Cryptotephra from the Icelandic Veiðivötn 1477 CE eruption in a Greenland ice core: confirming the dating of volcanic events in the 1450s CE and assessing the eruption’s climatic impact Climate of the Past DOI 10.5194/cp-17-565-2021 23 March 2021 Volcanic eruptions are a key source of climatic variability, and reconstructing their past impact can improve our understanding of the operation of the climate system and increase the accuracy of future climate projections. While many chronological mismatches have been resolved, the precise timing and climatic impact of two major sulfate-emitting volcanic eruptions during the 1450s CE, including the largest atmospheric sulfate-loading event in the last 700 years, have not been constrained. Here we explore this issue through a combination of tephrochronological evidence and high-resolution ice-core chemistry measurements from a Greenland ice core, the TUNU2013 record. Read more
The case of a southern European glacier which survived Roman and medieval warm periods but is disappearing under recent warming The Cryosphere DOI 10.5194/tc-15-1157-2021 22 March 2021 We present here the first chronological study of a glacier located in the Central Pyrenees (NE Spain), Monte Perdido Glacier (MPG),carried out by different radiochronological techniques and a comparison with geochemical proxies from neighbouring palaeoclimate records. The chronological model evidences that the glacier persisted during the Roman period and the Medieval Climate Anomaly. The apparent absence of ice in the past∼ 600 years suggests that any ice accumulated during the Little Ice Age has since ablated. Read more
Diverging responses of high-latitude CO2 and CH4 emissions in idealized climate change scenarios The Cryosphere DOI 10.5194/tc-15-1097-2021 19 March 2021 The present study investigates the response of the high-latitude carbon cycle to changes in atmospheric greenhouse gas (GHG) concentrations in idealized climate change scenarios. We find that at a global mean temperature of roughly 1.75 K (±0.5 K) above pre-industrial levels the high-latitude ecosystem turns from a CO2 sink into a source of atmospheric carbon, with the net fluxes into the atmosphere increasing substantially with rising atmospheric GHG concentrations. This is very different from scenario simulations with the standard version of the MPI-ESM, in which the region continues to take up atmospheric CO2 throughout the entire 21st century. Read more
A dynamical systems characterization of atmospheric jet regimes Earth System Dynamics DOI 10.5194/esd-12-233-2021 18 March 2021 Atmospheric jet streams are typically separated into primarily “eddy-driven” (or polar-front) jets and primarily “thermally driven” (or subtropical) jets. Here, we link the current understanding of dynamical jet maintenance mechanisms, mostly arising from conceptual or idealized models, to the phenomena observed in reanalysis data. Read more
Lower oceanic δ13C during the last interglacial period compared to the Holocene Climate of the Past DOI 10.5194/cp-17-507-2021 17 March 2021 The last time in Earth’s history when high latitudes were warmer than during pre-industrial times was the last interglacial period (LIG, 129–116 ka BP). Since the LIG is the most recent and best documented interglacial, it can provide insights into climate processes in a warmer world. However, some key features of the LIG are not well constrained, notably the oceanic circulation and the global carbon cycle. Here, we use a new database of LIG benthic δ13C to investigate these two aspects. Read more
Mapping avalanches with satellites – evaluation of performance andcompleteness The Cryosphere DOI 10.5194/tc-15-983-2021 16 March 2021 The spatial distribution and size of avalanches are essential parameters for avalanche warning, avalanche documentation, mitigation measure design and hazard zonation. Despite its importance, this information is incomplete today and only available for limited areas and limited time periods. Read more
A-Train estimates of the sensitivity of the cloud-to-rainwater ratio to cloud size, relative humidity, and aerosols Atmospheric Chemistry and Physics DOI 10.5194/acp-21-2765-2021 15 March 2021 Precipitation efficiency has been found to play an important role in constraining the sensitivity of the climate through its role in controlling cloud cover, yet its controls are not fully understood. Here we use CloudSat observations to identify individual contiguous shallow cumulus cloud objects and compute the ratio of cloud water path to rainwater (WRR) path as a proxy for warm-rain efficiency. Read more
Development of a MetUM (v 11.1) and NEMO (v 3.6) coupled operational forecastmodel for the Maritime Continent – Part 1: Evaluation of ocean forecasts Geoscientific Model Development DOI 10.5194/gmd-14-1081-2021 12 March 2021 This article describes the development and ocean forecast evaluation of an atmosphere–ocean coupled prediction system for the Maritime Continent (MC) domain, which includes the eastern Indian and western Pacific oceans. Overall, the model forecast deviation of SST, SSH, and subsurface temperature and salinity fields relative to observation is within acceptable error limits of operational forecast models. Read more
Long-term global ground heat flux and continental heat storage from geothermal data Climate of the Past DOI 10.5194/cp-17-451-2021 11 March 2021 Here, we provide new global estimates of changes in ground surface temperature, ground surface heat flux, and continental heat storage derived from geothermal data using an expanded database and new techniques. Read more
Radar-based assessment of hail frequency in Europe Natural Hazards and Earth System Sciences DOI 10.5194/nhess-21-683-2021 10 March 2021 In this study we present a unique 10 year climatology of severe convective storm tracks for a large European area covering Germany, France, Belgium and Luxembourg. For the period 2005–2014, a high-resolution hail potential composite of 1×1 km2 is produced from two-dimensional radar reflectivity and lightning data. Read more
