bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations of the (1-0) band of CO in Venus using VIRTIS-H aboard Venus Express
Authors: Freire Constança , Widemann Thomas , Encrenaz Thérèse , Machado Pedro , Dias João
Published: March 2022

We have used infrared spectra of the dark side of Venus, recorded by the VIRTIS-H spectrometer (Drossart et al. Proc. SPIE 5543, 175, 2014) aboard Venus Express (Svedhem et al. JGR 113, E00B33, 2008), to analyze the CO (1-0) band around 4.7 µm. The resolving power of VIRTIS-H (about 1200) is sufficient to separate the individual lines of CO. We have selected two sets of spectra, the first one at mid-latitude (43°S) and the other in the polar collar (69-83°S). The CO individual lines appear in absorption in the first case, and in emission in the second case, as a consequence of a temperature inversion occurring at high latitude at the level of the upper cloud top. Synthetic models have been calculated using the Planetary Spectrum Generator (Villanueva et al. JQSRT 217, 86, 2018). Information is retrieved on the thermal vertical profile and the CO vertical distribution at both latitudes. This work illustrates the capabilities of high-resolution infrared spectroscopy for monitoring minor atmospheric species in the mesosphere of Venus, in the perspective of the EnVision mission (Helbert et al. Proc. SPIE 11128, A1112804, 2019).
The contribution of glaciers to streamflow and surface water supply: a global-scale analysis
Authors: Cáceres Denise , Döll Petra
Published: March 2022

Glaciers are important contributors to streamflow (Q), acting as water storage units during the accumulation season of a glaciological year and releasing water during its melting season. Glaciers often play an essential role in semiarid regions where the anthropogenic pressure on surface water resources is very high (e.g., Indus basin). The climate-driven glacier retreat observed worldwide is having major consequences on surface water supply. Here, we present a model-based approach to estimate the contribution of glaciers to streamflow and surface water supply over the global continental area (except Greenland and Antarctica). We refer to this contribution, i.e. the fraction of Q that can be explained by the presence of glaciers as opposed to their absence, as glacier-dependent streamflow (GDS). GDS is derived from the global hydrology model WaterGAP 2.2d at 0.5° resolution; it is equal to the difference between Q computed with the standard version of the model, which does not include glaciers, and Q computed with a non-standard version that includes glaciers (Cáceres et al., 2020). Global maps of mean yearly and mean monthly GDS are given in absolute values (m3/s), and in percentage of Q and of consumptive water use from surface water over two 30-year periods, 1951-1980 and 1981-2010. The model performance is evaluated by comparing Q simulated with WaterGAP 2.2d including glaciers to observations from the Global Streamflow Indices and Metadata archive (GSIM) downstream from glaciers. With this study, we aim (1) to identify the regions that rely the most on GDS for surface water supply and are therefore most vulnerable to water scarcity problems related to glacier retreat, (2) to identify spatial and temporal changes (e.g., shifts in seasonality, long-term trend) in GDS between 1951-1980 and 1981-2010, and (3) to evaluate the performance of WaterGAP 2.2d including glaciers in terms of Q.

Cáceres, D., Marzeion, B., Malles, J. H., Gutknecht, B. D., Müller Schmied, H., and Döll, P.: Assessing global water mass transfers from continents to oceans over the period 1948–2016, 24, 4831–4851, https://doi.org/10.5194/hess-24-4831-2020, 2020.
Could the Laurentide Ice Sheet have exhibited internal oscillations?
Authors: Moreno Daniel , Alvarez-Solas Jorge , Montoya Marisa , Blasco Javier , Robinson Alexander
Published: March 2022

It is well known that the climate during the last glacial period was far from stable. The presence of layers of ice-rafted debris (IRD) in deep-sea sediments has been interpreted to reflect quasi-periodic episodes of massive iceberg calving from the Laurentide Ice Sheet (LIS). Several mechanisms have been proposed, yet the ultimate cause of these events is still under debate. From the point of view of ice dynamics, one of the main sources of uncertainty and diversity in model response is the choice of the basal friction law. Therefore, it is essential to determine the impact of basal friction on ice-stream surges. Here we study the effect of a wide range of basal friction parameters and laws for the LIS under constant LGM boundary conditions by running ensembles of simulations using a higher-order ice-sheet model. The potential feedbacks among till mechanics, basal hydrology and thermodynamics are also considered to shed light on the behaviour of the ice flow. Our aim is to determine under what conditions, if any, physically-based internal oscillations are possible in the LIS. Increasing our understanding of both basal friction laws and basal hydrology will improve not only reconstructions of paleo ice dynamics but also help to constrain the potential future evolution of current ice sheets.
Investigation of the spatial correlation structure of 2-D wave fields at the Aegean Sea
Authors: Trompouki Alexandra , Vrettou Sofia Efraimia , Sargentis G.-Foivos , Dimitriadis Panayiotis , Iliopoulou Theano , Koutsoyiannis Demetris
Published: March 2022

The great potential of oceanic energy resources adds a new challenge in the field of off-shore engineering, that of the efficient energy extraction from sophisticated structures in the open sea. An additional challenge that the engineers have to face is the intrinsic uncertainty of the oceanic processes. In this work, we investigate the uncertainty of the wave process through the estimation of the variability in two-dimensional wave height and direction data. These are retrieved from satellite images over the Aegean Sea for a 5-year period with a 3-hour resolution. Particularly, we estimate first-order moments, considering the double seasonality of the wave events, and also the correlation structure in terms of the climacogram (i.e., variance of the averaged process vs. spatial scale). Finally, we discuss on how the spatial dependence of the wave field is affected by various weather events.
Stochastic simulation of hydrological timeseries for data scarce regions - Case study at the Municipality of Western Mani 
Authors: Siganou Aimilia , Nikolinakou Maria , Markantonis David , Moraiti Konstantina , Sargentis G.-Fivos , Iliopoulou Theano , Dimitriadis Panayiotis , Chiotinis Michalis , Mamassis Nikos , Koutsoyiannis Demetris
Published: March 2022

West Mani, an attractive place in western Peloponnese, Greece, faces water shortage. The problem lies not only in the quantity but also in the quality of the available water. Investigating the options for the sustainable management of water resources, utilizing surface water seems to be the optimal solution. However, the complex geomorphology and geology of the study area, and its particular its karstic structure, when combined with the scarcity of hydrological data, makes the estimation of surface water availability challenging. As a result, it is considered necessary to take hydrological uncertainty into account using stochastic analysis. To this aim, we generate synthetic rainfall and streamflow timeseries based on available meteorological data from basins near the area of interest. We then appropriately adjust them so that they represent the magnitude and the variability of the rainfall and streamflow of the study area. For the timeseries generation algorithm, we employ a stochastic model following the Hurst-Kolmogorov dynamics by reproducing marginal distribution, seasonality and persistence.
Flood analysis using HEC-RAS: The case study of Majalaya, Indonesia under the CMIP6 projection
Authors: Rohmat Faizal Immaddudin Wira , Stamataki Ioanna , Sa'adi Zulfaqar , Fitriani Djelia
Published: March 2022

Flooding is a natural disaster with extremely wide-reaching impacts and is a recurring problem in Indonesia. Whilst possible impacts of climate change are expected to aggravate flood risk in already flood-vulnerable areas, many countries struggle to achieve the United Nations’ (UN) 2030 Sustainable Development Goals (SDGs) to achieve a better and more sustainable future for all. Using the case study of Majalaya, Indonesia, the authors investigated the impact of climate change and climate variability on urban flood risk through science-based spatio-temporal flood simulations. Based on the ensemble of 17 General Circulation Models (GCMs) CMIP6, the near-future (2021 to 2050) flood projection under Shared Socioeconomic Pathways (SSPs) 2.6 (low forcing), 4.5 (medium forcing) and 8.5 (high end forcing) common to historical (1981 to 2014) was simulated. The area’s future risk of flooding was then investigated and adaptation measures were suggested for reducing and mitigating worsening flood conditions. A numerical model was developed in HEC-RAS that represented the city of Majalaya and the results were combined with the ensemble of climate projections to enable the assessment of the effects of flooding due to the combined effect of climate change and urbanisation. The model was calibrated using historical stream gauge records and past extreme flood inundation boundaries. Using the model’s output metrics (e.g. flood depth, velocity) and local demographic data, the project aims then to use a vulnerability assessment framework to quantify the impact of climate change on flood risk. The modelling results will allow for spatio-temporal mapping of the flood-prone areas in Majalaya, which will help reduce risk and vulnerability for disadvantaged populations. The development of flood vulnerability maps and future flood risk projections will assist the government in developing land-use and flood prevention management policies. This research area, drawing from the combination of flood modelling and the use of climate projections, allows for an assessment of future flood risk scenarios of the city of Majalaya and paves new avenues towards future research.
Water harvesting by ancient farmers in the Negev desert, Israel: Overland flow generation and continuity considerations
Authors: Lavee Hanoch
Published: March 2022

Stone mounds and water conduits dating from the Nabatean, Roman and Byzantine periods (4th century B.C. to 7th century A.D.) can be found on hillslopes over large areas in the Negev Desert, as well as in other parts of the Middle East and North Africa.

Based on results from field and laboratory experiments it is suggested that the ancient farmers were very efficient in harvesting water; they took into consideration the size and position of the stones when clearing the hillslope surface in order to increase the overland flow yield.

A comparison of the volume of stones in the mounds to the volume of surface stones from the surrounding areas indicates that the ancient farmers removed only stones that had been rested on top of the soil surface and left the embedded stones untouched. According to the results of simulated rainfall experiments, this selective removal of stones increased the volume of overland flow generation by almost 250%, for small rainfall events, compared to natural untreated soil surfaces. In addition, they realized that installing closely spaced conduits running in parallel along the hillslope would increase the trapping efficiency of overland flow on its way downslope.

This means that the ancient farmers have been well aware of the mechanisms of overland flow generation on stony soils and of overland flow dis-continuity on arid hillslopes.
Reconstructing rainfall in sandy drylands of southern Africa: exploring the potential of the chloride mass balance hydrostratigraphy approach in Kalahari sand dunes. 
Authors: Stone Abi , Zeng Yijian , van der Ploeg Martine
Published: March 2022

Sand dunes sediments are a commonly used archive for palaeoenvironmental reconstruction, with chronologies for their accumulation rates, and migration rates, used in a large number of palaeoenvironmental reconstructions across global sand-rich drylands. A less common use of sand dunes as an archive is to explore the chemical and isotopic composition of the pore moisture stored within the sand. Sand dunes, constitute the uppermost unit above dryland aquifers, and represent part of the unsaturated (or vadose) zone in terms of hydrogeology. Chloride is a chemical tracer within the vadose zone that is commonly used to understand, and quantify rates of, recharge to the groundwater table, using a chloride mass balance (CMB) approach (e.g. Scanlon et al., 2006). In doing so, any variations in the concentration of pore-moisture chloride between discrete depths in the sand profile can also be used to provide a novel archive for tracking changes in palaeomoisture availability and land-use change (see review in Stone and Edmunds, 2016). This approach is known as a ‘hydrostratigraphy’.

This presentation will explore the utility of the CMB hydrostatigraphy approach for Kalahari linear dunes above the Stampriet Basin, which is a transboundary aquifer within southern Africa. This is a region for which palaeoenvironmental proxies for rainfall are extremely scarce, owing to poor preservation of organic-rich material in this oxygen-rich environment. Three repeat field visits for sampling the dunes (2011, 2013 and 2016) were used in the research design in order to explore the repeatability of this CMB hydrostratigraphy approach at this location. In addition, a transect of dunes, including dunes close to a pan, were sampled. It was hypothesised that those dunes in close proximity to the pan would be unsuitable, owing to the possible presence of Cl-rich evaporites and capillary zone influences on the behaviour of moisture in the sand-rich sediment. The trends in these profiles will be presented, along with attempts to understand the moisture pathway behaviour in these dune sediments.  

 

References

Scanlon, B.R., Mukerhjee, A., Gates, J., Reedy, R., Sinha, A.K., 2010. Groundwater recharge in natural dune systems and agricultural ecosystems in the Thar Desert region, Rajasthan, India. Hydrogeology Journal 18, 959–972.

Stone, A. E. C., Edmunds, W. M. (2016) Unsaturated zone hydrostratigraphies: A novel archive of past climates in dryland continental regions. Earth-Science Reviews 157, 121-144.
Fluid simulations accelerated with 16 bits: Approaching 4x speedup on A64FX by squeezing ShallowWaters.jl into Float16
Authors: Klöwer Milan , Hatfield Samuel , Croci Matteo , Düben Peter D. , Palmer Tim
Published: March 2022

Most Earth-system simulations run on conventional CPUs in 64-bit double precision floating-point numbers Float64, although the need for high-precision calculations in the presence of large uncertainties has been questioned. Fugaku, currently the world’s fastest supercomputer, is based on A64FX microprocessors, which also support the 16-bit low-precision format Float16. We investigate the Float16 performance on A64FX with ShallowWaters.jl, the first fluid circulation model that runs entirely with 16-bit arithmetic. The model implements techniques that address precision and dynamic range issues in 16 bits. The precision-critical time integration is augmented to include compensated summation to minimise rounding errors. Such a compensated time integration is as precise but faster than mixed-precision with 16 and 32-bit floats. As subnormals are inefficiently supported on A64FX the very limited range available in Float16 is 6·10-5 to 65,504. We develop the analysis-number format Sherlogs.jl to log the arithmetic results during the simulation. The equations in ShallowWaters.jl are then systematically rescaled to fit into Float16, using 97% of the available representable numbers. Consequently, we benchmark speedups of up to 3.8x on A64FX with Float16. Adding a compensated time integration, speedups reach up to 3.6x. Although ShallowWaters.jl is simplified compared to large Earth-system models, it shares essential algorithms and therefore shows that 16-bit calculations are indeed a competitive way to accelerate Earth-system simulations on available hardware.
Differential response of soil CO2, CH4, and N2O emissions to edaphic properties and microbial attributes following afforestation in central China
Authors: Chen Qiong , Cheng Xiaoli
Published: March 2022

Land use change specially affects greenhouse gases (GHGs) emissions, and it can act as a sink/source of GHGs. Alterations in edaphic properties and microbial attributes induced by land use change can individually/interactively contribute to GHGs emission, but how they predictably affect soil CO2, CH4, and N2O emissions remain unclear. Here, we investigated the direct and indirect controls of edaphic properties [i.e. dissolved organic C (DOC), soil organic C (SOC), total N (TN), C: N ratio, NH4+-N, NO3－-N, soil temperature (ST), soil moisture (SM), pH, bulk density (BD)] and microbial attributes [i.e. total PLFAs (Phospholipid fatty acids), 18:1ω7c, nitrifying genes (ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB)), and denitrifying genes (nirS, nirK, and nosZ)] over the annual soil CO2, CH4, and N2O emissions from the woodland, shrubland, and abandoned land in subtropical China. Soil CO2 and N2O emissions were higher in the afforested lands (woodland and shrubland) than in the abandoned land, but the annual cumulative CH4 uptake did not significantly differ among all land use types. The CO2 emission was positively associated with microbial activities (e.g., total PLFAs), while the CH4 uptake was tightly correlated with soil environments (i.e. ST, SM) and chemical properties (i.e. DOC, C:N ratio, NH4+-N concentration), but not significantly related to the methanotrophic bacteria (i.e. 18:1ω7c). Whereas, soil N2O emission was positively associated with nitrifying genes, but negatively correlated with denitrifying genes especially nosZ. Overall, our results suggested that soil CO2 and N2O emissions were directly dependent on microbial attributes, and soil CH4 uptake was more directly related to edaphic properties rather than microbial attributes. Thus, different patterns of soil CO2, CH4, and N2O emissions and associated controls following land use change provided novel insights into predicting the effects of afforestation on climate change mitigation outcomes.
Connecting spatial climate information to infrastructure operations using deep reinforcement learning
Authors: Ekblad Liam , Herman Jonathan , Steinschneider Scott , Giuliani Matteo , Castelletti Andrea
Published: March 2022

Water infrastructure operations can adapt to both short-term variability and long-term change. Studies that have leveraged climate information to reoperate infrastructure have yet to explore the direct use of spatially distributed information in operating policy training, which could enable learning from weather patterns associated with emerging risks—for example, flood and drought events associated with atmospheric rivers or high-pressure ridges, respectively, which result from co-occurring weather and climate patterns on multiple timescales. This study investigates the potential for spatial projections from large-ensemble climate models to directly inform reservoir operating policies using a deep reinforcement learning strategy, aiming to discover flexible, climate-informed policies without prior dimension reduction, which could cause loss of information. The approach is demonstrated for Folsom Reservoir in California. We investigate how learned policies interpret spatial climate information by connecting flood control and water supply shortage operations to the sensitivity and salience patterns associated with the input images. To assess the extent to which trained policies generalize to possible future climates, policies trained on historical data are tested on held-out scenarios drawn from the same period, and their performance is compared to flood and shortage scenarios drawn from a future period. Trained policies are robust to the variability present across climate model ensembles, demonstrate value in identifying spatial climate patterns for operations, and maintain the flexibility to dynamically adapt to climate change as it occurs, illustrating a broad benefit to global infrastructure systems facing climate risks.
Non-homogenous analysis of shoaling rogue wave statistics
Authors: Mendes Saulo , Scotti Alberto , Brunetti Maura , Kasparian Jerome
Published: March 2022

Non-equilibrium evolution of wave fields due to shoaling can amplify rogue wave statistics. This process is studied by the analysis of spatial variations in the energy density and time averages, affecting the Khintchine theorem. The resulting probability model reproduces the heavy tail of the probability distribution of unidirectional wave tank experiments, describes why the peak of rogue wave probability appears atop the shoal, and explains the influence of depth on variations in peak intensity.
Compressing atmospheric data into its real information content
Authors: Klöwer Milan , Razinger Miha , Dominguez Juan J. , Düben Peter D. , Palmer Tim
Published: March 2022

Hundreds of petabytes are produced annually at weather and climate forecast centres worldwide. Compression is essential to reduce storage and to facilitate data sharing. Current techniques do not distinguish the real from the false information in data, leaving the level of meaningful precision unassessed or often subjectively chosen. Many of the trailing mantissa bits in floating-point numbers occur independently with high information entropy, reducing the efficiency of compression algorithms. Here we define the bitwise real information content from information theory as the mutual information of bits in adjacent grid points. The analysis automatically determines a precision from the data itself, based on the separation of real and false information bits. Applied to data from the Copernicus Atmospheric Monitoring Service (CAMS), most variables contain fewer than 7  bits of real information per value and are highly compressible due to spatio-temporal correlation. Rounding bits without real information to zero facilitates lossless compression algorithms and encodes the uncertainty within the data itself. The removal of bits with high entropy but low real information allows us to minimize information loss but maximize the efficiency of the compression algorithms. All CAMS data are 17x compressed in the longitudinal dimension and relative to 64-bit floats, while preserving 99% of real information. Combined with four-dimensional compression using the floating-point compressor Zfp, factors beyond 60x are achieved, with no significant increase of the forecast error. For multidimensional compression it is generally advantageous to include as many highly correlated dimensions as possible. A data compression Turing test is proposed to optimize compressibility while minimizing information loss for the end use of weather and climate forecast data. 
Tracking mountain geohazards in Uzbekistan with application of remote sensing and advances in data analysis.
Authors: Sabitov Timur , Petrov Maxim , Mamirov Halim , Akbarov Fahriddin , Suvonqulov Sarkorbek , Sabitova Naila
Published: March 2022

Climate change is affecting the environment of Central Asia, the high mountains and particularly the paraglacial and glacial environments. Trends shown to affect the state and dynamics of glaciation; a gradual decrease in both area and volume, and the increase in the area of moraine deposits can be observed. Meanwhile, the frequency of occurrence of hazardous geological phenomena's related to glacial dynamics, such as outbursts of glacial lakes (GLOF'S), avalanches, rockfalls, blockages of river channels, as well as mudflows, is increasing. Observations after them are complicated by the inaccessibility of areas due to lack of infrastructure, seasonal restrictions, the required number of people to conduct observations in the field and financial costs. Studies shown that remote sensing technologies allow observation of changes and proved to have sufficient spatial and temporal resolution to assess the transformations taking place. In our study, we propose a method for assessing statistically significant changes occurring in the catchment for each of the image elements (pixel) over time using nonparametric statistics. The novelty of the work is the application of an assessment of the significance of these changes that allows to reduce the influence of human error in the analysis of images thus producing higher quality results and reducing time required. Although the technology is known in the world - and is used to solve the problems of machine learning and deep vision. For the territory of Uzbekistan and in this research area, this method is innovative, and the statistical assessment of significance over time is used for the first time. Thus, the method makes it possible to identify areas where significant changes have occurred due to events mentioned above, and reduces the amount of time and costs required to search for these areas to prevent or reduce further damage.
Angularly-resolved measurements of light scattering by smoke from wildfires during FIREX-AQ
Authors: Ahern Adam T. , Wagner Nicholas L. , Brock Charles A. , Lyu Ming , Moore Richard H. , Wiggins Elizabeth B. , Winstead Edward L. , Robinson Claire E. , Murphy Daniel M.
Published: March 2022

The open burning of biomass fuels is an important source of aerosols because they contribute significantly to the pre-industrial radiative forcing budget and they are a large source of aerosol in the modern era that is anticipated to increase due to climate change. However, the optical properties of smoke have been shown to be complex and variable, which in turn complicates a) the retrieval of aerosol properties using remote measurements and b) the estimation of the direct radiative forcing caused by smoke.

During the FIREX-AQ aircraft campaign, we measured the angular distribution of light (i.e. scattering phase function) scattered by smoke in situ using the NOAA Laser Imaging Nephelometer. We then used collocated measurements of the particle size distribution and literature values of the complex refractive indices to calculate expected phase functions using Mie theory. When comparing the measured versus calculated phase functions, we see there is more backscattered light in the measurements.

This enhanced backscatter has two important repercussions. First, when the measured phase function is used with an open source algorithm (GRASP) to retrieve the particle mode size, we find that the algorithm tends to undersize the particles by about 10%. Second, when the enhanced backscatter is included in a simple radiative transfer model, we observe an additional 20% cooling effect from fresh smoke.
Mass movement reconstruction and boulder size-frequency distribution of the Simud Vallis landslide, Mars
Authors: Pajola Maurizio , Mergili Martin , Cambianica Pamela , Lucchetti Alice , Brunetti Maria Teresa , Guimpier Anthony , Mastropietro Maria , Munaretto Giovanni , Conway Susan , Beccarelli Joel , Cremonese Gabriele
Published: March 2022

We study a young (~ 4.5 Ma), 3.4 km long landslide located in the floor of Simud Vallis, a large outflow channel that together with Tiu Vallis once connected the Valles Marineris with the Chryse Planitia on Mars (1). Multiple teardrop-shaped islands are present on Simud Vallis’ floor, all elongated in the S–N direction of the flow (2) that incised the Mid-Noachian plateau (3). The Simud Vallis (SV) landslide is located on the western side of one of such landforms. It is characterized by numerous boulders on its deposits (4). By making use of the 2 m-scale HiRISE DEM of (4) we reconstruct the terrain surface before the SV landslide. We thereby estimate the release and deposition heights and volumes related to the rotational slide of the landslide, called stage 1, and of the subsequent flow, called stage 2. Using the r.avaflow software (5) we simulate the mass movement of stage 2 and obtain simulated deposits that are comparable to the current landslide deposit in terms of both horizontal extent and thickness (6). Through two 0.25 m-scale HiRISE images we identify and manually count >130,000 boulders that are located along the landslide, deriving their size-frequency distribution and spatial density per unit area for boulders with an equivalent diameter ≥1.75 m. Our analyses (6) shows that the distribution is of a Weibull-type (7), which commonly results from sequential fragmentation and it is often used to describe the particle distribution derived from grinding experiments (8,9). This suggests that the rocky constituents of the SV landslide fractured and fragmented progressively during the course of the mass movement, consistent with our proposed two-stage model of landslide motion.

References:

 (1) Pajola, M. et al., 2016. Icarus, 268, 355. (2) Carr, M.H. & Clow, G.D., 1981. Icarus, 48 (1), 91. (3) Tanaka, K.L. et al., 2014. US Geological Survey. (4) Guimpier, A., et al., 2021. PSS, 206, 105303. (5) Mergili, M., et al., 2017. Geosci. Model Dev. 10, 553. (6) Pajola, M. et al., 2022. Icarus, 375, 114850. (7) Weibull, W., 1951. J. Appl. Mech., 18, 837. (8) Brown, W.K. & Wohletz, K.H., 1995. J. Appl. Phys. 78, 2758. (9) Turcotte, D.L., 1997. Cambridge University Press, Cambridge.
Distinguishing Capital Investment and Consumption of Material Footprint: A Comparative Analysis between Subnational China and Other Nations
Authors: Jiang Meng , Behrens Paul , Yang Yongheng , Tang Zhipeng , Chen Dingjiang , Yu Yadong , Liu Lin , Gong Pu , Zhu Shengjun , Zhou Wenji , Hertwich Edgar , Zhu Bing , Tukker Arnold
Published: March 2022

Economic prosperity is vital to human development, but heavy reliance on material extraction leads to environmental degradation. To successfully decouple growth from degradation, the main drivers of material footprint (MF) must be identified. Here, we focus on MFs in Chinese provinces as well as emerging economies in a global context. We employ a local-global input-output model that considers trade and classified investment/consumption to evaluate the relationship between MF and the Human Development Index (HDI). The results show that China's growing MFs exhibit different development trajectories. While GDP and Human Development Index (HDI) are generally correlated with MFs, some low-income provinces in China have higher MFs per capita than some affluent provinces and advanced economies. We find that capital investments related to buildings, infrastructure, and equipment in China explain the complexity. To explain this further, we distinguish between consumption-driven and investment-driven MFs. We demonstrate the different roles of consumption and investment in the physical economy. An interesting finding is that consumption-driven MFs are generally associated with HDI across Chinese provinces and countries, but investment-driven MFs are not. Such trends are also observed in some developing economies. Capital investment shapes the different trajectories of MFs in rapidly industrializing economies. Given the large infrastructure gaps in emerging economies and post-pandemic investment plans, these underline the need to consider the broader sustainability implications of future investment plans. The concept that investigating different roles of investment- and consumption-associated footprint in input-output framework suggests that modeling future MFs, especially in rapidly industrializing countries, requires a more sophisticated framework. Taking capital investment and stocks formation into the general modeling is important. We conclude by asking two open questions: (1) Does the development of consumption-driven and investment-driven MFs across countries follow a paradigm where the early process of development is high-infrastructure MFs, and then shifts to higher consumption MFs as capital stocks build up? (2) How much investment does an economy need to maintain healthy and green growth?
Towards a calibration of the HYDRUS-1D model on a wheat crop in the semi-arid conditions of Haouz region
Authors: Moumni Aicha , Lahrouni Abderrahman
Published: March 2022

Due to the water shortage and poor management of limited water resources in semi-arid region, the improvement of irrigation efficiency became crucial. In this context, the objective of this work is to estimate water content and evapotranspiration using the HYDRUS-1D model. 

The study was carried out over wheat fields of the R3 perimeter (located in the Haouz plain of Marrakesh-Safi region, Morocco) for the growing season of 2003/2004. Four types of data have been used, namely: data related to the soil, data related to the plant, data related climatic parameters (recorded in a station close to the study site), and data related to the local agricultural practice.

We firstly used the inverse method, available in HYDRUS-1D, in order to estimate the hydrodynamic parameters of cultivated soil. The analysis of the convergence and consistency of this method showed that for correct calibration of the model, it is necessary to take into account the vertical heterogeneity of the soil. Therefore, we proceeded to the manual calibration of the model by testing different choices of initial parameters and taking into account the soil  vertical heterogeneity. The calibration carried out concerned mainly the water content of the soil and the evapotranspiration of the surface.

The simulations of the real evapotranspiration (ET) were carried out using the inputs obtained for the manual calibration. The results obtained by the HYDRUS-1D model gave an overestimation of the soil water content. This underestimation can be explained either by an underestimation of the LAI inputs or by the root extraction module that needs to be readjusted.

In the present work, the HYDRUS-1D model was tested, for the first time, over an area of Haouz plain in central Morocco.  The obtained results are not yet final. The model needs to be tested sufficiently over a wide spatio-temporal range. The HYDRUS-1D model is widely used in different regions of the world and the extensive literature reports a good score on the consistency and robustness of the model. Thus we are convinced that, overall, HYDRUS-1D seems to be an adequate model to estimate with acceptable accuracy the water content and the real ET under semi-arid conditions. It is also a promising tool for planning and decision support in the field of water and agro-environmental research.
Linking the relative importance of input uncertainties of a flood risk model with basin characteristics.
Authors: Sarailidis Georgios , Pianosi Francesca , Wagener Thorsten , Lamb Rob , Styles Kirsty , Hutchings Stephen
Published: March 2022

Floods are extreme natural hazards often with disastrous impacts on the economy and society. Flood risk assessments are required to better manage risk associated with floods. Nowadays, numerous flood risk models are available at various scales, from catchment to regional or even global scale. They involve a complex modelling chain that estimates risk as the product of probability of occurrence of an event (hazard) with its footprint (exposure) and the consequences over society and economy (vulnerability). Each component of this chain contains uncertainties, that propagate and contribute to the uncertainty in the model outputs. Much effort has been made to quantify such output uncertainty and attribute it to the various uncertainty sources in the modelling chain. However, the key drivers of uncertainty in flood risk estimates are still unclear because previous studies have reached conflicting conclusions.  Two things could possibly explain these ambiguous outcomes. First, these studies were implemented with different models and with different data, as well as different assumptions for the uncertainty and sensitivity analysis. Second, the studies were conducted at catchment and/or city scale with limited variability of physical and socio-economic characteristics within a study region, but with potentially large differences across study regions. In this project, we study the question of uncertainty quantification and attribution at much larger scale, namely the heterogeneous region of the Rhine River basin. In this way, we can identify spatial patterns of dominant input uncertainties and link them to characteristics, e.g. physical, socio-economic, in the different sub-basins. To this end, we use an industry flood risk model (catastrophe model) provided by JBA Risk Management which is capable of simulating flood risk across such a large region. Our ultimate goal is to provide evidence of how the importance of uncertainties varies across places with different climatic, hydrologic and socio-economic characteristics.
Continuous monitoring of atmospheric aerosols by LIDAR remote sensing technics in the south-east of France at the Observatoire de Haute Provence and Marseille Longchamp sites in the framework of ACTRIS-France and of the ANR COoL-AMmetropolis project.
Authors: Xueref-Remy Irène , Riandet Aurélie , Bellon Clémence , Khaykin Sergey , Blanc Pierre-Eric , Gomez Frédéric , Armengaud Alexandre , Gille Grégory , Popovici Ioana , Pascal Nicolas , Podvin Thierry , Goloub Philippe
Published: March 2022

Since 2018, the continuous monitoring of atmospheric aerosols by remote sensing technics was developed in the Aix-Marseille area, south-east of France. Two complementary sites located about 70 kilometers from each other, the first one at the Observatoire de Haute Provence (OHP) in a rural area and the second one in an urban environment at Longchamp site in the Marseille city center, were equiped with automatic aerosols Lidars (CIMEL CE376) and photometers (CIMEL CE318-T). The OHP site is part of the ACTRIS-France infrastructure for the long-term monitoring of aerosols, water vapor and reactive trace gases. The Longchamp one, that belongs to the regional air quality agency ATMOSUD, should join this infrastructure soon as well and is supported by the ANR COoL-AMmetropolis project for the present study. The ACTRIS-Fr data are hosted in the national AERIS/ICARE database. Furthermore, two other sites are equiped with remote sensing facilities : a ceilometer (Vaisala CL31) at Marignane, 25 km west of Marseille center, and radiosoudings at Nimes, about 70 km away. The datasets collected at the four sites allow us to study the boundary layer height variability in this coastal area, which is characterized by complex atmospheric dynamics and a tortuous topography. The boundary layer height is a key parameter to understand the variability of greenhouse gases and pollutants and its determination will be of great help for air quality and climate related studies. Also, our Lidars datasets are exploited to study the long-range transport of aerosols plumes outcoming from different sources (pyrogenic, volcanic, desertic…) and to  characterise the optical properties of such aerosols, which play a role on air quality and climate that needs to be better characterized. An overview of the results obtained so far will be presented.
Unraveling the landscape evolution of the Atacama Desert coast of Northern Chile through numerical models: the Pan de Azúcar National Park study case (~26°S). 
Authors: Arróspide Camila , Aguilar Germán , Martinod Joseph , Rodríguez María Pía , Regard Vincent
Published: March 2022

The Atacama rocky coast in Northern Chile is a tectonically active region that displays a particular morphological assemblage along its extension. There is a major morphostructural element named the Great Coastal Cliff (GCC) that runs parallel to the coastline for almost 1000 km in hyper-arid conditions. This cliff reaches heights between 800 and 2000 m a.s.l. and its continuity is only interrupted by a few, great fluvial valleys that drain from the High Andes and by several, small creeks of the Coastal Cordillera. At the mouth of these creeks and valleys, it is possible to recognize sequences of staircased marine terraces formed and preserved by the interplay between the tectonic uplift, sea-level changes, and marine erosion action. The Pan de Azúcar National Park (~26°) is a segment of the Atacama rocky coast which exhibit a morphological segmentation along strike into three domains that shows how the GCC is limited by areas characterized by marine terraces: one domain with a high, steep scarp (>500 m) that sits on top a single shore platform, and two domains with a further inland, degraded cliff (heights <300 m) and a sequence of dated marine terraces (<400 kyr). A numerical model was used to study the morphological evolution of this segment. Results unravel that a particular tectonic history should have taken place to develop all domains. This history begins with a slow subsidence event (0.04 mm/yr) between 1 Myr and 400 kyr ago, followed to the present by several uplift events with different rates (0.25-0.35 mm/yr). These last allow the terrace emersion. Particularly, a faster uplift event after 100 kyr should have taken place to preserve the lowest terrace recorded in the study area at 7-20 m. With this tectonic history, models suggest marine erosion rates of at least > 1.5 m2/yr (1.5 m3 for one meter of coast length) to develop the morphology of the GCC without stair-cased terraces. Instead, much lower erosion rates of 0.25-0.5 m2/yr or less are necessary to reproduce a shorter cliff with different terraces, i.e. low erosion rates to preserve terraces. This erosion variability is likely due to alongshore gradients in erosion efficiency by sediments-fed beaches that act as natural barriers against incoming waves, dissipating their energy. These sediments are provided by creeks with large catchment areas that discharge into the Pacific Ocean.
Space-time variations of seismicity: quantitative assessment and systematic changes before large earthquakes
Authors: Zaliapin Ilya , Ben-Zion Yehuda
Published: March 2022

We discuss recent results aimed at robust identification and quantification of space-time variations of earthquakes, with the ultimate goal of tracking preparation processes of large earthquakes. The first part focuses on progressive localization of seismicity, which corresponds to mechanical evolution of deformation from distributed failures in a rock volume to localized shear zones, culminating in generation of primary slip zones and large earthquakes. We present a methodology for estimation of localization using earthquake catalogs and acoustic emission experimental data, and showcase its applications to tracking localization processes of large failure events. This analysis is performed with declustered catalogs. The second part describes a technique to assess the degree of regional clustering of earthquakes, and justifies the need for declustering in localization and other analyses of seismicity. We demonstrate that events included in the existing short-duration instrumental catalogs are concentrated strongly within a very small fraction of the space-time volume, which is highly amplified by activity associated with the largest recorded events. The earthquakes that are included in instrumental catalogs are unlikely to be fully representative of the long-term behavior of regional seismicity, creating a bias in a range of seismicity analyses. Methodologically, both discussed topics are based on using the Receiver Operating Characteristic (ROC) framework. We demonstrate how this unified framework is adopted for diverse tasks, including assessment of coupled space-time clustering after controlling for space and time marginal inhomogeneities of earthquake rates, and tracking time-dependent transformations of a highly inhomogeneous earthquake space distribution. The examined data include crustal seismicity in California, Alaska and other regions, synthetic catalogs of the ETAS model, and acoustic emission data of laboratory fracturing experiments.
Ventilation revisited: how dry continental air splits the ITCZ and stops the monsoon
Authors: Biasutti Michela , Voigt Aiko
Published: March 2022

The Tropical Rain belts with an Annual cycle and Continent Model Intercomparison Project (TRACMIP) ensemble includes slab-ocean aquaplanet controls and experiments with a highly idealized narrow equatorial continent. In the control simulation, the rain band moves between hemispheres over the annual cycle, so that the annual-mean state displays a broad ITCZ straddling the equator. The introduction of the continent causes an equatorial cold tongue to develop off the western coast and, correspondingly, dry anomalies and a split in the oceanic ITCZ.  The oceanic cooling is initiated by the advection of cold, dry air from the winter portion of the continent, but it persists and is amplified by positive feedbacks. In the long wave (LW) feedback, a colder SST leads to drier and colder air, reduced downwelling LW flux, and enhanced net surface LW cooling. On the equator, the wind, evaporation, and SST (WES feedback) also contributes to the establishment and maintenance of the cold tongue.  The annual mean signal over the ocean is dominated by the continental winter cooling and drying because warm, humid anomalies in the summer hemisphere are restricted to the continent by anomalous surface convergence.   Over land itself, aside for the timing of rainfall’s seasonal progression (i.e., the rainy season occurring close to the time of maximum insolation) the continental rain band remains in an ITCZ-like regime akin deep-tropical monsoons, with a smooth latitudinal transition, a poleward reach only slightly farther than the oceanic ITCZ's, and a constant width throughout the year. The confinement of the monsoon to the deep tropics, especially in the western portion of the continent, is the result of advection of dry, low moist static energy air–a process known as ventilation. Contrary to much previous literature, though, we find that ventilation is not achieved by the mean westerly jet aloft bringing colder oceanic air over the continent, but by the anomalous low-level meridional circulation, which brings dry air from the subtropical portion of the continent equatorward. Because the anomalous circulation is in turn a response to the convection anomalies, we conclude that the limiting mechanism for the monsoon is coupled and sensitive to the surface properties of the land. 
Characteristics of Hazes in the Atmosphere of Jupiter from JunoCam Observations
Authors: Orton Glenn , Momary Thomas , Rogers John , Eichstaedt Gerald , Hansen Candice , Keaveney Caleb , Kelly Kevin , Wen Daniel , Brueshaber Shawn
Published: March 2022

A complex series of high-altitude clouds and hazes have been unveiled by images from the Juno mission’s JunoCam instrument. They appear to be ubiquitous at higher latitudes in both of Jupiter’s hemispheres but are particularly pronounced in the north. Juno’s polar orbit and JunoCam’s filter centered on the 889-nm absorption band of methane make JunoCam uniquely suited to observing high-altitude polar features. Among these are the North and South Polar Hoods, which JunoCam’s methane-band filter reveals in greater detail than from the Earth, together with bright and dark haze bands. These bright and dark bands commonly appear together in bundles, indicating vertical structure in widespread haze layers. Some bright hazes near the terminator exhibit an apparent color dispersion, appearing bluish on the side generally in the direction of illumination and reddish on the other, an effect that is consistent with more efficient scattering by shorter-wavelength light. The morphology of the observed haze bands appears to be quite different from the well-known zonal wind profile affecting the main cloud deck. On the other hand, some, including a semi-persistent long band of haze near the South Pole, are related to the locations of underlying cyclones and chaotic cyclonic features known as folded filamentary regions. Our high-resolution observations of Jupiter’s limb have revealed hazes, some continuous with the lower atmosphere and others that are singly and doubly detached.  Toward high northern latitudes, these limb hazes become completely opaque.