Alpine lacustrine varved record reveals summer temperature as main control of glacier fluctuations over the past 2250 years

Glacier fluctuations are a key indicator of changing climate. Their reconstruction beyond historical times unravels glacier variability and its forcing factors on long time scales, which can considerably improve our understanding of the climate–glacier relationship. Here, we present a 2250-year-long reconstruction of particle-mass accumulation rates recorded in the lacustrine sediments of Lake Trüebsee (Central Swiss Alps) that are directly related to glacier extent, thus reflecting a continuous record of fluctuations of the upstream-located Titlis Glacier. Mass accumulation rate values show strong centennial to multi-centennial fluctuations and reveal 12 well-pronounced periods of enhanced values corresponding to times of maximum extent of the neighboring Lower Grindelwald Glacier. This result supports previous studies of proglacial lake sediments that documented high mass accumulation rate values during glacier advances. The strong variability in the Lake Trüebsee mass accumulation rate record thus represents a highly sensitive paleoclimatic archive, which mirrors rapid and pronounced feedbacks of Titlis Glacier to climatic changes over the past 2250years. The comparison of our data with independent paleo-temperature reconstructions from tree rings suggests that variations in mean summer temperature were the primary driving factor of fluctuations of Titlis Glacier. Also, advances of Titlis Glacier occurred during the grand solar minima (Dalton, Maunder, Spörer, Wolf) of the last millennium. This relation of glacier extent with summer temperature reveals strong evidence that the mass balance of this Alpine glacier is primarily controlled by the intensity of glacier melting during summer.

Ice core-based isotopic constraints on past carbon cycle changes

High-precision ice core data on both atmospheric CO2 concentrations and their carbon isotopic composition (δ13Catm) provide improved constraints on the marine and terrestrial processes responsible for carbon cycle changes during the last two interglacials and the preceding glacial/interglacial transitions.

An Unscathed Past in the Face of Death: Mortality Salience Reduces Individuals’ Regrets

Folk wisdom and popular literature hold that, in the face of death, individuals tend to regret things in their lives that they have done or failed to do. Terror Management Theory (TMT), in contrast, allows for the prediction that individuals who are confronted with death try to minimize the experience of regret in order to retain a positive self-esteem. Three experiments put these competing perspectives to test. Drawing on TMT, we hypothesized and found that participants primed with their own death regret fewer things than control-group participants. This pattern of results cannot be attributed to differing types of regrets (Study 1). Furthermore, we provide evidence suggesting that the effect is not purely a product of cognitive mechanisms such as differing levels of construal (Study 2), cognitive contrast, or deficits (Study 3). Rather, the reported results are best explained in terms of a motivational coping mechanism: When death is salient, individuals strive to bolster as well as protect their self-esteem and accordingly try to minimize the experience of regret. The results add to our conceptual understanding of regret and TMT, and suggest that a multitude of lifestyle guidebooks need updating.

Widows may have fewer social and financial problems than in the past (Interview von Shereen Lehman mit Prof. Pasqualina Perrig-Chiello zu finanziellen und sozialen Problemen von Verwitweten)

(Reuters Health) – - A new Swiss study says that widows and widowers still mourn their spouses as much as ever, but compared to 35 years ago, everyday life is easier, especially for women. Widows, at least in Switzerland, have fewer financial troubles and more social connections than their counterparts in 1979, but widowers still complain of loneliness, researchers found.

Preconceptional use of folic acid in the region of the Kantonsspital Münsterlingen/Thurgau: has it changed over the past 10 years?

BACKGROUND  Numerous studies have shown that the preconceptional use of folic acid prevents neural tube defects. We created a study to find out whether the preconceptional use of folic acid has improved in the past 10 years, in the area of Münsterlingen, Switzerland. MATERIAL AND METHODS  We interviewed 2 groups of patients who delivered at our Institution, namely between 2000 and 2002 (period A) involving 287 women and from 2009 to 2010 (period B) involving 305 pregnant women. We asked them whether they used folic acid by means of a standardised questionnaire. RESULTS  In period B significantly more women have taken folic acid preconceptionally (period A: 27.5% vs. period B: 40.7%; p=0.001). A significant increase in folic acid intake was seen in the German speaking group from period A to B (30.3% vs. 52.7%; p=0.0005), while this was not the case in the non-German speaking group (21.4% in both periods). More multiparaé women were taking folic acid compared to nulliparae. A significant increase from period A to B was noted only in the German speaking group. Unexpectedly, in nulliparae non-German speaking women, folic acid supplementation decreased from 14% to 6.1%. DISCUSSION  We have found a significant increase in preconceptional folic acid supplementation from 2001 to 2010. The percentage of women taking folic acid is disappointingly low in all groups, particularly in nulliparae women of non-German ethnicity.

Links between atmospheric carbon dioxide, the land carbon reservoir and climate over the past millennium

The stability of terrestrial carbon reservoirs is thought to be closely linked to variations in climate 1, but the magnitude of carbon–climate feedbacks has proved dificult to constrain for both modern 2–4 and millennial 5–13 timescales. Reconstructions of atmospheric CO2 concentrations for the past thousand years have shown fluctuations on multidecadal to centennial timescales 5–7, but the causes of these fluctuations are unclear. Here we report high-resolution carbon isotope measurements of CO2 trapped within the ice of the West Antarctic Ice Sheet Divide ice core for the past 1,000 years. We use a deconvolution approach 14 to show that changes in terrestrial organic carbon stores best explain the observed multidecadal variations in the 13 C of CO2 and in CO2 concentrations from 755 to 1850 CE. If significant long-term carbon emissions came from pre-industrial anthropogenic land-use changes over this interval, the emissions must have been offset by a natural terrestrial sink for 13 C-depleted carbon, such as peatlands. We find that on multidecadal timescales, carbon cycle changes seem to vary with reconstructed regional climate changes. We conclude that climate variability could be an important control of fluctuations in land carbon storage on these timescales.

A chrysophyte-based quantitative reconstruction of winter severity from varved lake sediments in NE Poland during the past millennium and its relationship to natural climate variability

Chrysophyte cysts are recognized as powerful proxies of cold-season temperatures. In this paper we use the relationship between chrysophyte assemblages and the number of days below 4 °C (DB4 °C) in the epilimnion of a lake in northern Poland to develop a transfer function and to reconstruct winter severity in Poland for the last millennium. DB4 °C is a climate variable related to the length of the winter. Multivariate ordination techniques were used to study the distribution of chrysophytes from sediment traps of 37 low-land lakes distributed along a variety of environmental and climatic gradients in northern Poland. Of all the environmental variables measured, stepwise variable selection and individual Redundancy analyses (RDA) identified DB4 °C as the most important variable for chrysophytes, explaining a portion of variance independent of variables related to water chemistry (conductivity, chlorides, K, sulfates), which were also important. A quantitative transfer function was created to estimate DB4 °C from sedimentary assemblages using partial least square regression (PLS). The two-component model (PLS-2) had a coefficient of determination of View the MathML sourceRcross2 = 0.58, with root mean squared error of prediction (RMSEP, based on leave-one-out) of 3.41 days. The resulting transfer function was applied to an annually-varved sediment core from Lake Żabińskie, providing a new sub-decadal quantitative reconstruction of DB4 °C with high chronological accuracy for the period AD 1000–2010. During Medieval Times (AD 1180–1440) winters were generally shorter (warmer) except for a decade with very long and severe winters around AD 1260–1270 (following the AD 1258 volcanic eruption). The 16th and 17th centuries and the beginning of the 19th century experienced very long severe winters. Comparison with other European cold-season reconstructions and atmospheric indices for this region indicates that large parts of the winter variability (reconstructed DB4 °C) is due to the interplay between the oscillations of the zonal flow controlled by the North Atlantic Oscillation (NAO) and the influence of continental anticyclonic systems (Siberian High, East Atlantic/Western Russia pattern). Differences with other European records are attributed to geographic climatological differences between Poland and Western Europe (Low Countries, Alps). Striking correspondence between the combined volcanic and solar forcing and the DB4 °C reconstruction prior to the 20th century suggests that winter climate in Poland responds mostly to natural forced variability (volcanic and solar) and the influence of unforced variability is low.