bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting the solar cycle amplitude with the new catalogue of hemispheric sunspot numbers
Authors: Jain Shantanu , Podladchikova Tatiana , Veronig Astrid M. , Sutyrina Olga , Dumbović Mateja , Clette Frédéric , Pötzi Werner
Published: March 2022

The sun’s magnetic field drives the 11-year solar cycle, and predicting its strength has practical importance for many space weather applications. Previous studies have shown that analysing the solar activity of the two hemispheres separately instead of the full sun can provide more detailed information on the activity evolution. However, the existing Hemispheric Sunspot Number data series (1945 onwards) was too short for meaningful solar cycle predictions. Based on a newly created hemispheric sunspot number catalogue for the time range 1874-2020 (Veronig et al. 2021, http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/652/A56) that is compatible with the International Sunspot Number from World Data Centre SILSO, we investigate the evolution of the solar cycle for the two hemispheres and develop a novel method for predicting the solar cycle amplitude. We demonstrate a steady relationship between the maximal growth rate of activity in the ascending phase of a cycle and its subsequent amplitude and form a 3rd order regression for the predictions. Testing this method for cycles 12-24, we show that the forecast made by the sum of the maximal growth rate from the North and South Hemispheric Sunspot number is more accurate than the same forecast from the Total Sunspot Number: The rms error of predictions is smaller by 27%, the correlation coefficient r is higher by 11% on average reaching values in the range r = 0.8-0.9 depending of the smoothing window of the monthly mean data. These findings demonstrate that empirical solar cycle prediction methods can be enhanced by investigating the solar cycle dynamics in terms of the hemispheric sunspot numbers, which is a strong argument supporting regular monitoring, recording, and analysing solar activity separately for the two hemispheres.
A comprehensive assessment of palaeowildfire activity across the Danian-C2 hyperthermal event by means of Raman spectroscopy-geothermometry
Authors: Theurer Thomas , Muirhead David , Jolley David , Mauquoy Dmitri
Published: March 2022

Widespread intensification in wildfire activity within recent years suggests our future alongside flammable ecosystems is one of complexity and likely severity. Understanding changes to wildfire behaviour under a shifting climate state relies considerably upon determining key changes in palaeowildfire activity, particularly those occurring during ‘similar’ instances of prehistoric climate change i.e., hyperthermals. The application of palaeoclimatological and palynological study alongside palaeowildfire analyses, in particular charcoal geothermometry, allows for relationships between plants, climate and fire to be derived, in turn revealing the potential changes to wildfires we may come to experience. Implementation of multiple palaeoenvironmental proxies alongside assessments of relative palaeofire intensity change are becoming increasingly more common. However, very few consider assemblages ‘analogous’ to anthropogenic climate. Within this study, we have applied Raman spectroscopy-geothermometry to detrital charcoals, preserved within lacustrine sediments of the Boltysh Impact Crater sediment core – sampling from four distinct climatic states across the Danian-C2 hyperthermal event. Developing upon preliminary work, we present the most extensive assessment of wildfire activity during a hyperthermal period to date, including pre-, syn-, and post-negative carbon isotope excursion stages, as well as ecosystem recovery. We have corresponded established palaeoclimatological and palynological data to our assessments of relative intensity change, with significant implications for our understanding of wildfire activity under anthropogenic climate upheaval. Our data further highlight the effectivity and applicability of quantifying palaeowildfire behaviour in order to better understand our own future in flames.
Old and cold contributions to the oxygen minimum zones
Authors: Davila Xabier , Gebbie Geoffrey , McDonagh Elaine , Lauvset Siv , Brakstad Ailin , Olsen Are
Published: March 2022

Oxygen minimum zones (OMZs) are oxygen-poor layers in the water column of great importance for marine ecosystems and biogeochemical processes. The position, size and extent of the OMZs are set by the source water properties, transport timescales, as well as respiration, both upstream of and within OMZs. Here we use an adjoint ocean circulation model built upon observations of ocean tracers to explore the complex interplay between chemical, biological and physical processes. Specifically, we determine the contributions of different water masses to the volume and oxygen deficiency of the OMZs. Among the tracers used, phosphate, oxygen and radiocarbons are included. These allow to first, constrain the ocean circulation and its timescales, and second, to determine where in the ocean oxygen utilization takes place. Here we show that the OMZs are ventilated at a wide range of timescales, ranging from a few years from adjacent regions in the tropics and subtropics, to more than 3000 years from distant deep water formation areas. Preliminary results suggest that the Antarctic marginal seas are key source water regions. While the fraction of water volume that originates in the Ross and Weddell Sea is relatively low (~20-30%), the contribution to the OMZs oxygen deficit is as large as ~40%, i.e., 40% of the apparent oxygen utilization is associated with these waters. This is a consequence of the long transit times involved, about 3000 years. Our results stress the importance of the contributions of the Ross and Weddell Seas to the climate sensitivity of the OMZs.
Impacts of continuous cover forestry and clear-cutting on water quality and the biodegradability of dissolved organic carbon in a drained boreal peatland 
Authors: Palviainen Marjo , Peltomaa Elina , Laurén Annamari (Ari) , Kinnunen Niko , Ojala Anne , Berninger Frank , Zhu Xudan , Pumpanen Jukka
Published: March 2022

Boreal peatlands are major sources of nitrogen (N), phosphorus (P) and dissolved organic carbon (DOC) to downstream aquatic ecosystems, and peatland forest harvesting further increases the export of DOC and nutrients. Increased DOC and nutrient loading affects biogeochemical processes and food webs of surface waters, and may cause eutrophication and hypoxia. Furthermore, lateral carbon (C) flux from terrestrial to aquatic ecosystems is an important but often ignored component of the global C cycle, because DOC mineralization to CO2 in inland waters markedly contributes to the total C emissions to the atmosphere. Continuous cover forestry (CCF) is proposed to be an environmentally more sustainable management option for peatland forests than clear-cutting. However, the environmental effects of CCF are poorly known. We studied ground water and ditch water N, P and DOC concentrations in clear-cut, partially harvested, i.e. CCF, and uncut drained peatland forests in Finland. We also investigated the effects of harvesting intensity on DOC quality and DOC biodegradation to CO2. Groundwater nutrient and DOC concentrations were lower in CCF and uncut forest than in the clear-cut forest. Groundwater DOC aromaticity was higher in the uncut forest than in the clear-cut and CCF, whereas ditch water aromaticity did not differ between the treatments. The biodegradation of DOC was studied by incubating water (at 15 °C for 24 h) 1, 3, 7 and 21 days after the sampling. The results indicated that the majority of the CO2 production took place during the first three days, and CO2 fluxes were considerably higher from the ditch water than from the groundwater. Biodegradability of DOC was lower in summer than in the other seasons. Ditch water and groundwater CO2 production were generally significantly higher in the clear-cut than in the uncut forest. The results suggest that partial harvesting used in CCF reduces DOC and nutrient concentrations in watercourses, decreases DOC biodegradability, and therefore the aquatic CO2 emissions compared to clear-cutting in drained peatland forests. Thus, CCF can cause less environmental drawbacks than the conventional clear-cutting.
Volcanic Debris Avalanche and accompanying shear zone slip surface formed by a perched scoria cone collapse on Ascension Island, South Atlantic 
Authors: James Honor
Published: March 2022

Volcanic debris avalanches occur when volcanic edifices collapse and flow as landslides. They are preserved in the geological record as volcanic debris avalanche deposits (VDADs). Analysis of these deposits can provide insight into the flow characteristics of the avalanche and its possible triggers.

Here we provide preliminary textural data on the shear zone layer at the base of a small-volume VDAD on Ascension Island, South Atlantic. The deposit has a volume of ~4 x 106 m3, covers 2 km2 and originated from the partial collapse of the northern flank of the 300ka Green Mountain scoria cone, which sits at 550 metres above sea level. The avalanche flowed 2 km down a ~10° slope, before stopping at in a small basin against a lava dome at 190 m above sea level.

Over most of its length the VDAD overlies an in-situ Green Mountain scoria fall deposit that was dispersed north during the eruption. The base of the deposit is marked by a fine-grained, ~2 cm-thick shear zone with slickensides. The shear zone is distinguishable in hand specimen from the rest of the deposit by being finer grained and indurated. The bulk of the VDAD is composed of semi-coherent, metre scale blocks of scoria with a poorly sorted volcaniclastic matrix composed of a hetereolithic clast population including randomly orientated clasts of basaltic scoria, pumice and lavas. The toe of the deposit is fractured and flame structures are abundant.

Preliminary Back-scattered Scanning Electron Microscope imaging of the shear zone reveal that porosity and pore interconnectivity decrease markedly towards the centre of the shear zone, and clasts become finer-grained, better sorted and more rounded. Experiments will be conducted on samples of Green Mountain Scoria using Rotary Shear Equipment to place constraints on slip rates and shear parameters. Ultimately, we hope to understand potential triggers of the failure and explore the hazards and potential for similar events on the island in the future.

 
Invisible Ship Tracks as Opportunistic Experiments for Aerosol Cloud Interactions
Authors: Manshausen Peter , Watson-Parris Duncan , Christensen Matthew , Jalkanen Jukka-Pekka , Stier Philip
Published: March 2022

Cloud reflectivity changes due to anthropogenic aerosol remain a source of significant uncertainty in our understanding of climate change. Ship tracks, long lines of polluted clouds that are visible in satellite images, have been used widely as opportunistic experiments for quantifying aerosol-cloud-interactions. However, only a small fraction of the clouds polluted by shipping show ship tracks, potentially introducing a sampling bias when extrapolating such studies to a wider range of environmental conditions.

To overcome this issue, we develop a novel method to investigate all clouds polluted by shipping, regardless of whether they exhibit visible ship tracks. While previous studies are limited to on the order of thousands of tracks, we use on the order of two million equivalent ship paths. Combined with reanalysis winds and trajectory modelling, these paths enable us to identify clouds that are exposed to pollution and compare them to unpolluted ones nearby. This way we show that formerly invisible ship emissions change cloud properties considerably: cloud droplet numbers increase even when no ship tracks are visible, with the anomaly roughly half as large as in visible tracks. These “invisible” ship tracks also show a more positive liquid water response. For the first time, we directly detect shipping-induced cloud property changes in the trade cumulus regions of the Atlantic. These regions also show stronger liquid water responses than the stratocumulus regions previously studied for ship tracks. We estimate the global radiative forcing from liquid water adjustment to be between (-1.89, -0.30) W m-2, well outside the equivalent IPCC estimate of (0.0, +0.4) W m-2. We also show that only 30 days of satellite observations are needed to confidently detect changes in cloud droplet number from known shipping, with implications for potential marine cloud brightening experiments.

Our results indicate that earlier studies of ship tracks may be suffering from selection biases by focusing only on visible tracks from satellite imagery. The strong liquid water path response we find translates to a larger aerosol cooling effect on the climate, potentially masking a higher climate sensitivity than observations would otherwise suggest. Further work is in progress to evaluate the dependency of aerosol effects on environmental factors such as atmospheric stability and sea surface temperature, as well as extending the analysis to cloud top height and, if possible, to cloud fraction.
Scale-wise relaxation to isotropy in direct numerical simulations
Authors: Bagiatis Georgios , Medvedova Alzbeta , Stiperski Ivana , Rotach Mathias , Kendl Alexander
Published: March 2022

The Kolmogorov hypothesis of local isotropy is fundamental in stochastic models of turbulence and generally assumed to hold for atmospheric turbulence. According to Kolmogorov’s second similarity hypothesis, there is a range of turbulent scales (inertial subrange) that are statistically isotropic and the statistics of these scales have a universal form that is uniquely determined by the TKE dissipation rate. Recent work based on atmospheric turbulence measurements has shown that the scale-wise route turbulence takes to reach isotropy at these smallest scales is uniquely determined by the anisotropy of the energy containing eddies.

In this study we explore the connection between large-scale anisotropy and the route to small-scale isotropy through direct numerical simulations (DNS). We perform simulations of neutral flow over flat and rough (wavy) surfaces at different Reynolds numbers, to investigate the scale-wise anisotropy as a function of height from the surface and surface-roughness. The resulting trajectories of relaxation to isotropy are compared to the experimental ones and the differences between the two are explored in light of the return-to-isotropy terms and Reynolds number.
Joint inversion of DC resistivity and potential field data under different model weighting functions 
Authors: Milano Maurizio , Varfinezhad Ramin , Fedi Maurizio
Published: March 2022

In this study we analyze the role of model weighting functions for resistivity and potential field data in both separate and joint inversion. We show that the model weighting function built with depth weighting and compacting factor, formerly formulated for the gravity and magnetics inversion, can be useful also for DC resistivity data modelling. The comparison was made using the depth weighting with different exponents and the roughness matrix under L1- and L2-norm Constrained Optimization. We then analyze the 2-D joint inversion of DC resistivity and potential field data, based on the above model weighting function and the cross-gradients constraint. We provide a number of synthetic cases to discuss the pro and cons of each model-weighting function and to examine the feasibility of the joint inversion algorithm. We then provide results from two real case datasets for mining and archeological exploration. The results show that the value of the β exponent is decisive for potential field problems, but it also leads to a faster convergence for the resistivity data inversion. Similarly, the role of compactness is important for modelling compact source from gravity and magnetic, and to warrant an even faster and compact solution for DC resistivity. On the other hand, the results of the joint inversion reveal that the cross gradient constraints allow a successful joint inversion even when resistivity and magnetic data are often not easily comparable.
Assessment of REgional MOdel REMO and its coupled version REMO-iMOVE over Central Asia
Authors: Rai Praveen , Ziegler Katrin , Abel Daniel , Pollinger Felix , Paeth Heiko
Published: March 2022

The climate over Central Asia has been investigated using the REMO (v2015) and its recent vegetation coupled version, REMO-iMOVE for the period of 2000-2015 at horizontal resolutions of 0.44° and 0.11°. Model evaluation is performed using the mean monthly bias patterns for temperature, precipitation, and leaf area index along with different statistical matrices. In comparison to the lower resolution of 0.44°, the spatial precipitation pattern at 0.11° is represented better. In the case of mean temperature, higher resolution simulation from both models tends to agree quite well with the validation dataset. Reduced bias in maximum and minimum temperature at 0.11° resolution is also observed over the study domain. There is improved temperature bias in REMO-iMOVE in comparison to the standard REMO version which has static vegetation while in the case of precipitation, the bias is larger in REMO-iMOVE. Since the iMOVE version is coupled to atmospheric and hydrological components, it has a clear advantage in capturing the vegetation cover and leaf area index better in comparison to the standalone REMO version. Overall, iMOVE is able to perform quite similar to REMO in simulating the mean climate of Central Asia but clearly advantageous in simulating vegetation parameters and temperature.
Paleocene stage boundaries and hyperthermal events (Wadi Nukhul and Gebel El Beida, Egypt): a possible link to global volcanism
Authors: Khozyem Hassan , Mahmoud Abdullah , Adatte Thierry , Keller Gerta , Spangenberg Jorge
Published: March 2022

Wadi Nukhul, Sinai and El-Beida mine section, Red Sea, Egypt are expanded sedimentary succession covering the time interval from upper Cretaceous to lower Eocene ind different depositional settings (inner shelf and epi-continental sea). Several stage boundaries and paleoclimatic changes have been recorded in El-Bieda mine section. Based on the integration of biostratigraphic data (planktonic foraminifera and nannofossils) and organic carbon isotope excursions, the following boundary and/or events are recorded (from the base to the top of the section): 1. Cretaceous Tertiary Maas extinction event (KTB), 2. Danian-C2 event (Dan-C2),  3. late Danian event (LDE), 4. Danian-Selandian boundary (DSB), 5. early-latest Paleocene event (ELPE), 6. Selandian/Thanetian boundary (S/Th), and 7. Paleocene/Eocene boundary (PEB). The same stage boundaries and events are present in Wadi Nukhul, and can be assessed by the correlation of isotopic profile of both sections, as well as the global carbon isotopic curve.

Mercury anomaly can help to investigate the relationships between the Large Igneous Provinces (LIPs) and the environmental perturbation occurred through the earth’s history, in both wadi Nukhul and El-Bieda mine, using of mercury anomaly profile can provide crucial information on the linkage between the LIPs and environmental changes that took place through its time of deposition. Therefore, based on the mercury anomaly and its correlation to organic matter contents, several of the determined Paleocene hypothermal events in both Wadi Nukhul and El-Bieda mine can be linked to LIPs such as the upper Cretaceous (Deccan trap) to the end of Paleocene (North Atlantic Igneous provinces NAIP- Phase1 and 2).

Keywords: El-Beida section, Wadi Nukhul, Stage boundaries, hyperthermal events, LIPs   
Global sensitivity of inundation extent and population exposure to flood magnitude 
Authors: Devitt Laura , Neal Jeffrey , Coxon Gemma , Wagener Thorsten
Published: March 2022

Understanding global river flood risk is fundamental for impact assessment of future climate and socio-economic change. There is a growing interest in understanding future flood risk using alternative methods that are independent of the uncertainties associated with the common approach based on a model cascade of global climate models coupled with hydrological and inundation models. Here, we propose a new sensitivity index that quantifies whether river reaches are more sensitive to flooding from low or high return periods using flood hazard data from a global flood model. We assess the sensitivity of flood extents and population exposure to increasing river flow magnitudes of 1.1 million river reaches globally. The dominant control on the sensitivity of reaches is the local topography and upstream drainage area. We find that steep bedrock and low slope alluvial streams are sensitive to high return periods, while intermediate and transitional streams are sensitive to low return periods. We find a clear spatial pattern in where the largest proportions of populations have settled on floodplains, which are found in North Africa, South America and South and East Asia. This analysis allows us to identify regions where river reaches and populations might be most affected by climate change and an increase in frequency and magnitude of flood events. 
Mid-Cenozoic absolute plate motion changes in the South Atlantic from relative plate motion analyses.
Authors: Espinoza Valentina , Iaffaldano Giampiero
Published: March 2022

Absolute plate motion (APM) estimates are key to understand the driving forces of plates, particularly the role of the sublithospheric mantle flow, which has recently gained renewed recognition as a dominant driver. Tectonic plates that lack a subducting boundary (e.g., South America and Nubia) are prime examples of dynamics governed by mantle flow. Both the aforementioned plates, however, lack the hotspot space/age coverage required for high-resolution, well-constrained APM estimates. Here we resort to highly-resolved data sets of relative plate motions (RPM) across a number of spreading ridges in order to extract information on APM changes through geological time. Our analyses involve first mitigating the impact of noise in RPM data sets via Bayesian inference. This allows us to identify time periods that feature a relatively high probability of staging RPM changes. By extending these analyses to several neighboring plates, we can assess whether any of them is likely to feature an APM change through geological time. We apply such a method to RPM data sets in the Atlantic realm and identify three time-intervals for changes in the APMs of the Nubia and South America plates. Our analyses are complemented by a quantitative assessment of the forces required to generate such APM changes.
An Integrated Approach of AHP-GIS Based Dam Site Suitability Mapping - A Noval Approach for Flood Alleviating Measures
Authors: Raaj Saran , Pathan Azazkhan , Mohseni Usman , Patidar Nilesh , jariwala Khushboo , Kachhawa Nitin , Agnihotri Dr. P.G , Patel Dr. Dhruvesh , Prieto Dr. Cristina , Gandhi Dr. Pankaj , Đurin Dr. Bojan
Published: March 2022

Surat is a district that has seen numerous floods and high rainfall over the last two decades. The solution to the problem, and the primary aim of this study, is to construct a storage facility, such as a dam, as part of flood prevention measures. The concept of multi-criteria decision making (MCDM) is now widely employed for everyday real-life challenges. Recent advancements and diverse approaches in geographic information systems (GIS) and remote sensing, along with the MCDM technique, will enable us to make an informed decision about where to build a dam site location model (DSLM). The Analytic Hierarchy Process (AHP) is the most frequently utilised MCDM technique for resolving water-related issues. To produce DSLM, ten thematic layers were considered: precipitation, stream order, geomorphology, geology, LULC, soil, distance to road, elevation, slope, and major fault fracture. Precipitation and stream order were the two most important elements affecting the DSLM. The weights of the thematic map layers were determined using the analytical hierarchy process (AHP) technique. These thematic maps and weights are used to perform overlay analysis, resulting in a suitability map with five classes ranging from high to low suitability. Three main sites have been selected as the best candidates for the construction of a new dam. By implementing this low-cost strategy, we may be able to reduce the amount of effort required in the traditional method of dam site selection while increasing decision-makers' accuracy. Approximately 14% of the Surat district is classified as a very high adaptability area, while 27.2 percent is classified as a high suitability area. This method can be applied all over the world to locate possible dam sites, which can be helpful for flood mitigation measures. In addition to that, the presented approach unveiled the scientific method for flood mitigation measures, which are in immediate demand all over the globe, especially in data-scarce regions.
Observed and modelled stem respiration CO2 and O2 fluxes in mature beech trees
Authors: Helm Juliane , Salomón Roberto , Muhr Jan , Steppe Kathy , Hilman Boaz , Hartmann Henrik
Published: March 2022

We lack a detailed understanding of tree carbon flux dynamics to quantify stem respiration correctly. Stem CO2 radial diffusivity and vertical CO2 transport with the xylem sap produce uncertainties in respiration estimates based on stem CO2 efflux measurements. Two independent approaches have been applied for comparison to assess such uncertainties: (1) the mass balance approach accounts for CO2 efflux from the stem to the atmosphere, CO2 transport through the xylem and CO2 stored within the stem to estimate total respiration rates, and (2) measurements of stem O2 consumption as a more robust proxy for stem respiration than stem CO2 efflux, because O2 is less soluble than CO2 in the sap solution and hence less  affected by vertical transport.

In this study, we compare these two approaches and study CO2 and O2 flux dynamics along the stem height to capture CO2 transport. During summer 2019, we measured vertical CO2 and radial CO2 and O2 fluxes, sap flow, stem temperature and xylem sap pH from twigs. Stem CO2 and O2 fluxes were calculated along 4-m stem segments on mature beech trees in a managed forest in Germany.

We found that xylem [CO2] and CO2 and O2 fluxes did not vary with stem height. Interestingly, stem CO2 efflux was a poor predictor of stem respiration in the monitored mature trees. O2 influx was always higher than CO2 efflux (on average CO2-to-O2 ratios was 0.72), resulting in an underestimation of stem respiration when using CO2 measurements only, which is standard practice.

Preliminary results of the implementation of this dataset into a biophysical stem respiration model (TReSpire) suggest that CO2 respired in the xylem of mature trees encounter a relatively long diffusive pathway to reach the bark tissues, so that a significant fraction of CO2 dissolves in the sap and is transported upwards before being detected by traditional approaches. Our study provides insights into stem carbon flux dynamics in large trees, and thus helps to improve estimation of ecosystem carbon cycling.  
On the rheology of dense flow regimes in snow avalanches
Authors: Ligneau Camille , Sovilla Betty , Gaume Johan
Published: March 2022

The effect of climate change becomes more and more perceptible in mountain areas. For instance, in low to medium elevations, the avalanche activity is already impacted because of a warmer snow cover. This warming has an important effect on the mechanical properties of snow, especially close to 0°C, where the temperature and the presence of liquid water greatly affects the cohesion and friction. In snow avalanches, the transition from cold (T < -2°C) to warm (T = 0°C) snow generates a variety of dense flow regimes which differ drastically in terms of velocity and shearing profiles. For a cold and loose snow, one can typically observe fast flows with Bagnold-shaped profiles of a few tens of meters per second, while a warm and wet snow exhibits low- or zero-sheared velocity profiles with a magnitude of a few meters per second, over the same topography.

The present work aims to investigate the rheology of flowing snow as a function of its physical properties, with a view to bring more physics into continuum avalanches models based on empirical coefficients. We use a 2D Discrete Element Modeling (DEM) to model snow as a cohesive granular material. The simulated distinct particles interact through a contact model that can be tuned in terms of cohesion and friction, in order to satisfy the four dense flow regimes: cold dense regime, sliding slab regime, warm shear regime and warm plug regime.

First, we calibrate the contact model to find the adequate ranges of cohesion and friction corresponding to the four flow regimes. We also highlight the particular boundary conditions that are required for specific flow regimes to occur, particularly the importance of the ground friction and the initial cohesion of the snow. Second, we extract rheological features such as the friction law μ(I) and the values of θstop for each flow regime and discuss their relevance regarding avalanche dynamics. Finally, the interaction of the flow regimes with an erodible snow cover is explored and discussed qualitatively.
Perceptions of heat-health impacts and the effects of knowledge andpreventive actions by outdoor workers in Hanoi, Vietnam
Authors: Lohrey Steffen , Chua Melissa , Gros Clemens , Faucet Jerôme , Lee Jason K.W.
Published: March 2022

Extreme heat is an increasing climate threat, most pronounced in urban areaswhere poor populations are at particular risk.Weanalyzed heat impacts and vulnerabilities of 1027 outdoorworkerswho participated in a KAP survey in Hanoi, Vietnam in 2018, and the influence of their mitigation actions, their knowledge of heat-risks, and access to early warnings.
We grouped respondents by their main income (vendors, builders, shippers, others, multiple jobs, and nonworking) and analyzed their reported heat-health impacts, taking into consideration socioeconomics, knowledge of heat impacts and preventive measures, actions taken, access to air-conditioning, drinking amounts and use of weather forecasts. We applied linear and logistic regression analyses using R.
Construction workers were younger and had less knowledge of heat-health impacts, but also reported fewer symptoms. Older females were more likely to report symptoms and visit a doctor. Access to air-conditioning in the bedroom depended on age and house ownership, but did not influence heat impacts as cooling was too expensive. Respondents who knew more heat exhaustion symptomswere more likely to report impacts (p< 0.01) or consult a doctor (p<0.05). Similarly, thosewho checkedweather updateswere more likely to report heat impacts (p< 0.01) and experienced about 0.6 more symptoms (p< 0.01). Even though occupation type did not explain heat illness, builders knewconsiderably less (40%; p<0.05) about heat than other groups butwere twice as likely to consult a doctor than street vendors (p < 0.01). Knowledge of preventive actions and taking these actions both correlated positively with reporting of heat-health symptoms, while drinking water did not reduce these symptoms (p < 0.01). Child carers and homeowners experienced income losses in heatwaves (p < 0.01). The differences support directed actions, such as dissemination of educational materials and weather forecasts for construction workers. The Red Cross assisted all groups with cooling tents, provision of drinks and health advice.
Sea level rise along the coastline of Colombia: A vulnerability assessment
Authors: Nevermann Hannes , Becerra Gomez Jorge Nicolas , Fröhle Peter , Shokri Nima
Published: March 2022

Abstract

In recent decades, the sea level has risen notably compared to the most recent millennia. This poses serious threats to environment and human population over the next century especially in coastal zones. Every region has climatic and non-climatic drivers of sea level rise which needs to be considered when adaptation and mitigation policies are implemented. We analyzed the coastal consequences of sea level rise along the Caribbean and Pacific coastlines of Colombia. Sea level rise projections published in August 2021 by the Intergovernmental Panel on Climate Change in the 6th assessment report were used in this study (IPCC, 2021). Five Shared Socioeconomic Pathways for the 21st century (SSP1-1.9, SSP1-2.6, SSP2-4.5. SSP3-7.0, SSP5-8.5) were examined. Our results indicate a sea level rise of 1.04 m in the worst-case scenario (SSP5-8.5) which could cause land loss in an area of 2840.64 km². The area at risk will impact 12 departments or 86 municipalities with different social, environmental, economic, and cultural conditions that need to be considered when implementing mitigation policies. Our results illustrate how the projected sea level changes influence a variety of parameters such as area at the potential risk of inundation, land use of the affected area and general socio-economic impacts along the Caribbean and Pacific coastlines of Colombia.

 

Reference

IPCC (2021), Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press. In Press.
Crowd modelling: Launching an open gravity-modelling call to challenge the Balmuccia peridotite body
Authors: Hetényi György , Baron Ludovic , Scarponi Matteo , Subedi Shiba , Michailos Konstantinos , Dal Fergus , Gerle Anna , Petri Benoît , Langone Antonio , Greenwood Andrew , Ziberna Luca , Pistone Mattia , Zanetti Alberto , Müntener Othmar
Published: March 2022

Modelling of geophysical data is often subject to choices made by the researcher undertaking the work. The level of structural complexity in the model, the bounds on parameters imposed by a priori knowledge, the thoroughness and efficiency in exploring the parameter space may all lead to bias in determining what the best fitting models can be.

To avoid bias from our own ideas in constraining the subsurface shape of a given density anomaly, we hereby invite anyone interested to create their own models. This is planned by sharing the same gravity data measured in the field, the same digital elevation model, the main features of the local geological maps, and bounds on the encountered rock density values. These data will be shared openly, in the form of a modelling challenge: each participating researcher or group is expected to submit their solution(s). All these will be compared during a dedicated workshop, ultimately resulting in a joint publication.

The target of this modelling challenge is the world-famous Balmuccia peridotite body (45.84°N, 8.16°E) in the Ivrea-Verbano Zone (IVZ). Here mantle rocks are naturally exposed at the surface, in the broader context of the IVZ, a middle- to lower crustal terrain along the Europe-Adria plate boundary’s eastern side. The surface exposure of the Balmuccia peridotite is ~ 4.4 km N-S by 0.6 km E-W, with outcrop elevation changes exceeding 1000 m. About 150 new gravity data points have been measured within a radius of 3 km from the centre of the peridotite body, along more or less accessible paths and slopes. The measurements have been carried out with a Scintrex CG-5 relative gravimeter, tied to a reference point, and all points located via differential GPS with typical vertical precision of a few cm. Farther away regional gravity data is available at few km spacing.

Beyond the modelling challenge, the interest in constraining the subsurface shape of the Balmuccia peridotite body is its future target role in the ICDP DIVE continental drilling project (www.dive2ivrea.org).
Modelling the 3-D evolution of glaciers at regional to global scales: challenges and opportunities
Authors: Zekollari Harry , Huss Matthias , Compagno Loris , Pattyn Frank , Goelzer Heiko , Lhermitte Stef , Wouters Bert , Farinotti Daniel
Published: March 2022

Various techniques exist to model the evolution from glaciers at regional to global scales. Whereas pioneering efforts typically relied on volume-area scaling approximations or parameterizations based on observed glacier changes (retreat parameterization), more recent approaches now also explicitly incorporate ice-dynamical processes. In these latter studies, glaciers are typically represented through central flowlines. Such flowline approaches are particularly suited for mountain glaciers that span over a large elevation range, i.e. valley-glaciers with an elongated shape. However, flowline approaches are not ideal to represent the geometry of ice caps (large glaciers) that generally have a dome-shaped geometry. For ice caps, a model representation that explicitly accounts for the glacier’s 3D geometry and that allows for the glacier to lose and gain mass in all directions, both through mass balance and ice dynamic processes, is needed.

Here we present simulations performed with a coupled surface mass balance – ice flow model that explicitly accounts for the 3D geometry of individual glaciers. The model, written in Python, relies on the shallow ice approximation to describe ice flow, allowing to run large ensembles of simulations. The goal is to simulate the temporal evolution of glaciers with distinct shapes and situated in various climatic regimes, i.e. having a model that allows for an automated intialization and that is suited for regional to global-scale applications.

In this contribution, we present simulations performed with this new large-scale model for regions with mountain glaciers (e.g. European Alps and Scandinavia), as well as regions with large ice caps (e.g. Iceland). Through this, we highlight various challenges that relate to model initialization or the choice of model settings, for instance. We also explore how simulated glacier evolutions compare to those simulated with a retreat parameterzation and through flowline modelling, thereby shedding light on the need for a 3D modelling approach.
MERMAIDs in the South Pacific Ocean: Observations, Measurements, Modeling, Data Availability, and First Hints at Mantle Structure
Authors: Irving Jessica , Simon Joel , Pipatprathanporn Sirawich , Simons Frederik , EarthScope-Oceans Consortium The
Published: March 2022

MERMAIDs (Mobile Earthquake Recording in Marine Areas by Independent Divers) are seismic instruments which record local, regional and teleseismic earthquakes, and other signals, in the oceans. In the Southern Pacific Ocean, some fifty MERMAIDs are collecting acoustic pressure time series as part of the South Pacific Plume Imaging and Modeling (SPPIM) project. Deployed in 2018 and 2019 by members of the EarthScope-Oceans consortium, these instruments record continuous time series data on a one-year buffer and autonomously report a wealth of waveforms, selectively triggered mostly by teleseismic events, suitable for mantle tomography. 

Listening for signals while roughly 1.5 km below the ocean surface, MERMAIDs' primary mission is to detect and deliver records of P-waves generated by distant earthquakes, and collectively they have returned many thousands of seismograms corresponding to such signals. We present highlights from our earthquake catalog and discuss the changing character and causes of the background noise. Whilst the South Pacific fleet is programmed to only send short seismic records, corresponding to confident identifications of teleseismic first arrivals, some records contain later-arriving phases. In addition to P-waves, we present a miscellany of observations of other signals, including core phases, converted S- and surface waves, and T-phases. Furthermore, we illustrate that we are able to obtain other recorded data segments through buffer requests via satellite. 

Data from the MERMAIDs owned by Geoazur and Princeton University that we report on here are being archived by IRIS—those from three instruments is available without embargo. We highlight MERMAID waveform availability and its utility to the scientific community via examples of their modeling and preliminary interpretations that can be made regarding wavespeed heterogeneity in the dynamic mantle below the Pacific Ocean. 
Modeling clinopyroxene and plagioclase growth kinetics at Mt. Etna and Stromboli
Authors: Moschini Piergiorgio , Mollo Silvio , Pontesilli Alessio , Gaeta Mario , Nazzari Manuela , Scarlato Piergiorgio
Published: March 2022

Textural and compositional changes of clinopyroxene and plagioclase crystals from mafic alkaline magmas are unequivocally related to specific dynamic processes, which extend over a broad range of spatial and temporal scales. Decoding the mechanisms controlling the growth of clinopyroxene and plagioclase crystals may play a key role for interpreting the final crystal cargo of variably undercooled magmas from active alkaline volcanoes. In this context, isothermal-isobaric and undercooling (i.e., cooling rate and decompression) experiments were conducted on primitive basalts from Mt. Etna and Stromboli volcanoes (Sicily, Italy). Clinopyroxene and plagioclase crystals were obtained at variable pressures (30-300 MPa), temperatures (1,050-1,150 °C), volatile contents (0-4.4 wt.% H2O and 0-0.2 wt.% CO2), and crystallization times (0.25-72 h). Compositional and textural features (i.e., length of major and minor axes, surface area per unit volume, area fraction, and growth rate) of the experimental charges were determined to constrain the key parameters governing the crystallization process. The correlation between growth rate and other system parameters, such as degree of undercooling, crystallization temperature, crystallization time, melt composition/structure (NBO/T) and melt-H2O concentration, was investigated via principal component analysis (PCA). Results point out that the crystal growth rate is primary controlled by experimental time and only subordinately by the degree of undercooling. Progressive decay of crystal growth rate over time is due to the transition between diffusion-controlled (skeletal and acicular morphologies) and interface-controlled (blocky, prismatic, and tabular morphologies) growth regimes. The growth rate-time relationship derived in laboratory is interpolated with natural textures from crystal size distribution (CSD) analysis of products recently erupted at Mt. Etna and Stromboli. Results indicate that the crystallization of clinopyroxene and plagioclase microlites is extremely fast, on the order of ~100-101 min. This temporal information allows to better constrain the cooling-decompression paths of magmas accelerating within the uppermost part of the plumbing system, providing new insights for the modeling of conduit dynamics.
Predicting resilience through the lens of competing adjustments to vegetation function
Authors: Sabot Manon , De Kauwe Martin , Pitman Andy , Medlyn Belinda , Ellsworth David , Caldararu Silvia , Zaehle Sönke , Mu Mengyuan , Gimeno Teresa
Published: March 2022

Predicting ecosystem resilience to droughts and heatwaves requires a predictive capacity that is currently lacking in land-surface models (LSMs). Eco-evolutionary optimisation approaches have the potential to increase predictability, but competing approaches are yet to be probed together in LSMs. Here, we coupled schemes that optimise canopy gas-exchange vs. leaf nitrogen investment, and both approaches were extended to account for hydraulic legacies from water-stress. We assessed model predictions using observations from a South-Eastern Australian woodland exposed to repeated drought between 2013 and 2020, under both ambient and elevated [CO2]. Our simulations were in good agreement with observations of transpiration (r2∼0.7), leaf water potential (±0.1 MPa), and leaf photosynthetic capacities (±5% of the observations). Despite predictions of significant percentage loss of conductivity (PLC) due to water stress in 2013, 2014, 2016, and 2017 (p99 > 45%), hydraulic legacy effects were small and recovered rapidly. Combining the optimisation schemes and hydraulic legacies led to improved model predictions and enhanced the simulated magnitude fertilisation effect on GPP at elevated [CO2], albeit that the impact on the canopy fluxes was small overall. Our simulations suggested that leaf shedding and/or suppressed foliage growth formed an active strategy to mitigate drought risk, with leaves being grown during wet years to replenish carbon stores, whereas LAI dropped in anticipation of severe water stress to prevent high PLC. Accounting for leaf acclimation in response to drought therefore has the potential to improve predictions of ecosystem resilience to drought in water-limited regions.
Cloud type machine learning shows better present-day cloud representation in climate models is associated with higher climate sensitivity
Authors: Kuma Peter , Bender Frida , Schuddeboom Alex , McDonald Adrian
Published: March 2022

Uncertainty in cloud feedback in climate models is a major limitation in projections of future climate. We analyse cloud biases and trends in climate models relative to satellite observations, and relate them to equilibrium climate sensitivity, transient climate response and cloud feedback. For this purpose, we develop a deep convolutional artificial neural network for determination of cloud types from low-resolution daily mean top of atmosphere shortwave and longwave radiation images, corresponding to the World Meteorological Organization (WMO) cloud genera recorded by human observers in the Global Telecommunication System. We train this network on a satellite top of atmosphere radiation dataset, and apply it on the Climate Model Intercomparison Project phase 5 and 6 (CMIP5 and CMIP6) historical and abrupt-4xCO2 experiment model output and the ERA5 and Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2) reanalyses. We compare these with satellite observations, link cloud type occurrence biases and trends to climate sensitivity, and compare our cloud types with an existing cloud regime classification based on the Moderate Resolution Imaging Spectroradiometer (MODIS) and International Satellite Cloud Climatology Project (ISCCP) satellite data. We show that there is a strong linear relationship between the root mean square error of cloud type occurrence and model equilibrium climate sensitivity, transient climate response and cloud feedback (Bayes factor 7×102, 4×102 and 13, respectively). This indicates that models with a better representation of the cloud types have a more positive cloud feedback and higher climate sensitivity. Along with other studies, our results point to a choice between two explanations: either high sensitivity models are plausible, contrary to combined assessments of climate sensitivity and cloud feedback in previous review studies, or the accuracy of representation of present-day clouds in models is negatively correlated with the accuracy of representation of future projected clouds.