bluuebunny/crossref_metadata_2025 huggingface dataset:
Detecting flash drought impact on terrestrial ecosystems using observational data
Authors: Oh Sungmin , Park Seon Ki
Published: February 2023

Flash droughts are characterised by rapid onset and can therefore cause severe impacts on agriculture and ecosystems without sufficient early warning. The increasing occurrence of flash droughts due to climate change calls for a better understanding of the terrestrial ecosystem responses to flash drought events. Here we study the ecological impact of flash drought in Europe between 2001 and 2020. To do this, we define flash drought events based on soil moisture percentiles and compare temporal behaviours of various ecological data obtained from satellite observations and machine learning-supported upscaled in-situ measurements. We find that in arid regions, an abrupt transition to water-stressed conditions occurs within a few weeks, negatively affecting vegetation status and reducing carbon uptake in the initial stages of drought. By contrast, vegetation in humid regions is not as severely affected, given that soil moisture recovers relatively quickly. We also show that soil moisture status before the onset of drought significantly impacts the timing and degree of drought-induced vegetation stress, particularly in arid regions. Our study highlights the regional characteristics of flash drought impacts, contributing to better drought adaptation and management strategies. Moreover, our observational evidence of ecosystem responses to flash drought can be used as a reference to evaluate land surface models’ performance.
The hourly volcanic SO2 column density and physical characteristics using Geostationary Environment Monitoring Spectrometer (GEMS) measurements
Authors: Park Jeonghyeon , Lee Hanlim , Yang Jiwon , Hong Hyunkee , Kim Jhoon , Roozendael Michel Van , Theys Nicolas , Li Can , Ahn Myong-Hwan , Lee Dong-won , Park Junsung , Choi Wonei , Park Rokjin , Kim Daewon
Published: February 2023

The Geostationary Environment Monitoring Spectrometer (GEMS) onboard the Geostationary Korea Multi-Purpose Satellite-2B (GEO-KOMPSAT-2B) satellite observes the hourly volcanic SO2 over Asia. In this study, the various physical characteristics of volcanic plumes have been investigated based on hourly volcanic SO2 measurements. The transport direction, path and speed, and altitude of volcanic SO2 plume emitted from Nishinoshima in Japan, Etna in Italy, and Dukono located in Halmahera, Indonesia were calculated. The SO2 plume from Nishinoshima, Japan, moved westward at a maximum speed of 57 km/h on August 4, 2020. The SO2 plume generated from Etna was observed to move over China using both GEMS and TROPOMI, and moved at an altitude of 11–14 km and a speed of 162–190 km/h. In the case of the SO2 plume from the Dukono volcano flowed into an average of 3.6 Mg of SO2 per hour to the cities of nearby islands. GEMS can be utilized for an improvement in the prediction accuracy of SO2 plume transport using a chemical transport model due to the availability of hourly volcanic SO2 height information. In addition, hourly observations of SO2 concentrations are expected to protect SO2 exposure through rapid forecasting for people in cities around the volcano.
Estimating high spatiotemporal terrestrial carbon flux using geostationary and polar-orbiting satellites: CArbon Simulator from Space (CASS)
Authors: Kim Jongho , Jeong Sujong
Published: February 2023

Quantitative assessment of the carbon cycle for terrestrial ecosystem is significant to improve our understanding on climate change, as it absorbs about 30% of annual global anthropogenic CO2 emission. To refine the carbon flux estimation, we construct a data-based model named CArbon Simulator from Space (CASS), motivated by the representative Light Use Efficiency (LUE) model VPRM. The model simply estimates carbon flux with the information of air temperature, relative humidity, photosynthetically active radiation (PAR), Enhanced Vegetation Index (EVI), and Land Surface Water Index (LSWI). CASS construct the hourly NEP dataset in 250m resolution for the Seoul Metropolitan Area using refined datasets, including PAR from the HIMAWARI8, geostationary satellite. Notably, CASS does not have Plant function type (PFT) dependency by replacing empirical coefficients with the machine learning regressor. The result confirms the increased ability to capture the spatiotemporal variation at local scale for NEP especially in the urban area. Our refined estimation of carbon flux is expected to help understanding the role of terrestrial ecosystem in climate crsis.
Lost In Transition – aquatic carbon evolution along a headwater stream network
Authors: Wang Brian , Johnson Mark
Published: February 2023

Large amounts of carbon (C) are transported through Earth’s aquatic conduit every year. While the C transported to freshwater systems as dissolved organic C (DOC) and dissolved inorganic C (DIC) has been investigated for some time, the dynamics controlling how much DIC gets evaded to the atmosphere (as CO2) remains uncertain and an area of active investigation. Recent technological advancement using in-situ dissolved CO2 (pCO2) sensors increased previously established global C evasion estimates but sensor networks that inform this estimate have an inherent spatial bias towards major tributaries. Contributions from headwater streams where pCO2 values tend to be higher are less well constrained and tend to be biased towards daytime measurements. This research seeks to highlight how much C (as DOC and pCO2) is transported at multiple locations along a headwater to 2nd order stream system, along with an investigation of local dynamics controlling DOC and DIC transformation within the stream network.Headwater monitoring stations were installed in University of British Columbia’s Malcolm Knapp Research Forest in the North American Pacific Coastal temperate rainforest (PCTR) region - an aquatic C hotspot due to its high productivity rainforest ecosystems and steep elevation gradient. This research reports trends of aquatic DOC dynamics and CO2 evasion fluxes where continuous DOC measurements [s::can UV-Vis Spectrolyzer] are validated monthly with the Shimadzu Total Organic Carbon analyzer and time series data obtained from dissolved CO2 probes [Vaisala GMP221] are corrected using gas chromatography [Agilent 7890A]. Monitoring stations (DOC and pCO2) installed over several kilometers in the same stream permitted an investigation into how aquatic carbon evolves between organic and inorganic phases, as well as CO2 transfer between the dissolved phase and the atmosphere.Preliminary data indicates that over the 2 km reach, pCO2 decreased by an average of 22.8%, while DOC declined by 2.35 mg/L between upstream and downstream sites - a 74.9% reduction in DOC concentration over this distance. Ongoing research seeks to disentangle dilusion vs. aquatic metabolism as controlling factors of the observed DOC concentration reduction. In this presentation I will also discuss temporal dynamics (e.g., high flow vs. low flow conditions and hysteresis behaviour), DOC characterization (as SUVA254 and spectral slopes), and evasion flux calculations at the two locations. Results from this study will help establish transformation pathways that connect DOC and DIC with contributions to biogeochemical understanding of catchment carbon cycle and aid in identifying the role of PCTR headwater streams in the global evasion estimate context.
An assessment of extreme precipitation within cyclone composites using ERA5
Authors: McErlich Cameron , McDonald Adrian , Renwick James
Published: February 2023

Extra-tropical cyclones are key components of the atmospheric general circulation due to their ability to transport large quantities of heat, moisture, and momentum. Cyclones are an important contributor to extreme weather as their passage is associated with strong winds, and large precipitation accumulations. Here we connect a cyclone compositing scheme with regionally derived distributions of precipitation to present a framework for classifying spatially dependent extremes relative to the cyclone centre. Using this framework, cyclone composites for both average (50th percentile) and extreme (90th and 98th percentile) precipitation are derived from ERA5 reanalysis output. Composites are then partitioned into different stages of the cyclone lifecycle to assess the spatial and temporal evolution of precipitation extremes. We find that most extreme precipitation occurs within the comma-cloud structure close to the cyclone centre, with the extreme precipitation occurrence and intensity occurring in that region. Extreme precipitation is also identified to be largest during the period of deepening before the maximum cyclone intensity is reached. These regions of the cyclone correspond to places where large fractions of precipitation are above the extreme threshold. Strong spatial correlation are also seen between the average and extreme precipitation during the deepening phase for the precipitation mean, occurrence and fraction. This correlation weakens as the cyclone evolves and as the threshold used to determine extreme precipitation increases.
Parametrizing the evolution of convective updraft vertical velocities
Authors: Haddad Ziad , Prasanth Sai , van den Heever Sue , Marinescu Peter , Freeman Sean , Posselt Derek
Published: February 2023

Moisture convergence, latent heat, upper-level divergence all contribute to the genesis and growth of convective updrafts. In order to characterize the morphology of this evolution, and identify its constituent modes, we analyzed a large data set of synthetic updrafts simulated using a convection-resolving differential-equation solver run at high spatial and temporal resolutions (respectively 100 meters and 10 seconds). The analysis started by fitting each simulated updraft with a 6-parameter analytic representation, so that the joint statistics of the 6 parameters and of their evolution in time can be quantified. The first result is that an effective 6-parameter representation does exist and approximates the vertical profiles with a residual relative error whose r.m.s. value is smaller than 10% for 59% of all cases, and smaller than 20% for 89% of all cases. The r.m.s value of the absolute error is smaller than 0.4 m/s for 97% of all cases. Having established the suitability of this approximation, the variability of the 6 parameters for the 2-minute average Wa of a profile W was quantified, as was the variability of the evolution of W – Wa over a two-minute interval. The analysis reveals that 4 scalars suffice to capture the bulk of the variability of the evolution of convective updrafts. The modes (spanning the range of values of these 4 scalars) turn out to be related to the maximum amplitudes of w and to the heights at which they are achieved. This description paves the way toward the characterization of the environmental determinants of updraft evolution and, in turn, the determination of the effects of updraft characteristics on upper-level air density, divergence and the resulting anvil clouds.
Anorthosite and associated gabbronorite plutons of Barabar hills in Chotanagpur granite gneiss complex (CGGC), eastern India: Estimation of parental melt for gabbronorite using equilibrium distribution method (EDM)
Authors: Negi Priyanka , Belousov Ivan , Danyushevsky Leonid V , Saikia Ashima , Ahmad Mansoor
Published: February 2023

The small plutons of anorthosite and associated gabbronorite exposed near Barabar hills form a component of Chotanagpur granite gneiss complex (CGGC) in eastern India. Plagioclase (>90 vol %) make up the majority of anorthosite rock with minor mafic minerals (amphibole, mica), while orthopyroxene (>40 vol %), plagioclase (40-50 vol %) and clinopyroxene (>20 vol %) make up the associated gabbronorite. These are cumulate rocks with anorthosite and gabbronorite showing adcumulate and mesocumulate textures, respectively. Compositionally, plagioclase ranges from anorthite to labradorite (An60-96) in anorthosite and from oligoclase to bytownite (An50-70) in gabbronorite. In gabbronorite, the clinopyroxene composition ranges from diopside to augite (En36-43 Fs12-15 Wo43-47), and the orthopyroxenes are hypersthene (Wo39-40 En46-50 Fe10–21).Anorthosite show enrichment of LILE (Rb, Ba, Sr, Th, Pb) with respect to the HFSE (Zr, Ti, Nb and display enrichment in LREE ((La/Yb) N = 2.78-15.29) with positive Eu anomaly (Eu/Eu* = 1.29-3.45) and variable MREE. A flat to depleted trend for HREE ((Sm/Yb) N = 1.02-2.95) is observed for anorthosites. Associated gabbronorites show enrichment of LREE ((La/Yb) N=1.99-4.93), depleted HREE ((Sm/Yb) N = 0.88-3.24) with negative to positive Eu anomaly (Eu/Eu* = 0.78-2.95). Also, the gabbronorite shows enrichment of LILE (Rb, Ba, Sr, Th, Pb) compared to HFSE (Zr, Ti, Nb). Clinopyroxenes of gabbronorite have low REE abundances (53.29-60.29 ppm). Clinopyroxenes are depleted in light rare earth elements (LREEs) (La/Yb) N = 0.75–0.80 and depleted in LILEs such as Ba, Sr. and also exhibit negative anomalies in Zr and Ti.REE composition of gabbronorite clinopyroxene is constrained between TMF = 15-30% calculated using the equilibrium distribution method (EDM). This is substantiated by whole rock parental melt REE composition calculated using the concentration ratio approach (Nernst equation), the result of which is consistent with those made using EDM. In chondrite normalized plot, the estimated parental melt display (1) near-horizontal trend from Lu to Gd at rock/chondrite = ~100, (2) negative anomaly at Eu, (3) gradual rise from Sm to Ce and (4) slight dip from Ce to La.
US National Academy report on Greenhouse Gas Information for Decision Making
Authors: gurney kevin , Wuebbles Don , Bawa Kamal , Dreyfus gabrielle , Eldering Annmarie , george fiji , graven heather , Hsu angel , Oda Tomohiro , Xueref-Remy Irene , Silvern Rachel , Stoudt Amanda , McGovern Bridget , Razafindrambinina Patricia
Published: February 2023

The National Academy of Sciences convened a committee to generate a report titled “Development of a Framework for Evaluating Global Greenhouse Gas Emissions Information for Decision Making”. The report:  Described approaches used to develop global anthropogenic greenhouse gas emissions inventories, including the use of surveys
Discussed the potential uses and limitations of these approaches
Provided a framework to evaluate emissions information and inventories
Presented several case studies to demonstrate how the framework could be applied to evaluate emissions information and inventory approaches and identify strengths and opportunities for improvement for each case study.
Identified ways to improve methodological transparency, sustainability and continuity of relevant observations, and product confidence in global anthropogenic greenhouse gas emissions inventories
 To accomplish this the committee identified a series of “pillars” that were deemed ideal characteristics of GHG inventories for decisionmaking. Three dominant GHG inventory development approaches were identified from the existing work and ranked within the series of pillars. The committee made a series of recommendations for continued development of inventories to enhance their quality and utility to decisionmakers.In this presentation I will describe the major content of the report, describing the evaluation matrix and a summary of the committee’s recommendations.
Towards the Anthropocene peatlands and forests – old-growth forest loss in Western Poland initiated peat growth and peatland state shifts
Authors: Lamentowicz Mariusz , Czerwiński Sambor , Karpińska-Kołaczek Monika , Kołaczek Piotr , Gałka Mariusz , Guzowski Piotr , Marcisz Katarzyna
Published: February 2023

During European states’ development, various past societies utilized natural resources, but their impact was not uniformly spatially and temporally distributed. Considerable changes resulted in landscape fragmentation, especially during the Middle Ages. Changes in state advances that affected the local economy significantly drove the trajectories of ecosystems’ development. The legacy of significant changes from pristine forests to farming is visible in natural archives as novel ecosystems. Here, we present two high‑resolution, densely dated multi‑proxy studies covering the last 1000 years from peatlands in CE Europe. In that case, the economic activity of medieval societies was related to the emerging Polish state and new rulers, the Piasts (in Greater Poland) and the Joannites (the Order of St. John of Jerusalem, Knights Hospitaller). Our research revealed rapid deforestation and subsequent critical land-use transition in the high and late Middle Ages and its consequences on the peatland ecosystem development. The shift from the old-growth forests correlates well with raising the local economy, deforestation and enhanced peat initiation. Along with the emerging landscape openness, the wetlands switched from wet fen with open water to terrestrial habitats. Both sites possess a different timing of the shift, but they also show that the catchment deforestation caused accelerated terrestrialization. Our data show how closely the ecological state of wetlands relates to forest microclimate. We identified a significant impact of economic development and the onset of intensive agriculture processes near the study sites. Our results revealed a surprisingly fast rate at which the feudal economy eliminated pristine nature from the studied area and led to intensive nature exploitation in the Anthropocene. In consequence, its activities led to the creation of novel peatlands types.
Wildfires in Warming Siberia: Trends, Transportation and Implications on Arctic Climate
Authors: Kim Sang-Woo , Cho Yeonsoo , Yoon Jin-Ho , Kim Baek-Min , Jeong Jee-Hoon
Published: February 2023

Wildfires in carbon-rich northern high latitudes, especially Siberia, is an important phenomenon because it can worsen the air quality and accelerate warming over the Pan-Arctic regions. We investigate the shift of wildfire regimes in northern high latitudes over the recent decades using Moderate Resolution Imaging Spectroradiometer (MODIS) active fire data. Northeast Siberia has experienced a significant increase in the number of wildfires (+11.04 % year-1) and the mean period of events (+0.16 days year-1). Strengthened anomalous anti-cyclonic circulation from the surface to the upper troposphere over Northeast Siberia under the Pan-Arctic warming is responsible for more active wildfires over the last decades. This causes strong and long-lasting warm and dry conditions conducive to the ignition and persistence of wildfire. Additionally, extreme wildfire events in Northeast Siberia show that biomass-burning aerosols and gases are transported into the Arctic Ocean, contributing to the rapid melting of sea ice and snow by altering the surface radiation budget. These results suggest that extended wildfire activities in Northeast Siberia are critical to predicting the future Arctic climate.
Estimation of annual Cesium-137 influx from the FDNPP to the coastal water
Authors: Satoh Shun , Takata Hyoe
Published: February 2023

Due to the accident at the Fukushima Daiichi Nuclear Power Plant (1F) in March 2011, radionuclides were introduced into the environment, and one of the release pathways to the ocean is the direct discharge from the 1F (on-going release). This was mainly caused immediately after the accident, but even now, the on-going release is continuing. In this study, firstly we estimated the on-going release of 137Cs from 1F over 10 years after the accident, using the TEPCO’s 137Cs monitoring results in the coastal area around 1F. Secondly, change in the monitoring data related to countermeasures by TEPCO (e.g. construction of iced walls) to reduce the introduction of contaminated water into the ocean or detect 137Cs in nearby seawater, so their effects on the on-going release estimation were also discussed. A box model including inside and outside of the port was assumed for the area around 1F, and the amount of 137Cs in the box was estimated (estimated value: modeled data). Then, the difference between the estimated value and the amount of 137Cs obtained from actual observed concentrations (measured value: monitoring data) was calculated. The result showed that the measured value was higher than the estimated value, suggesting the on-going release from 1F. As for decrease in monitoring data after the countermeasures, it is implied that the estimation of rate of on-going release has been reduced by the countermeasures.
A First Look at Surface Ocean Measurements during the SASSIE Field Campaign in 2022
Authors: Schanze Julian ,   Salinity and Stratification at the Sea Ice Edge (SASSIE)
Published: February 2023

The NASA Salinity and Stratification at the Sea Ice Edge (SASSIE) field campaign took during place between August and October of 2022. Using three major components, the aim is to understand the relationship between both haline and thermal stratification and sea-ice advance, and to test the hypothesis that a significant fresh layer at the surface can accelerate the formation of sea ice by limiting convective processes. The three components of the field campaign include: 1) A one-month shipboard hydrographic and atmospheric survey in the Beaufort Sea, 2) A concurrent airborne campaign to observe ocean salinity, temperature, and other parameters from a low-flying aircraft, and 3) The deployment of autonomous assets, buoys, and floats that are able to observe both the melt season and the sea ice advance.Here, we focus on the novel results from the month-long research cruise aboard the R/V Woldstad that took place during September and October of 2022, particularly measurements of salinity and temperature at radiometric depths (1-2 cm) from the salinity snake instrument. These measurements will be contextualized with all other components of the cruise, including uCTD, air-sea flux, airborne, and satellite data to examine the effects of stratification on ocean dynamics in the Beaufort Sea near at the sea ice edge.
Spatial downscaling of IMERG precipitation estimates using statistical techniques
Authors: Stathopoulos Stavros , Gemitzi Alexandra
Published: February 2023

The aim of this study was to spatially downscale the Precipitation Estimates (PEs) from the Global Precipitation Measurement (GPM) mission, using the Integrated Multi-satellite Retrievals for GPM (IMERG), over a complex region in Greece. For this purpose, the Multivariate Linear Regression (MLR) and the Residual Correction (RC) techniques were utilized, in conjunction with remote sensing cloud properties from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, onboard Aqua satellite, namely Cloud Optical Thickness (COT), Cloud Effective Radius (CER) and Cloud Water Path (CWP). The downscaled PEs were then validated using regional rain gauges’ measurements. According to our analysis, the 0.01o downscaled IMERG PEs were found to be more accurate than the original 0.1o IMERG data, over the region. In addition, the implementation of the RC technique to the 0.01o downscaled PEs was observed to improve the performance of the MLR downscaling method. This research was funded by the EU project titled: WATERLINE project id CHIST-ERA-19-CES-006.
Ground subsidence risk mapping and assessment along Shanghai metro lines by PS-InSAR and LightGBM
Authors: Chai Long , Xie Xiongyao , Zhou Biao , Zeng Li
Published: February 2023

Ground subsidence is a typical geological hazard in urban areas. It endangers the safety of infrastructures, such as subways. In this study, the ground subsidence risk of Shanghai metro lines was mapped and assessed. Firstly, PS-InSAR was used for the ground subsidence survey, and subsidence intensity was divided into five classes according to subsidence velocity. 10 subsidence causal factors were collected and the frequency ratio method was applied to analyze the correlation between subsidence and its causal factors. Then LightGBM model was used to generate a ground subsidence susceptibility map. And receiver operating characteristic curve and area under the curve (AUC) were adopted to assess the model. And AUC is 0.904, which suggests the model's performance is excellent. Finally, a risk matrix was introduced to consider the intensity and susceptibility of ground subsidence. The risk of ground subsidence was mapped and classified into five levels: R1 (very low), R2 (low), R3 (medium), R4 (high), and R5 (very high). The results showed that the risk of subway ground subsidence exhibited a regional-related characteristic. Metro lines located in areas with higher ground subsidence risk levels also had higher ground subsidence risk levels. Meanwhile, the statistical results of subway ground subsidence risk levels showed that subway stations were safer than sections.
A study on marine physical characteristics around an underwater reef using computational fluid dynamics
Authors: Kim Dongha , Lee Seung-Woo , Jeong Jin-Yong , Jang Sung-Chul
Published: February 2023

The marine physical characteristics occurring around the underwater reef in waters more than 100 km away from the land were analyzed through computational fluid dynamics (CFD). A fixed jacket structure so-called Ieodo Ocean Research Station (I-ORS) for marine and atmospheric observations is installed on this underwater reef, and marine observation data have been continuously produced for 20 years. However, there is a concern that observation data may be affected by the underwater reef. We built a numerical modeling framework based on observational data and analyzed the results to find out how underwater reef affects I-ORS. As a result, it was confirmed that various marine physical characteristics (wake region, local upwelling region, suspended sediments, vortex shedding, etc.) appear around the underwater reef. Especially, particle analysis was performed considering the tidal cycle and density stratification to identify the mechanism of suspended sediments generation. Consequently, we were able to find a pattern for the diffusion of suspended sediments around the underwater reef and it is possible to understand various marine physical characteristics around the underwater reef.
Paradigm Shifts in Parameter Space
Authors: Pietsch Stephan
Published: February 2023

There exists a long going discussion on how many parameters are needed within complex ecological, ecosystem and earth system models. Overparameterization is an often-used term to describe an overshoot in parameter space dimensionality, which sometimes may lead to better results, but goes hand in hand with a loss in generality. Oversimplification of parameter space dimensions - on the other hand - may lead to results that may be correct in the mean, but incorrect in each single case.So, one question arises: How can we determine the number of parameters needed to describe a system with the desired accuracy and precision for a given application?A possible answer lies in the relationship between the correlation among, and the respective information content within, some given data or model outputs. Alfréd Rényi provided dimensional descriptors for this issue, i.e. the correlation dimension and the information dimension embedded in a given data series.When both dimensions are equal, the most simple model description with least parameters is best. When information content exceeds the correlation, then a higher dimensional parameter space is needed to achieve accurate results.We will use two examples to demonstrate this principle: temperate alpine ecosystems and tropical lowland ecosystems, both modelled with BGC-MAN. The degree of difference between correlation and information will show the differences in parameter space needed to get an accurate and precise description of the modelled system.
Deconvolution of site effects in ground-motion using site response function derived from HVSR method
Authors: Ahn Byeong Seok , Kang Tae-Seob , Yoo Hyun Jae
Published: February 2023

Site effects caused by unconsolidated sediments laying on the bedrock amplify or attenuate ground motions propagated to the surface. Site effect is unique site-by-site, and thus, makes analyzing actual attenuation characteristics of ground motions difficult. In the southern Korean Peninsula, 17 seismic stations administered by KMA and KIGAM were equipped with a pair of accelerometers; one is installed at the surface, and the other at the borehole (namely SB station). We estimate the site response functions of the stations using ambient noise data. First, the horizontal-to-vertical spectral ratios (HVSR) of the stations were calculated. Then, calibration ratios to adjust the amplitude of HVSR to that of surface-to-borehole spectral ratio (SBSR) were estimated and applied to the amplitude of HVSR. These amplitude-corrected HVSRs are used as the site response function to correct linear site effects in ground motions. To deconvolve the site effect of ground motions, we designed linear zero-phase FIR filters based on the site response functions. Then we divided the spectral amplitudes of the ground motions by the frequency response of the FIR filter. For the SB stations, site response functions of ten stations were obtained, and ground-motion data of 39 events with ML > 2 were corrected using these site response functions. In the result, the peak ground motion (PGA) of corrected ground motions at the surface was reduced by 20-76% on average compared to raw ground motions. Comparing ground motions of the borehole and surface sensors, the corrected PGA of the surface was 1.8-4.9 times bigger than the raw PGA of the borehole. For the whole surface stations of 176, the site-response functions of 75 stations were estimated, and ground-motion data of 210 events with ML > 3 were corrected by their site-response functions. We found that surface ground motions are deamplified to the level of borehole ground motions through the site effect correction.
The influence of microplastics on the dry end of the soil-water retention curve
Authors: Laermanns Hannes , Rolf Markus , Forche Susanne , Castrucci Elena , Stelzer Alexander , Bogner Christina
Published: February 2023

Most studies focus on the detection of microplastic particles in different compartments of the environment. While impacts of microplastics on aquatic systems have already a wide acceptance in public, the research on microplastics in terrestrial systems is quite young. Our study aims to decipher the consequences of microplastics on the soil-water retention curve beyond the wilting point. Using a dew point WP4C hygrometer, we measured water retention curves of loess and sand samples with added microplastics, namely amorphous biopolymer, polystyrene in two sizes and three different types of UV-aged particles. All the different microplastics were added in concentrations of 0.1 wt.%, 0.5 wt.%, and 4.5 mg/kg. Reference samples without microplastics were prepared as well. For the analysis, we fitted the Webb model and calculated the water content at the wilting point and the slope of the soil-water retention curve. Our preliminary results did not show any significant differences between the different microplastics and their concentrations, however, the lowest slope and highest water content at pF 4.2 were observed in the samples without microplastics. Furthermore, the results indicated a greater variability with increasing size of microplastic particles.
The record-breaking 2022 long-lasting marine heatwaves in East China Sea
Authors: Oh Hyoeun , Jeong Jin-Yong
Published: February 2023

In 2022, there were record-breaking long-lasting marine heatwaves in the East China Sea, which persisted for 62 days during boreal summer. It was more than sixfold compared to the average duration of the marine heatwaves, which is 9.73 days. It would be recorded as a year when not only marine heatwaves but also various extreme events occurred throughout Asia, such as the summer flood in China and Pakistan. The question arises whether it is caused by La Niña, the first “triple-dip” of the century. Here we will show key local and remote processes that caused the 2022 long-lasting marine heatwaves in the East China Sea. We have conducted a diagnostic analysis based on the mixed-layer heat budget equation to discover the characteristics of the marine heatwaves, i.e., frequency, duration, and intensity. Based on the equation, we found that weakening ocean vertical mixing and entrainment caused by a density stratification would drive the onset of the marine heatwave in the East China Sea. A large river discharge from the Yangtze River related to extreme rainfall in China would be responsible for the stratification by inducing a shallow mixed layer, and it could affect the weak ocean dynamics. Simultaneously, an anomalous anticyclonic circulation was settled in the corresponding region, and the combined effect of the ocean and atmosphere led to the onset of the marine heatwave. The anticyclonic circulation was sustained longer, resulting in the prolonged marine heatwaves in the East China Sea via enhanced shortwave radiation. In this study, we will discuss further where the stationary Rossby wave train originated and how it could lead to the persistent anticyclonic circulation in the East China Sea.
Observed Changes in Springtime Nutrient Flux Budget along the Korean Peninsula (2012-2021): Roles of Streamflow and Nutrient
Authors: Kim Yena , Kam Jonghun
Published: February 2023

Through precipitation, nutrients on the surface flow along the river and flow out to the coast. In order to effectively manage coastal water quality and ecosystem, it is essential to study the changes in terrestrial nutrient discharge to the coast through streamflow. However, research on long-term on estuarial or coastal water quality and river streamflow data remains limited particularly around the Korean Peninsula where long-term data for water quality and streamflow are available. Here, this study aimed to investigate changes in inland nutrient fluxes the coastal regions around the Korean Peninsula and the contribution of changes of streamflow and water quality. The overarching question of this study is to which extent can changes in nutrient flux discharge be contributed by changes in streamflow or nutrient concentrations? First, we used observational data of rivers during the spring months (March through May) to assess changes in the nutrient fluxes over 2012–2021, which were springtime TN, TP and Chlorophyll-a nutrient fluxes from the inland to the coastal regions of the surrounding Korean Peninsula. Second, we conducted analytically a simple decomposition analysis of the relative contribution of changes in streamflow and nutrient concentration to the changes of nutrient fluxes model. Results show that the change rate of annual spring nutrient (TN, TP, Chlorophyll-a) flux was more affected by streamflow flowrate (84, 51, 91%, respectively) than nutrient concentration (19, 48, 5%, respectively). In addition, the regional analysis of the nutrient flux on the Korean Peninsula (the western, northern, and eastern sides) showed the contribution of the western side was the largest to changes the total nutrient fluxes.This study emphasized the importance of hydrological linkage between the water and nutrient cycles through an analytical approach, highlighting the potential impacts of changes of nutrient fluxes on off-shore ecological communities and aquacultural productivities.  
Viscosity, rogue waves, and permanent downshift in nonlinear Schrodinger models
Authors: Schober Constance
Published: February 2023

In this talk we consider the impact of viscosity on the stabilization of spatially periodic breathers (SPBs), related rogue wave activity, and permanent downshift in the framework of a higher order nonlinear Schrodinger (HONLS) model. The Floquet spectral theory of the NLS  equation is used to characterizethe perturbed dynamics in terms of nearby solutions of the NLS equation.Bands of complex spectrum in the Floquet decomposition of the viscous HONLS data shrink almost to complex points indicating the breakup of the SPB into asoliton-like structure. Rogue waves in the viscous HONLS flow are found totypically occur when the spectrum is in a one or more soliton-like  configuration. Rogue wave activity in the viscous HONLS is compared with  results  on the emergence of soliton-like rogue waves in a nonlinear damped HONLS model.Although permanent frequency downshift is observed in both the viscous and nonlinear damped HONLS models, there are important differences in their respective impact on the growth of instabilities.
Seasonal variabiltiy of the surface ocean carbon cycle: a global synthesis
Authors: Rodgers Keith ,   RECCAP2 coauthors: seasonal variabiltiy in surface ocean carbon cycle
Published: February 2023

Here we present a synthesis of surface ocean pCO2 and air-sea CO2 flux seasonality for a modern climatology and      their decadal trends between the 1980s and 2010s, as part of the REgional Carbon Cycle Assessment and Processes Phase 2 (RECCAP2) project. Working with both surface ocean pCO2-observation products (pCO2 products) and global ocean biogeochemistry models (GOBMs), our main findings are: (i) Over biome scales, both pCO2 products and GOBMs confirm increases in the seasonal amplitude of pCO2 and integrated CO2 fluxes between 1985-1989 and 2014-2018. (ii) For the 2014-2018 climatology, GOBMs exhibit a systematic bias with too-weak biologically-driven seasonal variability in surface dissolved inorganic carbon (DIC), such that the pCO2 seasonal cycle in subtropical biomes is spuriously large and both the amplitude and phase of seasonal pCO2 variations diverge from those in the pCO2 products in subpolar and circumpolar biomes. (iii) Decadal increases in pCO2 seasonal cycle amplitude in subtropical biomes are attributed to being largely driven by reducing CO2 buffering capacity and increasing sensitivity to temperature due to increasing anthropogenic carbon (Cant) content insurface waters for both the pCO2 products and GOBMs. In subpolar and circumpolar biomes, the seasonality change for GOBMs is dominated by Cant invasion, whereas for pCO2 products modulations of the climate state are equally important. (iv) Considered together, the subtropical biomes exhibit decadal increases in CO2 flux seasonality that are larger during winter than summer, consistent with the mechanism described by Fassbender et al. (2022) and potentially promoting a negative feedback in the climate system by increasing the CO2 uptake in winter, by virtue of surface winds being stronger in winter than summer. (v) Large ensemble simulations with ESMs were applied to confirm the validity of biomes as aggregation domains for identifying forced signals. Despite compromises to DIC seasonality impacting pCO2 seasonality, the chosen biome-scale is appropriate for representing the decadal rate of increase of pCO2 seasonality for both GOBMs  and pCO2 products.
Self-Potential signatures on monitoring a rainfall-induced landslide based on a laboratory experiment
Authors: Hu Kaiyan , Han Peng , Mo Chunyu , Zhang Yihua , Li Shuangshuang , Sun Jianwei , Huang Qinghua
Published: February 2023

Based on the electrokinetic effect, the pore-water flows can produce electrical streaming currents. The electrokinetic mechanism makes electrical voltage differences on the ground or underground be observed, which can be called as Self-Potential (SP). SP as a passive geophysical method could be used to understand water flow, which has a potential application in monitoring rainfall-induced landslides. In this study, we implemented a laboratory experiment by imposing rainfall to measure SP data variations due to soil imbibition and water flows. SP, pore-water pressure inside the slope and surface displacement are synchronously measured by a data acquisition system from National Instruments (NI Compact DAQ). The observed results indicate that (1) SP sensitively responds to the pore-water pressure variations, and (2) the significant increase of surface displacement lagging behind changes in SP. The experimental results show the potential that SP can be used to quantitatively interpret the changes in the water flowing pattern inside the slope.
From spectra to functional plant traits: Transferable multi-trait models from heterogeneous and sparse data
Authors: Cherif Eya , Feilhauer Hannes , Berger Katja , Ewald Michael , Hank Tobias B. , Kovach Kyle R. , Townsend Philip A. , Wang Zhihui , Kattenborn Teja
Published: February 2023

Our understanding of the Earth´s functional biodiversity and its imprint on ecosystem functioning, structure and resilience is still incomplete. Large-scale information on vegetation properties (‘plant traits’) is critical to assess functional diversity and its role in the Earth system. Such parameters are constantly changing due to variations in environmental conditions which makes extensive in-situ measurements in the field not logistically feasible. The advent of the upcoming space-borne hyperspectral missions will facilitate to map these properties. However, we are still lacking efficient and accurate methods to translate hyperspectral reflectance into large scale information on plant traits across biomes, land cover and sensor types. Yet, the absence of globally representative data sets on reflectance data and the corresponding in-situ measurements represents a bottleneck to develop empirical models for estimating plant traits from hyperspectral reflectance. Recent and ongoing initiatives (e.g. EcoSIS) provide a constantly growing source of hyperspectral data and plant trait observations from different vegetation types and sensors. In this study we integrated 29 data sets including four different ecosystem types spanning from Europe to north America. By combining these heterogeneous data sets, we propose multi-trait models based on Convolutional Neural Networks (CNNs) that simultaneously infer multiple plant traits from canopy spectra. We targeted a broad set of structural and chemical traits (n=20) related to light harvesting, growth, propagation and defense (e.g. leaf mass per area, leaf area index, pigments nitrogen, phosphorus). The performance of our multi-trait CNN models predicting these traits was compared to single-trait CNNs as well as single-trait partial least squares regression (PLSR) models. The results of the multi-trait models across a broad range of vegetation types (crops, forest, tundra, grassland, shrubland) and sensor types were promising and outcompeted state-of-the-art PLSR models. We found that the overall prediction performances significantly increased from single- to multi-trait CNN models and those of PLSR models. The key contribution of this study is to highlight the potential of weakly supervised approaches together with Deep Learning to overcome the scarcity of in-situ measurements and take a step forward in creating large-scale maps of Earth’s biophysical properties with the increase in availability of hyperspectral Earth observation data.
On the choice of turbulence eddy fluxes to learn from in data-driven methods
Authors: Yan Feier , Mak Julian , Wang Yan
Published: February 2023

Recent works have demonstrated the viability of employing data-driven / machine learning methods for the purposes of learning more about ocean turbulence, with applications to turbulence parameterisations in ocean general circulation models. Focusing on mesoscale geostrophic turbulence in the ocean context, works thus far have mostly focused on the choice of algorithms and testing of trained up models. Here we focus instead on the choice of eddy flux data to learn from. We argue that, for mesoscale geostrophic turbulence, it might be beneficial from a theoretical as well as practical point of view to learn from eddy fluxes with dynamically inert rotational fluxes removed (ideally in a gauge invariant fashion), instead of the divergence of the eddy fluxes as has been considered thus far. Outlooks for physically constrained and interpretable machine learning will be given in light of the results. 
What controls carbon and nutrient cycling in soil? Microbial growth as the fundamental driver of soil biogeochemistry.
Authors: Richter Andreas
Published: February 2023

Growth and death of microorganisms is central to the understanding of almost all global element cycles. To grow, heterotrophic microorganisms need to assimilate organic carbon, and to sustain a flux of readily available organic carbon, they need to depolymerize and deconstruct soil organic matter. When soil organisms die, their remnants become part of the soil organic matter. Thus, the processes that lead to both the decomposition and the accumulation of organic matter in terrestrial environments, are driven by the growth, activity and turnover of heterotrophic microbial communities in soil. Yet, little is known about how microbial growth, turnover, and activity is controlled in the current and in a future climate. In this lecture, I will share insights from a range of experiments that aimed at understanding the effects of soil warming, elevated CO2, and drought, alone or in combination on microbial growth, turnover, and carbon use efficiency. I will draw on examples not only from my own work, but those of others, covering different levels of resolution, from the growth of microbial communities to that of individual bacterial taxa. I will argue that activity, growth, and turnover of microorganisms are the fundamental units of biogeochemical functioning in soils and that we need to move beyond the commonly reported metrices in soil ecology, and even beyond measuring rates of decomposition and mineralization themselves, if we are to understand the effects of climate changes on soil processes.
A mathematical investigation of stirring and mixing of passive tracers by an anisotropic flow field characterized by chaotic advection
Authors: Jimenez-Urias Miguel Angel , Haine Thomas
Published: February 2023

Stirring and mixing plays a central role in the oceans and atmosphere, where the large-scale circulation is characterized by strong anisotropy. When the tracer evolution has no effect on the inertia of the velocity field, i.e., the tracer is passive, the governing evolution equation for the tracer is linear no matter how complicated the advecting velocity field is. Exploiting the linearity of the problem, we present a general approach for computing analytical solutions to the governing tracer equation for prescribed, time-evolving velocity fields. We apply it to analyze the evolution of a passive tracer in the case the advecting velocity field is a form of renewing flow, a prototype of chaotic advection, with stronger transport along a preferred axis. We consider both the freely decaying case and the case with a source of scalar variance (equilibrated), and discuss the possibility to generalize this approach for reacting tracers (biogeochemistry) and more complicated time-varying velocity fields.