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
A dynamical adjustment perspective on extreme event attribution Weather and Climate Dynamics DOI 10.5194/wcd-2-971-2021 12 January 2022 Attribution of the causes of extreme temperature events has become active research due to the wide-ranging impacts of recent heat waves and cold spells. Here we show that a purely observational approach based on atmospheric circulation analogues and resampling provides a robust quantification of the various dynamic and thermodynamic contributions to specific extreme temperature events. The approach can easily be integrated in the toolbox of any real-time extreme event attribution system. Read more
An Arctic ozone hole in 2020 if not for the Montreal Protocol Atmospheric Chemistry and Physics DOI 10.5194/acp-21-15771-2021 10 January 2022 We use satellite and balloon measurements to evaluate modeled ozone loss seen in the unusually cold Arctic of 2020 in the real world and compare it to simulations of a world avoided. We show that extensive denitrification in 2020 provides an important test case for stratospheric model process representations. If the Montreal Protocol had not banned ozone-depleting substances, an Arctic ozone hole would have emerged for the first time in spring 2020 that is comparable to those in the Antarctic. Read more
Assessing the representation of the Australian carbon cycle in global vegetation models Biogeosciences DOI 10.5194/bg-18-5639-2021 7 January 2022 The Australian continent is included in global assessments of the carbon cycle such as the global carbon budget, yet the performance of dynamic global vegetation models (DGVMs) over Australia has rarely been evaluated. We assessed simulations by an ensemble of dynamic global vegetation models over Australia and highlighted a number of key areas that lead to model divergence on both short (inter-annual) and long (decadal) timescales. Read more
Assessment of direct economic losses of flood disasters based on spatial valuation of land use and quantification of vulnerabilities: a case study on the 2014 flood in Lishui city of China Natural Hazards and Earth System Sciences DOI 10.5194/nhess-21-3161-2021 5 January 2022 Taking a single flood disaster in Lishui city as an example, a rapid and refined assessment of economic loss is studied and verified, which can effectively simulate the distribution of loss ratio and loss value. It includes the construction of land use type and value based on data fusion and an expert questionnaire survey, the fitting and calibration of vulnerability curves based on an existing database and disaster loss reporting, and estimation of loss ratio and loss value by spatial analysis. Read more