bluuebunny/crossref_metadata_2025 huggingface dataset:
Satellite observations and modeling of the 2022 Hunga Tonga-Hunga Ha'apai eruption
Authors: Carn Simon , Andrews Benjamin , Aquila Valentina , Cauley Christina , Colarco Peter , Dufek Josef , Fischer Tobias , Kenis Lexi , Krotkov Nickolay , Li Can , Mastin Larry , Newman Paul , Wallace Paul
Published: March 2022

The 15 January 2022 eruption of the submarine Hunga Tonga-Hunga Ha'apai (HTHH) volcano (Tonga) ranks among the largest volcanic explosions of the satellite remote sensing era, and perhaps the last century. It shares many characteristics with the 1883 Krakatau eruption (Indonesia), including atmospheric pressure waves and tsunamis, and the phreatomagmatic interaction of magma and seawater likely played a major role in the dynamics of both events. A portion of the HTHH eruption column rose to lower mesospheric altitudes (~55 km) and the umbrella cloud extent (~500 km diameter at ~30-35 km altitude) rivalled that of the 1991 Pinatubo eruption, indicative of very high mass eruption rates. However, sulfur dioxide (SO2) emissions measured in the HTHH volcanic cloud (~0.4 Tg) were significantly lower than the post-Pinatubo SO2 loading (~10–15 Tg SO2), and on this basis we would expect minimal climate impacts from the HTHH event. Yet, in the aftermath of the eruption satellite observations show a persistent stratospheric aerosol layer with the characteristics of sulfate aerosol, along with a large stratospheric water vapor anomaly. At the time of writing, the origin, composition and eventual impacts of this stratospheric gas and aerosol veil are unclear. We present the preliminary results of a multi-disciplinary approach to understanding the HTHH eruption, including 1D- and 3D-modeling of the eruption column coupled to a 3D atmospheric general circulation model (NASA’s GEOS-5 model), volatile mass balance considerations involving potential magmatic, seawater and atmospheric volatile and aerosol sources, and an extensive suite of satellite observations. Analysis of the HTHH eruption will provide new insight into the dynamics and atmospheric impacts of large, shallow submarine eruptions. Such eruptions have likely occurred throughout Earth’s history but have never been observed with modern instrumentation.
Volcanogenic tsunami on January 15, 2022: insights from deep-ocean measurements
Authors: Nosov Mikhail , Sementsov Kirill , Kolesov Sergey , Pryadun Vasilisa
Published: March 2022

The explosive eruption of the Hunga Tonga-Hunga Ha'apai volcano on January 15, 2022 triggered tsunami waves that were observed throughout the Pacific Ocean. In particular, the waves were recorded by several dozen deep-ocean DART stations located at source distances from hundreds to more than 10 thousand kilometers. Our study is aimed at analyzing tsunami waveforms recorded by DART stations in order to identify the formation mechanisms of this volcanogenic tsunami. Waveforms are processed using wavelet analysis. The arrival times of signals of different genesis are estimated making use robust physical assumptions, numerical modeling and satellite images. It has been found that in all records the tsunami signal is clearly observed long before the calculated moment of arrival of gravity surface waves caused by sources localized in the immediate vicinity of the volcano. On the records obtained by distant stations (~10000 km) dispersive gravity waves arrive with a delay of several hours after the signals following the passage of acoustic wave in the atmosphere. In addition to the analysis of waveforms, theoretical estimates of the amplitude of gravity waves in the ocean, caused by an acoustic wave in the atmosphere, will be presented. We also provide a theoretical estimate on how acoustic waves in the atmosphere manifest in pressure variations recorded by an ocean-bottom sensor.

This study was funded by a grant of the Russian Science Foundation № 22-27-00415, https://rscf.ru/en/project/22-27-00415/.
The Near Real time analysis of Hunga Tonga-Hunga Ha’apai eruption in the ionosphere by GNSS
Authors: Maletckii Boris , Astafyeva Elvira
Published: March 2022

The 15th January 2022 Hunga Tonga- Hunga Ha’apai (HTHH) volcano explosion is one of the most powerful eruptive events over the last 30 years. Based on early computations, its VEI was at least 5. The explosion caused atmospheric air shock waves that propagated around the globe, and also generated a tsunami. All these effects seemed to have produced quite a significant response in the ionosphere.

In this contribution, we analyze the ionospheric disturbances generated by the HTHH volcano eruption by using ground-based 8 GNSS receivers located in the near-field of the volcano (i.e., less than 2000 km). We test our previously developed methods to detect and locate the explosive event and its ionospheric signatures in a near-real-time (NRT) scenario. 

To detect co-volcanic ionospheric disturbances (co-VID), we use the TEC time derivative approach that was previously used for detection of ionospheric disturbances generated by large earthquakes. For this event, we modified the previously developed method to proceed not only 1-second but also 30 sec data. This approach detects the first perturbations ~12-15 minutes after the eruption onset. Further, it estimates the instantaneous velocities in a near field to be about ~500-800 m/s. Finally, from the obtained velocity vectors and the azimuths of co-VID propagation we calculate the position of the source in the ionosphere. 

Besides, we used the same TEC time derivative approach to produce NRT Travel Time Diagrams. The NRT TTD additionally verify the correlation with the source and velocities’ values.
Observation and simulation of the meteotsunami generated in the Mediterranean Sea by the Tonga eruption on 15 January 2022
Authors: Gailler Audrey , Heinrich Philippe , Rey Vincent , Hébert Hélène , Dupont Aurélien , Listowski Constantino , Forestier Edouard , Ntafis Stavros
Published: March 2022

Meteotsunamis are long ocean waves generated by atmospheric disturbances. The Tonga volcano eruption on 15 January 2022 generated a Lamb pressure wave propagating all over the globe and generating a tsunami observed at most tide gauges in the world. A first atmospheric wave arrived 20 hours after the eruption on the French Mediterranean coasts and propagated southward. This abrupt atmospheric pressure change was recorded by hundreds of barometers of weather stations around Europe. A second one originating from Africa was observed four hours later with an attenuated amplitude. The first wave can be roughly defined by a sinusoid signal with a period close to one hour and an amplitude of 150 Pa. The associated tsunami was observed by the French stations of the HTM-NET network (https://htmnet.mio.osupytheas.fr/) [1]. Amplitudes range from a few cm to 15 cm and periods range from 20 min to 1 hour.

 

Numerical simulation of the tsunami is performed by the operational code Taitoko developed at CEA [2]. The nested multigrid approach is used to simulate the water waves propagating in the bay of Toulon. The meteotsunami is generated by calculating analytically the atmospheric pressure gradient in the momentum equation. Comparisons of time series between numerical solutions and records are very satisfactory in regions defined by a high resolution topo-bathymetry. A second tsunami simulation is performed by introducing a second pressure wave propagating in the North direction and reaching the HTM-NET stations 4 hours after the first arrival. This second pressure wave results in additional and higher tsunami water waves in agreement with records.

 

 

[1] Rey, V., Dufresne, C., Fuda, J. L., Mallarino, D., Missamou, T., Paugam, C., Rougier, G., Taupier-Letage, I., On the use of long term observation of water level and temperature along the shore for a better understanding of the dynamics: Example of Toulon area, France Ocean Dyn., 2020, https://doi.org/10.1007/s10236-020-01363-7.

[2] Heinrich, P, Jamelot, A., Cauquis, A., Gailler A., 2021. Taitoko, an advanced code for tsunami propagation, developed at the French Tsunami Warning Centers. European Journal of Mechanics - B/Fluids 88(84) . DOI: 10.1016/j.euromechflu.2021.03.001.
Early evolution of the Hunga – Tonga Volcanic Plume from Lidar Observations at Reunion Island (Indian Ocean, 21°S, 55°E)
Authors: Baron Alexandre , Payen Guillaume , Duflot Valentin , Chazette Patrick , Khaykin Sergey , Hello Yann , Marquestaut Nicolas , Ranaivombola Marion , Bègue Nelson , Portafaix Thierry , Cammas Jean-Pierre
Published: March 2022

Explosive volcanism periodically induces disturbances of the upper troposphere and low stratosphere. These injections of massive amount of aerosols, ash and gases perturb locally the physico-chemical balance of the impacted atmospheric layers, in particular the ozone concentration via heterogeneous chemistry on particles. On a larger scale some exceptional eruption can have a significant influence on the Earth radiative budget as it was the case following eruptions of El Chichon in 1982 and Mount Pinatubo in 1991.

On January 15, 2022, the Hunga-Tonga volcano erupted in the Tonga archipelago (20.5°S, 175.4°W). The Plinian eruption was of a rare intensity, especially because of the depth of the underwater caldera. The first estimates indicate a power between 10 and 15 Mt TNT, probably the most powerful since the eruption of Krakatoa in 1883. This short (~ 8min) but intense explosion whose pressure wave was observed all around the globe injected about 400 kt of material into the atmosphere (to be compared to the 20 Mt injected during the Mount Pinatubo eruption). The Volcano Stratospheric Plume (VSP) quickly moved westwards and then overflew the island of La Réunion (21°S, 55°E), located at ~12000 km away from Tonga.

In order to monitor the evolution of the VSP, lidar observations were performed at the Observatoire de Physique de l’Atmosphère de La Réunion (OPAR). This observatory is equipped with three lidars capable of stratospheric aerosols measurements at two wavelengths (355 nm and 532 nm). First observations were performed every night from 19 to 27 January 2022 when the first passage of the VSP occurred. The plume structures appeared to be highly variable along time, with altitudes ranging from 19 km to 36 km above the mean sea level while plume thicknesses were ranging from ~1 km to more than 3 km. Remarkable aerosol optical depth were associated with these stratospheric aerosol layers, up to 0.8 at 532 nm on January 21.

The temporal evolution of the VSP structure and optical properties will be presented and discussed.
Morphotectonics of the eastern Rhine Graben Boundary Fault (Germany): an active fault within the plate interiors of Central Europe
Authors: Pena-Castellnou Sara , Baize Stephane , Hürtgen Jochen , Reicherter Klaus
Published: March 2022

The eastern Rhine Graben Boundary fault zone (RGBF) constitutes the oriental margin of the Upper Rhine Graben (URG) which forms part of the European Cenozoic Rift System. The URG with low to moderate intraplate seismicity is one of the most seismically active areas in the plate interiors of Central Europe. Assessing seismic hazard in intraplate Europe is challenging as modest lithospheric deformation (<1 mm/yr) resulting from far-field stresses is accommodated by slow-slip faults. The instrumental and historical earthquake catalog of the URG (dating back to 800 AD) is too short to include the complete earthquake history and, for instance, document the occurrence of large earthquakes, potentially leading to underestimate capable faults.

Identifying and characterizing active faults is essential towards a comprehensive seismic hazard assessment in the URG. Several research efforts have been made towards this direction, focusing on the western RGBF and the southern end of the eastern RGBF. However, neotectonic studies integrating the whole eastern RGBF are lacking. As a first step, we here present a study of the neotectonic imprint in the morphology of the eastern margin of the URG based on the 12 m resolution TanDEM-X DEM and the 1 m resolution DEM of Baden-Württemberg derived from LIDAR data together with data from regional geological maps. We performed geomorphological mapping of Quaternary deposits, paleoseismic features, and faults. Besides, we calculated several morphometric parameters, including mountain front sinuosity, basin asymmetry, knickpoints, and hypsometric curve analysis to depict long-term deformation. The eastern RGBF consists of several NNE-SSW parallel fault strands marked by topographic steps that constitute the boundary between the Rhine River plain and the eastern uplifted URG shoulder. We have identified along the fault landforms that appear typical of active tectonic landscapes: a) topographical scarps, b) well-defined triangular facets developed on the hillslope associated with the main fault trace, c) displaced alluvial fans, d) left-lateral channel deflections and beheaded channels, and e) hanging valleys; that allows us to prove the kinematics of the fault as transtensional left-lateral strike-slip which is consistent with the regional stress (SH max). The occurrence of these neotectonic features varies along the 300 km long eastern RGBF fault, which, together with the results from the morphometric analysis, allow us to differentiate areas with differential tectonic activity suggesting fault segmentation. These results point out the seismic potential of the eastern RGBF, are critical to find suitable sites for paleoseismological trenching and are key to later propose plausible rupture scenarios for further PSHA studies.
Avoiding Day Zero water crisis management La Paz
Authors: Nomden Harm , Riemersma Michel , Zamora Adrian , Kats Hidde , Huting Ric , Engel Wouter , Quisbert Tomas
Published: March 2022

Bolivia, November 2016: the reservoirs high in the mountains around the city of La Paz completely dried out after an dry year, limiting the supply of (drinking) water to the city. Heavy rationing had to take place over a period of 6 weeks, resulting in social unrest. 

The drinking water company EPSAS is responsible for the water supply to the city and region. Over the period 2016-2030, the number of inhabitants will grow from 1.6 to 2.1 million and the water demand increases with 58% while raw water resources are limited and further constrained (climate change and loss of glaciers). To cope with these conditions, the supply infrastructure will double in size: from 3 to 6 treatment plants and from 14 to 26 reservoirs spread over 9 catchments. Total water storage capacity doubles from 54 hm3 to 110 hm3. Additional stream intakes are constructed to extract water, water can even be pumped over the mountains in dry periods. Water is transported from the reservoirs to plants via pipe lines, channels and free flowing streams.

A continuously changing and expanding reservoir network, signifies an increase in complexity, more choices to be made on a daily and weekly basis by the operational staff, influencing (forecasted) water availability. Since 2016 Royal HaskoningDHV and EPSAS have been working together to develop a Monitoring & Decision Support System which is able to monitor the water availability and the status of the catchments, generate hydrological forecasts and optimize (future) use of available raw water resources.

This is done by:

installing a system of 40-60 monitoring stations at all dams and upstream in all catchments - monitoring water levels, discharges, extraction volumes and meteorological variables. New to be constructed telemetry stations will send all data to the control room;

developing an operational software system to translate measured variables into water volumes and other indicators; to generate hydrological run-off forecasts using advanced hydrological models; to optimize the distribution of water over the reservoirs and the use of water; and forecast resulting water availability and shortages over the coming 18 months. The system generates forecasts and advices on a daily or weekly basis, as defined by the user.
Observed relationships between circulation and cloud feedbacks in the tropics
Authors: Van de Koot Emily , Byrne Michael P. , Woollings Tim
Published: March 2022

Significant challenges in modelling clouds render observational data an important resource for quantifying cloud feedbacks. Here, we use data from satellite and reanalysis products to estimate tropical cloud feedbacks over a wide range of circulation regimes. We use two distinct methods, month-to-month variability and linear multi-decadal trends, to gain insight as to whether short-term feedbacks are representative of feedbacks associated with CO2-induced warming. We also investigate the extent to which cloud feedbacks are circulation-driven by decomposing the relative contributions of circulation versus thermodynamic changes to the feedbacks in each regime. The influence of thermodynamic processes on cloud feedbacks has been shown to be dominant at large spatial scales in global climate models (Byrne and Schneider, 2018), but it is unclear whether observed feedbacks are consistent with model behaviour. A particular focus of our analysis is the effect of circulation on the tropical anvil cloud area feedback in ascending regions, as this feedback constitutes the largest source of uncertainty in the overall cloud feedback yet is relatively understudied (Sherwood et al. 2020).   

References:

Byrne, M. P., & Schneider, T. (2018). Atmospheric dynamics feedback: Concept, simulations, and climate implications. Journal of Climate, 31(8), 3249-3264.

Sherwood, S. C., Webb, M. J., Annan, J. D., Armour, K. C., Forster, P. M., Hargreaves, J. C., ... & Zelinka, M. D. (2020). An assessment of Earth's climate sensitivity using multiple lines of evidence. Reviews of Geophysics, 58(4), e2019RG000678.
Deposition of Carcinogenic Atmospheric Anthraquinone on Tea Plantation
Authors: Li Cathy Wing Yi , Walters Stacy , Müller Jean-François , Orlando John , Brasseur Guy
Published: March 2022

The detection of the presence of anthraquinone in tea leaves has raised concerns due to a potential health risk associated with anthraquinone. This led the European Union to impose a maximum residue limit of 0.02 mg/kg in dried tea leaves. This study investigates the possible contamination of tea leaves resulting from the deposition of atmospheric anthraquinone using a global chemical transport model that accounts for the emission, atmospheric transport, chemical transformation, and deposition of anthraquinone on the surface, based on the limited existing information on the atmospheric behavior of anthraquinone.  Despite of the large uncertainties in some model parameters, the model shows reasonable agreement with measurements of surface concentrations of anthraquinone. The largest contribution to the global budget of anthraquinone is from residential combustion followed by the secondary formation from oxidation of anthracene, traffic, biomass burning, power generation and industry. The simulations suggest that, in addition to the direct sources of anthraquinone generated during tea manufacturing, the deposition of atmospheric anthraquinone could be a substantial source of the anthraquinone content found on tea leaves in several tea-producing regions, especially near highly industrialized and populated areas of southern and eastern Asia.
The Lomba Lake sedimentary record over the last 23.5 ky: implications for the Holocene volcanic history of Flores Island (Azores) 
Authors: Andrade Mariana , S. Ramalho Ricardo , Pimentel Adriano , Hernández Armand , Kutterolf Steffen , Sáez Alberto , Benavente Mario , M. Raposeiro Pedro , Giralt Santiago
Published: March 2022

Lake sedimentary archives from volcanic regions frequently contain a rich and continuous record of tephra layers, providing a critical source of information to reconstruct a most complete eruptive history of neighbouring volcanic centres. Lake sediments from volcanic islands are particularly useful as the typical small size of these islands and their steep subaerial and submarine slopes lead to a lower preservation potential of primary pyroclastic deposits. Here we study the volcano-sedimentary record of Lagoa da Lomba (Lomba Lake), an old crater lake located in the central upland area of Flores Island (Azores), to gain insight into the recent volcanic history of this island. The strategic location of Lagoa da Lomba, half distance between the two clusters of recent volcanic activity of the island, together with its 23.52 cal kyr BP record, makes this lake a privileged site to investigate the Holocene volcanic history of Flores. We conducted a detailed characterization of the sedimentary facies from a transect of three cores to differentiate primary from reworked/redeposited tephra deposits, which was complemented by glass shard geochemical analysis and radiocarbon dating.

We recognized four eruptive events taking place between 6.28 and 2.36 cal kyr BP, demonstrating that the Holocene volcanic activity at Flores Island may have lasted longer than previously reported. Glass shard geochemistry from the different tephra layers suggests three populations, ranging from basaltic to trachybasaltic in composition, where the last eruption is the least evolved endmember. Two of the four eruptive events correlate geochemically and stratigraphically with subaerially-exposed pyroclastic sequences. The most recent event recorded at Lagoa da Lomba was constrained to 3.66 – 2.36 cal kyr BP and associated with an eruption sourced from Lagoa Comprida Volcanic System. The second most recent eruptive event was sourced from Lagoa Funda Volcanic System and dated at 3.66 cal kyr BP. Our observations show that Flores Island experienced vigorous volcanic activity during the Late Holocene. Therefore, contrary to what was previously assumed, the possibility of future eruptions should not be underestimated, and the volcanic hazard here should be properly assessed. Moreover, our results highlight the importance of tephrostratigraphy in recent lake sediments to reconstruct past volcanic activity in those contexts where outcrops exposure is limited.

This work was supported by SFRH/BD/138261/2018 doctoral grant and DISCOVERAZORES (PTDC/CTA-AMB/28511/2017) project funded by FCT (Portugal), and projects PaleoModes (CGL 2016-75281-C2) and RapidNAO (CGL 2013-40608-R), financed by MINECO (Spain). This work was also supported by project FCT-UIDB/50019/2020 - IDL funded by FCT.
FESSTVaL: Field Experiment on sub-mesoscale spatio-temporal variability in Lindenberg – the campaign, first results and data availability
Authors: Lundgren Kristina , Hohenegger Cathy , Ament Felix , Beyrich Frank , Löhnert Ulrich , Göber Martin , Rust Henning , Sakradzija Mirjana , Bastak-Duran Ivan , Masbou Matthieu , Jahnke-Bornemann Annika
Published: March 2022

The field campaign FESSTVaL (Field Experiment on sub-mesoscale spatio-temporal variability in Lindenberg) was carried out by 16 institutions from May to August 2021 in the surroundings of the Meteorological Observatory Lindenberg – Richard-Aßmann-Observatory of the German Meteorological Service (DWD). The project aims at an improved understanding of the initiation and interaction of cold pools and wind gusts in the summertime convective boundary layer. Such weather phenomena can cause great damage, but are, however, difficult to capture by conventional surface networks due to their small-scale nature. Unique to this campaign is the deployment of a high-density near-surface measurement network made of over 100 ground-level stations for measurements of temperature and pressure, complemented by 20 automatic weather stations as well as a dense network of soil moisture measurements. An X-band radar and several energy balance stations were also used. The surface network was augmented by a network of vertical profiling instruments including nine Doppler LiDAR systems for measurements of the wind profile and turbulence variables up to an altitude of several kilometers, four microwave radiometers, and measurement flights with unmanned and remotely-controlled aircraft. As a supplement to these measurements, the project investigates the gain of a citizen science measurement network.

This presentation will shed light on the 4D structure and evolution of cold pools associated with a strong convective event as viewed by the different sensors. The cold pool observations will be compared to forecasts and to large-eddy simulations conducted for that particular case. Overall, the results of the project will serve to improve the representation of such small-scale processes in numerical weather prediction and to define new measurement strategies. The data products of the campaign are treated under the FAIR principle and are made available via a platform at the Integrated Climate Data Center of the University of Hamburg. 
The ancient ports of Rome revisited: a multiple proxy of environmental changes in relation to human occupation
Authors: Sadori Laura , Masi Alessia , Mazzini Ilaria
Published: March 2022

The city of Rome neither have nor had natural bays in its vicinity working as ports. The navigable stretch of the Tiber River that extends from the sea to Rome compensated the lack of natural harbours along this part of the Tyrrhenian coast. The first marine port of Rome was the river dock of ancient Ostia that served Rome since the 4th cent. BC, well before the excavation of the imperial ports of Claudius and Trajan during the first and the second cent. AD in the Tiber delta.

The fate of the harbour system of Rome is closely linked to the fluvial dynamics of the Tiber river and the winter storms that characterise the Tyrrhenian sea even today. It is well known that during Imperial time, intense floods occurred and ships were lost or prevented to reach the harbours because of heavy storms. During the 9th century AD, when the entrance of Claudius harbour was silted up and the Trajan basin became a lake isolated from the sea, ships started to use again the Tiber river mouth at Ostia. The progradation of the Tiber delta is well explained by the present location of Claudius and Trajan basins, ca. 3.5 km far from the Tyrrhenian coast.

The palynological and ostracodological investigations integrated by other proxies in six chronologically framed sediment cores in the Tiber delta, close to ancient Ostia and Portus towns, provide a picture of complex environmental and historical changes for the last three millennia. Core dating was a challenge. AMS radiocarbon ages from terrestrial and marine plant macro-remains and sediment bulk, as well as historical events, archaeological pottery and palaeomagnetism have been used.

The six considered sediment cores record different periods of time, at times overlapping. Lagoon and freshwater conditions were reconstructed through ostracod and foraminifer analyses of the sediments, and pollen analyses described a plant landscape typical of a coastal deltaic environment before harbour activities, with increasing human impact related to the presence of Ostia and Portus and of medieval settlements. Imperial age floods are evidenced by ostracod assemblages, while a thick cover of Renaissance floods is spread on most of the Tiber delta area. Natural sedimentation continued only in the Trajan lake, and its sediments record the recent environmental and historical changes such as the reclamation works of the area during the first half of the last century, as well as the nuclear explosions occurred during the second half of the last century.
Impact of the South China Sea summer monsoon on the Indian Ocean dipole in CMIP5 models
Authors: Zhang Yazhou , Li Jianping
Published: March 2022

The impact of the South China Sea summer monsoon (SCSSM) on the Indian Ocean dipole (IOD) has been systematically investigated in observations. This study focuses on the ability of climate models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5) to reproduce the observed relationship between the SCSSM and IOD, and the relevant physical mechanisms. All 23 models reproduce significant correlations between the SCSSM and IOD during boreal summer (June–July–August, JJA), whereas the influence of the SCSSM on the IOD varies considerably across the CMIP5 models. To explore the causes, all models are divided into two groups. Models that successfully simulated both the correlations between the SCSSM and JJA IOD and of the SCSSM and JJA IOD with precipitation over the western North Pacific and Maritime Continent are classified as Type-I, and these produce stronger low-level wind anomalies over the tropical southeastern Indian Ocean. The stronger low-level wind anomalies enhance local sea surface temperature (SST) anomalies via positive wind–evaporation–SST (WES) and wind–thermocline–SST (Bjerknes) feedbacks. This corresponds to a strengthening of IOD events due to the increased zonal gradient of SST anomalies over the tropical Indian Ocean. In contrast, Type-II models perform poorly in representing the relationship between the SCSSM and JJA IOD or relevant atmospheric bridges, corresponding to weaker WES and Bjerknes feedbacks, and produce weaker IOD events. These results demonstrate that the better the model simulation of the atmospheric bridge, the larger contribution of the SCSSM to the IOD.
A Semi-Lagrangian Advection Algorithm for Falling Raindrops in aTwo-Moment Microphysics Schemes
Authors: Hong Songyou , Li Haiqin , Bao Jian-Wen , Grell Georg , Sun Ruiyu
Published: March 2022

A semi-Lagrangian algorithm (SLA) is implemented in NOAA's Global Forecast System (GFS) for
simulating raindrop sedimentation in a double-moment microphysics schemes. This SLA includes
a significant improvement to its predecessor for single-moment raindrop sedimentation. It is
numerically stable and mass-conserving when used to sediment raindrops in double-moment
microphysics schemes. Numerical results from an idealized single-column model show that the
SLA overcomes an issue of mass accumulation at the cloud bottom in the case of the Eulerian
algorithm for raindrop sedimentation, which is due to the assumption of constant terminal
velocity within a time step of sedimentation. The results from the single-column model also show
that the time step in the SLA can be 10 times greater than that in the Eulerian algorithm for
sedimentation. Further numerical experiments using NOAA's GFS show that using the SLA
mitigates the numerical instability problem associated with a newly-implemented double-moment
microphysics scheme in the GFS.
Mapping the World at 10 m: A Novel Deep-Learning Land Use Land Cover Product and Beyond
Authors: Wright Dawn , Brumby Steve , Breyer Sean , Fitzgibbon Abigail , Pisut Dan , Statman-Weil Zoe , Hannel Mark , Mathis Mark , Kontgis Caitlin
Published: March 2022

Land use / land cover (LULC) maps provide critical information to governments, land use planners, and decision-makers about the spatial layout of the environment and how it is changing.  While a variety of LULC products exist, they are often coarse in resolution, not updated regularly, or require manual editing to be useful.  In partnership, Esri, Microsoft Planetary Computer, and Impact Observatory created the world’s first publicly available 10-m LULC map by automating and sharing a deep-learning model that was run on over 450,000 Sentinel-2 scenes.  The resulting map, released freely on Esri’s Living Atlas in June 2021, displays ten classes across the globe: built area, trees, scrub/shrub, cropland, bare ground, flooded vegetation, water, grassland, permanent snow/ice, clouds.  Here, we discuss key findings from the resulting map, including a quantitative analysis of how 10-m resolution allows us to assess small, low density urban areas compared to other LULC products, including the Copernicus CGLS-LC100 100-m resolution global map.  We will also share how we support project-based, on-demand LULC mapping and will present preliminary findings from a new globally consistent 2017-2021 annual LULC dataset across the entire Sentinel-2 archive.
Methane clumped isotope signature of anaerobic oxidation of methane
Authors: Liu Jiarui , Harris Rachel L. , Ash Jeanine L. , Ferry James G. , Labidi Jabrane , Krause Sebastian J.E. , Prakash Divya , Sherwood Lollar Barbara , Treude Tina , Warr Oliver , Young Edward D.
Published: March 2022

Microbial anaerobic oxidation of methane (AOM) significantly mitigates atmospheric methane emissions on Earth and represents a thermodynamically favorable metabolic strategy for astrobiological targets where methane has been detected. The bulk carbon and hydrogen isotope ratios produced by AOM have been used to probe the thermodynamic drive for intracellular reactions that involve the bi-directional enzymes of the methanogenesis pathway. Recently, measurements of the abundance of doubly-substituted methane isotopologues provide another dimension for assessing kinetic and equilibrium isotope effects and thus the AOM process itself. Towards this end, we measured methane clumped isotope ratios of residual methane in AOM-active microbial incubations using sediment slurry and/or fracture fluid from Svalbard methane seeps, Santa Barbara Channel methane seeps, Nankai Trough, and Beatrix Gold Mine. We also analyzed methane isotopologue abundances in sub-seafloor fluids from a Mariana mud volcano where AOM occurs. Extremely high Δ13CH3D and Δ12CH2D2 values were found in the Svalbard sediment slurry and the Mariana fluids where minimal reversibility of AOM intracellular reactions preserved signatures of kinetic fractionation of clumped isotopologues. When conditions were consistent with a low thermodynamic drive for AOM, however, methane isotopologues approached intramolecular quasi-equilibrium. This was notably observed in the microbial incubations of the deep biosphere samples from Nankai Trough and Beatrix Mine. This presentation will highlight the environmental controls on the enzymatic activity of intracellular pathways and the reversibility of AOM, and their intrinsic link to methane isotopologue ratios.
Determining sources of the 137Cs concentration in seawater at Fukushima Daiichi Nuclear Power Plant using Antecedent Precipitation Index
Authors: Sato Hikaru , Onda Yuichi
Published: March 2022

Radiocesium (137Cs) was one of the radioactive materials released from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011. Highly 137Cs contaminated water from groundwater to the sea was reduced after installation of the sea-side impermeable wall as a countermeasure against contaminated water in October 2015. As a result, 137Cs contamination in water from other sources became more prominent and the levels of 137Cs concentration in seawater was correlated with rainfall fluctuation. To determine the source of contamination, we estimated the fluctuation patterns of 137Cs concentration in seawater, groundwater level, and discharge from the channels using the Antecedent Precipitation Index (Rw) method.
The results indicated that the fluctuation in seawater collected near the 1-4 Units had strong agreement with the 3 day half-life of Rw. The half-life is shorter than that estimated by groundwater level (7 to 30 day). Therefore, the 137Cs concentration in seawater was influenced by relatively faster runoff than the deep groundwater flow. We also made the spatial distribution map of 137Cs concentration in seawater to determine the sources of contamination. It showed that the 137Cs contaminated area was the highest at “south- inside the intake of 1-4 Units” where the outlets of the K and BC discharge channels are located. In particular, the concentration of 137Cs in the channel K was found to correlate with the concentration of 137Cs in seawater near the 1-4 Units (average of R2 = 0.5). These results indicate that the concentration of 137Cs in seawater inside the FDNPP port can be estimated by the Rw method and that the source of the contamination could be determined using the half-life.
Drivers of the distribution of soil organic matter fractions along a geo-climatic gradient
Authors: Wasner Daniel , Abramoff Rose , Zagal Erick , Griepentrog Marco , Dötterl Sebastian
Published: March 2022

The concept of distinct soil organic matter (SOM) fractions – with differing formation pathways, stabilization mechanisms and responses to change – is a promising avenue to improve our understanding of soil carbon (C) dynamics. While there is widespread consensus on the general usefulness of conceptual fractions with specific functional implications, there is still a lack of information on the patterns with which they contribute to bulk soil organic carbon (SOC) stock at larger scales and across climatic and soil physicochemical gradients. In this study, we aimed to assess first the quantitative importance of three key SOM fractions across a diverse range of 12 soil groups with global significance. Secondly, we wanted to gain insights on the environmental drivers that shape the contribution of these fractions to SOC stocks.

Here we sampled a set of 35 grassland topsoils (0 – 10 cm) along a 3000 km north-south transect in Chile ranging from subpolar to Mediterranean climate, and covering 12 WRB major soil groups. Following a modified version of the protocol in Zimmermann et. al (2007), we partitioned the soils into three functional SOM fractions defined by particle size and density (free silt and clay, free particulate organic matter, stable microaggregates), enabling us to quantify SOC stocks and the relative contribution to SOC in these three fractions. In order to identify links between fractions and potential drivers of C stabilization, we further characterized extensively relevant physico-chemical properties of the soils, compiled climatic data of the sites and characterized OM maturity (DRIFT spectroscopy and Rock-Eval pyrolysis) as well as pedogenic, secondary Fe-, Al- and Mn-oxide concentrations through sequential extraction.

We found that the contributions of mineral-associated SOM fractions to bulk SOC varied strongly across the soil gradient, while the contribution of free particulate organic matter was comparatively stable and low. SOM associated with free silt and clay sized particles are the most important C reservoir in soils with less than 4 % SOC, whereas in soils with higher SOC content, the majority of the SOC is contained in stable microaggregates. The SOC stock in various fractions was sensitive to changes in temperature, pedogenic oxides, and OM input vs. decomposition. Comparison of OM maturity showed that free particulate OM and free silt and clay associated OM can be clearly distinguished, while OM in microaggregates is likely a mixture of both. However, drivers of OM composition in microaggregates could not be identified.

This study demonstrates that in SOC-rich soils, microaggregates represent a major fraction of bulk SOC, and that SOC stocks in key SOM fractions can be linked to distinct climatic and soil physicochemical factors.
Subsurface characterization of geological CO2 storage sites from gravity, passive seismic and seismic data; a case study from the southern Ebro basin (Spain) 
Authors: Ayala Conxi , Benjumea Beatriz , Mediato José Francisco , Rubio Félix , Rey-Moral Carmen , García-Crespo Jesús , Clariana Pilar , Soto Ruth , Pueyo Emilio L. , Fernández-Canteli Álvarez Paula
Published: March 2022

The geological storage of CO2 requires the search and characterization of a suitable porous formation and caprock to ensure a favorable and safe trap. One of the first steps of this search consists of performing a detailed definition of its geometry at depth.  The structure of Lopín (southern Ebro basin, Spain) was identified as a potential structure valid for CO2 storage in the frame of the ALGECO2 project (Selection and characterization plan of favorable areas and structures for Geological CO2 Storage in Spain, 2009-2014) led by IGME. A preliminary characterization carried out during these years showed positive conditions for the storage of this gas. However, the poor quality of the available reflection seismic data precluded accurate enough conclusions to select this location as geological storage site. The biggest uncertainty was the closure of the structure in its SE margin and further exploration was ruled out at that time. Within the PilotStrategy project (2021-2026), funded by UE on the frame of the H2020, the structure of Lopin is proposed for further studies and a gravimetric and passive seismic surveys have been carried out for in order to resolve this question.  The Lopín structure constitutes an antiform affecting Paleozoic and Mesozoic sequences overlain by subhorizontal Neogene deposits located in the southern Ebro basin. It is defined by NW-SE and NNW-SSE oriented faults several tenths of kilometres long which are subparallel to the orientation of the dominant structures of the Iberian Chain, located to the South of the study area. At the Lopín structure, the target reservoir and seal formations consist of the Lower and Upper Triassic rocks, respectively.  

 The aim of the new geophysical surveys is to improve the geometric characterization at depth of the Lopín structure.  The gravimetric surveys have coverage of two stations for km2 in the structure area. In addition, 7 profiles have been built up in the uncertainty area with a coverage of a station every 250 m. The models have been constrained by the newly acquired passive seismic data and the reinterpretation of some of the vintage seismic reflection profiles. The preliminary results of the joint modelling improve the geometrical characterization of the Lopín structure at depth in order to define its suitability as geological CO2 reservoir site. 
Modeling of Residual GNSS Station Motions through Meteorological Data in a Machine Learning Approach
Authors: Ruttner Pia , Hohensinn Roland , D'Aronco Stefano , Wegner Jan Dirk , Soja Benedikt
Published: March 2022

Global Navigation Satellite System (GNSS) long-term residual height time series exhibit signals related to environmental influences. These can partly b explained through environmental surface loads, which are described with physical models. In this work, a model is computed to connect the GNSS residuals with raw meteorological parameters. A Temporal Convolutional Network (TCN) is trained on 206 GNSS stations in central Europe, and applied to 68 test stations in the same area. The resulting Root Mean Square (RMS) error reduction is on average 0.8% lower for the TCN modeled time series, compared to using physical models for the reduction. In a further experiment, the TCN is trained on the GNSS time series after reducing those by the surface loading models. The aim is a further increase of RMS reduction, which is achieved with 2.7% on average, resulting in an overall mean reduction of 28.6%. The results suggest that with meteorological features as input data, TCN modeled reductions are able to compete with reductions derived from physical models. Trained on the residuals reduced by environmental loading models, the TCN is able to slightly increase the overall reduction of variations in the GNSS station position time series.
Hydroacoustic expression of offshore tsunami deposits on the Algarve shelf, Portugal
Authors: Feist Lisa , Costa Pedro J.M. , Santisteban Juan I. , Albers Stijn , De Batist Marc , Duarte João F. , Reicherter Klaus
Published: March 2022

Continental shelves are often affected by high-density sediment flows triggered by high-energy events such as floods, storms, submarine slope failures or tsunamis. The sedimentary imprints of these events are recorded as erosive or depositional features in the geological record of the shelves. Especially floods, storms and tsunamis can severely affect coastal societies and have an impact on local economies. Research focus on the sedimentary imprints of these events has relied essentially on onshore studies where their impacts are more noticeable and access is facilitated. However, investigations into the offshore domain become more important for palaeotsunami research as, in theory, their Holocene record can be better preserved there compared to shallower areas. The Algarve area, southern Portugal, provides conditions for a proof-of-concept study on offshore tsunami imprints as it was affected by the 1755 CE Lisbon tsunami and, probably, older events.

Here, we present sub-bottom profiles from an investigation into the shallow sedimentary cover of this area. Along with a coring campaign, the profiles were recorded in November 2018, within the scope of RV METEOR cruise M152, aiming to a) analyse the shelf’s Holocene sedimentary record in the most tsunamigenic earthquake-prone region in Atlantic Europe; and b) identify sedimentological features of offshore tsunami deposits. To support the results obtained from cruise M152 and to extend the collected profiles further towards the coast into shallower water depths, an additional hydroacoustic campaign was conducted in January 2020.

According to the profiles, the study area is generally marked by rough erosional seafloor and frequent exposure of bedrock. Sub-bottom profiles show different geomorphological conditions and sediment dynamics between the western and eastern parts of the study area. Already onboard METEOR during cruise M152, a strong reflector was noticed in the sub-bottom profiles of the western study area down to a water depth of 75 m and about 1.20-1.55 m below the seafloor. This reflector correlates with a conspicuous sediment layer in the cores of this transect which we interpret as a tsunami (backwash) deposit based on a multi-proxy approach applying various well-established and innovative analytical techniques. This tsunami deposit is unique in Portugal and dates to ca. 3400 cal. years BP. The January 2020 survey was also able to find the same strong reflector and trace it into shallower water depths. With a detailed analysis of the obtained profiles, we aim to investigate the lateral extent of this tsunami deposit, to better understand offshore tsunami processes, related sediment transport and the prevailing sediment dynamics of the Algarve shelf in general.