are projected to be at risk of severe degradation due to temperature-induced bleaching from 2050 onwards. This fraction is reduced to about 90% in 2050 and projected to decline to 70% by 2100 for a 1.5 degrees C scenario. Analyses of precipitation-related impacts reveal distinct regional differences and hot-spots of change emerge. Regional reduction in median water availability for the Mediterranean is found to nearly double from 9% to 17% between 1.5 degrees C and 2 degrees C, and the projected lengthening of regional dry spells increases from 7 to 11%. Projections for agricultural yields differ between crop types as well as world regions. While some (in particular high-latitude) regions may benefit, tropical regions like West Africa, South-East Asia, as well as Central and northern South America are projected to face substantial local yield reductions, particularly for wheat and maize. Best estimate sea-level rise projections based on two illustrative scenarios indicate a 50cm rise by 2100 relative to year 2000-levels for a 2 degrees C scenario, and about 10 cm lower levels for a 1.5 degrees C scenario. In a 1.5 degrees C scenario, the rate of sea-level rise in 2100 would be reduced by about 30% compared to a 2 degrees C scenario. Our findings highlight the importance of regional differentiation to assess both future climate risks and different vulnerabilities to incremental increases in global-mean temperature. The article provides a consistent and comprehensive assessment of existing projections and a good basis for future work on refining our understanding of the difference between impacts at 1.5 degrees C and 2 degrees C warming. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 426 KW - sea-level rise KW - Greenland ice-sheet KW - coral-reefs KW - precipitation extremes KW - West Antarctica KW - pine Island KW - model KW - projections KW - temperature KW - scenarios Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-410258 ER - TY - JOUR A1 - Schleussner, Carl-Friedrich A1 - Frieler, Katja A1 - Meinshausen, Malte A1 - Yin, J. A1 - Levermann, Anders T1 - Emulating Atlantic overturning strength for low emission scenarios consequences for sea-level rise along the North American east coast JF - Earth system dynamics N2 - In order to provide probabilistic projections of the future evolution of the Atlantic Meridional Overturning Circulation (AMOC), we calibrated a simple Stommel-type box model to emulate the output of fully coupled three-dimensional atmosphere-ocean general circulation models (AOGCMs) of the Coupled Model Intercomparison Project (CMIP). Based on this calibration to idealised global warming scenarios with and without interactive atmosphere-ocean fluxes and freshwater perturbation simulations, we project the future evolution of the AMOC mean strength within the covered calibration range for the lower two Representative Concentration Pathways (RCPs) until 2100 obtained from the reduced complexity carbon cycle-climate model MAGICC 6. For RCP3-PD with a global mean temperature median below 1.0 degrees C warming relative to the year 2000, we project an ensemble median weakening of up to 11% compared to 22% under RCP4.5 with a warming median up to 1.9 degrees C over the 21st century. Additional Greenland meltwater of 10 and 20 cm of global sea-level rise equivalent further weakens the AMOC by about 4.5 and 10 %, respectively. By combining our outcome with a multi-model sea-level rise study we project a dynamic sea-level rise along the New York City coastline of 4 cm for the RCP3-PD and of 8 cm for the RCP4.5 scenario over the 21st century. We estimate the total steric and dynamic sea-level rise for New York City to be about 24 cm until 2100 for the RCP3-PD scenario, which can hold as a lower bound for sea-level rise projections in this region, as it does not include ice sheet and mountain glacier contributions. Y1 - 2011 U6 - https://doi.org/10.5194/esd-2-191-2011 SN - 2190-4979 SN - 2190-4987 VL - 2 IS - 2 SP - 191 EP - 200 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Schleussner, Carl-Friedrich A1 - Rogelj, Joeri A1 - Schaeffer, Michiel A1 - Lissner, Tabea A1 - Licker, Rachel A1 - Fischer, Erich M. A1 - Knutti, Reto A1 - Levermann, Anders A1 - Frieler, Katja A1 - Hare, William T1 - Science and policy characteristics of the Paris Agreement temperature goal JF - Nature climate change Y1 - 2016 U6 - https://doi.org/10.1038/NCLIMATE3096 SN - 1758-678X SN - 1758-6798 VL - 6 SP - 827 EP - 835 PB - Nature Publ. Group CY - London ER -