bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism and Characteristics of Flash Droughts in India and their Evaluation Using Evaporative Soil Moisture Index (ESMI)
Authors: Mahto Shanti Shwarup , Mishra Vimal
Published: March 2020

Flash droughts can cause a short-term but severe devastating impacts to agriculture and the ecosystem. However, the mechanism and characteristics of flash droughts remain unexplored in the monsoon dominating climate over India. Here, we use the hydro-meteorological variables from ERA-5 reanalysis to derive surface vapour pressure deficit (VPD), and soil moisture (SM) from GLEAM to construct a copula based SM-VPD index [named as Evaporative Soil Moisture Index (ESMI)], which is used to identify flash droughts in India. First, we evaluate the land-atmospheric coupling, which suggests that SM-VPD has a strong negative correlation in both monsoon and non-monsoon seasons. Soil Moisture and evapotranspiration (ET) show a strong negative and positive relationship in the monsoon and non-monsoon season, respectively. Our results show that unlike ET based indices (e.g. evaporative stress index), ESMI captures flash droughts in both monsoon and non-monsoon seasons over India. We identified and evaluated six major flash drought that occurred during the 1980-2018 period using ESMI along with their driving mechanism.
Modeling and Extrapolating Arctic Feedback Loops using Macroeconometric Techniques
Authors: Goulet Coulombe Philippe , Göbel Maximilian
Published: March 2020

The minimum extent of arctic sea ice (SIE) in 2019 ranked second-to-lowest in history and is trending downward. Hence, there is an immediate need for flexible statistical modeling approaches that both explain endogenously the trend of SIE and permits its extrapolation to generate a long-run forecast. To that end, we propose the VARCTIC, which is a Vector Autoregression (VAR) specifically designed to capture and extrapolate feedback loops that characterize the Arctic system.  VARs are dynamic simultaneous systems of equations routinely estimated in economics to predict and understand the interactions of multiple macroeconomic time series. The VARCTIC is a compromise between fully structural/deterministic modeling and purely statistical approaches that usually offer little explanation of the underlying mechanism. Our "business as usual" completely unconditional forecast has September SIE hitting 0 around the middle of the century. By studying the impulse response functions of Bayesian VARs including different sets of variables, we single out CO2 shocks as main drivers of the long-run evolution of SIE. Additionally, we document that the corresponding responses of Sea Ice Albedo and Thickness largely amplify the long-run impact of CO2 on SIE.  Finally, we conduct conditional forecasts analysis of remedies like reducing CO2 emissions or the implementation of Albedo-enhancing Geo-Engineering technologies.
Spatial distribution of U-Pb ages across a basement uplift in the Northern Andes and its implications for the interpretation of the detrital record in adjacent basins.
Authors: Sandoval Jose R. , Perez-Consuegra Nicolas , Gomez Ricardo A. , Mora Andres , Parra Mauricio , Valencia Victor , Horton Brian , Bueno Ricardo , Reyes Andres , Beltran Alejandro , Cardenas Andres
Published: March 2020

Foreland basins represent a unique record of the evolution of mountain building processes in the adjacent hinterland. In the southern Colombian Andes and the adjacent foreland basin (i.e. Caguán-Putumayo Basin) no detrital U-Pb and heavy mineral studies have been conducted. This is due to the fact that the geochronological characterization of the basement rocks is poor, complicating the interpretation of source areas for provenance analysis.  Here we present a complete provenance study using U-Pb and Heavy mineral data. In order to gain a better understanding of the spatial distribution of the different potential basement sources we planned a characterization of the different basement provinces west of the Caguan-Putumayo basin. Here we present results from samples of active sediments (N=21), basements (N=16) and sedimentary rocks (N=4) older than Cretaceous. This characterization allowed the identification of eight (8) different domains with different age ranges. (1) The southern part of the Central Cordillera with populations of 150 - 250 m.y., (2) Southern part of the eastern flank of the Eastern Cordillera with ages around 150 - 180 m.y., (3) south of the Garzón Massif with age ranges between 1000 - 1150 m.y, (4) north of the Garzón Massif where rocks of 1500 m.y. dominate, (5) Paleozoic sedimentary rocks above the basement to the north of the Garzón Massif and the Serrania de la Macarena with a distinct population of 1300 m.y, (6). The basement of the Serrania de la Macarena with ages between 1650-1800 m, (7). The Serranía de Lindosa with ages around 500 m.y and (8). Amazonian Craton with ages between 1500 - 2000 m.y. Additionally, the relationship between Epidotes and Garnets displays a special behavior in each area. The provinces related to the Garzon Massif have a high amount of Garnets and low amount of Epidotes. On the other hand, the behavior of the areas away from the Garzon Massif is different. Based on the U-Pb detrital signal and the Epidote/Garnet relationship, we suggest that the stratigraphic intervals where we observe ages between 1000 and 1150 m.y. for the first time and high Garnet contents reflect uplift peaks of the Garzon Massif.
Heavy metals speciation with prediction model for heavy metal mobility and risk assessment in mine-affected soils
Authors: Choi Jaeyoung , Ahn Yongtae
Published: March 2020

Heavy metals from mines affect soil and groundwater, cause aand severely impact on the health of local residents. The soil samples were characterized the for distribution, and by the chemical speciation method , and then estimated the human health risks of the two mine-affected soils after stabilization were estimated. Two extraction techniques (Tessier and Wenzel methods) were applied to fractionate metals, such as arsenic (As) and zinc (Zn), to quantify the chemical status of metals in the soils. The mobility of As and Zn was predicted using ASTM test and sequential extraction (Tessier and Wenzel) methods results. The correlation coefficients of As and Zn mobility prediction using Tessier and Wenzel Fraction 1 were (0.920 and 0.815), respectively. Sum The of fractionsum of fractions (F1+F2+F3) showed the highest correlation coefficients value and F value for mobility prediction of both As and Zn. The hazardous indices (HI) for non-carcinogenic risk and carcinogenic risk (CR) to humans were evaluated according to the pseudo-total concentrations of metal in soils. The CR values of carcinogenic for As were within the ranges from 1.38 × 10-4 to 1.25 × 10-3 and 3.71 × 10-4 to 3.35 × 10-3 for both Young Dong (YD) and Dea San (DS), respectively. The HI for non-carcinogenic risk was highest for As in the YD (2.77) and DS (7.46) soils, which covered approximately 96 and 84% of HI, respectively. In summary, the contribution of As to risk from heavy metals was dominant.
A Mathematical Modeling for Stability of Ice Shelves
Authors: Zarrinderakht Maryam , Schoof Christian
Published: March 2020

Iceberg calving is the reason for more than half of mass loss in both Greenland and Antarctica. It also indirectly contributes to sea-level rise; changes in calving rate can shorten the ice shelves, speed up the grounded ice and increase changes in ice sheets. Therefore, having a better understanding of this phenomenon by a mathematical modeling seems essential.
Lacking of a precise representation of calving in ice sheet and glacier models may yield to nonphysical predictions.
We perform a parameter study to identify groups of key parameters. Here we use boundary element method and compare our result to works done by van der Veen (1998) and Nick et al. (2010). 
 A hydraulic crack propagation is assumed to happen vertically from both base and surface of the shelf. The solution for different scenarios is analysed in the form of stability of a dynamical system. An unstable solution results in an iceberg calving which leads us to a general calving law. 
From ice to ocean: Understanding the impacts of melting glaciers on marine biogeochemical cycles in the Canadian Arctic Archipelago
Authors: Bhatia Maya , Waterman Stephanie , Burgess David , Williams Patrick , Roberts Megan , Dhoonmoon Charvanaa , Bertrand Erin
Published: March 2020

When glaciers melt, they contribute significant quantities of water and ice, sediments and dissolved chemicals to the ocean. Recent efforts in Greenland and Antarctica show that both the delivery of materials to the marine environment, as well as local changes to ocean circulation induced by the input of freshwater, have the potential to profoundly impact key processes such as primary and secondary production, and by extension the biological carbon pump. Yet, extensive knowledge gaps remain about the chemical composition of glacial meltwater runoff at the ice-ocean interface, the spatial extent of its influence within coastal environs, and the mechanisms by which glaciers affect surface marine microbial communities. Nowhere are these knowledge gaps more prominent than in the Canadian Arctic Archipelago (CAA) – a region where the role of glacial meltwater in marine biogeochemical cycles is almost fully unexplored – despite the fact that it is a hotspot for glacial retreat and meltwater runoff to the ocean. Here, we conduct a regional comparative study of the nearshore coastal zone of glaciated and non-glaciated fjords and of multiple glaciers of varying type (land-terminating, tidewater) and size draining large ice caps. Our study site in Jones Sound, NU is home to the Inuit hamlet of Grise Fiord. Traditional knowledge from this community indicates that the termini of tidewater glaciers in this region are rich in wildlife, providing habitual hunting grounds for its citizens. Guided by this information, we combined shipboard measurements of temperature, salinity, turbidity, and chlorophyll a with bottle samples characterizing oxygen, sediment, carbon, nutrient, metal, and biological community composition to elucidate how these properties evolve with distance from the shore. Results from this study substantially further our understanding of glacier-ocean impacts in the CAA and beyond, while also providing data critical to accurate future projections of high-latitude marine ecosystem productivity and function in this era of climate change.
Depth, area, volume, and kinematics of slow-moving landslides from airborne synthetic aperture radar and mass conservation
Authors: Handwerger Alexander , Fielding Eric , Booth Adam , Huang Mong-Han
Published: March 2020

Slow-moving, deep-seated landslides travel downslope at rates of only a few meters per year and can remain active for decades and possibly centuries. As a result, they transmit large quantities of sediment to the channel network and are a major natural hazard that impact transport corridors and infrastructure. However, because slow-moving landslides rarely fail catastrophically, it is challenging, and often infeasible to directly measure their thickness and volume, two key parameters required to quantify sediment flux and to model landslide motion. Here we use remote sensing data from the NASA/JPL Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) to measure the 3-D surface velocity and geometry of over 90 slow-moving landslides in the California Coast Ranges. We then use mass conservation techniques to infer the thickness and volume of each landslide. These landslides have volumes that span between 104 and 107 m3, thicknesses between 3 and 90 m, and move at average annual rates < 5 m/yr. We also examined landslide depth-area and volume-area geometric scaling relations and compared our findings to a worldwide inventory of soil and bedrock landslides compiled by Larsen et al. (2010). We find that the landslide thickness, area, and volume are larger than soil landslides and smaller than bedrock landslides globally. Lastly, we estimate the subsurface geometry of the catastrophic Mud Creek landslide, central California Coast Ranges, during a period of slow motion that lasted at least 8 years before its ultimate failure. We find a volume of ~2.0 x 106 m3, which is close to the post-catastrophic failure volume measured using Structure From Motion (~2.1 x 106 m3) by Warrick et al. (2019). Therefore, in certain cases, it is possible to constrain landslide thickness and volume prior to catastrophic collapse. Our work shows how state-of-the-art remote sensing techniques can be used to better understand landslide processes and quantify their contribution to landscape evolution.
Seasonal to multi-annual speedup and slowdown of Greenland outlet glaciers inferred from time-dependent remote sensing observations
Authors: Ultee Lizz , Riel Bryan , Minchew Brent
Published: March 2020

The rate of ice flux from the Greenland Ice Sheet to the ocean depends on the ice flow velocity through outlet glaciers. Ice flow velocity, in turn, evolves in response to multiple geographic and environmental forcings at different timescales. For example, velocity may vary daily in response to ocean tides, seasonally in response to surface air temperature, and multi-annually in response to long-term trends in climate. The satellite observations processed as part of the NASA MEaSUREs Greenland Ice Sheet Velocity Map allow us to analyse variations in ice surface velocity at multiple timescales. Here, we decompose short-term and long-term signals in time-dependent velocity fields for Greenland outlet glaciers based on the methods of Riel et al. (2018). Patterns found in short-term signals can constrain basal sliding relations and ice rheology, while the longer-term signals hint at decadal in/stability of outlet glaciers. We present example velocity time series for outlets including Sermeq Kujalleq (Jakobshavn Isbrae) and Helheim Glacier, and we highlight features indicative of dynamic drawdown or advective restabilization. Finally, we comment on the capabilities of a time series analysis software under development for glaciological applications.
Exploring the interplay of wave climate, vertical land motion, and rocky coast evolution
Authors: Masteller Claire , Hovius Niels , Thomspon Catriona , Vann-Jones Emma , Woo Han Byul , Adams Pete , Dickson Mark , Young Adam , Rosser Nick
Published: March 2020

The integration of wave energy imparted to sea cliffs and its conversion into erosion and mechanical work drives the evolution of rocky coasts. However, this near-shore transformation of wave energy remains poorly constrained.

We compare 4 cliff-top seismic records (Orkney Islands, UK; La Jolla, USA; Santa Cruz, USA; Boulby Cliffs, UK) to characterize the response of sea cliffs to the prevailing wave climate. Across all sites, ground displacement scales with wave height and decays with distance from the cliff, but with varying degrees of sensitivity. 3 of 4 sites behave in a mechanically consistent manner - only showing modest increases in ground shaking. Further, decay in displacement at these 3 sites is consistent with energy loss due entirely to geometric spreading of seismic waves. Near-shore wave modeling suggests that shore platform morphology at these sites has evolved to an equilibrium state, such that delivered cliff-face wave energy is roughly constant across the full range of wave conditions.

Ground displacement on Orkney is significantly more sensitive to changes in wave height. Landward energy loss at Orkney is also more pronounced, potentially a signature of active rock damage processes. This increased sensitivity suggests that the near-shore has not yet evolved to reflect the incident wave climate. Indeed, wave breaking on Orkney is concentrated at the cliff face. As such, the transfer of wave energy is more efficient, resulting in wave energy flux orders of magnitude larger, and more variable, than all other sites.

Vertical land motion on Orkney is 2x more rapid than all other sites. This more rapid vertical motion is likely to outpace cliff retreat and beveling of the shore platform. As such, the near near-shore cannot adjust to the incoming wave climate, and does not reach an equilibrium state. Instead, wave breaking remains pinned at the cliff face, enhancing wave energy transfer.

We compile vertical land motion rates across the United Kingdom with coincident wave buoy data and bathymetry. We find that for more rapid vertical land motion, wave breaking is concentrated at the coast in comparison with more distributed wave breaking at sites with more gradual vertical motion. We suggest that these differences in vertical land motion exert a first order control on the transfer of wave energy to rocky coasts, such that areas with rapid vertical land motion rates are (1) more susceptible to changes in wave climate and (2) remain in a prolonged transient state relative to the dominant wave climate.

These results have implications both for the processes and timescales governing the long-term evolution of rocky coasts, as well as for determining the susceptibility of modern coastlines to a changing wave climate.
Asthenosphere viscosity in the Caribbean region constrained by gravity anomalies, seismic structure and regional magmatism
Authors: Chen Yi-Wei , Colli Lorenzo , Bird Dale E. , Wu Jonny , Zhu Hejun
Published: March 2020

The Caribbean region has been proposed as a candidate for outflow of asthenospheric mantle, from a shrinking Pacific region to an expanding Atlantic region. If this flow exists it should be associated to a dynamic topography gradient across the region. Estimating dynamic topography requires constraining the thicknesses and densities of sediment, crust and lithosphere to remove their isostatic response from the total topography. Dynamic topography has been studied globally in areas of ‘normal’ oceanic lithosphere but the Caribbean region, characterized by overthickened oceanic lithosphere, has not been fully analyzed due to the challenges of estimating crustal thicknesses.

Thanks to the wealth of seismic reflection, as well as borehole data, the basement relief and bulk sediment density in the Caribbean are well constrained. We performed a structural inversion of free air gravity anomalies, constrained by seismic refraction data, to established an improved Moho surface which provides more detail than existing global models such as Crust 1.0. With the improved basement and Moho relief, we computed residual basement depth. We obtained a ~300 m dynamic topography high on the Pacific-side of the Caribbean, gradually decaying to 0 m to the east near the Aves ridge.

This result supports the hypothesis of Pacific outflow through the Caribbean. Assuming a ~200 km thick asthenosphere and a flow velocity a few to a few tens of cm/yr, as suggested by tomographic imaging and regional magmatism, our results suggest the viscosity is ~5*1018 Pa s.
Comparison of volatility, hygroscopicity and oxidation state of submicron aerosols over the Pearl River Delta region in China
Authors: Han Shuang , Hong Juan , Xu Hanbing , Tan Haobo , Li Fei , Wang Lin , Ma Nan
Published: March 2020

Volatility and hygroscopicity properties of atmospheric particles with dry sizes of 60 and 145 nm were measured by using a Volatility-Hygroscopicity Tandem Differential Mobility Analyzer (VH-TDMA) at a suburban site over the Pearl River Delta region in China during the late summer of 2016. Specifically, volatility properties of the aerosols were studied by heating the ambient samples step-wise to seven temperatures ranging from 30 to 300℃. In general, particles started to evaporate at the heating temperature of 100℃. After heating the aerosols above 200℃, the probability density function of the volatility growth factor showed an apparent bimodal distribution with a distinct non-volatile mode and a volatile mode, indicating that the particle population was mainly externally mixed. Even at 300℃, around 20% of the aerosol volume still remained in the particle phase (non-volatile material). Black carbon (BC) mass fraction of aerosol mass correlated well (R2≈ 0.5) with the volume fraction remaining (VFR) at 300℃, but could not explain the non-volatile residual alone. On the basis of the comparison analysis between the VFR at different temperatures and the hygroscopic growth factor (HGF) at 90% RH, we observed the non-volatile residual material were hygroscopic (HGF=1.45). These results indicate that the observed non-volatile residual material at 300℃ did not consist solely of black carbon, but some other compounds such as sea salt, low-volatile ammonium or organic polymer.
Research on the Integration of Urban Flood Control Monitoring and Management Platform
Authors: Li Cheng-Wei , Yang Sheng-Hsueh , Wu Wen-Feng , Yeh Keh-Chia
Published: March 2020

Disaster prevention IoT monitoring technology can be used to solve some problems in urban disaster prevention. For example, in the past, urban areas often experienced extreme regional rainstorms, which caused flooding, traffic chaos, and emergency response time and insufficient support for disaster prevention personnel. Especially during commuting hours, the government has difficulty in flooding and traffic management. This research is to use the disaster prevention Internet of Things monitoring technology to investigate the causes of flooding in urban flood-prone areas, monitor network planning, and install monitoring equipment. Through the storm sewer system monitoring network, set the warning water level value in the sewer system, transmit the water level information in real-time, and determine whether the system downstream pump station can be started to pump in advance to reduce the water level of the storm sewer system and the occurrence of flooding. In areas where there is no sewer system, the pavement flooding sensor is installed to monitor the flooding situation on the land surface. When the land surface is flooded, it is necessary to add regional forecast rainfall information to determine whether it will affect regional traffic. Traffic instructions for no-entry areas. Other real-time information about rivers, regional drainage water level stations, and rainfall stations are the basis for decision-making. Finally, urban storm sewer monitoring and management platforms are built to provide real-time information and a grasp of possible disasters. Take New Taipei City, Taiwan as an example to carry out research on the integration of water conservancy information.
Validation of ICESat-2 Data along CHINARE Route in East Antarctica
Authors: Hao Tong , Li Rongxing , Qiao Gang , Li Hongwei , Hai Gang , Cui Haotian , He Youquan , Tang Hong , Xie Huan , Sun Bo
Published: March 2020

NASA launched the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) satellite on September 15, 2018. The photon counting altimeter of ICESat-2 is designed to provide centimeter-level accuracy surface elevation observations and is expected to reduce the uncertainty of the estimated sea level rise contribution from Antarctica. The ICESat-2 mission team has conducted a validation campaign and stated that the data released in the first year met the design requirements. In this study we designed and implemented an independent validation scheme along the 36th CHINARE (Chinese Antarctic Research Expedition) route in East Antarctica as a different validation site. 1) GNSS data collected during a week in December 2019 along the 500-km traverse from the Zhongshan Station to the Taishan Station are compared with the crossover ICESat-2 points. The GNSS receiver (CHC i70) was fixed on the roof of the Pisten Bully Polar 300 and cooperated with 5 GNSS base stations spaced every ~100 km. 2) To investigate photons reflectivity we used a rectangular area target for each site at three Chinese stations, with considerations of the reflectivity and satellite tracks. 22 upward-looking optical prisms were installed to capture photons with known ground elevations. 3) Finally, we utilized DJI Phantom 4 unmanned aerial vehicles (UAVs) to obtain centimeter-level DEMs of ice sheet surface and compare with the ICESat-2 points. The results are analyzed for several applications and compared against the published validation results of the mission team.
Age of Air in the Stratosphere from Observations
Authors: Linz Marianna , Birner Benjamin , Plumb Alan , Gerber Edwin , Haenel Florian , Stiller Gabriele , Kinnison Douglas , Neu Jessica
Published: March 2020

Age of air is an idealized tracer often used as a measure of the stratospheric circulation. We will show how to quantitatively relate age to the diabatic circulation and the adiabatic mixing. As it is an idealized tracer, age cannot be measured itself and must be inferred from other tracers. Typically, the two primary trace gases used are sulfur hexafluoride and carbon dioxide. Other tracers have a compact relationship with age, however, and can also be used to calculate age. We will discuss a range of tracer measurements from both satellites and in situ, including sulfur hexafluoride, carbon dioxide, nitrous oxide, methane, and the ratio of argon to nitrogen. We will compare the age derived from these different species, including different calculation methods and caveats, and compare with modeled ideal age and trace gas concentrations. We conclude by showing the strength of the diabatic circulation and the adiabatic mixing calculated from these trace gas calculations.
Using Stable Isotopes to Estimate Stream Water Age in the Qinghai-Tibet Plateau
Authors: Yang Yuheng , Weng Baisha
Published: March 2020

Stream water age is an essential indicator of stream water renewal and pollutant transport rates in the Qinghai-Tibet Plateau (QTP). Recently, the concept of a young water fraction (Fyw , calculated using stable isotopic data, was proposed as a measure of stream water age. The relative age of older stream in streams has yet to be quantified, however. In this study, we proposed a method to calculate the relative proportions of middle-aged and old-age water in runoff. The results revealed that in the Nagqu watershed, an average of 23% of the runoff was < 51.6 days old, whereas an average of 55% of the runoff had ages ranging from 51.6 days to 1. The change in stream water age is significantly influenced by the runoff composition, evaporation, air temperature, and soil moisture at a depth of 20 cm. The amount of stored glacial ice, soil ice, snow cover, groundwater, and other old water in the QTP appears to be decreasing under the influence of climate change. The results of this study are helpful for the study of runoff composition and stream water age, as well as their responses to climate change.
Closing the Combined Water and Energy Balance of Global Watersheds Based on Satellite Data
Authors: Alam Sarfaraz , Koppa Akash , Miralles Diego G. , Gebremichael Mekonnen
Published: March 2020

Satellite-based remote sensing offers potential pathways for accurately closing the water and energy balance of watersheds from observations, a fundamental challenge in hydrology. However, previous attempts based on purely satellite-based estimates have been hindered by large data uncertainties and lack of estimates for key components, such as runoff. Here, we use a novel approach based on the Budyko hypothesis to quantify both the degree of closure and its uncertainties in watershed-scale water and energy balance closure arising from an ensemble of 56 global satellite datasets for precipitation (P), terrestrial evaporation (ET), and net radiation (Rn). We use 7 quasi-global precipitation datasets which include CHIRPS, CMORPH, PERSIANN, PERSIANN-CCS, PERSIANN-CDR, TRMM 3B42RT, TRMM 3B43. For ET, we use 8 datasets - AVHRR, SSEBOp, MOD16A3, GLEAM v3.3a, GLEAM v3.3b, CSIRO-PML, BESS, and FluxCom. For Rn, we use the CERES dataset. We find large spatial variability along with aridity, elevation and other gradients. Results show that errors in water and energy balance closure can be attributed primarily to uncertainties in terrestrial evaporation data. These findings have implications for improving the understanding of global hydrology and regional water management and can guide the development of satellite remote sensing datasets and earth system models. In addition, we rank the P and ET datasets that perform the best in closing the combined water and energy balance of global catchments. For P, we see that gauge-calibrated datasets such as PERSIANN-CDR, TRMM 3B43 perform the best. In terms of ET, we see that BESS performs the best in the northern boreal forests and GLEAM performs the best in drylands.
Methodological approaches to assess the impact of landscaping on the microclimate of urban environment of southern mountain resorts
Authors: Chalaya Elena , Efimenko Natalia , Povolotskaya Nina , Senik Irina , Slepykh Victor
Published: March 2020

The changing urban system of resorts is characterized by a tendency towards a decrease in the volume of arborous phyto-resources of urban gardening involved in the environmental protection function of the environment, the appearance of pathogenic effects, the nature of which has not been sufficiently studied.

There have been considered some results of route landscape-climate monitoring in the southern region of the Caucasian Mineral Waters (the Russian Federation) by the methods adopted in balneology [1]. The subject of the study was the modules of the resort and recreational potential (RRP) in the experimental urbanized (open) and natural park areas (in the shade) at heights of 600, 800 and 1000 m above the sea level.

The obtained results indicate significant territorial differences in the values ​​of integral RRP in urbanized and natural areas. Differences between the extreme values ​​ranged from 0 to 2,55 points (out of 3 possible), that is from extremely unfavorable to comfortable conditions. Material analysis showed that in the “weight” ratio, the “pathogenicity” of microclimate of the urban systems had been formed due to differences in landscaping conditions at the experimental sites: by solar illumination (up to 100 lx), by total solar radiation (up to 600 W/m2), by the temperature of geological substate (up to 23-25​​°C), by relative air humidity on the Earth's surface (20%), by natural aeroanions (up to 420 ion/cm3), by the percentage of the minimum permissible level of anions (> 400 ion / cm3, up to 60%), by breathing ground-level aerosol pollution with a particle diameter of less than 1000 nm, penetrating to the alveoli (by 10-50%) when breathing, by terms of hypoxia (up to 10-20 g/m3 - 5-10%).

Conclusion: the obtained results indicate the dominant role of greening in the correction of microclimate modules and resort-recreational potential in urban mountain resorts. When developing urban planning standards for mountain resorts, it is necessary to provide a special type of urban landscaping aimed at reducing the area of stone coverings of buildings due to their vertical landscaping, increase in the “green shade” over urban pedestrians through the installation of "tent gardening" as well as bringing urban tree planting to 40-60% of the resort area.

References: 1.Resort study of Caucasian Mineralnye Vody region / Under the general edition of the prof. V.V. Uyba. Scientific publication. - Pyatigorsk. - 2011.– 368 p.

 

 

 
The Hydrological Observatory of Mexico City (OH-IIUNAM): a unique setup for hydrological research within large urban environments
Authors: Pedrozo-Acuña Adrián , Breña-Naranjo José Agustín , Soriano-Monzalvo Julio César , Blanco-Figueroa Jorge , Magos-Hernández Jorge , Sánchez-Peralta Juan Alejandro
Published: March 2020

The emergence of high-resolution observational tools, information and communication technologies, cloud computing and big data are disrupting the water sector in an unprecedented way. In the field of hydrological sciences, research calls aimed at observing, backcasting and forecasting terrestrial water resources at finer space-time resolutions have been made over the past years by the scientific community. Here, we introduce the Hydrological Observatory of Mexico City (OH-IIUNAM), an academic initiative consisting of a dense network of 55 state-of-the-art precipitation sensors (optical disdrometers and weighing rain gauges) located within Mexico City, one of the largest urban centers of the world. The objective of OH-IIUNAM, given its open-data philosophy, is to enable scientific research within urban environments by providing a real-time hydro-meteorological observational platform at the hyper-resolution (dt=1 minute). Potential niches of opportunity ranging from atmospheric processes to hydrological modeling and design in urban areas are envisaged and discussed. Future expansion phases of OH-IIUNAM are expected to incorporate streamflow, groundwater and water quality.

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Insights from Physics-based Hydrologic Models and Stochastic Storm Transposition into the Underlying Assumptions of Flood Quantile Regionalization Techniques
Authors: Mantilla Ricardo , Perez Gabriel , Velasquez Nicolas , Wright Daniel , Yu Guo
Published: March 2020

We use three hydrological models and the stochastic storm transposition (SST) framework to investigate the validity of implicit assumptions in the empirical methodology of regionalization of flood frequencies (RFF) for prediction in ungauged basins. In particular, we investigate the long-standing hypothesis that for a set of catchments physical homogeneity of meteorological and infiltration processes implies statistical homogeneity of flood peak distributions. Our modeling (theoretical) results do not support this hypothesis. We also show that power-law regressions (i.e. log-log linearity) do not seem to be an appropriate model to connect distributions across scales (either quantiles or distribution parameters). Finally, even though our results support the most fundamental hypothesis in RFF that the underlying distribution of peak flows is invariant under translation in the river network, our results do not support the simple-scaling or multi-scaling frameworks. First, we show that some moments of the distribution cannot be inferred from area alone, violating the definition put forward by Gupta et al. (1994). Second, the resulting scale invariant distributions that we identified are different from LP-III and GEV and cannot be rejected by data as valid distributions. Our framework provides a new avenue to test methods for flood data analysis and it opens the door towards a unified physics-informed framework for prediction of flood frequencies in ungauged basins embedded in gauged regions.
On new developments in accelerator mass spectrometry and how they promote our understanding of global carbon cycle dynamics during the last deglaciation
Authors: Gottschalk Julia , Anderson Robert F. , Hodell David A. , Martinez-Garcia Alfredo , Mazaud Alain , Michel Elisabeth , Skinner Luke C. , Studer Anja , Szidat Sönke , Thöle Lena M. , Jaccard Samuel L.
Published: March 2020

Ocean-atmosphere 14C disequilibria of the surface and deep ocean reflect past changes in the efficiency of ocean-atmosphere CO2 exchange and ocean mixing, while it may also be related to variations in global-ocean respired carbon content. A full assessment of the oceanic mechanisms controlling deglacial changes in atmospheric CO2 is complicated by a lack of high-resolution 14C ventilation age estimates from the Southern Ocean and other key regions due to low foraminiferal abundances in marine sediments in those areas. Here we present high-resolution deglacial 14C ventilation age records from key sites in the Atlantic and Indian Sector of the Southern Ocean obtained by radiocarbon analyses of small benthic and planktic foraminiferal samples (<1 mg CaCO3) with the UniBe Mini-Carbon Dating System (MICADAS). Our analyses specifically circumvent foraminiferal sample size requirements related to “conventional” accelerator mass spectrometer analyses involving sample graphitization (>1 mg CaCO3 in most laboratories). Complementing multi-proxy analyses of sea surface temperature (SST) changes at these sites allow the construction of a radiocarbon-independent age model through a stratigraphic alignment of SST changes to Antarctic (ice core) temperature variations. We demonstrate the value of refining the age models of our study cores on the basis of high-resolution sedimentary U- and Th flux estimates, which allows an improved quantification of surface ocean reservoir age variations in the past. The resulting deep-ocean ventilation age changes are compared against qualitative and quantitative indicators of bottom water [O2] variations, in order to assess the role of Southern Ocean overturning dynamics in respired carbon changes at our study sites. We discuss the implications of our new radiocarbon- and bottom water [O2] data for the ocean’s role in atmospheric CO2 changes throughout the last deglaciation, and evaluate down-stream effects of southern high-latitude surface ocean reservoir age anomalies.
Real-time modelling of dangerous wind speed gusts and thermal comfort conditions in campus of Moscow State University (Moscow, Russian Federation)
Authors: Konstantinov Pavel , Perkhurova Anastasia , Nikolaeva Elizaveta , Bukin Sergey , Varentsov Mikhail
Published: March 2020

Wind speed modeling on microscale can be important not only for local authorities but also for citizens.  Due to the heterogeneity of urban development in the Moscow region, wind gusts geography and thermal comfort conditions at different points in the same territory will differ noticeably with the same meteorological parameters. Thus, it is necessary to study such parameters  at the microscale. Therefore, within the framework of this study, in order to inform the public about the negative impact of the weather, and further to minimize the consequences on the human body, an attempt was made to develop an operational system for predicting dangerous conditions  of wind gusts and  thermal comfort.

In order to collect climate statistics, climate data were calculated for comfort conditions for the MSU campus using the RayMan model. Wind gusts modeling was performed using ENVI-MET model.   Therefore, it is possible to analyze the changes in biometric conditions and wind speed in recent years and track trends in various locations.

Since the input parameters for the RayMan diagnostic model, which processes only text documents, serve as predictive data for the Canadian GEM global meteorological parameters in grib2 format, a program for converting files using Command.exe and Fortran-90 language allowed us to create an online module for predicting biometric indices (UTCI, PET and mPET).

For the convenience of perception of information, the results of calculations are visualized on the basis of Yandex maps.

Research was supported by the grant program of Russian Foundation of Basic Research (project no. 19-35-70009 mol_a_mos ). The work of Pavel Konstantinov, Elizaveta Nikolaeva and Sergey Bukin was supported by Russian Science Foundation (project no. 19-77-30012)
Future change in precipitation seasonality over the Horn of Africa in high-resolution simulation
Authors: Kad Pratik , Ha Kyung-Ja
Published: March 2020

Extreme weather creating a widespread humanitarian crisis over East Africa in recent decades. The seasonal cycle of precipitation over the Horn of Africa (HOA) shows bimodality with long rain and short rain. Most of the models fail to capture biannual rainfall seasonal cycles, due to circulation response to unrealistically dominate the annual mean. The Community Earth System Model (CESM) high-resolution model simulation has been employed to study the sensitivity. Precipitation distribution over HOA shows regional variations where most of the region show the bimodal distribution and the intrinsically complex. This bimodality is nominally associated with tropical rain belt, but topography and SST-forcing also play an important role in influencing the timing and intensity of seasonal rainfall. The results show that overall rainfall seasonality is increased, with intensification over high elevation. Precise representation of rainfall seasonal cycle over HOA adds confidence for future projected changes in seasonality. An important question is whether and how the seasonal cycle over HOA responds to anthropogenic forcing. We show that the future change in precipitation seasonal cycle and accumulation over HOA can be explained by the surface ocean process which module SSTs along the coastline of Somalia. The moisture convergence over low elevation land is basically regulated through the north-south SST gradient. In conclusion, future global warming leads to the intensified seasonal cycle of precipitation with a projected increase in the short rain season over east Africa. Further analysis demonstrates how topography modulates the seasonality of HOA.
Slope stability study of the 2001 Taipei National University of the Arts landslide
Authors: Liu Chien , Lin Cheng-Han , Hung Ching
Published: March 2020

Situated within a subtropical and mountainous region where frequent typhoons hit, rainfall-induced landslides have been a critical issue in Taiwan. On September 29, 2001, due to the torrential rainfall brought by the Typhoon Nari and Lekima, a downslope in Taipei National University of the Arts failed. The sliding source hit and severely damaged the Tao-Yuan junior high school. Before the 2001 Taipei National University of the Arts landslide, several landslides had already occurred in this landslide-prone region. In this study, a two-dimensional (2D) slope stability analysis, based on the limit equilibrium analysis (LEA), is conducted to analyze the 2001 Taipei National University of the Arts landslide. LEA has been the most popular and widely used technique given that it can estimate the factor of safety of a slope with some preliminary site investigation information. By comparing the failure surface and factor of safety (FOS) suggested in the post-disaster report [1], reasonable soil parameters, which are in an agreement with the experimental results [1], can be obtained through the study. The obtained soil parameters can later be applied to coupled transient unsaturated seepage-stress finite element analysis (FEA) [2] that will help practical engineers to understand the onset of failure in the future study.

 

REFERENCE

Taiwan Professional Geotechnical Engineers Association. (2001). National Taipei University of the Arts tennis court down slope failure reason identification and long-term remediation plan suggestion work report.

Hung, C., Liu, C. H., & Chang, C. M. (2018). Numerical investigation of rainfall-induced landslide in mudstone using coupled finite and discrete element analysis. Geofluids, 2018.
Low-cost framework for hydrological monitoring in developing countries
Authors: Tassi Rutinéia , Minetto Bruna , Persh Cristiano , Campos Pimentel Fabiana , Allasia Daniel
Published: March 2020

The advancement of hydrological knowledge is dependent on observation data (Ex, Blume et al., 2017; Kirchner, 2006). Nevertheless, these needs may become financially unviable due to the high costs of monitoring, especially in developing countries with large territorial extensions as Brazil and scarce financial support for this purpose. Thus, it is not difficult to find large areas in Brazil without hydrological monitoring. Alternatively, satellite-based estimations have been explored to supply these deficiencies due to several advantages like measuring spatial variability, being rapidly and generally freely available on the Internet, and maintaining functionality even during catastrophic situations that can damage or temporarily shut down ground networks (e.g., flooding, overland effects of hurricanes). However, even if to calibrate these remote sensing products, the land-based monitoring is needed. In this light, citizen science where many volunteers can monitor more sites than a typical research team can be an interesting means of creating this information (Buytaert et al., 2014), although even for these volunteers, the cost could be a problem. In this perspective, we present here a low-cost framework developed and field-tested for monitoring hydrological variables (precipitation, humidity, temperature, barometric pressure, and water level) based on the Arduino Platform. The monitoring-set could be self-constructed by volunteers or distributed as assembly kits that, apart from providing reliable measures of the hydrological variables at a very low cost, can boost interest in monitoring and science. Reliability and quality tests showed that measures gathered with the developed monitoring-set are within commercial standards. However, as the Arduino Platform is open, which facilitates its application and diminish the costs, special care with the suppliers should be taken, as not all follow the same quality standards.
Quantitatively assessing the impacts of climate variability and human activities on runoff
Authors: Qin Yanhua , Sun Xun , Li Baofu
Published: March 2020

To quantitatively evaluate the impacts of climate variability and human activities on runoff at different time scales is a challenging task. In this study, a nonlinear hybrid model integrating extreme-point symmetric mode decomposition, back propagation artificial neural networks and weights connection method based on the physical nonlinear relationship between impact factors and runoff were developed to explore an approach for solving this problem. To validate the applicability of the nonlinear hybrid model, the Hotan River was employed to assess the impacts of climate variability and human activities on runoff. Results illustrated that a good performance was presented by this model. The contribution of the upper-air temperature at 500 hPa was the highest (70.5%), which is the most important factor for runoff change. At different time scales, this factor also has the highest contributions. However, the water vapor content was responsible for 22.0% of the runoff change. Furthermore, the human activities were only accounted for 7.5%, indicating that runoff in the Hotan River is more sensitive to climate variability than human activities.
Identifying the the key factors of uncertainty in Helheim Glacier’s response to climate change
Authors: Morlighem Mathieu , Brinkerhoff Doug
Published: March 2020

Helheim Glacier is one of the largest glaciers in Greenland and, despite its importance, remains poorly understood. While this glacier has been relatively stable in the 1980s and 1990s, its terminus retreated dramatically by 6 km between 2001 and 2005. By 2006, the glacier stopped thinning, slowed down, and re-advanced 4 km and has been stable since 2007. Helheim is today the third fastest glacier of Greenland, reaching speeds >7 km/a, and drains a surface area of 50,000 km2. It is not clear how this glacier will change over the coming century and if another episode of exceptional retreat will occur in the very near future. We construct here a large ensemble of simulations of Helheim glacier over the next century, using a numerical model that includes a dynamic ice front forced by oceanic and atmospheric scenarios. This large ensemble allows to quantify the uncertainty in future retreat and mass loss, and also to attribute the fraction of mass loss uncertainty due to poorly constrained model parameters using main-effect Sobol indices for each input variable. This work helps determine the processes that affect projections the most and provide error bars on model projections.