A regionally resolved inventory of High Mountain Asia surge-type glaciers, derived from a multi-factor remote sensing approach The Cryosphere DOI 10.5194/tc-16-603-2022 9 May 2022 Surging glaciers show cyclical changes in flow behaviour – between slow and fast flow – and can have drastic impacts on settlements in their vicinity. One of the clusters of surging glaciers worldwide is High Mountain Asia (HMA). We present an inventory of surging glaciers in HMA, identified from satellite imagery. We show that the number of surging glaciers was underestimated and that they represent 20% of the area covered by glaciers in HMA, before discussing new physics for glacier surges. Read more
Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters Ocean Science DOI 10.5194/os-18-233-2022 6 May 2022 Natural sources of atmospheric methane need to be better described and quantified. We present time series from ocean observatories monitoring two seabed methane seep sites in the Arctic. Methane concentration varied considerably on short timescales and seasonal scales. Seeps persisted throughout the year, with increased potential for atmospheric release in winter due to water mixing. The results highlight and constrain uncertainties in current methane estimates from seabed methane seepage. Read more
Acidification of the Nordic Seas Biogeosciences DOI 10.5194/bg-19-979-2022 4 May 2022 Ocean acidification, a direct consequence of the CO2 release by human activities, is a serious threat to marine ecosystems. In this study, we conduct a detailed investigation of the acidification of the Nordic Seas, from 1850 to 2100, by using a large set of samples taken during research cruises together with numerical model simulations. We estimate the effects of changes in different environmental factors on the rate of acidification and its potential effects on cold-water corals. Read more
Flash flood warnings in context: combining local knowledge and large-scale hydro-meteorological patterns Natural Hazards and Earth System Sciences DOI 10.5194/nhess-22-461-2022 2 May 2022 Local communities in northern Malawi have well-developed knowledge of the conditions leading to flash floods, spatially and temporally. Scientific analysis of catchment geomorphology and global reanalysis datasets corroborates this local knowledge, underlining the potential of these large-scale scientific datasets. Combining local knowledge with contemporary scientific datasets provides a common understanding of flash flood events, contributing to a more people-centred warning to flash floods. Read more
Abrupt climate changes and the astronomical theory: are they related? Climate of the Past DOI 10.5194/cp-18-249-2022 29 April 2022 The study of abrupt climate changes is a relatively new field of research that addresses paleoclimate variations that occur in intervals of tens to hundreds of years. Such timescales are much shorter than the tens to hundreds of thousands of years that the astronomical theory of climate addresses. We revisit several high-resolution proxy records of the past 3.2 Myr and show that the abrupt climate changes are nevertheless affected by the orbitally induced insolation changes. Read more
Evaluating the PurpleAir monitor as an aerosol light scattering instrument Atmospheric Measurement Techniques DOI 10.5194/amt-15-655-2022 27 April 2022 We show that the low-cost PurpleAir sensor can be characterized as a cell-reciprocal nephelometer. At two very different locations (Mauna Loa Observatory in Hawaii and the Table Mountain rural site in Colorado), the PurpleAir measurements are highly correlated with the submicrometer aerosol scattering coefficient measured by a research-grade integrating nephelometer. These results imply that, with care, PurpleAir data may be used to evaluate climate and air quality models. Read more
Late Neogene evolution of modern deep-dwelling plankton Biogeosciences DOI 10.5194/bg-19-743-2022 25 April 2022 Deep-living organisms are a major yet poorly known component of ocean biomass. Here we reconstruct the evolution of deep-living zooplankton and phytoplankton. Deep-dwelling zooplankton and phytoplankton did not occur 15 Myr ago, when the ocean was several degrees warmer than today. Deep-dwelling species first evolve around 7.5 Myr ago, following global climate cooling. Their evolution was driven by colder ocean temperatures allowing more food, oxygen, and light at depth. Read more
How many modes are needed to predict climate bifurcations? Lessons from an experiment Nonlinear Processes in Geophysics DOI 10.5194/npg-29-17-2022 22 April 2022 Present climate models discuss climate change but show no sign of bifurcation in the future. Is this because there is none or because they are in essence too simplified to be able to capture them? To get elements of an answer, we ran a laboratory experiment and discovered that the answer is not so simple. Read more
Vegetation change across the Drake Passage region linked to late Eocene cooling and glacial disturbance after the Eocene–Oligocene transition Climate of the Past DOI 10.5194/cp-18-209-2022 20 April 2022 New pollen and spore data from the Antarctic Peninsula region reveal temperate rainforests that changed and adapted in response to Eocene climatic cooling, roughly 35.5 Myr ago, and glacially related disturbance in the early Oligocene, approximately 33.5 Myr ago. The timing of these events indicates that the opening of ocean gateways alone did not trigger Antarctic glaciation, although ocean gateways may have played a role in climate cooling. Read more
Representativeness assessment of the pan-Arctic eddy covariance site network and optimized future enhancements Biogeosciences DOI 10.5194/bg-19-559-2022 18 April 2022 Thawing of Arctic permafrost soils could trigger the release of vast amounts of carbon to the atmosphere, thus enhancing climate change. Our study investigated how well the current network of eddy covariance sites to monitor greenhouse gas exchange at local scales captures pan-Arctic flux patterns. We identified large coverage gaps, e.g., in Siberia, but also demonstrated that a targeted addition of relatively few sites can significantly improve network performance. Read more
The Whole Antarctic Ocean Model (WAOM v1.0): development and evaluation Geoscientific Model Development DOI 10.5194/gmd-15-617-2022 15 April 2022 Here we present an improved model of the Antarctic continental shelf ocean and demonstrate that it is capable of reproducing present-day conditions. The improvements are fundamental and regard the inclusion of tides and ocean eddies. We conclude that the model is well suited to gain new insights into processes that are important for Antarctic ice sheet retreat and global ocean changes. The model will ultimately help to improve projections of sea level rise and climate change. Read more
Rhizodeposition efficiency of pearl millet genotypes assessed on a short growing period by carbon isotopes (δ13C and F14C) SOIL DOI 10.5194/soil-8-49-2022 13 April 2022 Unravelling relationships between plant rhizosheath, root exudation and soil C dynamic may bring interesting perspectives in breeding for sustainable agriculture. Using four pearl millet lines with contrasting rhizosheaths, we found that δ13C and F14C of root-adhering soil differed from those of bulk and control soil, indicating C exudation in the rhizosphere. This C exudation varied according to the genotype, and conceptual modelling performed with data showed a genotypic effect on the RPE. Read more
Impact of increased resolution on long-standing biases in HighResMIP-PRIMAVERA climate models Geoscientific Model Development DOI 10.5194/gmd-15-269-2022 11 April 2022 Climate models do not fully reproduce observations: they show differences (biases) in regional temperature, precipitation, or cloud cover. Reducing model biases is important to increase our confidence in their ability to reproduce present and future climate changes. Model realism is set by its resolution: the finer it is, the more physical processes and interactions it can resolve. We here show that increasing resolution of up to ~ 25 km can help reduce model biases but not remove them entirely. Read more
Improved representation of agricultural land use and crop management for large-scale hydrological impact simulation in Africa using SWAT+ Hydrology and Earth System Sciences DOI 10.5194/hess-26-71-2022 8 April 2022 We present an approach on how to incorporate crop phenology in a regional hydrological model using decision tables and global datasets of rain-fed and irrigated cropland with the associated cropping calendar and management practices. Results indicate improved temporal patterns of leaf area index (LAI) and evapotranspiration (ET) simulations in comparison with remote sensing data. In addition, the improvement of the cropping season also helps to improve soil erosion estimates in cultivated areas. Read more
Arctic sea level variability from high-resolution model simulations and implications for the Arctic observing system Ocean Science DOI 10.5194/os-18-51-2022 6 April 2022 This study explores the Arctic sea level variability depending on different timescales and the relation to temperature, salinity and mass changes, identifying key parameters and regions that need to be observed co-ordinately. The decadal sea level variability reflects salinity changes. But it can only reflect salinity change at periods of greater than 1 year, highlighting the requirement for enhancing in situ hydrographic observations and complicated interpolation methods. Read more
Dependency of the impacts of geoengineering on the stratospheric sulfur injection strategy – Part 1: Intercomparison of modal and sectional aerosol modules Atmospheric Chemistry and Physics DOI 10.5194/acp-22-93-2022 4 April 2022 The use of different spatio-temporal sulfur injection strategies with different magnitudes to create an artificial reflective aerosol layer to cool the climate is studied using sectional and modal aerosol schemes in a climate model. There are significant differences in the results depending on the aerosol microphysical module used. Different spatio-temporal injection strategies have a significant impact on the magnitude and zonal distribution of radiative forcing and atmospheric dynamics. Read more
Not all biodiversity rich spots are climate refugia Biogeosciences DOI 10.5194/bg-18-6567-2021 1 April 2022 Biodiversity is under threat from the effects of global warming, and assessing the effects of climate change on areas of high species richness is of prime importance to conservation. Terrestrial and freshwater rich spots have been and will be less affected by climate change than other areas. However, marine rich spots of biodiversity are expected to experience more pronounced warming. Read more
Balanced estimate and uncertainty assessment of European climate change using the large EURO-CORDEX regional climate model ensemble Earth System Dynamics DOI 10.5194/esd-12-1543-2021 30 March 2022 This research paper proposes an assessment of mean climate change responses and related uncertainties over Europe for mean seasonal temperature and total seasonal precipitation. An advanced statistical approach is applied to a large ensemble of 87 high-resolution EURO-CORDEX projections. For the first time, we provide a comprehensive estimation of the relative contribution of GCMs and RCMs, RCP scenarios, and internal variability to the total variance of a very large ensemble. Read more
The ESA MIPAS/Envisat level2-v8 dataset: 10 years of measurements retrieved with ORM v8.22 Atmospheric Measurement Techniques DOI 10.5194/amt-14-7975-2021 28 March 2022 The level-2 v8 database from the measurements of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), aboard the European Space Agency Envisat satellite, containing atmospheric fields of pressure, temperature, and volume mixing ratio of 21 trace gases, is described in this paper. The database covers all the measurements acquired by MIPAS (from July 2002 to April 2012). The number of species included makes it of particular importance for the studies of stratospheric chemistry. Read more
A simple model of ozone–temperature coupling in the tropical lower stratosphere Atmospheric Chemistry and Physics DOI 10.5194/acp-21-18531-2021 25 March 2022 Balloon and satellite observations show strong coupling between large-scale ozone and temperature fields in the tropical lower stratosphere, spanning timescales of days to years. We present a simple interpretation of this behaviour based on an idealized model of transport by the tropical stratospheric circulation, and good quantitative agreement with observations demonstrates that this is a useful simplification. The results provide simple understanding of observed atmospheric behaviour. Read more
Secondary ice production during the break-up of freezing water drops on impact with ice particles Atmospheric Chemistry and Physics DOI 10.5194/acp-21-18519-2021 23 March 2022 Secondary ice production (SIP) plays an important role in ice formation within mixed-phase clouds. We present a laboratory investigation of a potentially new SIP mechanism involving the collisions of supercooled water drops with ice particles. At impact, the supercooled water drop fragments form smaller secondary drops. Approximately 30 % of the secondary drops formed during the retraction phase of the supercooled water drop impact freeze over a temperature range of -4 °C to -12 °C. Read more
Deep oceanic submarine fieldwork with undergraduate students: an immersive experience with the Minerve software Solid Earth DOI 10.5194/se-12-2789-2021 21 March 2022 We use the Minerve virtual reality software to bring undergraduate students to an unusual field trip at 1200 m below sea level in the Lesser Antilles area. This region is located above an active subduction zone responsible for intense volcanic and seismic activity. In particular, we focus on the Roseau submarine fault that ruptured during the Mw 6.3 Les Saintes earthquake and presented a fresh scarp that the students can analyse and map in VR. They compile their results in a GIS project. Read more
Impact of the melt–albedo feedback on the future evolution of the Greenland Ice Sheet with PISM-dEBM-simple The Cryosphere DOI 10.5194/tc-15-5739-2021 18 March 2022 With the increasing melt of the Greenland Ice Sheet, which contributes to sea level rise, the surface of the ice darkens. The dark surfaces absorb more radiation and thus experience increased melt, resulting in the melt–albedo feedback. Using a simple surface melt model, we estimate that this positive feedback contributes to an additional 60 % ice loss in a high-warming scenario and additional 90 % ice loss for moderate warming. Albedo changes are important for Greenland’s future ice loss. Read more
The blue suns of 1831: was the eruption of Ferdinandea, near Sicily, one of the largest volcanic climate forcing events of the nineteenth century? Climate of the Past DOI 10.5194/cp-17-2607-2021 16 March 2022 An unidentified eruption in 1831 was one of the largest volcanic climate forcing events of the nineteenth century. We use reported observations of a blue sun to reconstruct the transport of an aerosol plume from that eruption and, hence, identify it as the 1831 eruption of Ferdinandea, near Sicily. We propose that, although it was only a modest eruption, its volcanic plume was enriched with sulphur from sedimentary deposits and that meteorological conditions helped it reach the stratosphere. Read more
Brief communication: A roadmap towards credible projections of ice sheet contribution to sea level The Cryosphere DOI 10.5194/tc-15-5705-2021 14 March 2022 Estimating how much ice loss from Greenland and Antarctica will contribute to sea level rise is of critical societal importance. However, our analysis shows that recent efforts are not trustworthy because the models fail at reproducing contemporary ice melt. Here we present a roadmap towards making more credible estimates of ice sheet melt. Read more
Options to correct local turbulent flux measurements for large-scale fluxes using an approach based on large-eddy simulation Atmospheric Measurement Techniques DOI 10.5194/amt-14-7835-2021 11 March 2022 Turbulent flux measurements suffer from a general systematic underestimation. One reason for this bias is non-local transport by large-scale circulations. A recently developed model for this additional transport of sensible and latent energy is evaluated for three different test sites. Different options on how to apply this correction are presented, and the results are evaluated against independent measurements. Read more
Dynamics of variable dusk–dawn flow associated with magnetotail current sheet flapping Annales Geophysicae DOI 10.5194/angeo-39-1037-2021 9 March 2022 The sun’s magnetic field is carried across space by the solar wind – a hot plasma “stream” of ions and electrons – forming the interplanetary magnetic field (IMF). The IMF can introduce asymmetries in the Earth’s magnetic field, giving plasma flowing within it a direction dependent on IMF orientation. Electric currents in near-Earth space can also influence these plasma flows. We investigate these two competing mechanisms and find that the currents can prevent the IMF from controlling the flow. Read more
Identifying community values related to heat: recommendations for forecast and health risk communication Geoscience Communication DOI 10.5194/gc-4-517-2021 7 March 2022 This paper presents an analysis of public responses to U.S. National Weather Service heat-related Facebook posts for the Phoenix (Arizona) County Warning Area to identify community norms that may present challenges to the effectiveness of heat risk communication. Findings suggest that local audiences tend to view heat as normal and the ability to withstand heat as a marker of community identity. Recommendations are provided for harnessing those norms to promote positive behavioural change. Read more
Modelling the volcanic ash plume from Eyjafjallajökull eruption (May 2010) over Europe: evaluation of the benefit of source term improvements and of the assimilation of aerosol measurements Natural Hazards and Earth System Sciences DOI 10.5194/nhess-21-3731-2021 4 March 2022 Volcanic eruptions that spread out ash over large areas, like Eyjafjallajökull in 2010, may have huge economic consequences due to flight cancellations. In this article, we demonstrate the benefits of source term improvement and of data assimilation for quantifying volcanic ash concentrations. The work, which was supported by the EUNADICS-AV project, is the first one, to our knowledge, that demonstrates the benefit of the assimilation of ground-based lidar data over Europe during an eruption. Read more
Ubiquity of human-induced changes in climate variability Earth System Dynamics DOI 10.5194/esd-12-1393-2021 2 March 2022 A large ensemble of simulations with 100 members has been conducted with the state-of-the-art CESM2 Earth system model, using historical and SSP3-7.0 forcing. Our main finding is that there are significant changes in the variance of the Earth system in response to anthropogenic forcing, with these changes spanning a broad range of variables important to impacts for human populations and ecosystems. Read more
SELF v1.0: a minimal physical model for predicting time of freeze-up in lakes Geoscientific Model Development DOI 10.5194/gmd-14-7527-2021 28 February 2022 The time when lakes freeze varies considerably from year to year. A common way to predict it is to use negative degree days, i.e., the sum of air temperatures below 0°C, a proxy for the heat lost to the atmosphere. Here, we show that this is insufficient as the mixing of the surface layer induced by wind tends to delay the formation of ice. To do so, we developed a minimal model based on a simplified energy balance, which can be used both for large-scale analyses and short-term predictions. Read more
Annual exposure to polycyclic aromatic hydrocarbons in urban environments linked to wintertime wood-burning episodes Atmospheric Chemistry and Physics DOI 10.5194/acp-21-17865-2021 25 February 2022 We analyse observations from year-long measurements at Athens, Greece. Nighttime wintertime PAH levels are 4 times higher than daytime, and wintertime values are 15 times higher than summertime. Biomass burning aerosol during wintertime pollution events is responsible for these significant wintertime enhancements and accounts for 43 % of the population exposure to PAH carcinogenic risk. Biomass burning poses additional health risks beyond those associated with the high PM levels that develop. Read more
Assessing the dependence structure between oceanographic, fluvial, and pluvial flooding drivers along the United States coastline Hydrology and Earth System Sciences DOI 10.5194/hess-25-6203-2021 23 February 2022 We analyse dependences between different flooding drivers around the USA coastline, where the Gulf of Mexico and the southeastern and southwestern coasts are regions of high dependence between flooding drivers. Dependence is higher during the tropical season in the Gulf and at some locations on the East Coast but higher during the extratropical season on the West Coast. The analysis gives new insights on locations, driver combinations, and the time of the year when compound flooding is likely. Read more
Extreme metrics from large ensembles: investigating the effects of ensemble size on their estimates Earth Surface Dynamics DOI 10.5194/esd-12-1427-2021 21 February 2022 We address the question of how large an initial condition ensemble of climate model simulations should be if we are concerned with accurately projecting future changes in temperature and precipitation extremes. We find that for most cases (and both models considered), an ensemble of 20-25 members is sufficient for many extreme metrics, spatial scales and time horizons. This may leave computational resources to tackle other uncertainties in climate model simulations with our ensembles. Read more
Tracking aerosols and SO2 clouds from the Raikoke eruption: 3D view from satellite observations Atmospheric Measurement Techniques DOI 10.5194/amt-14-7545-2021 18 February 2022 The 21 June 2019 eruption of the Raikoke volcano produced significant amounts of volcanic aerosols (sulfate and ash) and sulfur dioxide (SO2) gas that penetrated into the lower stratosphere. We showed that the amount of SO2 decreases with a characteristic period of 8–18 d and the peak of sulfate aerosol lags the initial peak of SO2 by 1.5 months. We also examined the dynamics of an unusual stratospheric coherent circular cloud of SO2 and aerosol observed from 18 July to 22 September 2019. Read more
Rectified tidal transport in Lofoten–Vesterålen, northern Norway Ocean Science DOI 10.5194/os-17-1753-2021 16 February 2022 Non-linear tidal dynamics can produce prominent time-mean transport in coastal regions where strong tidal currents interact with topography. We investigate tidal-induced transport using a tidally driven ocean model for Lofoten-Vesterålen in northern Norway and find that both tidal pumping and tidal rectification can play an important role for time-mean transport in the region. The study emphasizes the importance of non-linear tidal dynamics for time-mean transport in complex coastal regions. Read more
Assessment of the ParFlow–CLM CONUS 1.0 integrated hydrologic model: evaluation of hyper-resolution water balance components across the contiguous United States Geoscientific Model Development DOI 10.5194/gmd-14-7223-2021 14 February 2022 Modeling the hydrologic cycle at high resolution and at large spatial scales is an incredible opportunity and challenge for hydrologists. In this paper, we present the results of a high-resolution hydrologic simulation configured over the contiguous United States. We discuss simulated water fluxes through groundwater, soil, plants, and over land, and we compare model results to in situ observations and satellite products in order to build confidence and guide future model development. Read more
Spatiotemporal distribution of seasonal snow water equivalent in High Mountain Asia from an 18-year Landsat–MODIS era snow reanalysis dataset The Cryosphere DOI 10.5194/tc-15-5261-2021 11 February 2022 We examined the spatiotemporal distribution of stored water in the seasonal snowpack over High Mountain Asia, based on a new snow reanalysis dataset. The dataset was derived utilizing satellite-observed snow information, which spans across 18 water years, at a high spatial (~ 500 m) and temporal (daily) resolution. Snow mass and snow storage distribution over space and time are analysed in this paper, which brings new insights into understanding the snowpack variability over this region. Read more
Orogenic lithosphere and slabs in the greater Alpine area – interpretations based on teleseismic P-wave tomography Solid Earth DOI 10.5194/se-12-2633-2021 9 February 2022 New images from the multi-national AlpArray experiment illuminate the Alps from below. They indicate thick European mantle descending beneath the Alps and forming blobs that are mostly detached from the Alps above. In contrast, the Adriatic mantle in the Alps is much thinner. This difference helps explain the rugged mountains and the abundance of subducted and exhumed units at the core of the Alps. The blobs are stretched remnants of old ocean and its margins that reach down to at least 410 km. Read more
Seasonal evolution of Antarctic supraglacial lakes in 2015–2021 and links to environmental controls The Cryosphere DOI 10.5194/tc-15-5205-2021 7 February 2022 We provide novel insight into the temporal evolution of supraglacial lakes across six major Antarctic ice shelves in 2015–2021. For Antarctic Peninsula ice shelves, we observe extensive meltwater ponding during the 2019–2020 and 2020–2021 summers. Over East Antarctica, lakes were widespread during 2016–2019 and at a minimum in 2020–2021. We investigate environmental controls, revealing lake ponding to be coupled to atmospheric modes, the near-surface climate and the local glaciological setting. Read more
Future summer warming pattern under climate change is affected by lapse-rate changes Weather and Climate Dynamics DOI 10.5194/wcd-2-1093-2021 4 February 2022 In a warmer future climate, climate simulations predict that some land areas will experience excessive warming during summer. We show that the excessive summer warming is related to the vertical distribution of warming within the atmosphere. In regions characterized by excessive warming, much of the warming occurs close to the surface. In other regions, most of the warming is redistributed to higher levels in the atmosphere, which weakens the surface warming. Read more
Two decades of dynamic change and progressive destabilization on the Thwaites Eastern Ice Shelf The Cryosphere DOI 10.5194/tc-15-5187-2021 2 February 2022 We present a 20-year, satellite-based record of velocity and thickness change on the Thwaites Eastern Ice Shelf (TEIS), the largest remaining floating extension of Thwaites Glacier (TG). TG holds the single greatest control on sea-level rise over the next few centuries, so it is important to understand changes on the TEIS, which controls much of TG’s flow into the ocean. Our results suggest that the TEIS is progressively destabilizing and is likely to disintegrate over the next few decades. Read more
Accumulation of legacy fallout radionuclides in cryoconite on Isfallsglaciären (Arctic Sweden) and their downstream spatial distribution The Cryosphere DOI 10.5194/tc-15-5151-2021 31 January 2022 Our paper presents results of sample collection and subsequent geochemical analyses from the glaciated Isfallsglaciären catchment in Arctic Sweden. The data suggest that material found on the surface of glaciers, “cryoconite”, is very efficient at accumulating products of nuclear fallout transported in the atmosphere following events such as the Chernobyl disaster. We investigate how this compares with samples in the downstream environment and consider potential environmental implications. Read more
A sulfur dioxide Covariance-Based Retrieval Algorithm (COBRA): application to TROPOMI reveals new emission sources Atmospheric Chemistry and Physics DOI 10.5194/acp-21-16727-2021 28 January 2022 We present a new algorithm to retrieve sulfur dioxide from space UV measurements. We apply the technique to high-resolution TROPOMI measurements and demonstrate the high sensitivity of the approach to weak SO2 emissions worldwide with an unprecedented limit of detection of 8 kt yr-1. This result has broad implications for atmospheric science studies dealing with improving emission inventories and identifying and quantifying missing sources, in the context of air quality and climate. Read more
Feedback mechanisms between precipitation and dissolution reactions across randomly heterogeneous conductivity fields Hydrology and Earth System Sciences DOI 10.5194/hess-25-5905-2021 26 January 2022 The interplay between dissolution, precipitation and transport is widely encountered in porous media, from CO2 storage to cave formation in carbonate rocks. We show that dissolution occurs along preferential flow paths with high hydraulic conductivity, while precipitation occurs at locations close to yet separated from these flow paths, thus further funneling the flow and changing the probability density function of the transport, as measured on the altered conductivity field at various times. Read more
Dynamics of fortnightly water level variations along a tide-dominated estuary with negligible river discharge Ocean Science DOI 10.5194/os-17-1605-2021 24 January 2022 Understanding tidal hydrodynamics is essential for water resources management in estuarine environments. In this study, we propose an analytical model to examine the fortnightly water level variations due to tidal motions alone in tide-dominated estuaries. Details of the analytical model show that changes in the mean depth or length of semi-arid estuaries affect the fortnightly tide amplitude, which has significant potential impacts on the estuarine ecosystem management. Read more
A differential emissivity imaging technique for measuring hydrometeor mass and type Atmospheric Measurement Techniques DOI 10.5194/amt-14-6973-2021 21 January 2022 This paper describes a new instrument for quantifying the physical characteristics of hydrometeors such as snow and rain. The device can measure the mass, size, density and type of individual hydrometeors as well as their bulk properties. The instrument is called the Differential Emissivity Imaging Disdrometer (DEID) and is composed of a thermal camera and hotplate. The DEID measures hydrometeors at sampling frequencies up to 1 Hz with masses and effective diameters greater than 1 µg and 200 µm. Read more
Brief communication: Effective earthquake early warning systems: appropriate messaging and public awareness roles Natural Hazards and Earth System Sciences DOI 10.5194/nhess-21-3243-2021 19 January 2022 Earthquake early warning systems (EEWSs) can help reduce losses, but their effectiveness depends on adequate public perception and understanding of EEWSs. This study examined the performance of the EEWS in China’s Sichuan Province during the 2019 Changning earthquake. We found a big gap existed between the EEWS’s message, the public’s perception of it, and their response. The study highlights the importance of gauging EEWS alert effectiveness and public participation for long-term resiliency. Read more
Photosynthetic activity in Devonian Foraminifera Biogeosciences DOI 10.5194/bg-18-5719-2021 17 January 2022 Benthic foraminifera play a significant role in modern reefal ecosystems mainly due to their symbiosis with photosynthetic microorganisms. Foraminifera were also components of Devonian stromatoporoid coral reefs; however, whether they could have harbored symbionts has remained unclear. We show that Devonian foraminifera may have stayed photosynthetically active, which likely had an impact on their evolutionary radiation and possibly also on the functioning of Paleozoic shallow marine ecosystems. Read more
The interpretation of temperature and salinity variables in numerical ocean model output and the calculation of heat fluxes and heat content Geoscientific Model Development DOI 10.5194/gmd-14-6445-2021 14 January 2022 We show that the way that the air–sea heat flux is treated in ocean models means that the model’s temperature variable should be interpreted as being Conservative Temperature, irrespective of whether the equation of state used in an ocean model is EOS-80 or TEOS-10. Read more