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
In situ cosmogenic 10Be–14C–26Al measurements from recently deglaciated bedrock as a new tool to decipher changes in Greenland Ice Sheet size Climate of the Past DOI 10.5194/cp-17-419-2021 9 March 2021 Sometime during the middle to late Holocene (8.2 ka to ∼ 1850–1900 CE), the Greenland Ice Sheet (GrIS) was smaller than its current configuration. Contemporary retreat of the GrIS from its historical maximum extent in southwestern Greenland is exposing a landscape that holds clues regarding the configuration and timing of past ice-sheet minima. Read more
Reviews and syntheses: Impacts of plant-silica–herbivore interactions onterrestrial biogeochemical cycling Biogeosciences DOI 10.5194/bg-18-1259-2021 8 March 2021 Researchers have known for decades that silicon plays a major role in biogeochemical and plant–soil processes in terrestrial systems. We review and synthesize 119 available studies directly investigating silicon and herbivory to summarize key trends and highlight research gaps and opportunities. Read more
Response of tidal flow regime and sediment transport in North Malé Atoll, Maldives, to coastal modification and sea level rise Ocean Science DOI 10.5194/os-17-319-2021 5 March 2021 Changes to coastlines and bathymetry alter tidal dynamics and associated sediment transport processes, impacting upon a number of threats facing coastal regions, including flood risk and erosion. Especially vulnerable are coral atolls such as those that make up the Maldives archipelago, which has undergone significant land reclamation in recent years and decades and is also particularly exposed to sea level rise. Read more
Assessment of a full-field initialized decadal climate prediction system with the CMIP6 version of EC-Earth Earth System Dynamics DOI 10.5194/esd-12-173-2021 4 March 2021 In this paper, we present and evaluate the skill of an EC-Earth 3.3 decadal prediction system contributing to the Decadal Climate Prediction Project – Component A (DCPP-A). This prediction system is capable of skilfully simulating past global mean surface temperature variations at interannual and decadal forecast times as well as the local surface temperature in regions such as the tropical Atlantic, the Indian Ocean and most of the continental areas, although most of the skill comes from the representation of the external radiative forcings. Read more
Vapor plumes in a tropical wet forest: spotting the invisible evaporation Hydrology and Earth System Sciences DOI 10.5194/hess-25-619-2021 3 March 2021 Forest evaporation exports a vast amount of water vapor from land ecosystems into the atmosphere. This work describes the formation process of vapor plumes in a tropical wet forest as evidence of evaporation processes happening during rain events. Read more
Low-NO atmospheric oxidation pathways in a polluted megacity Atmospheric Chemistry and Physics DOI 10.5194/acp-21-1613-2021 2 March 2021 The impact of emissions of volatile organic compounds (VOCs) to the atmosphere on the production of secondary pollutants, such as ozone and secondary organic aerosol (SOA), is mediated by the concentration of nitric oxide (NO). Polluted urban atmospheres are typically considered to be high-NO” environments, while remote regions such as rainforests, with minimal anthropogenic influences, are considered to be “low NO”. However, our observations from central Beijing show that this simplistic separation of regimes is flawed. Read more
A limited effect of sub-tropical typhoons on phytoplankton dynamics Biogeosciences DOI 10.5194/bg-18-849-2021 1 March 2021 Typhoons are assumed to stimulate primary ocean production through the upward mixing of nutrients into the ocean surface. This assumption is based largely on observations of increased surface chlorophyll concentrations following the passage of typhoons. This surface chlorophyll enhancement, occasionally detected by satellites, is often undetected due to intense cloud coverage. Read more
Volcanoes in video games: the portrayal of volcanoes incommercial off-the-shelf (COTS) video games and their learning potential Geoscience Communication DOI 10.5194/gc-4-11-2021 26 February 2021 Volcanoes are a very common staple in mainstream video games. Particularly within the action–adventure genres, entire missions or even full storylines can require players to traverse an active volcano. Therefore, players can spend a lot of time immersed within the detailed graphics and unknowingly learn about volcanic traits while playing. Read more
Mass accommodation and gas–particle partitioning in secondary organicaerosols: dependence on diffusivity, volatility, particle-phase reactions,and penetration depth Atmospheric Chemistry and Physics DOI 10.5194/acp-21-1565-2021 25 February 2021 Mass accommodation is an essential process for gas–particle partitioning of organic compounds in secondary organic aerosols (SOA). The mass accommodation coefficient is commonly described as the probability of a gas molecule colliding with the surface to enter the particle phase. It is often applied, however, without specifying if and how deep a molecule has to penetrate beneath the surface to be regarded as being incorporated into the condensed phase (adsorption vs. absorption). Read more
A new view of heat wave dynamics and predictability over the easternMediterranean Earth System Dynamics DOI 10.5194/esd-12-133-2021 24 February 2021 Skillful forecasts of extreme weather events have a major socioeconomic relevance. Here, we compare two complementary approaches to diagnose the predictability of extreme weather: recent developments in dynamical systems theory and numerical ensemble weather forecasts. Read more
An overview of the ORACLES (ObseRvations of Aerosols above CLouds and theirintEractionS) project: aerosol–cloud–radiation interactions in the southeastAtlantic basin Atmospheric Chemistry and Physics DOI 10.5194/acp-21-1507-2021 23 February 2021 Southern Africa produces almost a third of the Earth’s biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) is a 5-year NASA EVS-2 (Earth Venture Suborbital-2) investigation with three intensive observation periods designed to study key atmospheric processes that determine the climate impacts of these aerosols. Read more
Synchronized spatial shifts of Hadley and Walker circulations Earth System Dynamics DOI 10.5194/esd-12-121-2021 22 February 2021 Here, by examining the spatiotemporal relationship between Hadley and Walker cells in observations and climate model experiments, we demonstrate that the seasonally evolving warm-pool sea surface temperature (SST) anomalies in the decay phase of an El Niño event generate a meridionally asymmetric Walker circulation response, which couples the zonal and meridional atmospheric overturning circulations. Read more
A revision of the Combined Drought Indicator (CDI)used in the European Drought Observatory (EDO) Natural Hazards and Earth System Sciences DOI 10.5194/nhess-21-481-2021 19 February 2021 Building on almost 10 years of expertise and operational application of the Combined Drought Indicator (CDI), which is implemented within the European Commission’s European Drought Observatory (EDO) for the purposes of early warning and monitoring of agricultural droughts in Europe, this paper proposes a revised version of the index. Read more