bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of simulated clear sky O2 A-band measurements from GOSAT over different surfaces - a sensitivity study
Authors: Kremmling Beke , Beirle Steffen , Wagner Thomas
Published: March 2020

We present a follow-up study on previous investigations of photon path lengths distributions in cloudy atmospheres using O2 A-band measurements from the GOSAT TANSO-FTS satellite instrument (Kremmling, B., Investigation of photon path length distributions derived from oxygen A-band measurements of the GOSAT satellite instrument, PhD thesis, 2018). The original study used TANSO-FTS measurements of high spectral resolution over cloud covered ocean areas and compared them to radiative transfer simulations using the Monte Carlo model McArtim. The comparison is based on a fitting process, allowing spectral alignment as well as an adjustment of the simulated O2 absorption. A systematic overestimation of 5-10% of the simulated O2 absorption was found for the considered case studies. Despite the investigation of different sensitivity studies, the cause of this overestimation remained unresolved.

The consequence of these finding was the thorough investigation of clear sky measurements from TANSO-FTS between 2009 and 2015. The analysis includes the retrieval of the surface albedos and their comparison to those included in the TANSO-FTS data products as well as the subsequent fitting results of the simulated spectra. The analysis is applied to two datasets, both consisting of measurements passing different clear sky and quality criteria. Dataset 1 additionally has information from independent lidar measurements of CALIOP (CALIPSO) and is limited to the northern hemisphere due to the spatial and temporal collocation criteria. Dataset 2 has no independent collocation measurements but a more uniform distribution in space and time.

While the retrieved surface albedos compare well, an overestimation of the simulated O2 absorption by about 5% is found for measurements over ocean. Good agreement is found for the land cases.

In order to better understand these observations, different sensitivity studies as well as fit settings are investigated. The sensitivity studies include parameters such as SZA, surface albedo, NDVI values as well as the polarization of the TANSO-FTS radiances. The presentation shows the outcome of these studies.
How good have our climate models been so far? A case study from West Africa.
Authors: Gaba Olayemi Ursula , Poméon Thomas , Diekkrueger Bernd , Gaba Yae Ulrich
Published: March 2020

This research compared a set of past projections made by the Intergovernmental Panel on Climate Change (IPCC) to observations originating from both gauged stations and satellite products. Three IPCC assessment reports were taken into account (First, Second and Third assessment reports- FAR, SAR and TAR) and for each, two scenarios from various models were chosen. The period 1998-2005 was considered. A focus was given to West Africa, which was divided in 3 subregions following the latitudes and two main variables for the region were analyzed: precipitation and temperature. The analyses were conducted on mean annual values and monthly annual cycles both at subregional and regional levels. They revealed that the differences are greater on lower latitudes and depend a lot on the scenarios. The Business-as-Usual scenario which assumes that few or no steps are taken to limit greenhouse gas emissions seems to be the one that is the closest to the observations. The relative importance and potential implications of the differences between projections and observations on the society were appreciated with regard to key development sectors in the region such as water, agriculture; health; breeding, fishery. We concluded by giving some recommendations that might be very useful for policy/decision makers but also by listing possible topics for further research that could be addressed by the scientific community.

Keywords: Climate change; Climate models; Past Projections; Observations; West Africa
Assessing the role of a priori user knowledge in climate services perception: An experiment with university students across Europe
Authors: Pimentel Rafael , Polo María José , Pérez-Palazón María José , Achleitner Stefan , Díez-Minguito Manuel , Huber Andreas , Kruse Philip , Lira Andrea , Lückenkötter Johannes , Ramos Maria-Helena
Published: March 2020

By definition a climate service (CS) is a provision of climate information to assist decision-making. Therefore, CS users are the crucial agent in the CS production chain. User role needs to go further than only making use of the CS, their function must be taken into account during CS design and implementation. This can be accomplished by creating a feedback loop, in which users interact with CS developers. Nevertheless, the a priori user knowledge (i.e. their background, expectations of CS, previous experiences with CS) can condition user role in this co-development process. Identifying this previous knowledge and how this can condition user perception about CS is not easy. On-line surveys and personal interviews which are the most extended technique to gather information about users, on the one hand, are not usually designed to dig into the user a priori knowledge, and on the other hand, can be influenced by many subjective aspects.

This work tries to assess the role of user previous knowledge and the perception that users have about CS. An experiment was designed and carried out with about 100 final year bachelor and master engineering students (agronomic, civil, forestry, geotechnical, hydraulic) across Europe (Germany, Austria, France and Spain) as potential CS users with similar initial knowledge. In the experiment the student population was split into two samples. Specific CS training was given to one, no training to the other. Therefore, users with and without a priori knowledge about CS were simulated. Then a role game, in which they become consultants hired by a water management authority to make a decision regarding the management of a lake, was played.  Different levels of information (i.e. ensemble mean, ensemble spread, robustness of climate model) are provided to the students along the game to evaluate basic climate concepts.

Experiment results show that previous knowledge has a role in the decision taken by the users. Trained users required more complex information before being willing to make a decision, while non-trained ones trust less complex information. No significant differences were found between countries or the two educational levels. 

This work was funded by the project AQUACLEW, which is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Commission [Grant 690462].
Dating habitability with nanoscale measurements of Early Mars
Authors: Moser Desmond
Published: March 2020

The earliest known physical records of Mars and Earth lie in microscopic grains of zirconium-rich geochronology minerals such as zircon and baddeleyite. The reconstruction of the pressure and temperature histories of these phases is one of the few ways in which we can bracket the onset of conditions permissive of microbiota survival, and requires an integration of several nanoscale measurement techniques. This presentation will overview a recent, detailed investigation of zircons and baddeleyite from Mars [1], the earliest known from planets to date, as well as comparator studies of thermally and/or shock metamorphosed samples from the Earth and Moon. The approach is to spatially correlate measurements of the chemical and orientation microstructure of individual grains in order to characterize thermal, shock and diffusion history and better interpret U-Pb geochronology data. Also revealed are proxies for high temperature metamorphism such as nanoclusters of Pb and trace elements and nanoveins of impact melt as well as trace elements introduced through subsequent lower-temperature hydrothermal metamorphism. The techniques required include electron microscopy and cathodoluminescence (CL), Electron Backscatter Diffraction (EBSD), Transmission Kikuchi diffraction (TKD), mass spectrometry, and Atom Probe Tomography (APT). The Mars records were collected from a population of zircon and baddeleyite grains within five meteoritic fragments of polymict breccia (e.g. NWA 7034, NWA 7475). These data were compared to those from analogue sites of heavily bombarded Archean crust such as the central uplift of the Vredefort structure of South Africa, the Earth’s largest and oldest recognized impact crater, the Sudbury impact structure in Canada, and Apollo samples of the lunar regolith. The Mars population of grains reveals little evidence of the nanofeatures of heavily bombarded and heated crust, and no exposure to life-limiting pressures or temperature since crystallization 4.48 billion years ago. The conclusion is that global, planet-shaping bombardment effects on Mars, such as those which created its distinctive hemispheric dichotomy, had ceased by the time these grains and their associated crust crystallized. It follows that Mars entered a window of habitable conditions very early in solar system history, a pathway likely mirrored by the Earth. In this way nanoscale measurements, required to investigate microscopic mineral grains, serve as important tools for reconstructing important time periods in planetary evolution and abiogenesis.

Reference:

[1] DE Moser, GA Arcuri, DA Reinhard, LF White, JR Darling, IR Barker, DJ Larson, AJ Irving, FM McCubbin, KT Tait, J Roszjar, A Wittmann, C Davis (2019) Decline of giant impacts on Mars by 4.48 billion years ago and an early opportunity for habitability. Nature Geoscience 12,  522–527.
HO2 reactive uptake on organic aerosols: a molecular level study
Authors: Roose Antoine , Toubin Celine , Dusanter Sebastien , Riffault Veronique , Duflot Denis
Published: March 2020

Significant uncertainties are still associated to chemical reaction mechanisms used in atmospheric models, in particular for ROx radicals (OH, HO2, RO2). Recent measurements of radicals in forested areas characterized by low NOx (NO2, NO) concentrations indicate that models can significantly overestimate peroxy radical concentrations.1,2 These results question the ability of models to correctly simulate the oxidative capacity of the troposphere since peroxy radicals are a main source of the hydroxyl radical (OH), one of the most important oxidative species in the atmosphere.3  One possible explanation is the occurrence of heterogeneous processes (uptake of radicals) on the surface of aerosols that are either misrepresented or not included in models. While recent studies have reported uptake coefficients of HO2 on different types of aerosols, the process is not completely understood yet.

Molecular dynamics combined with ab-initio calculations have been used to study HO2 reactive uptake on organic aerosols. The sticking process of HO2 and its reactivity have been modelled on a nanometer size aerosol particle.4 Those theoretical calculations provide insight into the uptake process at the molecular scale and are planned to be compared to experimental measurements carried out with an aerosol flow tube.

This work is supported by the CaPPA project (Chemical and Physical Properties of the Atmosphere), funded by the French National Research Agency (ANR) through the PIA (Programme d’investissement d’avenir) and by the regional council “Hauts-de-France”. The authors also thank CPER Climibio and FEDER for their financial support. Calculations were performed using HPC resources from GENCI-TGCC (Grant 2020- A0070801859).

References

[1] T. Griffith et al., Atmos. Chem. Phys. 13, 5403 (2013)

[2] Mao et al., Atmos. Chem. Phys. 12, 8009 (2012)

[3] Stone et al., Chem. Soc. Rev. 41, 6348 (2012)

[4] Roose et al., ACS Earth Space Chem. 3, 380 (2019)

 
Pore size effect on soil carbon dynamics during decomposition of switchgrass
Authors: Kim Kyungmin , Guber Andrey , Kravchenko Alexandra
Published: March 2020

Soil pore size distribution (PSD) regulates oxygen diffusion and transport of water/mineralized nutrients. Microbial activity, which drives the carbon (C) cycle in the soil system, can react to these physical factors regulated by PSD. In this study, we investigated the contribution of PSD to C-related microbial activity during the switchgrass decomposition. We used two types of soils, which have controlled PSD (dominant pore size of < 10um and > 30 um). 13C labeled switchgrass leaf and root were incorporated into different PSD of soils and incubated for 21 days under 50% water-filled pore space. During the incubation, microbial activity was assessed with several indicators. i) Fate and transport of mineralized switchgrass, ii) Priming effect, iii) Spatial distribution of b-glucosidase and phenol oxidase, and iv) Microbial biomass. Our preliminary results showed that CO2 emission from switchgrass leaf was greater in the soil dominated by < 10 um pores. Higher b -glucosidase activity and mineralized C from switchgrass leaf supported greater C-related activity in such soil. However, interestingly, we observed a greater priming effect in the soil dominated by > 30 um pores. Due to the less mineralization and transport of switchgrass-derived C in such pores, enzymes targeting more complex substrate could be more active in such soil stimulating mineralization of native soil C. Our full results of phenol oxidase, microbial biomass, and more detailed analysis on 13C and C dynamics will help understanding how PSD can affect biochemical reactions in plant decomposition system.
Measured greenhouse gas budgets challenge emission savings from palm-oil biodiesel
Authors: Meijide Ana , de la Rúa Cristina , Guillaume Thomas , Röll Alexander , Hassler Evelyn , Steigler Christian , Tjoa Aiyen , June Tania , Corre Marife D. , Veldkamp Edzo , Knohl Alexander
Published: March 2020

The potential of palm-oil biodiesel to reduce greenhouse gas (GHG) emissions compared to fossil fuels is increasingly questioned. So far, no measurement-based ecosystem GHG budgets were available, and plantation age was ignored in Life Cycle Analyses (LCA). We conducted LCA based on measured CO2, CH4 and N2O fluxes in young and mature Indonesian oil palm plantations. CO2 dominated the on-site GHG budgets in both the young and mature plantations. The young plantation was a carbon source (1012 ± 51 gC m-2 yr-1), while the mature plantation was a carbon sink (-754 ± 38 gC m-2 yr-1). LCA considering the measured fluxes showed higher GHG emissions for palm-oil biodiesel than traditional LCA assuming carbon neutrality. Plantation rotation-cycle extension and earlier-yielding varieties potentially decrease GHG emissions. Due to the high emissions associated with forest conversion to oil palm, our results indicate that no emission savings are achieved from biodiesel from first rotation-cycle oil palm plantations. Only biodiesel from second rotation-cycle plantations or plantations established on degraded land has the potential for pronounced GHG emission savings.
Lagrangian detection of moisture sources for an arid region in Northeast Greenland: relations to the North-Atlantic Oscillation and temporal trends from 1979 to 2017
Authors: Schuster Lilian , Maussion Fabien , Langhamer Lukas , Moseley Gina E.
Published: March 2020

Northeast Greenland is predicted to be one of the most sensitive terrestrial areas of the Arctic to anthropogenic climate change, resulting in an increase in temperature that is much greater than the global average. Associated with this temperature rise, precipitation is also expected to increase as a result of increased evaporation from an ice-free Arctic Ocean. In recent years, numerous palaeoclimate projects have begun working in the region with the aim of improving our understanding of how this highly-sensitive region responds to a warmer world. However, a lack of meteorological stations within the area makes it difficult to place the palaeoclimate records in the context of modern climate.

This study aims to improve our understanding of precipitation and moisture source dynamics over a small arid region located at 80 °N in Northeast Greenland. This region hosts many speleothem-containing caves that are being studied in the framework of the Greenland Caves Project (greenlandcavesproject.org). The origin of water vapour for precipitation over the study site is detected by a Lagrangian moisture source diagnostic, which is applied to reanalysis data from the European Centre for Medium-Range Weather Forecasts (ERA-Interim) from 1979 to 2017.

While precipitation amounts are relatively constant during the year, the regional moisture sources display a strong seasonality. The most dominant winter moisture sources are the ice-free North Atlantic ocean above 45 °N, while in summer the patterns shift towards more local and North Eurasian continental sources. During positive North-Atlantic Oscillation (NAO) phases evaporation and moisture transport from the Norwegian Sea is stronger, resulting in larger and more variable precipitation amounts. Although the annual mean temperature in the study region has increased by 0.7 °C dec -1 (95% confidence interval [0.4, 1.0] °C dec -1 ) according to ERA-Interim data, we do not detect any change in the amount of precipitation with the exception of autumn where precipitation increases by 8.2 [0.8, 15.5] mm dec -1 over the period. This increase is consistent with future predicted Arctic precipitation change.
Variability assessment of flood hazard indicators on the North Caucasus
Authors: Mironenko Anastasiia , Rets Ekaterina , Frolova Natalia
Published: March 2020

The result of maximum water levels variability analysis along with the information of the frequency of adverse and dangerous hydrological phenomena exceeding levels and fluctuations maximum amplitude of water levels are presented in this research. There are two periods of comparison of the water levels recorded at 146 hydrological gauges – 1926-1975 and 1976-2015. Statistical analysis of databases was selected as the main research method including agreement criteria with parametric and nonparametric criteria of homogeneity.

The recent rise in mathematical expectation of maximum water levels is a characteristic for all the North Caucasian rivers. Maximum water levels dispersion have a tendency to decrease in the south of the Black Sea Caucasian coast, the Psheha and the Belaya rivers, the Sulak and the Fortanga rivers, the Baksan upstream. The remaining gauges recorded an increase in water levels dispersion, which is the predominant trend for the North Caucasian rivers.

The frequency of the adverse events exceeding water levels reaches 50% on the Afips, the Belaya, the Kuma, the Laba, the Mzymta, the Ubinka and the Vulan rivers. By the number of hazard levels exceeded, the areas adjacent to the Kuma, the Laba, the Psekups, the Pshish and the Ubinka are most susceptible to the floods.

Another part of the framework was connected with potential flood-affected region mapping over the North Caucacus. Thus, a map of potential flood zones caused by North Caucasian rivers was created according to maximum water levels recorded at 232 hydrological gauges.

This study was funded by RFBR according to the research project № 20-35-70024.
Contributions of dinoflagellate cysts and ciliates to the sediment flux in the Beaufort Sea (Arctic Ocean): one year sediment trap record
Authors: Pospelova Vera , Lalande Catherine , Heikkilä Maija , Fortier Louis
Published: March 2020

Studies of dinoflagellate cysts or ciliates in sediment traps provide essential information on weekly, monthly, seasonal, annual, and/or multi-annual changes in their fluxes in relation to measured or implied environmental parameters. Such information is essential for understanding ecological preferences of individual taxa which is the foundation for performing reliable (paleo)environmental high-resolution regional reconstructions. Up to date, sediment trap studies are rare, and only three of those deal with dinoflagellate cysts production in ice-covered conditions: in Antarctic waters (Harland and Pudsey, 1999); Arctic fjords in the Svalbard archipelago (Howe et al., 2010); and Hudson Bay (Heikkilä et al., 2016). All these studies consistently show a very limited or no cyst recovery from the samples that were collected during the ice-covered intervals. However, the timing of individual species production (e.g. cysts of Pentapharsodinium dalei, Islandinium minutum, and Spiniferites elongatus) within the ice-free condition is inconsistent as it varies from region to region. In this session, we will present our preliminary results on dinoflagellate cyst continuous bi-weekly record at the Beaufort Sea shelf break from September 2014 to August 2015.
The effect of soil-moisture on human heat stress during hot spells
Authors: Wouters Hendrik , Miralles Diego G. , Keune Jessica , Petrova Irina Y. , Teuling Adriaan J. , van Heerwaarden Chiel C. , Vilà-Guerau de Arellano Jordi
Published: March 2020

Hot extremes are typically instigated by a combination of favorable large-scale conditions and positive land surface feedbacks: as heatwaves evolve, the soil dries out and the decreased evaporation is accompanied by further heating of the atmosphere. Extreme high temperatures are known to cause increased mortality, and thus dry soils are typically thought to be associated with higher risk for human health. However, empirical studies indicate that health-threatening consequences and overall human discomfort during heatwaves not only depend on air temperature, but on air humidity as well. Drying soils are expected to reduce air humidity, which may — to a yet-unknown degree — offset the detrimental effect of soil dryness on increased temperatures in what relates to human heat discomfort. Here, we provide observational evidence for the role of anomalies in soil moisture on heat stress worldwide. We use a novel framework that combines weather balloons, reanalysis and satellite data with a mechanistic model of the atmospheric boundary layer. The health-threatening nature of hot spells is diagnosed by adopting a definition based on the concept of wet-bulb temperature and findings from recent meta-analysis of global human lethal impact data. Results indicate that the detrimental effect of drying soils on air temperature is overcompensated by the beneficial effect on reduced air humidity, which is partly related to the enhanced dry air entrainment. These findings can be used to design climate change adaptation strategies, being aware that ongoing trends in land and atmospheric dryness will impact human heat stress during future heatwaves.
Burning trash for science - using waste to monitor wildfire energies
Authors: Losiak Anna , Avery Amber , Elliott Andy , Baker Sarah , Belcher Claire
Published: March 2020

     Properties of the wildfires are hard to precisely and accurately measure during the event. This limits our ability to estimate effects of the event on the environment (e.g., how quickly will the area be able to recover, and what will be the long-term carbon storage in an ecosystem Hurteau and Brooks, 2011). Currently used methods of estimating of the ‘fire severity’ (the amount of vegetation and carbon loss from an ecosystem following a fire) are either subjective (fire severity scales Ryan and Noste 1985), time consuming (charcoal reflectance Belcher et al. 2019) or expensive (thermocouples with data-loggers).

     Here we present results of our proof of concept tests of a new approach that may allow ecologists to monitor fire severity and the energy distribution across a burned area by looking at the effects of the fire on litter such as tin cans, bottles and plastic items, that are often revealed following wildfire events. The approach is based on the fact that different types of packages and materials are known to decompose at different temperatures. We will present results from: 1) Field observations of burned litter compared with the charcoal reflectance measurements based on samples collected in the same spot from the 2018 Ferndown, UK. 2) experimental heating of a range of typical litter based elements in the wildFIRE Lab, using it’s state-of-the-art fire testing equipment; 3) results of the field-scale experiments performed during the controlled burns in Dorset in the beginning of 2020.
Could past changes in El Niño inform its future?
Authors: DiNezio Pedro
Published: March 2020

Paleoclimate records show pronounced changes in the El Niño/Southern Oscillation (ENSO) phenomenon over past climatic intervals, but the application of these results to understand future changes is not straightforward. To address this issue we propose the following mechanism controlling ENSO variability across altered climate states. Numerical simulations show that extreme El Niño – the warm phase of ENSO – could become more frequent in climatic states with a shallower ocean mixed layer, as predicted for the future, and extremely infrequent under climatic states with a deeper mixed layer, typical of glacial intervals. Wind fluctuations involved in the onset of El Niño transfer momentum more efficiently over a thinner ocean mixed layer, thus favoring stronger ocean currents and faster warming during the event. The robustness of this momentum coupling mechanism across climatic states, together with the evidence that ENSO was weaker under glacial conditions, increases our confidence in model predictions of more frequent extreme El Niño under greenhouse warming.
Correcting Budyko-Sellers boundary conditions: The Half-order Energy Balance Equation (HEBE)
Authors: Lovejoy Shaun , Del Rio Amador Lenin , Procyk Roman
Published: March 2020

The conventional 1-D energy balance equation (EBE) has no vertical coordinate so that radiative imbalances between the earth and outer space are redirected in the horizontal in an ad hoc manner.  We retain the basic EBE but add a vertical coordinate so that the imbalances drive the system by imposing heat fluxes through the surface.   While this is theoretically correct, it leads to (apparently) difficult mixed boundary conditions.  However, using Babenko’s method, we directly obtain simple analytic equations for (2D) surface temperature anomalies Ts(x,t): the Half-order Energy Balance Equation (HEBE) and the Generalized HEBE, (GHEBE) [Lovejoy, 2019a].  The HEBE anomaly equation only depends on the local climate sensitivities and relaxation times.  We analytically solve the HEBE and GHEBE for Ts(x,t) and provide evidence that the HEBE applies at scales >≈10km.  We also calculate very long time diffusive transport dominated climate states as well as space-time statistics including the cross-correlation matrix needed for empirical orthogonal functions.

The HEBE is the special H = 1/2 case of the Fractional EBE (FEBE) [Lovejoy, 2019b], [Lovejoy, 2019c] and has a long (power law) memory up to its relaxation time t.  Several papers have empirically estimated H ≈ 0.5, as well as t ≈ 4 years, whereas the classical zero-dimensional EBE has H = 1 and t ≈ 4 years.   The former values permit accurate macroweather forecasts and low uncertainty climate projections; this suggests that the HEBE could apply to time scales as short as a month.  Future generalizations include albedo-temperature feedbacks and more realistic treatments of past and future climate states.

References

 

Lovejoy, S., The half-order energy balance equation, J. Geophys. Res. (Atmos.), (submitted, Nov. 2019), 2019a.

Lovejoy, S., Weather, Macroweather and Climate: our random yet predictable atmosphere, 334 pp., Oxford U. Press, 2019b.

Lovejoy, S., Fractional Relaxation noises, motions and the stochastic fractional relxation equation Nonlinear Proc. in Geophys. Disc., https://doi.org/10.5194/npg-2019-39, 2019c.
Improving estimates of UK soil moisture using the JULES land surface model with COSMOS-UK measurements in the LaVEnDAR data assimilation framework
Authors: Cooper Elizabeth , Pinnington Ewan , Ellis Richard , Blyth Eleanor , Dadson Simon , Cooper Hollie
Published: March 2020

Soil moisture predictions are increasingly important in hydrological, ecological and agricultural applications. In recent years the availability of wide-area assessments of current and future soil-moisture states has grown, yet few studies have combined model-based assessments with observations beyond the point scale. Here we use the JULES land surface model together with COSMOS-UK data to evaluate the extent to which data assimilation can improve predictions of soil moisture across the United Kingdom.

COSMOS-UK is a network of soil moisture sensors run by UKCEH. The network provides soil moisture measurements at around 50 sites throughout the UK using innovative Cosmic Ray Neutron Sensors (CRNS). Half hourly measurements of the meteorological variables that the Joint UK Land Environment Simulator (JULES) requires as driving data are also recorded at COSMOS-UK sites, allowing us to run JULES at observation locations. This provides a unique opportunity to compare soil moisture outputs from JULES with CRNS observations; these measurements have a footprint of up to 12 ha (approx 30 acres) and are therefore better scale matched with JULES outputs than those from point sensors.

We have used the Land Variational Ensemble Data Assimilation Framework (LaVEnDAR) to combine soil moisture estimates from JULES with daily CRNS observations from one year at a number of COSMOS-UK sites. We show that this results in improved soil moisture predictions from JULES over several years. This has been achieved by optimising parameters in the pedo-transfer function used to derive JULES soil physics parameters from soil texture information. Using data assimilation with LaVEnDAR in this way allows us to explore the relationships between soil moisture estimates, soil physics parameters and soil texture, as well as improving the agreement between JULES model outputs and observations.
Improvement of the simulation of the water and energy cycle using Multiscale Parameter Regionalization (MPR)
Authors: Thober Stephan , Kelbling Matthias , Pappenberger Florian , Prudhomme Christel , Balsamo Gianpaolo , Schweppe Robert , Attinger Sabine , Samaniego Luis
Published: March 2020

The representation of the water and energy cycle in environmental models is closely linked to the parameter values used in the process parametrizations. The dimension of the parameter space in spatially distributed environmental models corresponds to the number of grid cells multiplied by the number of parameters per grid cell. For large-scale simulations on national and continental scales, the dimensionality of the parameter space is too high for efficient parameter estimation using inverse estimation methods. A regularization of the parameter space is necessary to reduce its dimensionality. The Multiscale Parameter Regionalization (MPR) is one approach to achieve this.

MPR translates local geophysical properties into model parameters. It consists of two steps: 1) local high-resolution geophysical data sets (e.g. soil maps) are translated into model parameters using a transfer function. 2) the high-resolution model parameters are scaled to the model resolution using suitable upscaling operators (e.g., harmonic mean). The MPR technique was introduced into the mesoscale hydrologic model (mHM, Samaniego et al. 2010, Kumar et al. 2013) and it is key factor for its success on transferring parameters across scales and locations.  

In this study, we apply MPR to vegetation and soil parameters in the land surface model HTESSEL. This model is the land-surface component of the European Centre for Medium-Range Weather Forecasting seasonal forecasting system. About 100 hard-coded parameters have been extracted to allow for a comprehensive sensitivity analysis and parameter estimation.

We analyze simulated evaporation and runoff fluxes by HTESSEL using parameters estimated by MPR in comparison to a default HTESSEL setup over Europe. The magnitude of simulated long-term fluxes deviates the most (up to 10% and 20% for evapotranspiration and runoff, respectively) in regions with a large subgrid variability in geophysical attributes (e.g., soil texture). The choice of transfer functions and upscaling operators influences the magnitude of these differences and governs model performance assessed after calibration against observations (e.g. streamflow).

References:

Samaniego L., et al.  https://doi.org/10.1029/2008WR007327

Kumar, R., et al.  https://doi.org/10.1029/2012WR012195
AMOC recovery in a multi-centennial scenario using a coupled atmosphere-ocean-ice sheet model
Authors: Ackermann Lars , Gierz Paul , Lohmann Gerrit
Published: March 2020

Future global warming will affect ocean conditions by different mechanisms. One mechanism is the melting of the Greenland Ice Sheet (GIS), which may lead to a freshening of regions of deep water formation and eventually contribute to a possible slowdown of the Atlantic Meridional Overturning Circulation (AMOC). We simulate the two Coupled Model Intercomparison Project (CMIP) scenarios RCP4.5 and RCP8.5, to assess the effects of melt-induced fresh water on the AMOC. We use a newly developed coupled multi-resolution atmosphere-ocean-ice sheet model with high resolution at the coasts resolving the complex ocean dynamics. Our results show an AMOC recovery for both scenarios in simulations run with and without an included ice sheet model. We find that the ice sheet is not only acting as a source of freshwater to the ocean but also as a sink. This leads to local storage and redistribution of freshwater and largely compensates for the meltwater release. This physical consistency is missing in climate models without dynamic ice sheets. Therefore, we argue that freshwater hosing experiments should be assessed critically, as they might overestimate the North Atlantic freshening, induced by ice sheet melting. Because of the compensating effect, we find little effect of the included ice sheet model on the AMOC. Our results show a main freshwater release in West Greenland. There, the freshwater might be trapped in the Labrador Current and transported away from regions of deep water formation. Our results show an AMOC recovery, starting within the first half of the 22nd century. We assume the increase in net evaporation over the Atlantic and the resulting increase in ocean salinity, to be the main driver of this recovery.
The effects of flooding and drought on water quantity and quality in agricultural drainage systems and streams in Latvia
Authors: Lagzdins Ainis , Grinberga Linda , Veinbergs Arturs , Sudars Ritvars , Abramenko Kaspars
Published: March 2020

This study was conducted based on systematic and regular water quality and quantity monitoring activities carried out as a part of the Agricultural Runoff monitoring programme in Latvia. This programme was initiated in 1995 and since then aims to document and evaluate the current status and long-term trends in nutrient concentrations and losses at different spatial and temporal scales as affected by meteorological, hydrological, and farming conditions.

Water sampling and flow measurements were carried out at several spatial scales where subsurface and open drainage systems have been installed including 16 experimental plots, 3 subsurface drainage fields, 3 small agricultural catchments, 24 small and medium size rivers. In addition, 21 groundwater monitoring well was established at 6 locations to investigate the effects of agricultural activities on groundwater quality. Water samples were collected on a monthly basis and analyzed for nitrate-nitrogen, ammonium-nitrogen, total nitrogen, orthophosphate-phosphorus, total phosphorus. Continuous flow measurements were made at experimental plots, subsurface drainage fields and small agricultural catchments using hydraulic measurement structures, pressure sensors and data loggers.

The long-term monitoring data (1995 – 2019) showed that water quantity and quality in subsurface and open drainage systems were strongly affect by meteorological conditions at the research site mainly in terms of annual and seasonal patterns of precipitation. Moreover, the flooding conditions in 2017 and drought conditions in 2018 and 2019 indicated that the agronomic activities at the research sites such as crops, tillage operations, types and application rates of fertilizers have a minor role on water quality leaving the agricultural fields. Intensive precipitation outside the growing season in 2017 resulted in the highest nutrient losses, while drought conditions in 2018 resulted in the lowest nutrient losses since this monitoring programme was established. One year of flooding and two consecutive years of drought have emphasized that more specific water and nutrient retention measures are needed in agricultural areas to secure timely removal of excess water from fields and water storage for later use. The analysis of nitrate-nitrogen concentrations obtained at different scales of measurements showed that nutrient concentrations, especially nitrate-nitrogen, decrease if the scale of measurements increases with the highest concentrations at the experimental plot scale followed by subsurface drainage fields, small catchments, and rivers.
Environmental Defense Fund Permian Basin Campaign: a science and advocacy-based approach to quantify and mitigate methane emissions from the oil and gas industry
Authors: Lyon David , Omara Mark , Gautam Ritesh , Roberts Kate , Trask Beth , Leyden Colin , Mogstad Isabel , Zavala-Araiza Daniel , Hamburg Steven
Published: March 2020

The Permian Basin in west Texas and southeast New Mexico (United States) is one of the most productive oil and gas (O&G) basins in the world, but little methane emissions data have been collected from the region.  Environmental Defense Fund (EDF) is leading a year-long science and advocacy campaign to measure O&G methane emissions in the Permian Basin and quickly communicate the data to stakeholders including the public and O&G operators to facilitate emission reductions. EDF and our scientific partners are using three primary approaches to repeatedly quantify emissions at different spatial scales during the campaign. Pennsylvania State University is estimating regional methane emissions on a quarterly basis with atmospheric transport modeling of data collected from a network of five tower-based instruments. University of Wyoming is deploying a mobile laboratory on public roads to measure site-level emissions of methane and volatile organic compounds with EPA Other Test Method 33A and the transect approach.  Scientific Aviation is performing aerial mass balance flights to quantify emissions from small clusters of sites, gridded areas, and larger regions.  Additionally, EDF is collaborating with several groups using remote sensing approaches to quantify methane emissions including TROPOMI, AVIRIS-NG, GAO, and MethaneAIR.  Emissions data including site identities will be published on a custom public website as quickly as possible to educate stakeholders about the magnitude of emissions and facilitate the mitigation of detected emission sources. Following the campaign, data will be analyzed to understand patterns and trends in emissions.  Furthermore, we will discuss the potential for implementing similar monitoring approaches in other O&G basins to provide scientifically-rigorous, actionable data that supports effective mitigation of methane emissions.
Estimating b-values and biases in small earthquake catalogues
Authors: Geffers Gina-Maria , Main Ian , Naylor Mark
Published: March 2020

The Gutenberg-Richter (GR) b-value represents the relative proportion of small to large earthquakes in a scale-free population. For tectonic seismicity, this is often close to unity, but some studies have shown the b-value to be elevated (>1) in both volcanic and induced seismicity. However, many of these studies have used relatively small datasets – in sample size and magnitude range, easily introducing biases. This leads to incomplete catalogues above the threshold above which all events are assumed to be recorded – the completeness magnitude Mc. At high magnitudes, the scale-free behaviour must break down because natural tectonic and volcano-tectonic processes are incapable of an infinite release of energy, which is difficult to estimate accurately. In particular, it can be challenging to distinguish between regions of unlimited scale-free behaviour and physical roll-off at larger magnitudes. The latter model is often referred to as the modified Gutenberg-Richter (MGR) distribution.

We use the MGR distribution to describe the breakdown of scale-free behaviour at large magnitudes, introducing the roll-off parameter (θ) to the incremental distribution. Applying a maximum likelihood method to estimate the b-value could violate the implicit assumption that the underlying model is GR. If this is the case, the methods used will return a biased b-value rather than indicate that the method used is inappropriate for the underlying model. Using synthetic data and testing it on various earthquake catalogues, we show that when we have little data and low bandwidth, it is statistically challenging to test whether the sample is representative of the scale-free GR behaviour or whether it is controlled primarily by the finite size roll-off seen in MGR.
Diffuse He degassing monitoring of the Tenerife North-western Rift Zone (NWRZ) volcano, Canary Islands
Authors: Recio Guillermo , Dunn Eleanor , McInally Yasmin , Pérez Nemesio M. , Amonte Cecilia , Alonso Mar , Padrón Eleazar , Asensio-Ramos María , Morales Francisco A.
Published: March 2020

Tenerife (2034 km2), the largest island of the Canarian archipelago, is characterized by three volcanic rifts oriented NW-SE, NE-SW and N-S with a central volcanic complex, Las Cañadas Caldera, hosting Teide-Pico Viejo volcanoes. The North West volcanic Rift Zone (NWRZ, 72 km2) of Tenerife is one of the youngest and most active volcanic systems of the island, where two historical eruptions have occurred: Arenas Negras in 1706 and Chinyero in 1909. Diffuse degassing studies has become an important volcanic surveillance tool at those volcanic areas where visible manifestations of volcanic gases are absent, as in the case of NWRZ. Mapping soil gas emission along volcanic structures can provide a better understanding of the processes occurring at depth and allows monitoring the spatial distribution, magnitude and temporal evolution of the surface gas emissions. The geochemical properties of He, minimize the interaction of this noble gas on its movement toward the earth’s surface, and make this gas an almost ideal geochemical indicator of changes occurring in the magmatic plumbing system of the volcano (Padrón et al., 2013, Geology 41(5):539–542). Since 2014, surface He emission surveys have been performed once a year as an additional geochemical tool to monitor the volcanic activity of NWRZ. At 345 sampling sites soil gas samples were collected at 40 cm depth and analyzed for He concentration within 24 hours by means of QMS, model Pfeiffer Omnistar 422. The soil helium concentration data were used to estimate the diffusive helium flux at each point, to construct spatial distribution maps by sequential Gaussian simulation and then to estimate the total helium emission in the NWRZ. Helium emission ranged between non-detected values up to 7.2 mgm-2d-1, and the emission rate of the entire area was in the range ~1 – 45 kg d-1. An increasing trend was observed in the period 2016-2018, showing a good temporal coincidence with a significant increase in seismic activity recorded in Tenerife. The promising results observed in the NWRZ and in other volcanic systems (Padrón et al., 2013) indicate that soil helium emission monitoring could be an excellent early warning geochemical precursory signal for future volcanic unrest.
Contrasting contributions to future sea level under CMIP5 and CMIP6 scenarios from the Greenland and Antarctic ice sheets
Authors: Payne Tony , Nowicki Sophie , Goelzer Heiko ,   ISMIP6 team
Published: March 2020

Projections of sea level contribution from the Greenland and Antarctic ice sheets rely on atmospheric and oceanic drivers obtained from climate models.  The Earth System Models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6) generally project greater future warming compared to the previous CMIP5 effort. Here we use four CMIP6 models and a selection of CMIP5 models under two future climate scenarios to force multiple ice sheet models as part of the Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6). We find that the projected sea level contribution at 2100 from the multi ice sheet models under the CMIP6 scenarios falls within the CMIP5 range for the Antarctic ice sheet but is significantly increased for the Greenland ice sheet.  
Geosciences Interdisciplinary Articulation in the schools, an example of project work
Authors: Pereira Manuela
Published: March 2020

Non-higher education public schools nowadays face enormous challenges, for example the new societies and needs of the worklife.  The theoretical  knowledge must come from the environment observation and have a practical application. This is particularly important for our students nowadays because they have an easier access to the virtual world, but a lack interaction with the real world. Many times, different subjects study the same situation (in different points of view) and the students don´t understand that, so the interdisciplinary articulation is an opportunity to resolve this problem. Some kind of interdisciplinary articulation projects can help students to understand the application of the theoretical knowledge.
In the beginning of the 2019/2020 school year, the 7th grade students decided to involve in a Development and Curricular Autonomy (DAC) project between Natural Sciences and Spanish subjects with the collaboration of Portuguese and Arts subjects. This project intends to develop geosciences issues and the Spanish language. The main goals are increasing the Geo knowledge about the Iberian mountains, that integrates “Serra da Estrela” (Portugal), “Sierra de Béjar” e “Sierra de Francia” (Spanish), as well region cultural and gastronomic traditions. Serra da Estrela  integrates the Iberian Mountains territory, offers a huge scientific and touristic interest and, recently, was classified as a Geopark, and Sierra de Béjar and Francia are natural parks.
The students were organised in work groups and defined the method to use, in order to do the presentation resulted by the research done. The data/information was obtained by the use of internet, contacting of some institutions like Geopark Estrela, Interpretation Center of Serra da Estrela  (CISE), House Park,  and performed a field trip in order to see and feel in loccus.
With the data obtained from different sources, the students did a presentation in Portuguese and Spanish, a video about the geology, biology, culture and gastronomic traditions of Iberian mountains, a documentary movie and several different didactic games (word search puzzle).
This kind of projects are very important because,  its essential that the students know and understand their region, by feeling and seeing, in order to be able to respect and preserve. The interdisciplinary articulation is important for students to understand different perspectives.