(Table 1) Age determination on monospecies planktonic foraminifera of sediment core AN25-934

Reconstruction of regional climate and the Okhotsk Sea (OS) environment for the Last Glacial Maximum (LGM), deglaciation and Holocene were performed on the basis of high-resolution records of ice rafted debris (IRD), CaCO3, opal, total organic carbon (TOC), biogenic Ba (Ba_bio) and redox sensitive element (Mn, Mo) content, and diatom and pollen results of four cores that form a north-southern transect. Age models of the studied cores were earlier established by AMS 14C data, oxygen - isotope chronostratigraphy and tephrochronology. According to received results, since 25 ka the regional climate and OS environmental conditions have changed synchronously with LGM condition, cold Heinrich event 1, Bølling -Allerød (BA) warming, Younger Dryas (YD) cooling and Pre-Boreal (PB) warming recorded in the Greenland ice core, North Atlantic sediment, and China cave stalagmites. Calculation of IRD MAR in sediment of north-south transect cores indicate an increase of sea ice formation several times in the glacial OS as compared to the Late Holocene. Accompanying ice formation, increased brine rejection and the larger potential density of surface water at the north shelf due to a drop of glacial East Asia summer monsoon precipitation and Amur River run off, led to strong enhancement of the role of the OS in glacial North Pacific Intermediate Water (NPIW) formation. The remarkable increase in OS productivity during BA and PB warming was probably related with significant reorganisation of the North Pacific deep water ventilation and nutrient input into the NPIW and OS Intermediate Water (OSIW). Seven Holocene OS millennial cold events based on the elevated values of the detrended IRD stack record over the IRD broad trend in the sediments of the studied cores have occurred synchronously with cold events recorded in the North Atlantic, Greenland ice cores and China cave stalagmites after 9 ka. Diatom production in the OS were mostly controlled by sea ice cover changes and surface water stratification induced by sea-ice melting; therefore significant opal accumulation in sediments of this basin begin from 4-6 ka ago simultaneously with a remarkable decrease of sea ice cover.

Seawater carbonate chemistry and sperm swimming speed, fertilization success of the Australasian sea urchin Heliocidaris erythrogramma in lab experiment

Background: Climate change will lead to intense selection on many organisms, particularly during susceptible early life stages. To date, most studies on the likely biotic effects of climate change have focused on the mean responses of pooled groups of animals. Consequently, the extent to which inter-individual variation mediates different selection responses has not been tested. Investigating this variation is important, since some individuals may be preadapted to future climate scenarios. Methodology/Principal Findings: We examined the effect of CO2-induced pH changes ("ocean acidification") in sperm swimming behaviour on the fertilization success of the Australasian sea urchin Heliocidaris erythrogramma, focusing on the responses of separate individuals and pairs. Acidification significantly decreased the proportion of motile sperm but had no effect on sperm swimming speed. Subsequent fertilization experiments showed strong inter-individual variation in responses to ocean acidification, ranging from a 44% decrease to a 14% increase in fertilization success. This was partly explained by the significant relationship between decreases in percent sperm motility and fertilization success at delta pH = 0.3, but not at delta pH = 0.5. Conclusions and Significance: The effects of ocean acidification on reproductive success varied markedly between individuals. Our results suggest that some individuals will exhibit enhanced fertilization success in acidified oceans, supporting the concept of 'winners' and 'losers' of climate change at an individual level. If these differences are heritable it is likely that ocean acidification will lead to selection against susceptible phenotypes as well as to rapid fixation of alleles that allow reproduction under more acidic conditions. This selection may ameliorate the biotic effects of climate change if taxa have sufficient extant genetic variation upon which selection can act.

Characteristics of samples obtained during Pokhodsk 2012-2013 campaigns in the joint Russian-German POLYGON Project

Polygonal tundra, thermokarst basins and pingos are common and characteristic periglacial features of arctic lowlands underlain by permafrost in Northeast Siberia. Modern polygonal mires are in the focus of biogeochemical, biological, pedological, and cryolithological research with special attention to their carbon stocks and greenhouse-gas fluxes, their biodiversity and their dynamics and functioning under past, present and future climate scenarios. Within the frame of the joint German-Russian DFG-RFBR project Polygons in tundra wetlands: state and dynamics under climate variability in Polar Regions (POLYGON) field studies of recent and of late Quaternary environmental dynamics were carried out in the Indigirka lowland and in the Kolyma River Delta in summer 2012 and summer 2013. Using a multidisciplinary approach, several types of polygons and thermokarst lakes were studied in different landscapes units in the Kolyma Delta in 2012 around the small fishing settlement Pokhodsk. The floral and faunal associations of polygonal tundra were described during the fieldwork. Ecological, hydrological, meteorological, limnological, pedological and cryological features were studied in order to evaluate modern and past environmental conditions and their essential controlling parameters. The ecological monitoring and collection program of polygonal ponds were undertaken as in 2011 in the Indigirka lowland by a former POLYGON expedition (Schirrmeister et al. [eds.] 2012). Exposures, pits and drill cores in the Kolyma Delta were studied to understand the cryolithological structures of frozen ground and to collect samples for detailed paleoenvironmental research of the late Quaternary past. Dendrochronological and ecological studies were carried out in the tree line zone south of the Kolyma Delta. Based on previous work in the Indigirka lowland in 2011 (Schirrmeister et al. [eds.] 2012), the environmental monitoring around the Kytalyk research station was continued until the end of August 2012. In addition, a classical exposure of the late Pleistocene permafrost at the Achchaygy Allaikha River near Chokurdakh was studied. The ecological studies near Pokhodsk were continued in 2013 (chapter 13). Other fieldwork took place at the Pokhodsk-Yedoma-Island in the northwestern part of the Kolyma Delta.

Varve sediments of the Lake Meerfelder Maar

Lake Meerfelder Maar (Germany) provides a varved record from the Last Glacial/Interglacial transition back to ca 1500 years BP. This study shows results for the Holocene sequence from new cores collected in 2009 based on varve counting, microfacies and micro-XRF analyses. The main goal of combining those analyses is to provide a new approach for interpreting long-term palaeolimnological proxy data and testing the climate-proxy stationarity throughout the current interglacial period. Varve counting provides a new independent Holocene chronology (MFM2012) with an estimated counting error of 1-0.5% and supported by 14C dating. Varve structure and thickness and geochemical composition of the varves give information about the main environmental processes that affect the lake and its catchment as well as the possible climate variability behind. Varves are couplets of i) a spring/summer laminae composed of monospecific diatom blooms and ii) an autumn/winter sub-layer made of minerogenic material and re-worked sediments. Thickness of the varves and sub-layers reflect lake variability and allow seasons to be distinguished as well as seasonal proxies. Changes in the winter minerogenic influx into the lake are reflected by Ti intensities and the Si/Ti ratio as a indicator for diatom concentration, which can be used as a proxy for water circulation during the early spring. Long-term variability of geochemical composition shows a reduction of the detrital material input (Ti) at 5,000 varve yrs BP and a visible sensitivity to water mixing (Si/Ti) during the Late Holocene. Variations of Ti intensities during the early and mid-Holocene do not show a clear relationship with climate. In contrast, higher values of the Si/Ti ratio together with thicker varves have been interpreted as wind-stress phases, which coincide with centennial variability of European cold/wet episodes during the Late Holocene. Our findings show that a long-term change in the lake and/or variability of the climate system can influence proxy sensitivity of a lacustrine record.

Mass balances of different sectors in Antarctica in 1996, 2000 and 2006

Large uncertainties remain in the current and future contribution to sea level rise from Antarctica. Climate warming may increase snowfall in the continent's interior, but enhance glacier discharge at the coast where warmer air and ocean temperatures erode the buttressing ice shelves. Here, we use satellite interferometric synthetic-aperture radar observations from 1992 to 2006 covering 85% of Antarctica's coastline to estimate the total mass flux into the ocean. We compare the mass fluxes from large drainage basin units with interior snow accumulation calculated from a regional atmospheric climate model for 1980 to 2004. In East Antarctica, small glacier losses in Wilkes Land and glacier gains at the mouths of the Filchner and Ross ice shelves combine to a near-zero loss of 4 ± 61 Gt/yr. In West Antarctica, widespread losses along the Bellingshausen and Amundsen seas increased the ice sheet loss by 59% in 10 years to reach 132 ± 60 Gt/yr in 2006. In the Peninsula, losses increased by 140% to reach 60 ± 46 Gt/yr in 2006. Losses are concentrated along narrow channels occupied by outlet glaciers and are caused by ongoing and past glacier acceleration. Changes in glacier flow therefore have a significant, if not dominant impact on ice sheet mass balance.

Map of North African dust emission

Changes in the emission, transport and deposition of aeolian dust have profound effects on regional climate, so that characterizing the lifecycle of dust in observations and improving the representation of dust in global climate models is necessary. A fundamental aspect of characterizing the dust cycle is quantifying surface dust fluxes, yet no spatially explicit estimates of this flux exist for the World's major source regions. Here we present a novel technique for creating a map of the annual mean emitted dust flux for North Africa based on retrievals of dust storm frequency from the Meteosat Second Generation Spinning Enhanced Visible and InfraRed Imager (SEVIRI) and the relationship between dust storm frequency and emitted mass flux derived from the output of five models that simulate dust. Our results suggest that 64 (±16)% of all dust emitted from North Africa is from the Bodélé depression, and that 13 (±3)% of the North African dust flux is from a depression lying in the lee of the Aïr and Hoggar Mountains, making this area the second most important region of emission within North Africa.

(Table 1) Age determination of sediment cores CH07-98-22 and KNR140-2-59

Western subtropical North Atlantic oceanic and atmospheric circulations connect tropical and subpolar climates. Variations in these circulations can generate regional climate anomalies that are not reflected in Northern Hemisphere averages. Assessing the significance of anthropogenic climate change at regional scales requires proxy records that allow recent trends to be interpreted in the context of long-term regional variability. We present reconstructions of Gulf Stream sea surface temperature (SST) and hydrographic variability during the past two millennia based on the magnesium/calcium ratio and oxygen isotopic composition of planktic foraminifera preserved in two western subtropical North Atlantic sediment cores. Reconstructed SST suggests low-frequency variability of ~1°C during an interval that includes the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA). A warm interval near 1250 A.D. is distinct from regional and hemispheric temperature, possibly reflecting regional variations in ocean-atmosphere heat flux associated with changes in atmospheric circulation (e.g., the North Atlantic Oscillation) or the Atlantic Meridional Overturning Circulation. Seawater d18O, which is marked by a fresher MCA and a more saline LIA, covaries with meridional migrations of the Atlantic Intertropical Convergence Zone. The northward advection of tropical salinity anomalies by mean surface currents provides a plausible mechanism linking Carolina Slope and tropical Atlantic hydrology.

Dinoflagellate cysts counts of sediment core MD95-2042

Dinoflagellate cysts were analysed from IMAGES core MD952042 (37°48?N; 10°01?W) retrieved from the Tagus Abyssal Plain. Previous results of stable isotope and magnetic susceptibility measurements as well as of planktonic foraminiferal temperature reconstruction from this core, suggest the occurrence of "Heinrich-like events" (i.e. large ice-sheet decay) during Marine Isotopic Stage 5 (MIS 5). Dinoflagellate assemblages of this time period have revealed six dinocyst events that are characterised by peaks in Bitectatodinium tepikiense percentages. These events occur synchronously with "Heinrich-like events" previously identified. They are coeval with major retreats of the forest on land, indicating, therefore, drastic changes in the regional climate. However, results from the Ice-Rafted Detritus (IRD) analysis of the >150 ?m lithic fraction shows that MIS 5 of MD952042 has only recorded one significant input of iceberg discharge, located at the MIS 6/MIS 5 transition. It seems therefore that it is the only event that could be called a "true Heinrich event".

Bulk sediment and diatom silica carbon isotope composition from Antarctic coastal marine sediments

Organic carbon occluded in diatom silica is assumed to be protected from degradation in the sediment. d13C from diatom carbon (d13C(diatom)) therefore potentially provides a signal of conditions during diatom growth. However, there have been few studies based on d13C(diatom). Numerous variables can influence d13C of organic matter in the marine environment (e.g., salinity, light, nutrient and CO2 availability). Here we compare d13C(diatom) and d13C(TOC) from three sediment records from individual marine inlets (Rauer Group, East Antarctica) to (i) investigate deviations between d13C(diatom) and d13C(TOC), to (ii) identify biological and environmental controls on d13C(diatom) and d13C(TOC), and to (iii) discuss d13C(diatom) as a proxy for environmental and climate reconstructions. The records show individual d13C(diatom) and d13C(TOC) characteristics, which indicates that d13C is not primarily controlled by regional climate or atmospheric CO2 concentration. Since the inlets vary in water depths offsets in d13C are probably related to differences in water column stratification and mixing, which influences redistribution of nutrients and carbon within each inlet. In our dataset changes in d13C(diatom) and d13C(TOC) could not unequivocally be ascribed to changes in diatom species composition, either because the variation in d13C(diatom) between the observed species is too small or because other environmental controls are more dominant. Records from the Southern Ocean show depleted d13C(diatom) values (1-4 per mil) during glacial times compared to the Holocene. Although climate variability throughout the Holocene is low compared to glacial/interglacial variability, we find variability in d13C(diatom), which is in the same order of magnitude. d13C of organic matter produced in the costal marine environment seems to be much more sensitive to environmental changes than open ocean sites and d13C is of strongly local nature.

(Table 2) Lipid fluxes derived from sediment trap samples

Phytoplankton is a sentinel of marine ecosystem change. Composed by many species with different life-history strategies, it rapidly responds to environment changes. An analysis of the abundance of 54 phytoplankton species in Galicia (NW Spain) between 1989 and 2008 to determine the main components of temporal variability in relation to climate and upwelling showed that most of this variability was stochastic, as seasonality and long term trends contributed to relatively small fractions of the series. In general, trends appeared as non linear, and species clustered in 4 groups according to the trend pattern but there was no defined pattern for diatoms, dinoflagellates or other groups. While, in general, total abundance increased, no clear trend was found for 23 species, 14 species decreased, 4 species increased during the early 1990s, and only 13 species showed a general increase through the series. In contrast, series of local environmental conditions (temperature, stratification, nutrients) and climate-related variables (atmospheric pressure indices, upwelling winds) showed a high fraction of their variability in deterministic seasonality and trends. As a result, each species responded independently to environmental and climate variability, measured by generalized additive models. Most species showed a positive relationship with nutrient concentrations but only a few showed a direct relationship with stratification and upwelling. Climate variables had only measurable effects on some species but no common response emerged. Because its adaptation to frequent disturbances, phytoplankton communities in upwelling ecosystems appear less sensitive to changes in regional climate than other communities characterized by short and well defined productive periods.

Stable oxygen isotope data and geophysical measurements from Red Sea of core M174/Kl11

To settle debate on the timing of sea level fluctuations during marine isotope stage (MIS) 3, we present records of d18O ruber (sea level proxy) and magnetic susceptibility from the same samples within the single sediment archive (i.e., "coregistered") of central Red Sea core GeoTü-KL11. Core-scanning X-ray fluorescence and environmental magnetic data establish the suitability of magnetic susceptibility as a proxy for eolian dust content in Red Sea sediments. The eolian dust data record similar variability as Greenland d18O ice during early to middle MIS 3, in agreement with previous observations that regional Arabian Sea climate fluctuated with a timing similar to that of Greenland climate variations. In contrast, the sea level record fluctuates with a timing similar to that of Antarctic-style climate variations. The coregistered nature of the two records in core KL11 unambiguously reveals a distinct offset in the phase relationship between sea level and eolian dust fluctuations. The results confirm that sea level rises, indicated by shifts in Red Sea d18O ruber to lighter values, occurred during cold episodes in Greenland during early to middle MIS 3. This indicates that the amplitudes of the reconstructed MIS 3 sea level fluctuations would not be reduced by inclusion of regional climate fluctuations in the Red Sea sea level method. Our analysis comprehensively supports our earlier conclusions of large-amplitude sea level variations during MIS 3 with a timing that is strongly similar to Antarctic-style climate variations.

Stable carbon isotope ratios and accumulation rates of organic carbon and nutrients of DSDP Hole 79-545 (Appendix A)

Future warming is predicted to shift the Earth system into a mode with progressive increase and vigour of extreme climate events possibly stimulating other mechanisms that invigorate global warming. This study provides new data and modelling investigating climatic consequences and biogeochemical feedbacks that happened in a warmer world ~112 Myr ago. Our study focuses on the Cretaceous Oceanic Anoxic Event (OAE) 1b and explores how the Earth system responded to a moderate ~25,000 yr lasting climate perturbation that is modelled to be less than 1 °C in global average temperature. Using a new chronological model for OAE 1b we present high-resolution elemental and bulk carbon isotope records from DSDP Site 545 from Mazagan Plateau off NW Africa and combine this information with a coupled atmosphere-land-ocean model. The simulations suggest that a perturbation at the onset of OAE 1b caused almost instantaneous warming of the atmosphere on the order of 0.3 °C followed by a longer (~45,000 yr) period of ~0.8 °C cooling. The marine records from DSDP Site 545 support that these moderate swings in global climate had immediate consequences for African continental supply of mineral matter and nutrients (phosphorous), subsequent oxygen availability, and organic carbon burial in the eastern subtropical Atlantic, however, without turning the ocean anoxic. The match between modelling results and stratigraphic isotopic data support previous studies [summarized in Jenkyns 2003, doi:10.1098/rsta.2003.1240] in that methane emission from marine hydrates, albeit moderate in dimension, may have been the trigger for OAE 1b, though we can not finally rule out alternative mechanisms. Following the hydrate mechanism a total of 1.15 * 10**18 g methane carbon (delta13C=-60 ?), equivalent to about 10% to the total modern gas hydrate inventory, generated the delta13Ccarb profile recorded in the section. Modelling suggests a combination of moderate-scale methane pulses supplemented by continuous methane emission at elevated levels over ~25,000 yr. The proposed mechanism, though difficult to finally confirm in the geological past, is arguably more likely to occur in a warmer world and apparently perturbs global climate and ocean chemistry almost instantaneously. This study shows that, once set-off, this mechanism can maintain Earth's climate in a perturbed mode over geological time leading to pronounced changes in regional climate.

Marine Isotope Stage (MIS) 11 results of model data with Community Climate System Model version 3 including the Dynamic Global Vegetation Model (CCSM3-DGVM) in NetCDF format at global and regional scale

The climate of Marine Isotope Stage (MIS) 11, the interglacial roughly 400,000 years ago, is investigated for four time slices, 416, 410, 400, and 394 ka. The overall picture is that MIS 11 was a relatively warm interglacial in comparison to preindustrial, with Northern Hemisphere (NH) summer temperatures early in MIS 11 (416-410 ka) warmer than preindustrial, though winters were cooler. Later in MIS 11, especially around 400 ka, conditions were cooler in the NH summer, mainly in the high latitudes. Climate changes simulated by the models were mainly driven by insolation changes, with the exception of two local feedbacks that amplify climate changes. Here, the NH high latitudes, where reductions in sea ice cover lead to a winter warming early in MIS 11, as well as the tropics, where monsoon changes lead to stronger climate variations than one would expect on the basis of latitudinal mean insolation change alone, are especially prominent. The results support a northward expansion of trees at the expense of grasses in the high northern latitudes early during MIS 11, especially in northern Asia and North America.

Ensemble prediction distribution maps of macroalgae for current conditions and four climate change scenarios and high resultion bathymetry for Potter Cove, WAP, Antarctica

Species distribution models (SDM) predict species occurrence based on statistical relationships with environmental conditions. The R-package biomod2 which includes 10 different SDM techniques and 10 different evaluation methods was used in this study. Macroalgae are the main biomass producers in Potter Cove, King George Island (Isla 25 de Mayo), Antarctica, and they are sensitive to climate change factors such as suspended particulate matter (SPM). Macroalgae presence and absence data were used to test SDMs suitability and, simultaneously, to assess the environmental response of macroalgae as well as to model four scenarios of distribution shifts by varying SPM conditions due to climate change. According to the averaged evaluation scores of Relative Operating Characteristics (ROC) and True scale statistics (TSS) by models, those methods based on a multitude of decision trees such as Random Forest and Classification Tree Analysis, reached the highest predictive power followed by generalized boosted models (GBM) and maximum-entropy approaches (Maxent). The final ensemble model used 135 of 200 calculated models (TSS > 0.7) and identified hard substrate and SPM as the most influencing parameters followed by distance to glacier, total organic carbon (TOC), bathymetry and slope. The climate change scenarios show an invasive reaction of the macroalgae in case of less SPM and a retreat of the macroalgae in case of higher assumed SPM values.