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Little is known about the strong mediating effect of the ligand sphere and the coordination geometry on the strength and isotopologue selectivity of hydrogen adsorption on the undercoordinated copper(I) site. Here, we explore this effect using gas-phase complexes Cu+(H2O)(H2)n (with n ≤ 3) as model systems. Cu+(H2O) attracts dihydrogen (82 kJ mol−1) more strongly than bare Cu+ (64 kJ mol−1) does. Combining experimental and computational methods, we demonstrate a high isotopologue selectivity in dihydrogen binding to Cu+(H2O), which results from a large difference in the adsorption zero-point energies (2.8 kJ mol−1 between D2 and H2, including an anharmonic contribution of 0.4 kJ mol−1). We investigate its origins and the bond strengthening between Cu+ and H2 upon addition of a single H2O ligand. We discuss the role of the environment and the coordination geometry of the adsorption site in achieving a high selectivity and the ramifications for identifying and designing future materials for adsorptive dihydrogen isotopologue separation.

The dataset consists of Infrared photodissociation (IRPD) spectra of Cu+(H2O)(H2)n (with n ≤ 3) and its isotopologue measured on the Leipzig 5 K ring-electrode ion-trap triple mass spectrometer. Besides, it contains the Energy Decomposition Analysis (EDA), the benchmark results, the harmonic and the anharmonic VPT2 frequencies results as well as the script used to get the predicted separation factor for the adsorbed dihydrogen isotopologue.

During marine oxygen isotope stage (MIS) 2, the Swiss Plateau temporarily hosted large piedmont lobe glaciers that retreated after their maximum advance back to the fringe of the Alps. The presence of moraines in this region indicates that overall glacier recession was punctuated by repeated phases of ice-marginal stability and re-advances. The timing of these events in the region formerly covered by the eastern lobe of the Rhône (or Valais) glacier has been controversial but remains poorly constrained due to the lack of chronological data. To fill this gap, 10Be cosmic-ray exposure (CRE) dating was applied to erratic boulders inside the assumed MIS 2 maximum extent of this piedmont lobe. Erratic boulders close to the suspected MIS 2 maximum extent gave unrealistically young CRE ages. Erratic boulders at a presumably younger ice-marginal position (Brästenberg position) yielded an average age of ~19 ka, consistent with recalibrated basal radiocarbon ages from lakes and recomputed radiocarbon ages from large Late Pleistocene mammals buried in glacio-fluvial deposits. However, several erratic boulders beyond the Brästenberg position gave internally consistent, but stratigraphically too young ages of ~17 ka. We cannot rule out that glacier recession from the Brästenberg position began no later than ~17 ka. CRE dating of a moraine of a presumably younger ice-marginal position (Solothurn position) gave unrealistically old ages and an incredibly young age (86 ka, 41 ka, and 4 ka). 14C CRE dating should be applied to check whether the boulders associated with the Solothurn and Brästenberg positions were previously exposed to cosmicradiation. Nevertheless, despite outlying ages, the presented chronological data contribute to an overall consistent and increasingly refined chronology of the last deglaciation of the Swiss Plateau when compared with 59 previously published CRE ages.

Our paper about the impacts of the Laschamps Geomagnetic Excursion 42,000 years ago has provoked considerable scientific and public interest, particularly in the so-called Adams Event associated with the initial transition of the magnetic poles. Although we welcome the opportunity to discuss our new ideas, Hawks’ assertions of misrepresentation are especially disappointing given his limited examination of the material.

Our study on the exact timing, and potential climatic, environmental and evolutionary consequences of the Laschamps Geomagnetic Excursion has generated a novel hypothesis that geomagnetism represents an unrecognised driver in environmental and evolutionary change (1). It is important that this is tested with new data, and encouragingly, none of the studies presented by Picin et al. (2) undermine our model.

Geological archives record multiple reversals of Earth’s magnetic poles but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the Laschamps Excursion (41–42ka). Here we use ancient New Zealand kauri trees (Agathis australis) to develop a detailed record of atmospheric radiocarbon levels across the Laschamps. We precisely characterize the geomagnetic reversal and perform global chemistry-climate modelling and detailed radiocarbon-dating of paleoenvironmental records to investigate impacts. We find that geomagnetic field minima ~42ka in combination with Grand Solar Minima caused substantial changes in atmospheric ozone concentration and circulation, driving synchronous global climate shifts that caused major environmental changes, extinction events, and transformations in the archaeological record.

Mountain glaciers are very sensitive to (past) climate changes. Paleoglaciation of the Tibetan Plateau and the Himalaya received plenty of attention for the reconstruction of past climate and environmental conditions, whereas few studies have been conducted so far in the adjacent Altai and Sayan Mountains in Siberia, although they promise a complex history. The investigated Sayan Mountains in the Russian Altai indicate extensive glacial activity during the Pleistocene and a shifting of the local Last Glacial Maximum (LGM). Rich glacial residues in terms of moraine ridges and erratic boulders in the region provide excellent opportunities to establish a detailed age chronology using in-situ cosmogenic ¹⁰Be surface exposure dating and derive information about paleoclimatic conditions. We present 28 ¹⁰Be surface exposure ages from the Ergaki Range and Tuva Uplands in the western Sayan Mountains. Distinct lateral moraines document the extents of former glaciation during a last glacial maximum. Several recessional moraines in the Ergaki Range additionally record stand stills or readvances during the last glacial termination. The prominent lateral moraine in the Ergaki Range yields three exposure ages of ~19 ka, indicating a MIS 2 glaciation. The maximum advances correlate with the end of the global LGM. Concluding, glaciers in the Ergaki Range existed continuously during the late Pleistocene only varying in their extent. The well-clustered ages of the Ergaki Range provide a robust deglaciation chronology. The readvances/ stand stills consistently date to ~18 ka (three boulders), ~17.5 ka (two boulders), ~17 ka (three boulders), and ~16 ka (two boulders), with a deglaciation starting after 16 ka. The valley is not elevated enough to record younger, less extensive glaciation, e.g. during the Younger Dryas and the Holocene. Exposure ages from the Tuva Uplands are more difficult to interpret: The lateral moraine documenting the most extensive glaciation yields two exposure ag

In this study, we compare two independent paleoenvironmental proxies for a loess sequence in northern Serbia, in the southern Carpathian Basin: novel n-alkane biomarkers and traditional land snail assemblages. Both are associated with other, more widely used proxy data for loess sections, such as environmental magnetism, grain size, and geochemical indices. Together, these paleoenvironmental proxy records provide evidence for the continued dominance of grasslands during the Late Pleistocene in the Southern Carpathian Basin. It is contrary to other European loess provinces, which are characterized by high diversity of Late Pleistocene environments (ranging from tundra-like to deciduous forest habitats). These findings highlight the southeastern part of Carpathian Basin as an important, but still insufficiently investigated, biogeographical refugium, and biodivarsity preservation zone. The reason for this is a mostly stable paleoclimate for much of the Late Pleistocene.

Geomagnetic excursions, i.e. short periods in time with much weaker geomagnetic fields and substantial changes in the position of the geomagnetic pole, occurred repeatedly in the Earth's history, e.g. the Laschamp event about 41 kyr ago. Although the next such excursion is certain to come, little is known about the timing and possible consequences for the state of the atmosphere and the ecosystems. Here we use the global chemistry climate model SOCOL-MPIOM to simulate the effects of geomagnetic excursions on atmospheric ionization, chemistry and dynamics. Our simulations show significantly increased concentrations of nitrogen oxides (NOx) in the entire stratosphere, especially over Antarctica (+15%), due to enhanced ionization by galactic cosmic rays. Hydrogen oxides (HOx) are also produced in greater amounts (up to +40%) in the tropical and subtropical lower stratosphere, while their destruction by reactions with enhanced NOx prevails over the poles and in high altitudes (by -5%). Stratospheric ozone concentrations decrease globally above 20 km by 1-2% and at the northern hemispheric tropopause by up to 5% owing to the accelerated NOx-induced destruction. A 5% increase is found in the southern lower stratosphere and troposphere. In response to these changes in ozone and the concomitant changes in atmospheric heating rates, the Arctic vortex intensifies in boreal winter, while the Antarctic vortex weakens in austral winter and spring. Surface wind anomalies show significant intensification of the southern westerlies at their poleward edge during austral winter and a pronounced northward shift in spring. Major impacts on the global climate seem unlikely.

During the Last Glacial Maximum (19-30 ka) extensive ice caps and large outlet glaciers covered the alpine valleys and forelands in the Swiss Alps (e.g. Ivy-Ochs, 2015). The former Rhône Glacier expanded onto the Swiss Plateau, was deflected and bounded by the Jura Mountain Range, and reached 'Wangen an der Aare' (Niederbipp Stade). Various studies have investigated respective glacial deposits, but the maximum extent of glaciation and the exact timing of deglaciation is still under discussion (Wüthrich et al. 2018, 2017). We investigated 18 additional samples from 15 erratic boulders from the region by cosmogenic 10Be surface exposure dating to constrain the timing of deglaciation. The 10Be exposure ages from seven different locations vary mainly between 17-30 ka. Five outliers show three younger ages (4 ka, 7 ka, and 10 ka, respectively) and two older ages (42 ka and 87 ka, respectively) than expected, proofing again that geomorphological processes and inheritance can affect the exposure ages of the erratic boulders. Ivy-Ochs, S. (2015). Glacier variations in the European Alps at the end of the Last Glaciation. Cuadernos de Investigación Geográfica 41, 295–315. Wüthrich, L., Brändli, C., Braucher, R., Veit, H., Haghipour, N., Terrizzano, C., Christl, M., Gnägi, C., Zech, R. (2018): 10Be depth profiles in glacial sediments on the Swiss Plateau: deposition age, denudation and (pseudo-)inheritance, E&G Quaternary Sci. J., 66, 57–68. Wüthrich, L., Garcia Morabito, E., Zech, J., Gnägi, C., Trauerstein, M., Veit, H., Merchel, S., Scharf, A., Rugel, G., Christl, M., Zech, R. (under review, 2017): 10Be surface exposure dating of the last deglaciation in the Aare Valley, Switzerland. Swiss Journal of Geosciences.

The combined Rhone and Aare Glaciers presumably reached their last glacial maximum (LGM) extent on the Swiss Plateau prior to 24 ka. Two well-preserved, less extensive moraine stades, the Gurten and Bern Stade, document the last deglaciation of the Aare Valley, yet age constraints are very scarce. In order to establish a more robust chronology for the glacial/deglacial history of the Aare Valley, we applied 10Be surface exposure dating on eleven boulders from the Gurten and Bern Stade. Several exposure ages are of Holocene age and likely document post-depositional processes, including boulder toppling and quarrying. The remaining exposure ages, however yield oldest ages of 20.7 ± 2.2 ka for the Gurten Stade and 19.0 ± 2.0 ka for the Bern Stade. Our results are in good agreement with published chronologies from other sites in the Alps.

The arid Central Andes are a key site to study changes in intensity and movement of the three main atmospheric circulation systems over South America: the South American Summer Monsoon (SASM), the Westerlies and the El Niño Southern Oscillation (ENSO). In this semi-arid to arid region glaciers are particularly sensitive to precipitation changes and thus the timing of past glaciation is strongly linked to changes in moisture supply. Surface exposure ages from study sites between 41° and 22°S suggest that glaciers advanced: i) prior to the global Last Glacial Maximum (gLGM) at ~40 ka in the mid (26°- 30°S) and southern Central Andes (35°-41°S), ii) in phase with the gLGM in the northern and southern Central Andes and iii) during the late glacial in the northern Central Andes. Deglaciation started synchronous with the global rise in atmospheric CO2 concentration and increasing temperature starting at ~18 ka. The pre-gLGM glacial advances likely document enhanced precipitation related to the Southern Westerlies, which shifted further to the North at that time than previosuly assumed. During the gLGM glacial advances were favored by decreased temperatures in combination with increased humidity due to a southward shifted Intertropical Convergence Zone (ITCZ) and SASM. During the late-glacial a substantial increase in moisture can be explained by enhanced upper tropospheric easterlies as response to an intensified SASM and sustained La Niña-like conditions over the eastern equatorial Pacific that lead to glacial advances in the northern Central Andes and the lake level highstand Tauca (18-14 ka) on the Altiplano. In the southernmost Central Andes at 39º-41°S, further north at 31°S and in the northernmost Central Andes at 22°S glacial remnants even point to precipitation driven glaciations older than ~115 ka and 260 ka., Los Andes Centrales áridos constituyen un lugar clave para el estudio de los cambios en la dinámica e intensidad de los tres sistemas principales de circulación atmosférica presentes en Sudamérica: los vientos monzones, los vientos del oeste y el fenómeno El Niño-Oscilación del Sur. Debido a la aridez, los glaciares de esta región son particularmente sensibles a variaciones en las precipitaciones, por lo que la cronología de las glaciaciones está fuertemente controlada por el suministro de humedad. Las edades de exposición obtenidas en morrenas en un transecto comprendido entre 41° y 22° S de latitud indican avances glaciares que se sucedieron con anterioridad (unos 40 mil años BP) al Último Máximo Glacial global (gLGM) para los Andes Centrales del sur (35°-41°S) y medios (26°-30°S). Avances en fase con el gLGM aparecen documentados en los Andes Centrales del sur y del norte, y durante el período Tardiglaciar en los Andes Centrales del norte. La deglaciación fue sincrónica a lo largo de todo el transecto y coincide con el incremento de los niveles de CO2 globales. Los avances previos al gLGM documentan un posible aumento en las precipitaciones asociado a una migración hacia el norte de los vientos del oeste, de mayor magnitud a la asumida hasta el momento. Asimismo, durante el gLGM los avances glaciares fueron favorecidos por una disminución de la temperatura que coincide con un aumento de la humedad debido a la migración hacia el sur de la Zona de Convergencia Intertropical y de los vientos monzones. La mayor disponibilidad de humedad durante el período Tardiglaciar podría explicarse por un aumento de los vientos del este en las capas altas de la tropósfera, como respuesta a una intensificación de los vientos monzones y condiciones tipo La Niña sostenidas en el tiempo sobre la zona oriental del Pacífico ecuatorial. Estas condiciones condujeron a las glaciaciones registradas en los Andes Centrales del norte en concordancia con estadios de nivel alto en los lagos del

Substantial quantities of organic carbon (OC) are stored in the thick, ice-rich, and organic-rich sediments called yedoma deposits, distributed in eastern Siberia and Alaska today. Quantifying yedoma carbon stocks during the glacial period is important for understanding how much carbon could have been decomposed during the last deglaciation. Yet processes that yield the formation of thick frozen OC in yedoma deposits are missing in global carbon cycle models. Here we incorporate sedimentation parameterizations into the Organizing Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE-MICT) land surface model, which leads to reasonable results in OC vertical distribution and regional budgets, compared with site-specific observations and inventories for today's nondegraded yedoma region. Simulated total soil OC stock for the northern permafrost region during the Last Glacial Maximum (LGM) is 1536–1592 Pg C, of which 390–446 Pg C is within today's yedoma region. This result is an underestimation since we did not account for the potentially much larger yedoma area during the LGM than the present day.

Während der Eiszeiten sind wiederholt die Gletscher aus den Alpen bis weit in das Schweizer Mittelland vorgestossen. Genaues Ausmass und Zeitpunkt sind selbst für die letzte Vergletscherung umstritten. Publizierte 10Be Expositionsalter von Findlingen auf dem Niederbippstadium des Rhone-Aare-Gletschers dokumentieren scheinbar den maximalen Vorstoss während der letzten Vergletscherung vor ca. 24 ka. Allerdings ist die Bodenentwicklung auf dem Niederbippstadium deutlich fortgeschrittener (Entkalkungstiefen von 3 bis 4 m) als die Bodenentwicklung auf dem Bern- und Gurtenstadium mit vermuteten Altern von ca. 18 – 20 ka (Entkalkungstiefen dort <1,5 m). Wir haben mehrere Findlinge auf dem Bern- und Gurtenstadium beprobt und ihre 10Be Expositionsalter bestimmt. Die ältesten drei von sechs Findlingen vom Bernstadium liefern Expositionsalter um ca. 18 ka und dokumentieren den Gletscherstand des Aaregletschers kurz vor dem endgültigen und raschen Zerfall der Vorlandgletscher am Ende der letzten Eiszeit. Zwei von fünf Findlingen vom Gurtenstadium haben Expositionsalter um 20 ka und zeigen, dass der Aaregletscher zu diesem Zeitpunkt noch sehr viel grösser war. Auf beiden Stadien gibt es deutlich “zu junge” Expositionsalter, die höchstwahrscheinlich mit Erosion, geomorphologischer Instabilität, und menschlicher Aktivität erklärt werden müssen. Es kann bisher nicht vollständig ausgeschlossen werden, dass die Expositionsalter des Niederbippstadium ebenfalls “zu jung” sind. Dann liesse sich die Bodenentwicklung auf dem Niederbippstadium problemslos erklären. Dokumentieren die Expositionsalter tatsächlich den maximalen Gletschervorstoss vor 24 ka, muss davon ausgegangen werden, dass die mächtige Entkalkung und Tonverlagerung dort in wenigen tausend Jahren, und vor allem unter glazialen Bedingungen stattgefunden hat. Weitere Findlinge sind daher im Moment in Bearbeitung, um den Zeitpunkt der maximalen, letztglazialen Vergletscherung zu klären.

Mountain glaciers are sensitive indicators for climate change, mainly summer temperature and precipitation. Glacial chronologies from Central Asia have therefore been suggested to provide valuable information about past changes in temperature, as well as precipitation and related changes in atmospheric circulation. However, available age control is still sparse. Here we present a glacial chronology for the Gissar Range, Tajikistan, based on thirteen 10Be surface exposure ages. Prominent moraine lobes document glacial advances in phase with the global last glacial maximum (LGM) during marine isotope stage (MIS) 2. Rapid and significant deglaciation occurred already at ~20 ka as inferred from recessional stages. An older and slightly more extensive glaciation could be dated to MIS 4, whereas the timing of the most extensive glaciation remains speculative. In contrast to the glacial chronologies from the nearby, more arid Pamir and Tien Shan, where MIS 3 and MIS 5 moraines likely document past periods with increased precipitation, glaciers in the more humid Gissar Range predominantly recorded past changes in temperature and summer insolation.

Glacial chronologies from the Pamir may not only provide insights into past changes in temperature, but also into past changes in precipitation related to the northern-hemispheric westerlies and the monsoonal circulation. We present 18 new exposure ages from the Bogchigir Valleys that complement and refine our previous studies in these valleys. The most extensive dated glaciation in the area occurred ~. 100. ka, during Marine Oxygen Isotope Stage (MIS) 5, and indicates increased precipitation likely from both the westerlies and the monsoonal circulation. A subsequent glacier advance, which deposited characteristic 'chukur' moraine lobes, occurred at ~. 80-75. ka. Circumstantial evidence points to glacial advances at ~. 65 and 40. ka, the latter likely also documenting increased monsoonal moisture supply during MIS 3. Less extensive glacial advances occurred during MIS 2 at ~. 28 and 24. ka and reflect the aridization trend during the course of the last glacial cycle. Deglaciation started ~. 21. ka, interrupted by minor stillstands or readvances at ~. 16 and 12. ka. Local calibration sites and glacier-climate modeling would be very helpful to reduce the systematic methodological uncertainties (still at least 10%) and to draw more detailed paleoclimatic conclusions.

The Pamir Mountains have been extensively glaciated several times in the past. As glaciers are mainly sensitive to variations in temperature and precipitation, they reflect changes in large-scale atmospheric circulation patterns. The Pamir Mountains are situated in a climatic transition zone between mid-latitude westerlies, the Indian summer monsoon and the Siberian High. Today main moisture to the Pamir comes with SW-cyclones along the westerly jetstream. Up to now the impact of the Indian monsoon on former glaciations of the Pamir Mountains has not yet been adequately examined. Even chronological information about former glaciations in the Pamir are still sparse. The objective of our study is: To upgrade the present glacial chronology by 10Be surface exposure dating of erratic boulders on top of moraines along a moisture gradient from the north-western to the southern Pamir Mountain ranges. We present preliminary 10Be ages from moraine successions of three study sites (Iskenderkul area, Muksu-Kyslsu area, Alichur area). Our first results from the southern Pamir (Alichur area) corroborate and refine previously published findings: Extensive glaciation occurred during MIS 4 and during MIS 2 coinciding with lower insolation intensity. Because during climatic cold phases the Indian Monsoon was weakened we assume that these glacier advances were mainly triggered by westerly moisture supply. However, our data indicate that glaciers in the southern Pamir also advanced during ~58 to ~45 ka as also observed in monsoonal influenced Karakoram and eastern Hindu Kush regions. Our surface exposure ages point to rapid deglaciation after ~18 ka. So far there is no evidence for glacier advances during the Holocene. Analyses of further samples, from both the Muksu-Kyzlsu area and the Iskenderkul area are in progress.

The reconstruction of past climate changes in the Pamir Mountains has high potential for identifying the dynamics of circulation systems in Asia and for understanding global environmental changes during the Late Quaternary. The Pamir Mountains are situated in a climatic transition zone between mid-latitude westerlies, the Indian summer monsoon and the Siberian High. Today main moisture to the Pamir comes with SW- cyclones along the westerly jetstream whereas the influence of the Indian monsoon typically ends south of the NW-Himalaya. Up to now the impact of the Indian monsoon on former glaciations of the Pamir Mountains has not yet been adequately examined. Even chronological information about former glaciations in the Pamir is still sparse. The objectives of our study are: To upgrade the present glacial chronology by dating glacial successions along a moisture gradient from the north-western to the southern Pamir Mountain ranges. We present preliminary 10Be ages from moraine successions of three study sites (Iskenderkul area, Muksu-Kyzlsu area, Alichur area). Our first results from the southern Pamir (Alichur area) corroborate and refine previously published findings: Extensive glaciation occurred during MIS 4 and during MIS 2. However our data indicate that glaciers in the southern Pamir also advanced during ~50 to 40 ka. Rapid deglaciation occurred after ~18 ka. So far there is no evidence for glacier advances during the Holocene. Overall, we conclude that the glacial chronology of the Pamir seems to be mainly controlled by temperature, with maxima during ~70 to 60 ka, ~50 to 40 ka and ~20 ka. Because during climatic cold phases the Indian Monsoon was weakened, we assume that glacier advances in the Pamir Mountains during the Last Glacial cycle were mainly triggered by westerly moisture supply. Analyses of further samples, from both the Muksu-Kyzlsu area and the Iskenderkul area are in progress.