Hydrographic data from Atka Bay taken by Weddell seals during expedition NEU2008 with links to datasets

In order to gain insights into species-level behavioural responses to the physical environment, it is necessary to obtain information from various populations and at all times of year. We analysed the influences of physical environmental parameters on the mid-summer dive behaviour of Weddell seals (Leptonychotes weddellii) from a little-known population at Atka Bay, Antarctica. Dive depth distributions followed a typical bimodal pattern also exhibited by seals from other populations and seals targeted both shallow water layers of <50 m and depths near the seafloor. Increased stratification of temperature layers within the water column resulted in increased forage efforts by the seals through relatively high numbers of dives to the seafloor, as well as forage effort associated with shallow dives. We interpret these behavioural responses to be due to increased water temperature stratification resulting in the concentration of prey species in particular depth layers.

Studentisches Medienprojekt zur Internationalen REKLIM Konferenz in Kooperation mit der DEKRA-Hochschule Berlin

Ein interdisziplinäres und interaktives Medienprojekt von und für junge Menschen zum Thema "Regionale Klimaänderungen". Der Klimawandel ist eines der wichtigsten Zukunftsthemen und Handlungsfelder unserer Zivilgesellschaft, mit weltweiter Relevanz und regionalen Auswirkungen. Die jungen Menschen heute sind diejenigen, die in Zukunft von den Folgen der Klimaveränderungen besonders stark betroffen sein werden. Sie sind aber auch gleichzeitig gefordert zu erkennen, dass wir andere Lebensstile finden und Vermeidungs- und Anpassungsstrategien jetzt auf den Weg bringen müssen, da diese Maßnahmen nur sehr langfristig wirken. Es liegt noch zu wenig im Erfahrungs- und Erlebenshorizont vieler junger Menschen, Maßnahmen zu Klimaschutz und -anpassung als wichtige Bausteine für die eigene Zukunft zu begreifen und aktiv als Thema anzunehmen. Daher bedarf es einer frühen und intensiven Auseinandersetzung mit dieser gesellschaftlichen Herausforderung als Teil der eigenen Lebenswirklichkeit. Zielgruppe des Medienprojektes war hier die heranwachsende Generation im Ausbildungsalter (16-30 Jahre). Die Helmholtz-Klimainitiative REKLIM (Regionale Klimaänderungen) und die DEKRA Hochschule Berlin haben sich 2013 gemeinsam auf den Weg gemacht, den Prozess der Auseinandersetzung und der Bewusstseinsbildung für die Bedeutung dieses Themas für junge Menschen in einem gemeinsamen interdisziplinären Projekt anzustoßen (www.reklim-medienprojekt.de). Gewählt für die Umsetzung dieses Projektes wurde die internationale REKLIM Konferenz "Our Climate - Our Future, Regional Perspectives on a global Challenge", die vom 6. - 9. Oktober 2014 in Berlin stattfand. Das ins Leben gerufene Medienprojekt zu dieser wissenschaftlichen Konferenz vereinte die Expertisen beider Projektpartner, um das Thema "Regionale Klimaänderungen" von jungen Menschen für junge Menschen zu adressieren und sie in ihrer eigenen Sprache und Mediennutzung zu erreichen. Insgesamt konnten mehr als 80 Studierende aus den Studiengängen Fernsehen und Film, Journalismus und Medienmanagement der DEKRA Hochschule Berlin in diesem einzigartigen Projekt in die Wissenschaftskonferenz eingebunden werden. Mit selbst konzipierten und produzierten Medienprodukten (u.a. einem Blog, mehreren Dokumentarfilmen, Viralen Videos sowie täglichen Berichterstattungen) für die Öffentlichkeit sollten die regionalen Aspekte des Klimawandels, die in der Helmholtz-Klimainitiative REKLIM wissenschaftlich erarbeitet werden, der Öffentlichkeit zugänglich gemacht werden. Den Studierenden kam dabei die wichtige Rolle zu, die wissenschaftlichen Inhalte in eine filmkünstlerische, journalistische und junge Sprache zu transformieren, mit unvoreingenommener Perspektive auf die Probleme zu schauen und die Wissenschaftlerinnen und Wissenschaftler dabei gleichsam mit einzubinden. So ist in dem Projekt ein wichtiger Dialog- und Lernprozess zwischen den verschiedenen Disziplinen entstanden. Darüber hinaus bot die Zusammenarbeit für die Wissenschaftlerinnen und Wissenschaftler des REKLIM-Verbunds und der beteiligten Zentren eine einmalige Chance, eine mediale Öffentlichkeit herzustellen, die es in dieser Form vermutlich für eine derartige Konferenz noch nicht gegeben hat. Für die Studierenden der DEKRA Hochschule bedeutete das Medienprojekt wichtige Erfahrungen in der projektbezogenen Arbeit mit einem externen Partner zu einem gesellschaftsrelevanten Thema zu sammeln. Das REKLIM-Medienprojekt verfolgt die Ziele: - in einem interdisziplinären und interaktiven Projekt junge Menschen zur Auseinandersetzung mit dem Klimawandel und zur Bewusstseinsbildung für die Bedeutung der regionalen Klimaänderungen anzuregen, - durch die von den Studierenden entwickelten Medienprodukte eine Verbindung zwischen den wissenschaftlichen Arbeiten und einer breiten Öffentlichkeit zu ermöglichen, - einen Dialogprozess zwischen Wissenschaftler/-innen und Studierenden zu initiieren, - wissenschaftliche Inhalte über künstlerische und mediale Transferprozesse anschaulich und ansprechend einer breiten Öffentlichkeit, insbesondere jungen Menschen, näherzubringen, um sie für das Thema Klimawandel und seine regionalen Auswirkungen zu sensibilisieren, - einen Dialog- und Lernprozess zwischen den verschiedenen Disziplinen anzuregen.

30 years of synoptic observations from Neumayer Station with links to datasets

High temporal resolution (three hours) records of temperature, wind speed and sea level pressure recorded at Antarctic research station Neumayer (70°S, 8°W) during 1982-2011 are analysed to identify oscillations from daily to intraseasonal timescales. The diurnal cycle dominates the three-hourly time series of temperature during the Antarctic summer and is almost absent during winter. In contrast, the three-hourly time series of wind speed and sea level pressure show a weak diurnal cycle. The dominant pattern of the intraseasonal variability of these quantities, which captures the out-of-phase variation of temperature and wind speed with sea level pressure, shows enhanced variability at timescales of ~ 40 days and ~ 80 days, respectively. Correlation and composite analysis reveal that these oscillations may be related to tropical intraseasonal oscillations via large-scale eastward propagating atmospheric circulation wave-trains. The second pattern of intraseasonal variability, which captures in-phase variations of temperature, wind and sea level pressure, shows enhanced variability at timescales of ~ 35, ~ 60 and ~ 120 days. These oscillations are attributed to the Southern Annular Mode/Antarctic Oscillation (SAM/AAO) which shows enhanced variability at these timescales. We argue that intraseasonal oscillations of tropical climate and SAM/AAO are related to distinct patterns of climate variables measured at Neumayer.

Dive depth and dive duration data of female southern elephant seals from Marion Island between 2004 and 2008 with links to datasets

The at-sea behaviour of marine top predators provides valuable insights into the distribution of prey species and strategies used by predators to exploit patchily distributed resources. We describe the water column usage and dive strategies of female southern elephant seals from Marion Island tracked between 2004 and 2008. Dives representing increases in forage effort were identified using a method that combines dive type analyses and the calculation of relative amounts of time that animals spend in the bottom phases of dives. Results from this analysis indicate that female elephant seals from Marion Island tend to display lower levels of forage effort closer to the island and display intensive opportunistic forage bouts that occur at a minimum distance of approximately 215 km from the island. Females from Marion Island dived deeper and for longer periods of time, compared to females from other populations. Most animals displayed positive diel vertical migration, evidently foraging pelagically on vertically migrating prey. A few animals displayed periods of reverse (negative) diel vertical migration, however, diving to deeper depths at night, compared to daytime. This behaviour is difficult to explain and prey species targeted during such periods unknown. Our results illustrate plasticity in foraging behaviour of southern elephant seals, as well as inter-population differences in forage strategies.

Ocean temperature and salinity measured by CTD SRDLs deployed on southern elephant seals from King George Island with links to datasets

West Antarctic ice shelves have thinned dramatically over recent decades. Oceanographic measurements that explore connections between offshore warming and transport across a continental shelf with variable bathymetry toward ice shelves are needed to constrain future changes in melt rates. Six years of seal-acquired observations provide extensive hydrographic coverage in the Bellingshausen Sea, where ship-based measurements are scarce. Warm but modified Circumpolar Deep Water floods the shelf and establishes a cyclonic circulation within the Belgica Trough with flow extending toward the coast along the eastern boundaries and returning to the shelf break along western boundaries. These boundary currents are the primary water mass pathways that carry heat toward the coast and advect ice shelf meltwater offshore. The modified Circumpolar Deep Water and meltwater mixtures shoal and thin as they approach the continental slope before flowing westward at the shelf break, suggesting the presence of the Antarctic Slope Current. Constraining meltwater pathways is a key step in monitoring the stability of the West Antarctic Ice Sheet.

Dive depth and dive duration data of male southern elephant seals from Marion Island between 2004 and 2008 with links to datasets

We describe the habitat use of 22 male southern elephant seals (Mirounga leonina) satellite tagged at Marion Island between 2004 and 2008. While a few areas of increased utilization appeared to be associated with areas of shallower bathymetry (such as sea-floor ridges and fracture zones), seals in our study did not target other areas of shallow bathymetry within close proximity to Marion Island. Rather, most elephant seals foraged pelagically over very deep water where much variation was evident in diel vertical migration strategies. These strategies resulted in generally deeper and longer dives than what has been reported for male elephant seals from other colonies. No significant differences were recorded for dive durations or dive depths between adults and sub-adults. However, younger animals displayed a positive relationship between dive durations and age, as well as between dive depths and age, while these relationships became negative for older animals. Mixed model outputs suggested that seals increased their aerobic fitness as migrations progressed, enabling them to undertake longer dives. We conclude that Marion Island male elephant seals exhibit much variability in dive strategy and are seemingly capable of exploiting a range of different prey types occurring in various depth layers.

At surface behaviour, dive depth and dive duration and associated hydrographic data of adult male southern elephant seals from King George Island from expedition JUB2010 with links to datasets

Understanding the distribution and foraging ecology of major consumers within pelagic systems, specifically in relation to physical parameters, can be important for the management of bentho-pelagic systems undergoing rapid change associated with global climate change and other anthropogenic disturbances such as fishing (i.e., the Antarctic Peninsula and Scotia Sea). We tracked 11 adult male southern elephant seals (Mirounga leonina), during their five-month post-moult foraging migrations from King George Island (Isla 25 de Mayo), northern Antarctic Peninsula, using tags capable of recording and transmitting behavioural data and in situ temperature and salinity data. Seals foraged mostly within the Weddell-Scotia Confluence, while a few foraged along the western Antarctic Peninsula shelf of the Bellingshausen Sea. Mixed model outputs suggest that the at-sea behaviour of seals was associated with a number of environmental parameters, especially seafloor depth, sea-ice concentrations and the temperature structure of the water column. Seals increased dive bottom times and travelled at slower speeds in shallower areas and areas with increased sea-ice concentrations. Changes in dive depth and durations, as well as relative amount of time spent during the bottom phases of dives, were observed in relation to differences in overall temperature gradient, likely as a response to vertical changes in prey distribution associated with temperature stratification in the water column. Our results illustrate the likely complex influences of bathymetry, hydrography and sea ice on the behaviour of male southern elephant seals in a changing environment and highlight the need for region-specific approaches to studying environmental influences on behaviour.

Villefranche MedSeA mesocosm experiment 2013: perturbation studies and field studies

A joint mesocosm experiment took place in February/March 2013 in the bay of Villefranche in France as part of the european MedSeA project. Nine mesocosms (52 m**3) were deployed over a 2 weeks period and 6 different levels of pCO2 and 3 control mesocosms (about 450 µatm), were used, in order to cover the range of pCO2 anticipated for the end of the present century. During this experiment, the potential effects of these perturbations on chemistry, planktonic community composition and dynamics including: eucaryotic and prokaryotic species composition, primary production, nutrient and carbon utilization, calcification, diazotrophic nitrogen fixation, organic matter exudation and composition, micro-layer composition and biogas production were studied by a group of about 25 scientists from 8 institutes and 6 countries. This is one of the first mesocosm experiments conducted in oligotrophic waters. A blog dedicated to this experiment can be viewed at: http://medseavillefranche2013.obs-vlfr.fr.

Stareso MedSeA mesocosm experiment: field and perturbation studies 2012

A joint mesocosm experiment took place in June/July 2012 in Corsica (bay of Calvi, Stareso station;http://www.stareso.com/) as part of the european MedSeA project. Nine mesocosms (52 m**3) were deployed over a 20 days period and 6 different levels of pCO2 and 3 control mesocosms (about 450 µatm), were used, in order to cover the range of pCO2 anticipated for the end of the present century. During this experiment, the potential effects of these perturbations on chemistry, planktonic community composition and dynamics including: eucaryotic and prokaryotic species composition, primary production, nutrient and carbon utilization, calcification, diazotrophic nitrogen fixation, organic matter exudation and composition, micro-layer composition and biogas production were studied by a group of about 25 scientists from 8 institutes and 6 countries. This is one of the first mesocosm experiments conducted in oligotrophic waters. A blog dedicated to this experiment can be viewed at: http://medseastareso2012.wordpress.com/.

Basic and other measurements of radiation from the Baseline Surface Radiation Network (BSRN) Station Ny-Ålesund in the years 1992 to 2013, reference list of 253 datasets

At Ny-Ålesund (78.9° N), Svalbard, surface radiation measurements of up- and downward short- and longwave radiation are operated since August 1992 in the frame of the Baseline Surface Radiation Network (BSRN), complemented with surface and upper air meteorology since August 1993. The long-term observations are the base for a climatological presentation of the surface radiation data. Over the 21-year observation period, ongoing changes in the Arctic climate system are reflected. Particularly, the observations indicate a strong seasonality of surface warming and related changes in different radiation parameters. The annual mean temperature at Ny-Ålesund has risen by +1.3 ± 0.7 K per decade, with a maximum seasonal increase during the winter months of +3.1 ± 2.6 K per decade. At the same time, winter is also the season with the largest long-term changes in radiation, featuring an increase of +15.6 ± 11.6 W/m**2 per decade in the downward longwave radiation. Furthermore, changes in the reflected solar radiation during the months of snow melt indicate an earlier onset of the warm season by about 1 week compared to the beginning of the observations. The online available dataset of Ny-Ålesund surface radiation measurements provides a valuable data source for the validation of satellite instruments and climate models.

Reference list of 120 datasets from time series station Payerne used for exploratory search

The analysis of time-dependent data is an important problem in many application domains, and interactive visualization of time-series data can help in understanding patterns in large time series data. Many effective approaches already exist for visual analysis of univariate time series supporting tasks such as assessment of data quality, detection of outliers, or identification of periodically or frequently occurring patterns. However, much fewer approaches exist which support multivariate time series. The existence of multiple values per time stamp makes the analysis task per se harder, and existing visualization techniques often do not scale well. We introduce an approach for visual analysis of large multivariate time-dependent data, based on the idea of projecting multivariate measurements to a 2D display, visualizing the time dimension by trajectories. We use visual data aggregation metaphors based on grouping of similar data elements to scale with multivariate time series. Aggregation procedures can either be based on statistical properties of the data or on data clustering routines. Appropriately defined user controls allow to navigate and explore the data and interactively steer the parameters of the data aggregation to enhance data analysis. We present an implementation of our approach and apply it on a comprehensive data set from the field of earth bservation, demonstrating the applicability and usefulness of our approach.

Global LAI uncertainty and relative uncertainty datasets derived from a Triple Collocation Error Model (TCEM)

Uncertainty information for global leaf area index (LAI) products is important for global modeling studies but usually difficult to systematically obtain at a global scale. Here, we present a new method that cross-validates existing global LAI products and produces consistent uncertainty information. The method is based on a triple collocation error model (TCEM) that assumes errors among LAI products are not correlated. Global monthly absolute and relative uncertainties, in 0.05° spatial resolutions, were generated for MODIS, CYCLOPES, and GLOBCARBON LAI products, with reasonable agreement in terms of spatial patterns and biome types. CYCLOPES shows the lowest absolute and relative uncertainties, followed by GLOBCARBON and MODIS. Grasses, crops, shrubs, and savannas usually have lower uncertainties than forests in association with the relatively larger forest LAI. With their densely vegetated canopies, tropical regions exhibit the highest absolute uncertainties but the lowest relative uncertainties, the latter of which tend to increase with higher latitudes. The estimated uncertainties of CYCLOPES generally meet the quality requirements (± 0.5) proposed by the Global Climate Observing System (GCOS), whereas for MODIS and GLOBCARBON only non-forest biome types have met the requirement. Nevertheless, none of the products seems to be within a relative uncertainty requirements of 20%. Further independent validation and comparative studies are expected to provide a fair assessment of uncertainties derived from TCEM. Overall, the proposed TCEM is straightforward and could be automated for the systematic processing of real time remote sensing observations to provide theoretical uncertainty information for a wider range of land products.