bluuebunny/crossref_metadata_2025 huggingface dataset:
Regime shift of Jet over East Asian summer Monsoon in the early 2000s: its detection and dynamical driver
Authors: Nam Jiyun , Yoon Jin-Ho
Published: February 2023

The phase shift of climatic systems in decadal or interdecadal scale, also called as regime shift has occurred in East Asian Summer Monsoon (EASM) in the past. For example, the shifts of the late 1970s, mid 1990s, and early 2000s are the typical examples. Before and after these shifts, dominant teleconnection mode affecting the EASM had changed. On the other hand, the shift of early 2000s has not extensively investigated. Here, it is examined the characteristics of this particular shift in relation to variability of East Asian jet during summer. First, regime shifts earlier and in the early 2000s are detected based on the variance of summer East Asian jet. Second, the teleconnection pattern that influence summer East Asian jet was changed from the Atlantic-Eurasian (AEA) pattern to distinctly different zonal pattern around extratropical region of Eurasian. Finally, it was found that after this regime shift the land-atmosphere coupling induced by variability of soil moisture also strengthened. It is hypothesized that enhanced linkage between jet in the upper atmosphere and surface heat flux over Inner East Asia is a key mechanism of enhancing variability of the East Asian summer jet, i.e., the regime shift in 2000s. These results imply that over drier region, the regional climatic system might response more sensitively to regional-scale change on surface level than large-scale influence, such as wave-train.
Hydrological impacts of wildfires at a global scale
Authors: Grillakis Manolis , Voulgarakis Apostolos
Published: February 2023

Wildfires can affect the hydrological regime of a watershed until vegetation is reestablished and the hydrological cycle returns to its previous state. Wildfire induced changes can lead to increased high flows due to vegetation destruction that affects rainfall interception, evapotranspiration, but also fire induced soil imperviousness. Floods or water cycle changes after wildfire events have been extensively studied at a fire event and basin level, or at regional scale, yet changes at a global scale have not been studied systematically. Based on a wide discharge observation inventory from 651 basins globally and MODIS burned area data between 2001 and 2018, we show that the average annual discharge tends to increase in the first two years after the wildfire event, but gradually tends to return to its previous state. Furthermore, it is also found that high flow events tend to increase with wildfire size. This work focuses to a better understanding of the hydrological impacts of wildfires, and hence contribute to the improved modeling representation of fire – hydrology processes.
Leveraging IGSN to Enhance Data Management in Research Institutions
Authors: Maicher Doris , Petersen Thorge , Mehrtens Hela , Springer Pina
Published: February 2023

The International Generic Sample Number (IGSN) is a crucial tool for ensuring the traceability and preservation of physical specimens in the Earth Science community. As a persistent identifier (PID), IGSN serves as a link between published digital data and the physical samples stored in a repository, enabling the creation of synergies with other services through the harvesting of machine-readable data.The IGSN can be assigned to a physical specimen at the time of collection, either on board a research vessel or during a field campaign. This unique identifier will follow the sample through the various stages of processing and analysis. In this use case, we demonstrate how IGSN can be minted for sediment cores directly on board a research vessel and then subsequently linked to relevant research data infrastructures (RDIs) such as DSHIP and PANGAEA. This allows for the traceability and easy identification of the samples as they are transported and stored in different repositories.Incorporating IGSN into a RDI helps to broadcast the existence of physical material and makes it more easily discoverable by researchers. This is especially useful for marine field work, which can be expensive and may not be accessible to all researchers. By making information about samples available as open access, researchers are able to easily locate and reuse existing material, which can be particularly beneficial for smaller research projects or research communities with limited resources. This is especially relevant in times of crisis, when access to certain regions may be restricted and there is an increased demand for the reuse of existing samples.In our research institutions, there is close collaboration between RDI providers and sample curators to manage both the digital data and the physical objects, such as plant samples in a herbarium, rocks and sediment cores, and biological material. In this presentation, we will use our case studies to discuss the successes of sample management in relation to IGSN. In addition, we will address the challenges that we have encountered and how we are working to overcome them. Our goal is to provide reliable services to our communities with a long-term perspective, and we believe that the incorporation of IGSN into RDIs can help to foster cultural change and encourage international collaboration in the Earth Science community. In addition, the use of IGSN and RDIs can contribute to the sustainability and reproducibility of research.
Application of specific differential phase as indicator for severe rainfall produced by shallow convection
Authors: Jung Chi-June , Jou Ben Jong-Dao
Published: February 2023

The specific differential phase Kdp is defined as the slope of range profiles of the differential propagation phase shift Φdp between horizontal and vertical polarization states observed by polarimetric radar. The Kdp is an important parameter for meteorological applications because it is proportional to precipitation particle concentrations and size and closely related to rain intensity. Past studies showed that the high Kdp value above the environmental 0 °C level potentially is an early indicator of heavy rain produced by summertime deep convection.In autumn and winter, the stratiform precipitation system is the primary source of rainfall in north Taiwan. Additionally, embedded convective cells could lead to intense rain rates. But these cells’ top is not always developed higher than 0 °C level. This study uses a C-band polarimetric radar located in north Taiwan to discuss the evolution of Kdp and related rainfall of several heavy rain events in autumn. The application of Kdp to quantitative rainfall estimation is also illustrated.The result shows that the value of Kdp > 2° km-1 is closely related to the movement and intensity of the severe rainfall area (> 60 mm h-1). Kdp > 2.0° km-1 occurs for more than 30 minutes, which is related to the location of rainfall of 100mm in 3 hours. The development height of Kdp >1.5° km-1 reaches the melting level, or there is a core area with Kdp >3.0° km-1 below the melting level, which will cause local heavy rainfall on the ground in the next 10 to 20 minutes (>10 mm in 10 minutes). Kdp > 3.0° km-1 occurs for more than 1 hour, which is related to the rainfall of up to 200mm in 3 hours.
Biometeorological risk assessed by ITU in Suceava metropolitan agglomeration - NE Romania
Authors: Bistricean Petrut - Ionel , Mihăilă Dumitru , Prisacariu Alin , Mihăilă Emilian-Viorel , Horodnic Vasilică Dănuț , Lazurca (Andrei) Liliana Gina , Țiculeanu (Ciurlică) Mihaela
Published: February 2023

Introduction. The temperature-humidity index (TIH) is a fairly accurate indicator of medium-level biometeorological risk when it ranges from 66 to 80 units and high-level risk when it exceeds 80 units. Scientifically, but also practically (for the 186603 inhabitants living in the Suceava metropolitan agglomeration - AMPSv), detailed knowledge of the variability of ITU over time for observation points located in all urban districts and neighbouring suburban localities is a necessity. The study aims to establish the temporal and spatial coordinates of the ITU index in the AMPSv, for a real and synthetic information to all the factors involved in the good management of the economic and social activities of the studied perimeter.Data and methods. For this study we used hourly air temperature and humidity data from 1 January 2019 to 31 December 2021 from a network of 31 stations located on the territory of AMPSv municipality. For each point we calculated the frequency of ITU on different value thresholds and outlined the annual and diurnal range of occurrence of biometeorological risk when ITU exceeds the thresholds of 66 (P66) and 80 (P80) units.Results. During a year, sporadically, at some of the stations ITU passed P66 between 26 February and 9 November. Between 25 April and 5 November in AMPSv there were days when ITU climbed quasi-generally above P66. The average hourly duration of the intervals in which ITU ranged between 66 and 80 units in the whole AMPSv was 16.3% of the time (between 19.2% at the Burdujeni district station and 12.4% at the Dragomirna forest station). In this time interval the ITU rose at some of the posts to over 80 units on days between 9 June and 17 September. Overall ITU exceeded P80 on days between 15 June and 31 August. The average hourly duration of the intervals where ITU climbed above P80 at the entire AMPSv was 0.7% of the time (between 1.9% at the Children's Club station and 0.1% at the Suceava Meteorological Station). Cumulatively, at the level of the whole AMPSv, the time when the biometeorological risk  manifestes holds 17.9% (between 19.5% at the SV2 station in the city industrial park and 13.9% at the station from Dragomirna forest). The biometeorological risk covers an increasingly extended diurnal range from midday to morning/evening as we approach from February and November to July-August.Conclusions. The ITU indicates in the current climate context, the biometeorological risk due to hot and humid weather episodes has increased to almost 20% of the average year. This requires the adaptation of the inhabitants of the AMPSv to a changing climatic reality.
How to find water for groundwater table management in cultivated peatlands? – Catchment based approach
Authors: Läpikivi Miika , Liimatainen Maarit , Klöve Björn , Marttila Hannu
Published: February 2023

Cultivated peatlands cause greenhouse gas emissions and nutrient leaching into water courses but are often important for local agriculture. Water table management, namely raising the water table (WT) in the soil horizon with controlled drainage or subirrigation, has been suggested as the most important management option for minimizing environmental impacts while continuing conventional agriculture. However, in many regions, including the Finnish west coastal areas near Bothnian Bay, it is difficult to obtain sufficient water volume for subirrigation purposes. Even with a flat topography and positive annual water balance, many cultivated fields require additional water input (subirrigation) if a higher-than-normal water table is desired during the summer. In areas with low lake percentages, this would require utilization of runoff from the upper catchment areas or storage of springtime excess water if summertime runoff is insufficient.This project aims to improve practical knowledge and form an analytical framework to assist water management in cultivated peatlands. We measure WT fluctuations and soil physical properties, bulk density, and loss on ignition from 11 cultivated peatlands in the North Ostrobothnian region, and analyze the upper catchment properties, including the catchment area, soil surface, land use, and flow network for individual fields. We use WT and soil property measurements to analyze potential subirrigation needs for study fields, and catchment data to calculate the potential for upper catchment areas to produce or store the required water volumes. This analysis is used to form a practical framework for using a catchment-scale approach to address water management challenges in cultivated peatlands.
Rapid expansion of ice sheet area in transient simulations of the last glacial inception
Authors: Willeit Matteo , Talento Stefanie , Ganopolski Andrey
Published: February 2023

We present transient simulations of the last glacial inception using the Earth system model CLIMBER-X with interactive ice sheets and visco-elastic solid-Earth response. The simulations are initialized at the Eemian interglacial (125 ka) and run until 100 ka, driven by prescribed changes in orbital configuration and greenhouse gas concentrations from ice core data.CLIMBER-X simulates a robust ice sheet expansion over North America and Scandinavia through MIS5d, in accordance with proxy data. However, we show that the crossing of a bifurcation point in the ice-covered area, which leads to a rapid (~7 million square km over a few centuries) expansion of ice sheets over North America, is critical to get a large enough ice volume to match the sea level drop of ~40 m indicated by reconstructions during the last glacial inception. As a consequence of the presence of this bifurcation point, the model results are highly sensitive to climate model biases. We also show that in the model the vegetation feedback plays an important role during glacial inception.Further results suggest that, as long as the system responds almost linearly to insolation changes during the last glacial inception, the model results are not very sensitive to changes in the ice sheet model resolution and the acceleration factor used to speed-up the climate component. This is not valid, however, when the system response is characterized by strongly-nonlinear processes, such as a rapid increase in ice-covered area.
Pitfalls and Opportunities in the Use of Markov-Chain Monte Carlo Ensemble Samplers for Vadose Zone Model Calibration
Authors: Brunetti Giuseppe , Simunek Jiri , Wöhling Thomas , Stumpp Christine
Published: February 2023

Bayesian inference has become the most popular approach to uncertainty assessment in vadose zone hydrological modeling. By combining prior information with observations and model predictions, it became popular among hydrologists as it enables them to infer parameter posterior distributions, verify model adequacy, and assess the model's predictive uncertainty. In particular, the posterior distribution is frequently the variable of interest for modelers as it describes the epistemic uncertainty of model parameters conditioned on measurements. Gradient-free Markov-Chain Monte Carlo (MCMC) ensemble samplers based on Differential Evolution (DE) or Affine Invariant (AI) strategies have been used to approximate the posterior distribution, which is frequently anisotropic and correlated in vadose zone-related problems. However, a rigorous benchmark of different MCMC algorithms to provide guidelines for their application in vadose zone hydrological model calibration is still missing. In this study, we elucidate the behavior of MCMC ensemble samplers by performing an in-depth comparison of four samplers that use AI moves or DE-based strategies to approximate the target density. Two Rosenbrock distributions, and one synthetic and one actual case study focusing on the inverse estimation of soil hydraulic parameters using HYDRUS-1D, are used to compare algorithms in different dimensions. The analysis reveals that AI-based samplers are immune to affine transformations of the target density, which instead double the autocorrelation time for DE-based samplers. This behavior is reiterated in the synthetic scenario, for which AI-based algorithms outperform DE-based strategies. However, this performance gain disappears when the number of soil parameters increases from 7 to 16, with both samplers exhibiting poor acceptance rates, which are not improved by increasing the number of chains from 50 to 200 or by mixing different strategies.
Seismotectonics of the northeast Indian region based on GPS velocities, stress and strain rate field characterization
Authors: kumar Raj , Prajapati Sanjay Kumar , Pal Sanjit Kumar , Mishra Om Prakash
Published: February 2023

The North-Eastern (NE) area of India is bounded by the confluence of three major tectonic plates constituting two convergent plate boundaries that essentially govern the complex seismotectonic of this Himalayan region that renders it seismically most active.  The area studied in the present work is confined to the hyperactive zone contained in the grid 20o - 30o N latitude and 88o -100o E longitude.  We analyze five years of GPS data obtained from sixteen Global Positioning System (GPS) campaign mode stations and two permanent ones deployed in the NE region. These velocities are used in estimating dilatational and shear strain rates along with the principal axes of strains. The estimated dilatational strain rate ranges from -0.13 to 0.1 microstrain/yr. In general, the velocity and strain rate fields are consistent with ongoing India-Eurasia collision and Indo-Burma subduction processes. Superposed on this pattern, we find that the intense dilatational field corresponds to the vicinage of the region between the main boundary and central Himalayan thrusts (viz. MBT, MCT), and while it is moderate in some regions of Indo Burmese Arc (IBA). Three distinct regions with high compressive strain rate distribution are delineated along the thrust zones. Two of these regions corresponds to the regions where the Kopili fault and  Tista lineament transversely converge MCT and transgresses into the MBT/MCT in Sikkim Himalaya and Bhutan Himalaya respectively and other with northern syntax region,  posing a high seismic hazard. , Some pockets of moderate strain rate near to the intersection areas of Kopili, Dauki faults and IBA, positionally relate to the high seismic zones and are consistent well with the statistical seismology, seismic topography and potential field anomalies.  Our study focuses on velocity and strain rate distribution vis-à-vis seismicity and crustal heterogeneity in the region facilitating the estimation of earthquake hazard potential.
Climate succession: a framework for predicting vegetation dynamics driven by climate change
Authors: Medlyn Belinda , Williams Laura , Knauer Juergen , Inbar Assaf , Stephens Clare , Gallagher Rachael , Nolan Rachael , Choat Brendan , Boer Matthias , Smith Ben
Published: February 2023

Climate change, driven by rising atmospheric CO2 concentrations, is well under way, and we are already starting to see significant shifts in the function and distribution of vegetation as a result. Dynamic vegetation models, the main platform used to predict the likely magnitude, rate and nature of these shifts, were originally rooted in theories of successional dynamics following disturbance. A key question for these models is how well they can capture vegetation responses to climatic change, which includes both press and pulse disturbances. Here we develop a general framework for representing climate-driven successional dynamics in vegetation models. The framework is illustrated with a series of case studies from Australia of vegetation responses to the major global change drivers of rising CO2, warming, drought and fire. The Australian environment, intrinsically characterized by high climate variability, has experienced increasingly challenging climate extremes in recent years and thus provides an excellent testbed for predictive models.
Soil depth Prediction in a landslide prone tropical river basin under data-sparse conditions using machine-learning technique
Authors: Asokan Laila Achu , Gopinath Girish
Published: February 2023

Western Ghats (WG) of India is experiencing frequent landslides during every Indian summer monsoon. Due to the unique blend of topography and tropical humid climate, accelerates chemical weathering, forming a layer of unconsolidated soil unconformably overlies the Precambrian crystalline rock. Lack of cohesion or bonding in these contrasting geologic materials, makes WG vulnerable to various forms of landslides during the peak of Indian summer monsoon. Hence detailed information about soil thickness has a predominant role in identifying the landslide prone area and understanding the landslides in WG. However, soil thickness maps are not available for WG area and steep rugged terrain makes it difficult to collect detailed soil thickness data. This study used a random forest (RF) machine-learning model to predict the soil depth with a limited number of sparse samples in the Panniar river basin of WG. The model was combined using 70 soil depth observations with eleven covariates such as normalized difference vegetation index, topographic wetness index, valley depth, solar radiance, elevation, slope length, slope angle, slope aspect, convergence index, profile curvature and plan curvature. The results show that the RF model has good predictive accuracy with coefficient of determination (R2) of 0.822 and root mean square error (RMSE) of 2.968, i.e., almost 80% of soil depth variation explained. The spatially predicted soil depth map clearly shows regional patterns with local details. Both geomorphological processes and vegetation contributed to shaping the soil depth in the study area. The resulting map can be used for understating the soil characteristics and  modelling  the landslide susceptibility in the study area.
The vegetation characteristics of semi-mangrove Hibiscus hamabo Siebold & Zucc. and Paliurus ramosissimus (Lour.) Poir. in Jeju Island, Korea
Authors: Ju-eun Yang , Eun-Ha Park , Sang-eun Kwak , Min-Ji Park , Bora Lee
Published: February 2023

Hibiscus hamabo and Paliurus ramosissimus are Korea’s endangered flora species, are predominantly native to Jeju Island, with more limited native appearances on few of Korea’s southern islands. The differences between the northernmost area (Jeju) and Japan’s southwestern native habitat characteristics of H. hamabo and P. ramosissimus were investigated utilizing a B-B method. In the case of semi-mangrove plants on Jeju island, its native habitats are divided into the inlet and gulf areas. Over time as silt soil deposits took shape, Cnidium japonicum and Limonium tetragonum appeared along with H. hamabo in bay areas, while Vitex rotundifolia and Eurya emarginata appeared at bedrock sites that had poor soil conditions in gulf areas. 
P. ramosissimus appeared in three habitats: wetland type, seashore rock type, and costal roadside type. In wetland type, Cyclosorus interruptus and Persicaria japonica appeared with high contributions. In the seashore rock type, the woody and vines native to the coast, the Euonymus japonicus and the Lonicera japonica, are found. In the ruderal site beside the coastal road, Humulus scandens, Rosa multiiflora, and other annual plants appeared. Jeju’s habitat appeared to have a more limited natural propagation radius than found in Japan, and are vulnerable to damage by coastal development. Therefore, more preservations efforts are essential of H. hamabo and P. ramosissimus, which support the integrity of coastal ecosystems and contributes to carbon capture.
New Late Cretaceous and Central Atlantic Magmatic Province magmatic sources off West Iberia revealed by from high-resolution magnetic surveys on the continental shelf
Authors: Terrinha Pedro , Neres Marta , Noiva João , Brito Pedro , Rosa Marcos , Batista Luis , Ribeiro Carlos
Published: February 2023

This work investigates the existence and tectonic control of magmatic bodies in the continental shelf of the SW Iberia margin. Magnetic data were densely acquired for a total area of ~4400 km2 and carefully processed. Our new maps reveal a complex magnetic anomaly field, where distinct zones are defined based on the anomaly distribution. A wide number and variety of magmatic bodies are interpreted, from >10 km-scale deeply intruded plutons to small plug-like and dike-like intrusions. Interpretation of magnetic results together with bathymetry and seismic reflection data allows discussing the geometry, extension, and age of the magmatic sources and inferring the faults of fault systems related to their intrusion. The Cabo Raso complex is a densely intruded zone related to the Late Cretaceous alkaline event. The Sines complex comprises the known offshore prolongation of the on-land Sines magmatic rocks but also the newly mapped Côvo and Milfontes anomalies. Côvo is the largest magmatic intrusion recognized in West Iberia. Milfontes intrudes the non-rifted Paleozoic crust and is the first known evidence of a plutonic source of the Central Atlantic Magmatic Province (CAMP) in Iberia. The geographical distribution and geometry of the magmatic bodies are mostly controlled by the crustal tectonic fabric inherited from the Paleozoic Variscan orogeny, which was re-worked during the Mesozoic rifting and the Cenozoic Alpine collision. The magmatic bodies modify the rheological structure of the crust and may affect the strain localization during the Alpine collision and recent tectonics.
This work allowed for mapping not only unknown plutons of Mesozoic age but also to define the eastern limit of the West Iberia Late Cretaceous Alkaline Province (WILCAP), which together with the Madeira-Tore Rise north of the Africa-Eurasia plate boundary cover an area equivalent to a Large Igneous Province (LIP).
 
This work was funded by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through national funds (PIDDAC) – UIDB/50019/2020- IDL
Single-particle investigation of airborne microplastics of inhalable size (<10 μm) using fluorescence microscopy, Raman microspectrometry, and scanning electron microscopy/energy dispersive X-ray spectrometry in combination
Authors: Yoo Hanjin , Lee Yoojin , Ro Chul-Un
Published: February 2023

Nowadays, microplastics (MPs) are being found everywhere, ranging from water bottles to nearly pristine areas such as the Antarctic and Arctic regions. On the other hand, the physicochemical characteristics of airborne microplastics (AMPs) of inhalable size (<10 μm), which are particularly critical in respect of human health and climate change, are still poorly understood due to the lack of suitable analytical methods. An efficient and reliable analytical strategy is required for the investigation of inhalable AMPs, which constitute just a very small portion of ambient aerosol particles. In this study, a new analytical strategy that employs fluorescence microscopy, Raman microspectrometry (RMS), and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX) in combination was demonstrated to be powerful for a reliable and detailed investigation of inhalable AMPs in ambient aerosols. Fluorescent staining and fluorescence microscopy can provide an efficient screening for high MP potential particles among ambient aerosols. The combined application of RMS and SEM/EDX to the same stained individual particles allows a detailed physicochemical characterization of stained particles. In this study, stained, high MP potential particles were observed with a probability of ~0.008(±0.005)%, corresponding to ~800 particles/m3, in a PM10 ambient aerosol sample. Among the stained particles of <10 μm, 27% were found to be plastics, including polystyrene, polyethylene, poly(ethylene terephthalate), and acrylonitrile butadiene styrene, and 73% were from tire/road wear. The number of inhalable AMPs was estimated to be 192(±127) particles/m3.
4D-Atlantic Dust-Ocean Modelling & Observing Study (DOMOS)
Authors: Fiedler Stephanie , Benedetti Angela , Amiridis Vassilis , Pérez García-Pando Carlos , Stuut Jan-Berend , Griesfeller Jan ,   DOMOS team
Published: February 2023

The ESA-funded “4D-Atlantic Dust-Ocean Modelling & Observing Study” (DOMOS) kicked off in September 2021, with the overarching objective to advance our fundamental understanding on the complex atmospheric dust-ocean interactions in the Atlantic Ocean in the context of climate change. The project has an innovative approach with the integrated use of modelling, EO-based products and in-situ datasets. 

DOMOS has created and validated a novel EO-based product of dust deposition fluxes against in-situ observations and previously existing datasets of dust deposition. Specifically, the project has developed a product of pure-dust deposition fluxes across the Atlantic Ocean for 2007-2020, based on the exploitation of (1) the CALIPSO-based ESA-LIVAS pure-dust database, (2) the MODIS-MIDAS and Metop-IASI MAPIR/IMARS/LMD/ULB atmospheric pure-dust products, and (3) ERA5 U/V wind components. Moreover, DOMOS has provided a validation of the dust deposition field from the CAMS reanalysis and has performed assimilation tests of IASI and Aeolus aerosol products with the goal of providing a better description of the dust aerosol transport over the Tropical Atlantic. The DOMOS products also contribute to an improved representation of the physical and chemical characteristics of dust deposition over the ocean, which is crucial to interpret past changes in the atmosphere and ocean and to better understand the possible future development. This includes a better understanding and quantification of the contributions from natural and anthropogenic dust to the deposition of soluble iron, compared to depositions associated with biomass burning and anthropogenic aerosols. This has been achieved through new experiments with the climate model EC-Earth3-Iron. 

Finally, DOMOS foresees providing a scientific roadmap to highlight the findings of the project and identify possible gaps in the modeling and the observing approaches of atmospheric dust-ocean interactions. In this presentation, we give an overview of the project and highlight the most important results from the DOMOS dust deposition products and model experiments.

More information can be found at https://www.ecmwf.int/en/research/projects/domos
Modelling soil phosphorus cycle feedbacks in old-growth and regrowing tropical forests in Amazonia
Authors: Fleischer Katrin , Yu Lin , Fuchslueger Lucia , Quesada Carlos A. , Zaehle Sönke
Published: February 2023

Soil nutrient availability is a key constraint on tropical forest growth. On highly weathered soils, intact forests' carbon-nutrient cycles have developed over pedogenic time scales, leading to tight nutrient cycling of some depleted elements, such as phosphorus. Ecosystem nutrient recycling and plant nutrient limitation are predominant in lowland Amazonia, controlling the forests' response to disturbance and climate change. Deforestation, biomass removal, and fire lead to the loss of carbon and nutrients previously stored in vegetation, potentially enforcing nutrient limitation and reducing carbon storage in regrowing forests.   Here, we employ the process-based terrestrial biosphere model QUINCY (Thum et al., 2019), coupled with the microbial-explicit soil model JSM (Yu et al., 2020) to simulate carbon and nutrient cycling rates at intact Amazonian forest sites, which span a natural gradient of 30 to 727 mg phosphorus g dry soil-1, and from 2 to 81% clay. The model QUINCY-JSM accounts for dynamic plant carbon investment in growth and nutrient acquisition, and microbial-explicit growth, turnover, and nutrient cycling. We confront the ecosystems with historical changes in atmospheric CO2 and climate, and simulate an experimental harvest of the entire forest stand to assess the consequences of that nutrient loss on the regrowing forest stand. Simulations of the Amazon forest sites are in good agreement with forest census data on vegetation carbon dynamics. Biologically-driven nutrient mineralization represents the main source of nutrients for plants, with negligible contribution of inorganic nutrient cycling in highly weathered sites. After experimental deforestation, we find that the inorganic nutrient supply is insufficient and restricts forest growth, leading to lower vegetation biomass equilibrium after deforestation. Our simulations suggest that forest degradation may occur through biomass removal in tropical forests.Thum, T., Caldararu, S., Engel, J., Kern, M., Pallandt, M., Schnur, R., et al. (2019). A new model of the coupled carbon, nitrogen, and phosphorus cycles in the terrestrial biosphere (QUINCY v1.0; revision 1996). Geoscientific Model Development, 12(11), 4781–4802. https://doi.org/10.5194/gmd-12-4781-2019Yu, L., Ahrens, B., Wutzler, T., Schrumpf, M., & Zaehle, S. (2020). Jena Soil Model (JSM v1.0; Revision 1934): A microbial soil organic carbon model integrated with nitrogen and phosphorus processes. Geoscientific Model Development, 13(2), 783–803. https://doi.org/10.5194/gmd-13-783-202
Forecast quality of climate extreme predictions and its relevance for climate services
Authors: Doblas-Reyes Francisco J. , Agudetse Victoria , Delgado-Torres Carlos , Donat Markus G. , González-Reviriego Nube , De Luca Paolo , Milders Nadia , G. Muñoz Angel , Palma Lluis , Pérez-Zanón Núria , Ramon Jaume , Solaraju-Murali Balakrishnan , Soret Albert , Torralba Verónica
Published: February 2023

The forecast quality of multi-model seasonal-to-decadal climate predictions, as measured by metrics of, among others, accuracy and reliability, has been traditionally estimated considering time-average products and products for event thresholds that do not target the occurrence of unusual events of either monthly or seasonal duration. However, there is an increasing interest in some user communities for products that represent extreme and unusual events. This presentation will discuss the differences in forecast quality between traditional forecast products, like mean seasonal temperature, and products for intraseasonal extremes (e.g., those measured with the 95th percentile of high-frequency temperature over periods like a month or a season) and monthly and seasonal unusual events (such as the frequency of exceeding the 90th percentile of the daily climatological distribution of temperature at a given time of the year). The results will be discussed in the context of their implications to address a number of user requirements from different sectors. The relevance of the forecast quality estimated from hindcast sets and the role of the observational uncertainty will be discussed when delivering forecast products in a climate service context. The implications of this work for the standardisation of climate services based on climate predictions will also be discussed.
A study on the Estimate of Daily PAR at the ocean around Korean Peninsula using GOCI
Authors: Hwang Deuk Jae , Frouin Robert , Tan Jing , Ahn Jae-Hyun , Moon Jeong-Eon , Choi Jong-Kuk
Published: February 2023

Photosynthetically available radiation (PAR) has a key role in generating primary production at the ocean surface. Various satellite sensors were used to estimate PAR at the ocean, but GOCI, the world’s first geostationary ocean color sensor, didn’t service PAR as an official product yet. In this study, PAR for the ocean around Korean Peninsula was estimated by using GOCI and validation was carried out. GOCI daily PAR was estimated from plane-parallel theory based model and corrected with in-situ measurements PAR data which had been collected at two ocean research stations. Corrected GOCI daily PAR has a high R2 value (0.99) with in-situ measurements. GOCI daily PAR also shows a high accuracy in terms of root-mean-square error (RMSE) and mean bias error (MBE); 4.98 % and -0.52 %, respectively. As a result of the comparison with other sensors derived PAR data, GOCI daily PAR shows the highest performance at the ocean around Korean Peninsula. MODIS and AHI derived daily PAR have lower accuracy than GOCI. MODIS daily PAR has RMSE of 10.40 % and -4.15 % with in-situ measurements, and AHI daily PAR has 6.51 % and -4.65 %, respectively. GOCI daily PAR help to understand the marine environment around the Korean Peninsula. For the further study, PAR from GOCI-II will be discussed.
Expanding the Emirates Mars Infrared Spectrometer (EMIRS) Science Dataset using EMIRS off-axis detectors
Authors: Cann George H. , Young Roland M. B. , Edwards Christopher S. , Smith Michael D. , Wolff Michael J.
Published: February 2023

Keywords: Mars, Atmosphere, EMM, Emirates Mars Infrared Spectrometer, Off-axis Detectors.Introduction: The Emirates Mars Mission (EMM) Emirates Mars InfraRed Spectrometer (EMIRS) instrument is a Fourier Transform Infrared (FTIR) spectrometer designed to observe the Martian disk, with the primary scientific objective of determining the three-dimensional thermal state of the lower atmosphere and its diurnal variability on sub-seasonal timescales [1].EMIRS uses a 3x3 array of deuterated L-alanine doped triglycine sulfate (DLaTGS) pyroelectric detectors [1], however, following the integration of the EMIRS electronics with the optical and mechanical hardware it was observed that the performance of the off-axis (non-central) detectors of the array were lower than expected [1]. Investigations into the performance of these off-axis detectors has so far yielded inconclusive root causes. As EMIRS could meet its primary science objective with the on-axis (central) detector and was subject to a pressing instrument schedule, a project level decision was made to forgo any additional investigation and instead rely on the on-axis detector [1][2].Method: In this study we present a comparison of observations captured by EMIRS from the off-axis detectors against the on-axis detector. The comparison is performed via a top-down and bottom-up pathway approach using the EMM Science Team processing pipeline. The top-down pathway focuses on the effects of the pre-processing steps on the detector interferograms, whereas the bottom-up approach compares calibrated radiances derived from the pipeline with and without applying the pre-processing steps [3] [4]. Correction of these issues will expand the retrieval derived products by a factor of five.Results: The top-down comparison shows differences in terms interferogram amplitude and phase error between on and off-axis detectors. We assess the feasibility of correction, then apply correction methods to a subset of EMIRS observations, and propose the root cause of the issues. This study is presented along with the generation of a joint dataset of near-mutual EMIRS and EXI (Emirates eXploration Imager) observations [5].Acknowledgements: The authors would like to acknowledge support by a Joint Research Agreement between the Mohammed Bin Rashid Space Centre (MBRSC) and the National Space Science and Technology Center (NSSTC), UAE University (UAEU).References: [1] Edwards, C. S., et al. (2021). Space Science Reviews (2021) 217:77.[2] Amiri, H.E. S., et al. (2022). Space Science Reviews (2022) 218:4.[3] Forman, M. L., et al. (1966). J. Opt. Soc. Am. 56(1), 59–63.[4] Christensen, V.E., et al. (2018). Space Science Reviews (2018), 215:87.[5] Jones, A. R., et al. (2021). Space Science Reviews (2021) 217:81.
Copernicus Marine Service: Coastal Extension
Authors: Melet Angélique , Le Traon Pierre-Yves , Tonani Marina , Reppucci Antonio , Lux Muriel , Silovic Tina
Published: February 2023

Over the period 2021-2028, the Copernicus Marine Service will provide a continuity of service with incremental evolutions of products and services. Yet, major evolutions are proposed to better answer user needs, to keep the service at the state-of-the-art and to meet the new ocean monitoring and forecasting challenges required by European policies and users. In this context, a priority evolution for the Copernicus Marine Service to be implemented by 2028 is a major extension of the service towards the coastal ocean.In this presentation, an overview of the proposed evolutions of the Copernicus Marine Service towards the coastal ocean will be provided.Incremental evolutions are planned within the Copernicus Marine Service core service to better address coastal zones, including an improved representation of processes and forcings relevant for coastal zones, enhanced assimilation of observations over continental shelves, improved algorithms to provide satellite derived information on the ocean state and winds in the coastal zone, etc.In addition, new short, mid- and long-term activities are scheduled to develop new services. In the short-term, a Copernicus Coastal Thematic Hub will be implemented to gather in a single platform and access point the ensemble of information generated by several Copernicus Services on coastal zones. In addition, the Copernicus Marine Service will develop an improved coastal zone monitoring with new pan-European satellite-based products.In the mid-term, a co-design and co-production of marine information will be developed between Copernicus Marine and EU Member States. In that regard, a selection of coastal systems operated by Member States will be coupled to Copernicus Marine monitoring and forecasting operational systems.In the long-term, climate projections of the marine environment (physics, biogeochemistry, marine ecosystems) will be developed for the 21st century at basin scale. This long-term evolution is building on precursor R&D European projects and aims at developing regional to local ocean climate services to support policy implementation, including for coastal zones.
A direct numerical simulation of nonbreaking-surface-waves induced mixing
Authors: Yoshikawa Yutaka , Imamura Haruka , Fujiwara Yasushi
Published: February 2023

Nonbreaking surface waves (NBSWs) induce vertical mixing even under the windless condition (WLC).  Recent laboratory experiments (e.g., Dai et al. 2010) demonstrated this mixing clearly; stratified water was vertically mixed by the NBSWs under the WLC.  The estimated vertical diffusivity amounts to O(10-5 m2/s), two orders of magnitude lager than the molecular diffusivity.  Yet, the mechanism of the mixing was not clarified in this laboratory experiment.   Recent numerical studies (e.g., Tsai et al. 2017; Fujiwara et al. 2020) on the other hand showed that the NBSWs under the WLC formed streamwise vortices  beneath the water surface through the CL2 mechanism like Langmuir circulations.  However, the intensity of the mixing was not evaluated in their numerical studies due to short integration time or artificially large eddy viscosity/diffusivity.  As a consequence, how the NBSWs under the WLC could induce the vertical mixing remains to be investigated.  In fact, local generation of turbulence by the wave orbital velocity is proposed as another mechanism of the NBSW-induced turbulence (e.g., Dai et al. 2010; Qiao et al. 2016).  Here, in order to investigate whether and how the NBSW alone could induce such the large vertical mixing, we performed a direct numerical simulation (DNS) of the NBSW under the WLC as in Dai et al. (2010).  The DNS with a sigma-coordinate free-surface nonhydrostatic model reveals that streamwise vortices like Langmuir circulations, developed exponentially at first, grow to be finite amplitude and keep slowly increasing in size and intensity.  At the finite-amplitude stage, the simulated water temperature was vertically mixed from near the surface.  The vertical eddy diffusivity was O(10-5 m2/s) very near the surface, which is overall similar to the previous estimation (Dai et al.  2010), but its vertical profile was different.  Enstrophy analysys reveals that CL2 mechanism, the same as for Langmuir circulations, kept working even in the finite-amplitude stage to induce the intense mixing near the surface.
Marsh migration in the coastal critical zone: Drivers and impacts of hydrological, biogeochemical, and ecological change
Authors: Michael Holly , Pratt Dannielle , Chin Yu-Ping , Fagherazzi Sergio , Gedan Keryn , Kirwan Matthew , Seyfferth Angelia , Slater Lee , Stephanie Stotts , Tully Katherine
Published: February 2023

Ghost forests and abandoned farms are stark indicators of ecological change along world coastlines, caused by sea level rise (SLR). These changes adversely affect terrestrial ecosystems and economies, but expanding coastal marshes resulting from SLR also provide crucial ecosystem services such as carbon sequestration and mediate material fluxes to the ocean. We introduce a US-NSF Critical Zone Network project designed to untangle the hydrological, ecological, geomorphological, and biogeochemical processes that are altering the functioning of the marsh-upland transition in the coastal critical zone. We have instrumented six sites in the mid-Atlantic region of the US, along the coastlines of the Atlantic Ocean, Delaware Bay, and Chesapeake Bay where marshes are rapidly encroaching into forests and farmland. We have installed field sensors to observe the effects of slow hydrologic change (i.e. SLR) and fast episodic events such as high tides and storm surges on water levels, land surface elevation, salinity, redox conditions, and sap flow. We are coupling these measurements to laboratory experiments and analyses, as well as modeling to elucidate drivers and feedbacks in these complex and highly transient critical zone systems.
Stability assessment of a recurring rockslide on Dehradun – Mussoorie highway in the Uttarakhand state of India
Authors: Chandel Anoopsingh , Gupta Neha , Singh Mahendra
Published: February 2023

The Himalayan geology is complex and fragile in nature. Many landslides are witnessed every year in the region and the occurrence of landslides drastically increases during monsoon. An alarming increase in landslide occurrences has been noticed, which sometimes are attributed to anthropogenic activities. In the present article, stability assessment of a road-cut rock slope site has been discussed. The most recent landslide at the slope site occurred on July 9th, 2022. The rock slope site is situated on Dehradun – Mussoorie highway, and is 29 km away from Mussoorie and 22 km from Dehradun in Uttarakhand state of India. The location is strategically important and poses risk of landslide hazards that can cause loss of human lives and resources. After the landslide occurred, the scarp of the rock slide was of the height of nearly 80 m above road level (1370 m above MSL) with slope height more than 150 m. The entrainment of the slided debris mass was of the extent of 70 m below road level. The preliminary data after the rock-slide at the slope site were recorded and collected such as slope images, slope attributes, joint attributes, joint roughness, and rock chunks. Google earth imageries of past years were observed for the slope site and 1st instance of instability was recorded in 2017, followed by another slide in 2019. Lastly, a major slide occurred in 2022. Point-load strength index (PLSI) tests on irregular rock chunks were performed as per IS – 8764 (1998) and UCS of the intact rock was derived using empirical correlation. Normal distribution was applied on the PLSI results to better assess the UCS of the intact rock. The probabilistic mean of the UCS was 24.21 MPa. Rock mass at the slope site was classified using Rock Mass Rating (RMR) and Q-slope classification system. Evaluated RMR and Q values were 37 and 0.073 respectively. A general impression from the derived values was that the rock mass was of poor quality with calculated safe cut slope angle of 42.3°. In the present case, the slope inclination lies between 60° - 70° on an average and can be termed under the category of unstable slopes. Further, Slope Mass Rating (SMR) was implemented on the slope site. The site was categorized in class IV and termed as unstable with probability of failure of 0.6 and type of failure as planar or big wedges. To be more certain and specific about the type of failure, kinematic analysis was performed in DIPS. It was determined that the rock slope has the probability of direct toppling by 0.33 and wedge sliding by 0.33. Hence, proper mitigation and stabilisation measures should be adopted to avoid any potential hazard.