Fire proxies in ice cores Several tracers of past biomass burning can be measured in polar ice cores. Aerosols are transported in smoke plumes from Eurasia and North America over thousands of kilometers. Some of the aerosols are transported all the way to Greenland, deposited there and trapped within the ice sheet (Kehrwald et al. 2012; Zennaro et al. 2014). Ammonium is a tracer of biomass burning, especially in boreal regions (e.g. Legrand et al. 1992), but also enters the atmosphere through interactions with fertilizers, manure, and marine sources. Black carbon is a more specific proxy as it is produced by the incomplete combustion of both biomass and fossil fuels (McConnell et al. 2007). Both black carbon and ammonium can be determined using high-resolution continuous flow analysis techniques (CFA; Zennaro et al. 2014). Fire information is also inferred from the isotopic composition of methane (CH4). The δ13C of CH4 is enriched if it was produced by a pyrogenic process compared to biogenic sources including rice cultivation, ruminants or wetlands (Sapart et al., 2012) Note, however, that due to methane’s atmospheric lifetime of several decades, the δ13C of CH4 is a global mixture from sources with different isotopic signatures (Sapart et al. 2012). Finally, levoglucosan, a monosaccharide anhydride, has strong potential for tracing broad-scale fire activity. It is only produced by burning cellulose at temperatures of 300°C or higher (Simoneit 2002) and represents one of the principal constituents of smoke plumes. Levoglucosan is currently only determined in discrete samples, resulting in lower-resolution records than parameters analyzed by CFA techniques.
We present new atmospheric isotope simulations in order to investigate the effect of sea surface temperature changes on the relationship between Greenland surface temperature and water isotopes.
Fire impacts climate by changing atmospheric greenhouse gas concentrations, vegetation distributions, and surface albedo.We present a biomarker, levoglucosan, to reconstruct past fire activity from ice cores.This tracer allows us to investigate fire and climate interactions over glacial-interglacial cycles.
Emma J. StonE1, P. BakkEr2, S. CharBit3, S.P. ritz4 and V. Varma5 School of Geographical Sciences, University of Bristol, UK; emma.j.stone@bristol.ac.uk Earth & Climate Cluster, Department of Earth Sciences, Vrije Universiteit Amsterdam, The Netherlands; Laboratoire des Sciences du Climat et de l'Environnement, CEA Saclay, Gif-sur-Yvette, France; Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Switzerland; Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, Germany
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. The Art of Reviewing: Holding up quality in the scientific quality control system R. Panchang, A. Govin, C. Omuombo
The Last Interglacial Global Mean Sea Level is believed to be 6 to 9 m above the present and might have two distinct maxima.Here, we discuss the possible fluctuations and their implications
Simulations suggest that Pacific interannual changes in sea surface temperature (SST) are smaller than SST seasonality, whereas the opposite is modeled for precipitation.Nonstationarity in ENSO patterns may affect the interpretation of past variability changes from climate records.
Figure 2: An excerpt from the stakeholder survey: feedback to the question "How useful to you are the following methods of information delivery?"11 of the 13 stakeholders responded to whether they found the different methods of delivery very useful, useful or not useful.The remaining two stakeholders provided written feedback.
Sea level history throughout the Quaternary shows a complex spatial and temporal pattern, and provides a globally averaged record of continental ice volume variations (Alley et al. 2005; Lambeck and Chappell 2001). Observations of this variability provide key constraints on the timing and amplitude of the forcing mechanisms that trigger the growth and decay of ice masses. With over a third of the world’s population living near coastlines, understanding the history and future impacts of global sea level change ranks as a top priority in the Earth sciences. As uncertainties are inherent to the methodologies and settings of all sea level reconstructions, there is a continued need for additional, independent sources of sea level data that may provide unique insights and crosschecks to the existing framework of former eustatic changes in sea level. The coastal caves of Mallorca with their unique speleothem encrustations (Fig. 1) provide one such source of additional sea level data (Tuccimei et al. 2012), which can be used to precisely document the elevation and timing of various sea level stands in the western Mediterranean region with sub-meter resolution (Dorale et al. 2010). The western Mediterranean was chosen as the workshop site so that participants (especially those working with corals, ice, or models) could visit the coastal caves of Mallorca and acquaint themselves with the setting of this promising approaches (Fig. 1). The purpose of the workshop was to bring together an international group of researchers to discuss and promote opportunities for collaboration on the topics of sea level data acquisition, calibration, and modeling. The meeting attracted 43 participants from nine countries, including 15 students and early career scientists. The workshop focused on the interpretation of sea level changes during marine isotope stage 5 (MIS 5) and the onset of MIS 4. The event was organized into three distinct sections: two days of presentations (both oral and poster), two days of field trips, and a half-day round table discussion that concluded the meeting and explored directions for future research. The first section included 20 oral presentations, of which six were invited keynotes, and nine were posters. The speakers covered a wide spectrum of problems pertinent to sea level changes, including detailed studies of reef and marine terraces, submerged speleothems, marine notches, marine sediment sequences, phreatic overgrowth on speleothems, flank margin caves, cave minerals, timing of MIS 5, Quaternary fauna, and advanced sea level modeling studies. Sea level modeling was a major focus of discussion during the round table, which tackled the following topics: (1) ways of reconciling controversial MIS 5a data sets from sea level fields around the world, (2) the use of glacio-hydro-isostasy modeling to address the issue above, (3) challenges in addressing past sea level positions and how the community should bridge the gap between field observation and models, and (4) observational and modeling constraints on sea level rise/fall and ice extent/volume. Finally, the workshop highlighted the interactions among researchers at various stages of their careers, from well-established scientists to junior faculty members, with particular emphasis on the participation of post-doctoral, undergraduate, and graduate students.
Ice-rafted debris in fjord sediment cores provides information about outlet glacier activity beyond the instrumental time period.It tells us that the Helheim Glacier, Greenland's third most productive glacier, responds rapidly to short-term (3 to 10 years) climate changes.
In a true test of modern-day communication, the participants at the 2nd PAGES Young Scientists Meeting travelled virtually from the 26°C heat of a Goan afternoon to a brisk -2°C morning in New York City to join Gavin Schmidt (NASA, USA) for a lesson in the art of science communication. During this session, Gavin then delved into the nuts and bolts of why scientists are ethically obligated to publicly communicate their science and how communicating it well is an increasingly challenging but important aspect of our profession. This article highlights Gavin’s tips for effective public communication, some common traps scientists fall into, and tasks or next steps our community needs to take to improve the public’s access to accurate, high-quality scientific information. Despite the general public's interest in science, it is often hard to know where to go for accurate (and understandable) scientific information. In a world of rapid and wide dissemination of knowledge and opinions, it is increasingly important to communicate outside the scientific community. Not only do we have an obligation to communicate broadly, due to the typically high proportion of science funding coming from the taxpayer, but broad communication is essential to avoid misuse or misinterpretations of our work and to slow the propagation of scientific misconceptions. Crucially, many of the important scientific concepts that need to be conveyed are simply not “news”. For example, the physics of greenhouses gases will undoubtedly never make the headlines yet it is a fundamental building block to being literate in the issue of climate change. Communicating these types of facts requires scientists to step beyond traditional avenues of communication. Gavin emphasizes that we, as a community, need to engage with social media and webbased communications, in addition to traditional means of communication (e.g. press releases, interviews and essays). People increasingly rely on the internet as a primary source of information, which means there is a need to provide more accurate and appropriate information online through scientists’ blogs, videos, and social media platforms. We need to use this diverse set of tools to not only convey our expertise but importantly, to engage with different audiences. The challenge of clearly communicating the intended scientific message to the public is not insurmountable but requires an understanding of what works and what does not work. Falling into typical science communication traps can quickly turn an interview, article or outreach event into a counterproductive debate or an unintended source of misleading information. Here are some common traps and points on what does not work: • Avoid talking too much about technical details and avoid technical debates • Avoid using jargon that you don’t take time to explain • Avoid scientific stereotypes, e.g. arrogance or elitism • Avoid triggering issues of free speech, data access, and secrecy • Do not respond poorly to criticism by getting angry or taking it personally • Always distinguish between personal opinion and scientific consensus • Try to understand the context in which your statements will be heard or read • Try to defuse pseudo-debates but do not ignore them • Avoid sensationalism and over-extrapolated conclusions
At the 2nd YSM there was consensus among the young international paleoscientists that there is a great need to better develop skills for communicating with different types of non-academic audiences. Clear and effective communication to the public is becoming increasingly important as current and future climatic and environmental changes are frequently a major focus in the media and politics. However, for the paleoscience community there remains the challenge of properly conveying the concept of past change on longer timescales. Facilitating better public understanding of the scientific process is required to break down barriers and have objective discussions, especially regarding the issue of future climate change. A productive discussion at the YSM about how to address the challenges we face in communicating paleoscience resulted in two potential solutions: First, as scientists, we need to be proactive in making our research available in our local communities. Creating connections with internet platforms, classrooms, media outlets and other informal science education venues can be highly productive and rewarding, but also difficult and time consuming to develop. To address this problem and to facilitate paleoscience communication, we propose to link with the PAGES scientist database and outline researchers availability for specific outreach activities (e.g. classroom visits, blog articles, Skype calls, laboratory tours, radio interviews). This type of additional database should be communicated through educational networks such as Polar Education International (PEI). The ultimate hope is that this freely accessible database can begin building lasting relationships between the public and local researchers by making it easy for the public to find local scientists. An encouraging example is the Social Media Knowledge Exchange (www.smke.org), which provides a platform for early career scientists in history and archeology to share their research with non-academic audiences. Second, the current lack of formal training opportunities in science communication is a major obstacle preventing the effective communication of our research. Coursework and other training opportunities, beyond short workshops, are needed to instruct researchers how to effectively and concisely communicate the significance of their research to any audience. In a highly inter-connected world, it is critical that scientists develop an appropriate level of fluency and understanding of how to use communication tools ranging from social media to informal writing. Ultimately, communicating our scientific results should become a regular and professionally recognized part of the scientific process. Developing the skills to effectively share our science will undoubtedly increase our broader impacts, and PAGES is in a unique position to facilitate this development in the paleoscience community. Already the YSM has stimulated discussion, and we hope that this dialogue can continue in the broader PAGES network to strengthen and broaden our science communication skills into the future.
Snapshot simulations are obtained for the preindustrial, the mid-Holocene and the last interglacial time periods characterized by different atmospheric CO 2 concentrations and orbital forcing.We evaluate the natural variability of vegetation cover, land carbon storage, and fire activity using a coupled climate-carbon cycle model.
The Atlantic Ocean receives warm, saline water from the Indo-Pacific Ocean through Agulhas leakage around the southern tip of Africa. Recent findings suggest that Agulhas leakage is a crucial component of the climate system and that ongoing increases in leakage under anthropogenic warming could strengthen the Atlantic overturning circulation at a time when warming and accelerated meltwater input in the North Atlantic is predicted to weaken it. Yet in comparison with processes in the North Atlantic, the overall Agulhas system is largely overlooked as a potential climate trigger or feedback mechanism. Detailed modelling experiments-backed by palaeoceanographic and sustained modern observations-are required to establish firmly the role of the Agulhas system in a warming climate.
11th International Conference on Paleoceanography - Sitges, Spain, 1-6 September 2013.-- 1 page, 1 figure
