bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementing a process-based contrail parametrization in the Unified Model
Authors: Francis Timmy , Rap Alex , Van Weverberg Kwinten , Manners James , Furtado Kalli , Zhang Weiyu , Forster Piers , Morcrette Cyril
Published: February 2023

     The global aviation fleet modifies cloudiness through contrail formation and their subsequent competition with natural cirrus for ambient water vapor, along with enhanced ice-nuclei concentrations from aircraft soot emissions. Contrails form in the upper troposphere at temperatures below 233 K and pressures below 300 hPa, when plume gases from jet engines, having appreciable water vapor content, saturate with respect to liquid water (Schmidt-Appleman Criterion, SAC). Realistic assessments of the aviation-induced modifications to global cloud cover demand improved representation of contrails and their interaction with background cloudiness in climate models. We have implemented a process-based parametrization of contrail cirrus, that applies to both young (≤ 5 h) and aged contrails, in the UK Met Office Unified Model, version 12.0. Contrail cirrus is introduced as a new prognostic cloud class, forming in the parametrized, fractional ice supersaturated area which then undergoes advection, depositional growth, sublimation and sedimentation. The proxy for the fractional supersaturated area is calculated using the same total water PDF as used for natural cirrus but with a different critical relative humidity, rcc - a value at which part of the model grid box is at least ice-saturated. The persistence of contrails being allowed in the ice supersaturated areas, the simulated coverage is not confined to flight corridors, but is advected to air traffic free zones as well. The simulated annual mean global coverage due to young contrails is 0.13%, with the main traffic areas of Europe and North America having the maximum coverage. Similar to natural cirrus, the contrail ice particles reflect the solar short-wave (SW) radiation and trap outgoing long-wave (LW) radiation, thereby modifying the radiative balance of the Earth’s atmosphere. Contrail cirrus is radiatively active in the model with forcing studies enabled via a ‘double radiation call’ approach, wherein parallel runs of the radiation scheme ‘with’ (prognostic) and ‘without’ (diagnostic) the contrail radiative effects isolates the contrail-induced perturbations. Contrails are seen to induce a short-wave cooling and long-wave warming and the net (SW+LW) direct top-of-atmosphere radiative forcing by young contrails amounts globally to 0.5 mWm-2, with the peak forcing seen along the main air traffic areas of North America, Europe and East Asia. The implementation of this process-based parametrization in the UM enables the simulation of the life cycle of persistent contrails, and can provide valuable insights to the aviation-induced modifications to the global cloud cover.
SuPy and SUEWS urban land surface modelling: new developments and capabilities
Authors: Sun Ting , Grimmond Sue , Backlin Oskar , Bluun Lewis , Hogan Robin , Stretton Meg , Xie Xiaoxiong
Published: February 2023

Accurate and agile modelling of weather, climate, hydrology and air quality in cities is essential for delivering integrated urban services. SUEWS (Surface Urban Energy and Water balance Scheme) allows simulation of urban–atmospheric interactions by quantifying the energy, water and carbon fluxes.  SuPy (SUEWS in Python) provides the SUEWS computation kernel, a Python-based data stack that streamlines pre-processing, computation and post-processing to facilitate common urban climate modelling. This paper documents the recent developments in both SuPy and SUEWS, and the background principles of their interface, F2PY (Fortran to Python) configuration and Python front-end implementation. SuPy is deployed via PyPI (Python Package Index) allowing an automated workflow for cross-platform compilation on all mainstream operating systems (Windows, Linux and macOS). The online tutorials, using Jupyter Notebooks, allow users to become familiar with SuPy. A brief overview of other complementary SUEWS developments will be given, and include within canopy layer profiles of temperature, humidity, wind, and radiation that are supporting a wide range of applications; and database developments for obtaining model parameters.
Advancing Operational Modeling Systems at NOAA’s Environmental Modeling Center: Transitioning to Unified Forecast System Applications
Authors: Stajner Ivanka , Gross Brian , Tallapragada Vijay , Levit Jason , Chawla Arun , Mehra Avichal , Kleist Daryl , Yang Fanglin
Published: February 2023

National Oceanic and Atmospheric Administration’s (NOAA’s) Environmental Modeling Center (EMC) is a lead developer of Numerical Weather Prediction (NWP) systems that also transitions to operations and maintains more than 20 numerical prediction systems that are used across the National Weather Service (NWS), the broader NOAA, by other United States (U.S.) federal agencies, and various other stakeholders. These systems are developed through a close collaboration with partners from the academic, federal and commercial sectors. EMC maintains, enhances and transitions-to-operations numerical forecast systems for weather, ocean, climate, land surface and hydrology, hurricanes, and air quality for the U.S. and the global community and for the protection of life and property and the enhancement of the economy. NOAA’s Next Generation Global Prediction System (NGGPS) Project initiated a major shift in the development of operational Earth system predictions with a goal to simplify the National Centers for Environmental Prediction (NCEP) Production Suite using the Unified Forecast System (UFS) framework (https://ufscommunity.org/). EMC has taken a lead in further development and consolidation of NCEP’s operational systems into UFS based applications.  The UFS is being designed as a community-based, comprehensive atmosphere-ocean-sea-ice-wave-aerosol-land coupled Earth modeling system with coupled data assimilation and ensemble capabilities, organized around applications spanning local to global domains and predictive time scales ranging from sub-hourly analyses to seasonal predictions.  Disparate operational applications that have been developed and maintained by EMC in support of various stakeholder requirements are being transitioned to the UFS framework. The transition started a few years ago and is planned to continue over the next few years. The resulting applications will consolidate NCEP’s Production Suite into far fewer applications that share a set of common scientific components and technical infrastructure.  This approach is expected to accelerate the transition of research into operations and simplify maintenance of operational systems. This talk describes major development and operational implementation projects at EMC over the last few years and the plans for the next five years (2023-2027), how those fit within the broader strategic plans of NOAA, and how these projects link with other model-related projects internally within NOAA and with the broader U.S. and international modeling community.
Microplastic emission characteristics of stormwater runoff in an urban area: Intra-event variability and influencing factors
Authors: Cho Youna , Shim Won Joon , Ha Sung Yong , Han Gi Myung , Jang Mi , Hong Sang Hee
Published: February 2023

Stormwater runoff is considered a major pathway for land-based microplastic transportation to aquatic environments. By applying time-weighted stormwater sampling at stormwater outlets from industrial and residential catchments, we investigated the emission characteristics and loads (number- and mass-based) of microplastics to aquatic environments through urban stormwater runoff during rainfall events. Microplastics were detected in stormwater runoff from industrial and residential catchments in the concentration range of 68-568 n/L and 54-639 n/L, respectively. Polypropylene and polyethylene were found as major polymers accounting for around 60% of total microplastics. The fragment was the dominant shape of microplastics, and the most common size class were 20-100 μm or 100-200 μm. The microplastic load emitted from industrial and residential catchments were estimated to be 1.54 - 46.1 x 108 and 0.63 - 28.5 x 108 particles, respectively. The discharge characteristics of microplastics inter– and intra–event were affected by the land-use pattern and rainfall characteristics. The concentration of microplastics did not significantly differ between industrial and residential catchments, but the composition of polymer types reflected the land-use pattern. The microplastics in stormwater were more concentrated when the number of antecedent dry days (ADDs) was higher; the concentration of microplastics was generally peaked in the early stage of runoff and varied according to rainfall intensity during a rainfall event. The contamination level and load of microplastics were heavily affected by the total rainfall depth. Most microplastics were transported in the early stage of runoff (19–37% of total runoff time), but the proportion of larger and heavier particles increased in the later period of runoff. The microplastic emission via stormwater runoff was significantly higher than that through the discharge of wastewater treatment plant effluent in the same area, implying that stormwater runoff is the dominant pathway for transporting microplastics to aquatic environments.  
Four Decades of Trends in Snowmelt and Greenup over High-latitude Terrestrial Ecosystems
Authors: Kim JiHyun , Kim Yeonjoo
Published: February 2023

The ongoing climate change has primarily affected snowmelt and greenup timings, which are the two crucial regulators for every component of biogeochemical cycles of the terrestrial ecosystems in high-latitude regions. Previous studies, using various datasets at different regional scales, have focused on either trend, therefore not thoroughly analyzing relative long-term changes in both timings over the entire high-latitudes. In this study, we assessed the four decades (1982-2021) of trends in those two timings for the regions (latitude > 45°N). First, we used Google Earth Engine to derive snowmelt and greenup timings based on normalized indices (i.e., normalized difference snow index and normalized difference vegetation index) that were retrieved from the surface reflectance of Advanced Very High Resolution Radiometer (AVHRR, daily at 0.05°) from National Oceanic and Atmospheric Administration (NOAA) Climate Data Record (CDR). Then, we evaluated those timings against various ground datasets and remote sensing-based estimates, such as PhenoCam, PEP725, SNOTEL, and MODIS. Finally, we investigated the meteorological and geographical effects on the long-term trends of the two timings across the high-latitude regions. Our results imply that the increases in the spatial heterogeneity on snow-free days may considerably alter the spatiotemporal pattern of the vegetation growth and, therefore, the relevant carbon cycle across the high-latitudes.This study is supported by the National Research Foundation of Korea (NRF) grants funded by the Korea government (MSIT) (2020R1A2C2007670, 2020R1C1C1014886 and 2022R1C1C2009543).
Developing the real-time water quality program using machine learning and API.
Authors: Bang Gihun , Gwon Na-Hyeon , Cho Min-Jeong , Park Ji-Ye , Baek Sang-Soo
Published: February 2023

The importance of water quality monitoring (e.g., TOC, DO, Chl-a, TN, and TP) is increasing in part of agriculture, water treatment, and policy decision. As the computing power has been increased, we could develop the real-time water quality system. Our system can forecast the water quality after 2 days from now. To simulate the water quality of ND river, the random forest (RF) and artificial neural network (ANN) were adopted. Furthermore, the program provides a user-friendly system using a graphic user interface (GUI). Our prediction program consists of 3 major phases. Phase 1 utilizes an application programming interface (API) to load the data from national institutes (NI). Phase 2 is the simulation of flowrate of ND River. Phase 3 simulates the water quality using machine learning. RF models produced R2 values of 0.46, 0.8, 0.59, 0.46, 0.67 for chl-a, DO, TN, TOC, and TP respectively while ANN models resulted in R2 values of 0.22, 0.72, 0.53, 0.35, 0.63. Overall, DO shows the most accurate result while TN and TP showed reasonable simulation results, by showing over 0.5 of R2. Our study demonstrates that API service with machine learning is useful for simulating real-time water quality.
The circularity of marine microplastics under the influence of climate change
Authors: Fan Chihhao , Lee You-Yi
Published: February 2023

Since plastics were first made in the early 20 century, global plastic production has increased dramatically and annual plastic use reached 460 million metric tons (Mt) in 2019. Although the advent of plastics creates miraculous economic achievements, it brings about severe pollution at the same time. As the life cycle of plastic use worldwide is still in linear form, mismanaged plastic waste might break into microplastics and accumulate in the environment. Rivers are the main route by which plastics enter the ocean. The process may take years or decades for microplastics to reach the ocean. The ocean surface currents were responsible for the transport of plastic waste and the ocean is its ultimate destination. This study correlated the fate of marine microplastics with economic growth under the influence of climate change. Taking 1960 as a benchmark, the trend of world GDP growth coincided with the growth of annual plastic production, indicating that economic growth heavily relies on plastic-related industries. Plastics emit a high amount of greenhouse gas (GHG) through their life span, enhancing the negative impact of climate change, causing the faster weathering process to form microplastics, and further enabling the leakage into the aquatic environment. According to the OECD statistics, 1.7 Mt of plastics entered the ocean system in 2019, reaching the total accumulation of 30 Mt of plastic waste since 1970. Global warming over past decades enhances the Earth's ocean currents which induced the acceleration of ocean plastic distribution. The accelerated ocean transportation may increase plastic accumulation at the garbage patches within five gyres and the Arctic Ocean which are ultimate sinks for plastic waste in the ocean. The abundance of microplastics in the ocean interferes with the carbon fixation capacity of the ocean, forming a nexus implication between climate change, ocean currents, and marine plastic redistribution. The accumulation of marine microplastic is suggested to be a factor in aggravating the impact of climate change. To deal with the dilemma, economic growth should be decoupled with the massive use of plastic utilization to reduce plastic production and GHG emission. Moreover, higher plastic waste recycling is urgently needed to prevent extra microplastics from entering the ocean.
Sensitivity analysis and research of hydraulic characteristic parameter and observation wells during the pumping test
Authors: Kuo Jen-Tsung , Wen Jet-Chau , Lin Hong-Ru
Published: February 2023

Since there are many uncertainties in the state of groundwater, after determining the research direction and objectives, a numerical model should be established by means of simulation to analyze the hydraulic characteristics such as transmissivity and storativity in the research area. Sensitivity analysis is carried out effectively, and the optimal pumping test strategy is designed based on it. In many previous studies, the sensitivity map made by the two-dimensional model was used to discuss the sensitivity. However, after a long period of data accumulation, it was found that although there would be a continuous change in the discharge, the pumping well and the vicinity of the observation well's hydraulic gradient did not change significantly. From this we get an inference, that is, we cannot obtain the exact location of the sensitivity source in space by simply using a two-dimensional sensitivity map, at most, only the average parameter value of the active area can be obtained. In addition, most of the current research is based on the assumption of homogeneous steady-state conditions, but groundwater mostly exists in the form of heterogeneous transient state in nature. Therefore, this research hopes to use the method of inverse calculating the heterogeneous field to plan and use the developed software (VSAFT2 and VSAFT3) for effective 2D and 3D space simulation, so as to use the characteristics of the three-dimensional space concept to confirm various information and extend the discussion of the source. This will have a great contribution to the changes of water bodies in the future analysis area, groundwater recharge patterns and diffusion control of underground pollution.
Variations in floods associated with Tropical Cyclones over Mexico under ENSO conditions
Authors: Dominguez Christian , Jaramillo Alejandro
Published: February 2023

Tropical cyclones (TCs) are among the most hazardous hydrometeorological phenomena. Mexico is affected by TCs from the North Atlantic and Eastern Pacific oceans, and they originate 86.5% of domestic disasters. The natural hazards associated with TCs are extreme precipitation events, floods, storm surges, and landslides. In the present preliminary study, we focus on exploring how El Niño-Southern Oscillation (ENSO) modulates the frequency and magnitude of extreme precipitation events and floods caused by TCs. We use the CHIRPS dataset for determining the extreme precipitation events (defined by the 95th percentile of daily precipitation) and Mexican rain gauge stations from May to November during the 1981-2013 period. We find that TCs are responsible for ~60% of floods in coastal regions, but this percentage decreases inland. Under El Niño conditions, most floods occur over southwestern Mexico. During neutral conditions, the western coast of Mexico is mainly affected. Under La Niña conditions, most floods occur over the eastern coast of Mexico. Additionally, trends in floods are explored. We conclude that local decision-makers need this information to decrease the hydrometeorological risk before the tropical cyclone season begins. Implementing this information on Early Warning Systems for TCs is also discussed.
Energy Conversion and Partition in Plasma Turbulence Driven by Magnetotail Reconnection
Authors: Li Xinmin , Wang Rongsheng , Huang Can , Lu Quanming , Lu San
Published: February 2023

A long-outstanding issue in fundamental plasma physics is how magnetic energy is finally dissipated in kinetic scale in the turbulent plasma. Based on the Magnetospheric Multiscale mission data in the plasma turbulence driven by magnetotail reconnection, we establish the quantitative relation between energy conversion (J·E , J is current density and E is electric field) and current density (J). The results show that the magnetic energy is primarily released in the perpendicular directions (up to 90%), in the region with current density less than 2.3 Jrms, where Jrms  is the root mean square value of the total current density J. In the relatively weak current region (< 1.0 Jrms ), the ions get most of the released energy while the largely negative energy conversion rate of the electrons means a dynamo action. In the strong currents (>1.0 Jrms), the ion energization was negligible and the electrons are significantly energized. Moreover, a linearly increasing relationship was established between J·E and J. The observations indicate that ions overall dominate energy conversion in turbulence, but the electron dynamics are crucial for energy conversion in intense currents and the turbulence evolution.
Do published field experiments inform the longevity of biochar in soil?
Authors: Xu Chenzhe , Sohi Saran , Hillier Jonathan , Baggs Elizabeth
Published: February 2023

The efficiency of biochar application in soil carbon sequestration (SCS) is highly sensitive to biochar longevity. To predict biochar longevity at extended timescales, modelling is essential. It is often expressed that data from field experiments can support this understanding, especially long-term field experiments (LTEs). Our work tests this assertion, using the existing evidence base. A literature search for LTEs of greater than 3-year duration and other criteria was conducted, with the null assumption that biochar C is inert in soil. Observations of soil organic carbon (SOC) after biochar additions from selected LTEs were made against predictions from the Roth C model, assuming no biochar decay.At the end of July 2022, we found 982 articles describing field experiments that concerned biochar longevity and SCS and initiated within the last two decades. Among them, only 17 reported LTEs matching our screening criteria and providing long-term data suitable for modelling. In these LTEs, a range of SOC dynamics were observed where an acceptable level of fit could not be achieved using a plausible range in parameters. A range of potential reasons for the deviation between measured observations and model predictions were considered, including priming effects on native SOC, migration of biochar particles, sampling and measurement issues, etc. Such factors could not be isolated with sufficient confidence to adjust observational data or model parameters, confounded by the inability to distinguish the dynamics of biochar C and non-biochar C.Current field data do not enable us to reject the null hypothesis. Reliable parameterization for biochar longevity solely based on field experiments may not be possible on timescales relevant to mitigation of climate change. Instead, alternative strategies for assessing biochar longevity are required, that can be verified in real-time alongside a set of permanent benchmark sites, across different agro-ecological zones with uniform experimental standards, not least in sampling strategy and biochar C and non-biochar C distinction. That will support the incremental adoption of biochar, while providing a robust method for post-hoc adjustment of mitigation benefit.
Land subsidence induced by groundwater withdrawal: from conceptual model to Hydromechanical model in Chousui River Alluvial Fan, Taiwan
Authors: Utamas Nugraha Gumilar , Ni Chuen-Fa , Vinh Truong Nguyen Thai
Published: February 2023

The Choushui River Alluvial Fan (CRAF) is facing serious land subsidence problems. In recent years, the main subsidence areas have gradually moved inland, causing security issues for the Taiwan High-Speed Rail (THSR) in the Yunlin county. Although pumping groundwater along the high-speed railway is forbidden, the problem of sinking land has remained. The causes of land subsidence can be multiple and complex. There are discussions about the causes of land subsidence in the Chousui River Alluvial Fan. This study aimed to develop a hydromechanical land subsidence model in this groundwater basin. The modeling process is divided into two broad parts: the groundwater flow model and the hydromechanical/land subsidence model. The development of the model was focused on the severe area of land subsidence in this basin; for this situation, the so-called “site specific model” was developed. Another reason this study used the site-specific model is that the Taiwan government has installed an integrated land subsidence monitoring system in the severe area, including Multilevel Compacting Well (MLCW), GNSS, and Groundwater observation well. This abundant data can be used when calibrating the groundwater flow and mechanical model. The modeling process starts with the construction of site-specific conceptual modeling derived from the basin scale conceptual modeling. This process revealed that the site consists of four aquifers and four aquitard layers with various thicknesses. The next process was creating a numerical groundwater model that began with creating a grid of the model domain. The model consists of fifty rows and fifty columns with ten by-ten meter grid cells and eight layers representing four aquifers and four aquitards. For perimeter boundary conditions, the model has specified head boundary conditions on the east and west part and no-flow boundary conditions on the north, south, and bottom of the model. the hydraulic and mechanical for the initial input of the model were generated using the previous study in this basin. Groundwater flow calibration processes were done using the PEST package. The model was evaluated using a multi-criteria performance meter: R-squared, root mean squared error (RMSE), mean absolute error (MAE), and Nash Sutcliffe Error (NSE). The calibration process for the groundwater flow model shows an excellent result for both mechanical and groundwater flow. The next step is modeling simulated subsidence using scheduling pumping using a different pumping rate scenario. This simulation aimed to reduce subsidence using calibrated pumping rate value but the difference in time of pumping. The result shows a significant subsidence reduction with scheduling pumping in a certain well. Any stakeholder can consider this result to reduce subsidence in the Chousui River Alluvial Fan.
Spatio-temporal variability of rainfall and temperature extremes over Southern Africa
Authors: Mengistu Tsidu Gizaw
Published: February 2023

Climate change can be reflected in terms of  shift in mean climatology as well as shift in the distribution of rainfall and temperature extremes over time. Southern Africa has distinct climate regimes that includes arid and semi-arid climates as well as relatively humid climate. This results in distinct spatio-temporal response of the region to climate change. In this study, major extreme climate indices for the region are derived from daily CHIRPS rainfall, ERA-Interim minimum, maximum and average temperatures to understand the spatio-temporal variability. The long term mean of the coldest annual day-time maximum temperature (90thpercentile) is observed over Lesotho highlands and adjoining areas in South Africa (21.0oC) whereas the warmest day-time temperature (37.4oC) is observed over areas bordering South Africa, southern Botswana and Namibia during the recent four decades. The trend in this indices shows warming (up to 1oC/decade) over southwestern South Africa, along coastal strips of South Africa, much of Mozambique, northwestern Zimbabwe, northern and western Zambia, eastern Angola and cooling over central Botswana. The annual night-time minimum temperature (10th percentile) is increasing northward in contrast to day-time maximum temperature which, in addition, exhibits zonal gradient. In terms of frequency, 10 to 12% of  the days in a year experienced maximum temperature above 90th percentile whereas 9 to 11 % of the days in a year observe night-time minimum temperature below 10th percentile. The annual heat wave duration indices show longest duration (8 days) over Southern Angola, northern Namibia, southern  Zambia, northern Zimbabwe and Botswana and decrease from here northward and southward. Annual number of days with rainfall  above 10 mm is about 10 days over western South Africa, Botswana, southern Zimbabwe, Namibia and southern Angola. In contrast,  it is in the range of 32 to 74 days over northern Angola, Zambia and Mozambique with increasing trend over Botswana, eastern parts of Zambia and Angola.  Similar trend in maximum 5 to 10 day total rainfall is observed over the same areas. Central part of the Southern Africa region exhibits the highest annual continuous dry days (147 to 254 days) whereas the southern and northern parts of the region has the lowest annual continuous dry days ( about 76 days). The long term mean of maximum annual continuous wet days increases northward from 3 days over western parts of South Africa and Namibia to 21 days over  Angola and northern Malawi. Besides secular trend, the rainfall extreme indices have coherent cyclic modes of variability with a period of 3.6 to 3.8 years accounting for 9 to 12 % of the total variance whereas the temperature extreme indices show periodicity of about 2.5 years accounting for 18 to 19% of the total variance. The periodicities are possibly associated with ENSO events that modulate interannual variability.
Effect of air pollutant concentration according to the height of the Planetary boundary layer in Ulsan
Authors: Choi Kang-chan , Song Chang-keun
Published: February 2023

The atmospheric boundary layer is a layer that directly responds to energy emitted or absorbed from the ground into the atmosphere, and is greatly affected by various meteorological factors, which change the concentration of air pollutants. There is generally an inversion layer above the atmospheric boundary layer, so most of the air pollutants emitted by humans cannot escape to the outside of the atmospheric boundary layer and remain there. Ulsan Metropolitan City in Korea is known as the largest industrial city in Korea. These industrial cities generally emit more air pollutants than other cities. Since these air pollutants are greatly affected by the boundary layer, it is important to accurately calculate the height of the boundary layer. In this study, we compare the height of the atmospheric boundary layer based on LiDAR and the height of the atmospheric boundary layer in the Weather Research and Forecasting numerical model, and examine how the height of the atmospheric boundary layer affects the change in the concentration of air pollutants.
Hydrological implications of pervasive permafrost thaw across the Tibetan Plateau
Authors: Wang Taihua , Yang Dawen
Published: February 2023

Rivers originating from the Tibetan Plateau (TP) provide water to more than one billion people living downstream. Almost 40% of the TP is currently underlain by permafrost, which serves as both an ice reserve and a flow barrier and is expected to degrade drastically in a warming climate. The hydrological impacts of permafrost thaw across the TP, however, remain poorly understood. Here we quantify the permafrost change on the TP over 1980-2100 and evaluate its hydrological impacts using a physically-based cryospheric-hydrological model. Our results indicate widespread permafrost thaw and prominent ground ice losses under warming. The declining ground ice reserve provides locally important but unsustainable meltwater runoff. In addition, the lowering of the permafrost table and removal of permafrost as a flow barrier would enhance infiltration and raise subsurface storage capacity. The diminished water supply from ground ice melt and enhanced subsurface storage capacity could jointly reduce annual runoff and exacerbate the risk of regional water shortage when facing future droughts. Our findings highlight the important role of permafrost thaw in future water resources management and drought risk assessment across the TP.
Riverine CO2 and CH4 concentrations and fluxes in the subtropical Pearl River system
Authors: Chen Shuai , Ran Lishan , Liu Boyi
Published: February 2023

Subtropical rivers and streams are identified as significant ecosystems of CO2 and CH4 emissions, yet their contribution to the global carbon cycle remains highly uncertain, partly due to field-based data paucity for the subtropics and spatial-temporal heterogeneity of CO2 and CH4 concentrations and fluxes. Here we examine the regional pattern of CO2 and CH4 concentrations and fluxes from headwater catchments (i.e., the Xijiuxi, Xiaojianghe, Liujiang, and Nanshanhe river catchments) and large river basins (i.e., the Xijiang, Beijiang, and Dongjiang river basins) in the subtropical Pearl River basin in south China. The river water CO2 partial pressure (pCO2) ranged from 208 to 3141 μatm and 433 to 4527 μatm during the high flow season and the low flow season, respectively. Positive relationships between CO2 partial pressure (pCO2) and dissolved oxygen (DO) and between pCO2 and the stable carbon isotope of dissolved inorganic carbon (δ13CDIC) demonstrated that aquatic photosynthesis and CO2 exchange at the water-air interface play significant roles in controlling the magnitude of stream water pCO2. The rivers were consistently oversaturated in CH4, ranging from 14 to 11119 μatm during the high flow season and 43 to 9596 μatm during the low flow season. The mean CO2 effluxes showed higher values in the high flow season (97 mmol m-2 d-1) and lower values in the low flow season (28 mmol m-2 d-1). The results also showed that CO2 effluxes in the four headwater streams were much higher than those in the three large rivers during both seasons. This suggested that headwater streams are significant sources of CO2 for the atmosphere. In comparison, the mean CH4 fluxes were 6.3 mmol m-2 d-1 (high flow season) to 0.5 mmol m-2 d-1 (low flow season), and CH4 concentrations and fluxes were higher in high flow season than in low flow season in headwater streams. Additionally, dissolved CH4 concentrations in urban and agricultural rivers are higher than those in forest rivers. This study highlighted the significant role of CH4 emissions from urban and agricultural river systems and CO2 emissions from headwater streams in riverine carbon cycling.
Multi-step-ahead forecasting of groundwater levels using a Long Short-Term Memory based Encoder-Decoder (LSTM-ED) model
Authors: Koch Julian , Kidmose Jacob , Liu Jun , Schneider Raphael , Stisen Simon , Troldborg Lars
Published: February 2023

Operational forecasts of groundwater levels provide critical real-time knowledge during extreme events, such as floods and droughts. This study proposes a Long Short-Term Memory based Encoder-Decoder (LSTM-ED) model for multi-step-ahead groundwater level forecasting. The LSTM-ED is a well-suited architecture for sequence-to-sequence modelling tasks but has not yet been applied to forecast groundwater levels. The proposed LSTM-ED model is designed in the context of the Danish online monitoring system grundvandsstanden.dk to serve as operational groundwater level forecasting system. In the encoder LSTM model, sequences of past precipitation, temperature and groundwater levels are processed to initialize the decoder LSTM model which, in addition takes in forecast sequences of precipitation and temperature to output a sequence of groundwater levels. We train LSTM-ED models individually for each well, with all data aggregated to daily timescale. We demonstrate the performance of the LSTM-ED architecture for numerous wells from grundvandsstanden.dk and test varying lead times of up to 30 days. The LSTM-ED model forecasts are contrasted with simple benchmark models as well as with a sequence-to-sequence LSTM model that does not incorporate forecasts of precipitation and temperature for outputting the groundwater sequence. Initial results underpin that integrating forecasts of precipitation and temperature is a crucial component, especially for wells with shallow intakes where surface and sub-surface processes are well connected. The sequence-to-sequence LSTM model yields similar accuracy as the simple benchmark models, whereas accuracy clearly improves for the LSTM-ED model. Overall, this study highlights the potential of LSTM-ED models as an operational tool for multi-step-ahead forecasting of groundwater levels.
Nano-strain resolution fiber-optic Fabry-Perot sensors based measuring systems
Authors: Pevec Simon , Donlagic Denis
Published: February 2023

A work describes a deeply etched, long active length, high sensitivity short Fabry-Perot cavity nano-strain resolution sensor. The presented sensors exhibit high spectral sensitivity, low intrinsic temperature sensitivity which is for about 40 times lower than in case of FBG, small size and mounting comparable to conventional Fiber Bragg gratings. The sensor high potential is not only high sensitivity and low temperature intrinsic sensitivity, but also in short cavity length and its tunability, which can be simply accomplished in one production step. This brings versatility in interrogation with different general purpose and cost-efficient VIS-NIR widely available linear detector array-based spectrometers, while still providing strain sensing resolution within the range of few 10 nε. A strain resolution of 20 to 70 nε was demonstrated when using a cost-efficient VIS spectrometer. Furthermore, the sensor structure can be combined with multimode telecom lead-in fibers and low-cost broadband LEDs intended for automotive/lightning applications, which allow production of cost efficient solutions.
Frictional properties of sandstone gouges within Himalayan Main Frontal thrust: constraints on seismicity of shallow crustal deformation
Authors: Sarkar Dyuti Prakash , Hirose Takehiro
Published: February 2023

The present mean convergence rate of Himalaya is ~ 15 mm/year. In comparison to the convergence and stress accumulation, only few stress release events represented by greater than M5+magnitude earthquakes in the Himalayan region have been observed. Understanding the constraints leading to the disparity in stress accumulation and stress release, is crucial to understand the stress accommodation mechanism and seismicity in the Himalayas. The current active subduction boundary is marked by Main Frontal Thrust separating the sub-Himalayas and the Gangetic alluvial plains. The rock types within the Main Frontal Thrust sheet show two primary types of sandstone protoliths, and gouges exhibiting cataclastic to foliated microstructural features. In this study, we have performed rotary-shear velocity step experiments on the powdered samples of the sandstone within the Main Frontal Thrust to determine their frictional properties at slow (creep) to fast (seismic) velocity under 10 MPa effective normal stress condition.  We discuss these results and their implications on seismic nucleation in Himalayan Main Frontal Thrust.
Protecting global forest to avoid carbon emissions
Authors: Qin Zhangcai
Published: February 2023

The Glasgow Declaration on forests signed at the recent UN Climate Change Conference (COP 26) committed to halt forest loss by 2030. Over 141 countries and regions, collectively covering over 90% of global forest, endorsed this declaration, making it by far one of the largest forest protection programs in the world. Avoiding forest loss can generally contribute to climate change mitigation, however, the impacts of the declaration on global CO2 emissions reduction is still unclear. Here we show that by stopping global forest area loss, a large portion of deforestation-related CO2 emissions could be reduced, and the socio-economic damage to global society could be largely avoided. Over three quarters of emissions could be reduced over the next three decades, though any delays in implementing the declaration would decrease the avoided emissions. The value of the public goods provided by avoided deforestation could compensate for loss of private goods gained from clearing the land for agriculture. The Glasgow Declaration, if implemented fully and in a timely fashion, could help the world move closer to carbon neutrality.
Improvement of wind vector retrieval method for increasing data acquisition rate of the wind profiler and the wind lidar
Authors: Kim Yujin , Kwon Byung Hyuk , Seo Jiwoo , Lee Geon Myeong , Lee KyungHun
Published: February 2023

Representative meteorological instruments that utilize the Doppler effect include Doppler radar, wind profiler, and wind lidar. The latter two instruments produce a vertical profile of winds in high spatio-temporal resolution, in the atmospheric boundary layer. Wind lidar observes with a vertical resolution of 50 m or less and a temporal resolution in minutes, so it fills the observation gap in the lower layer where the wind profiler misses meteorological data. The wind lidar makes the wind vector using DBS (Doppler Beam Swinging) and VAD (Velocity Azimuth Display) methods. It is known that the wind by the VAD method is more accurate than the wind by the DBS method. The DBS method has the advantage of obtaining a wind profile with a fast scan time. On the other hand, there is a restriction that requires at least two beams including vertical beams (one of the east and west beams, and one of the south and north beams), which causes a decrease in the data acquisition rate. The VAD method was improved to produce more wind vector of the wind profiler as well as the wind lidar, which generally uses 5 beams. First, the Fourier series was estimated with the radial velocity by the DBS method. Next, the wind vector was determined by setting the azimuth interval and applying the radial velocity by the Fourier series to the VAD method. The wind vectors were retrieved at the altitude where the wind was not calculated by the DBS method, and the results of the two methods were consistent at the altitude where the wind was calculated by the DBS and the improved VAD method. In this study, we propose a method to increase the data acquisition rate even if the vertical beam or one of the inclined beams is insufficient.
Water-energy-food-ecosystem nexus governance: methodological aspects of the assessement of supportive and restrictive contexts
Authors: La Jeunesse Isabelle , Mooren Caro E. , Munaretto Stefania , Hüesker Frank , Cirelli Claudia , Canovas Ingrid , Sievers Eva , Mounir Kaoutar
Published: February 2023

Managing water resources in a sustainable way means, a fortiori in the context of increasingly visible climate change impacts, taking into account decisions made by other sectors having a significant effect on the availability and quality of water. Water quality and quantity are often affected by the energy sector on the one hand, and agriculture and food production on the other. Moreover, ecosystem requirements, such as minimum ecological flows or water quality, should always be considered. Thus, facing climate change impacts calls for increasing water-energy-food-ecosystems nexus considerations.This being said, how can managers of these natural resources and stakeholders using them consider intersectoral coherence needs? Are these needs only theoretical or are they reflected by concrete actions in practice? Last but not least, how to assess the state of WEFE nexus governance in territories?In order to address these questions, the present paper describes the methodological aspects of the WEFE nexus governance assessment tool (NXGAT) co-developed in the NEXOGENESIS project (H2020-funded). This tool assesses the state of the WEFE nexus governance in catchments. The goal of the NXGAT is to highlight what is actually supportive and what is actually restrictive to WEFE nexus governance.The NXGAT is the first step in the WEFE nexus governance approach (Hüesker et al., 2022 ; Mooren et al., 2022) aiming at developing WEFE nexus policies. The NXGAT lays the foundation for cross-sectoral dialogue by both raising awareness and identifying solutions for more WEFE nexus governance.  The NXGAT assesses five dimensions (levels and scales; actors and networks; problem perspectives and goal ambitions; strategies and instruments; and responsibilities and resources) and five qualities (extent, coherence, flexibility, intensity of action, and fit) of the governance system. The tool is implemented in the Lielupe transboundary catchment (Lithuania-Latvia) by a team of transdisciplinary experts during face-to-face interviews. Interviewees are selected to cover the multi-scalar levels of all sectors.The results of the implementation in the Lielupe transboundary catchment provide preliminary results on the efficiency of the method and the importance of the preparatory phases of the field investigation. The implementation of the NXGAT contributed to both underline blockages and leverages to urge for more intersectoral governance in this case study.
Determining the distribution and accumulation patterns of floating litter using modelling tools in the Baltic Sea
Authors: Stips Adolf , Macias Diego , Parn Ove
Published: February 2023

Marine plastic ﬂoating on the sea surface is a major environmental problem. The present studyinvestigated the potential transport patterns of floating marine litter and areas of itsaccumulation in the Baltic Sea by using a hydrodynamic model coupled with a particle-trackingmodel (Parcels). Mapping of marine plastic debris distribution in 2017–2018 revealed that the largestplastic accumulation area is between latitude 59° and 61°, which includes the Northern BalticProper, Archipelago Sea, and the Gulf of Finland. The floating plastic spreads from the largestplastic pollution site River Vistula to the waters of all the countries around the Baltic Sea.
Long-term SOC stabilization in sandy subsoils – evidence from historical tillage experiments
Authors: Sommer Michael , Gerriets Marisa , Burger Dymphie , Bauke Sara , Amelung Wulf
Published: February 2023

Large SOC sequestration rates can be achieved by admixing C undersaturated subsoil into topsoil (e.g. by deep tillage), hence creating a strong disequilibrium in the C cycle of the local soil-plant-microbiome system. The magnitude of C sequestration (sum of SOC changes in top- and subsoil) strongly depends on the fate of SOC translocated into the subsoil. Here we present evidence for a strong preservation of subsoil SOC even after 40-60 years by re-analyses of historical field trials on sandy soils (Albic Luvisols, Arenic, Neocambic) in E Germany. Compared to Ap horizons (retain samples),  which were translocated into subsoil decades ago, 50-70% of former SOC is still detectable after 40-60years. From one field experiment (V210) a non-linear decline of SOC contents can be concluded (levelling off after 20y).
Predicting Effective Angular Momentum Function Forecast Errors
Authors: Dill Robert , Dobslaw Henryk
Published: February 2023

Time-variations in the orientation of the solid Earth are largely governed by the exchange of angular momentum with the surface geophysical fluids of atmosphere, oceans, and the land surface. Modelled fields of atmospheric winds, atmospheric surface pressure, ocean currents, ocean bottom pressure, and terrestrial water storage allow to calculate effective angular momentum (EAM) functions that provide highly reliable information about the orientation changes of the Earth. EAM forecasts derived from model forecast runs support substantially short-term Earth Orientation Parameters (EOP) Predictions. So far, routinely available EAM forecasts do not include any error information needed for rigorous combination of EAM forecasts with EOP predictions from various geodetic techniques. Based on hindcast experiments, we analysed the EAM forecast error and trained a neural network to predict EAM forecast errors. As expected, EAM forecast errors increase with the prediction horizon but we found also irregular large variation in the EAM forecast error that seem to be well predictable with machine learning methods. 
Framework to Integrate Community-Based Participatory Research in Geoscience Research and Curriculum
Authors: Hall Caitlyn , Antebi Nicole , Bugaj Aaron , Davi Lysette , Horley Laura , Kokroko Kenneth , Munguia-Vega Adrian
Published: February 2023

We are developing a framework to guide researchers and educators to incorporate the community-based participatory research (CBPR) framework in research and course curricula. The framework is a circular process including 1) Community Relationship Building, 2) Scoping and Information Discovery, 3) Co-Create Opportunities, 4) Developing Community-Driven Solutions, 5) Sharing Lived Experiences, and 6) Multi-stakeholder Evaluation and Iteration. In this session, we will share how this framework has been applied in water-focused courses, our successes and lessons learned, and provide guidance for others looking to meet their learning objectives through CBPR. We are developing our framework to be discipline-agnostic by piloting and evaluating the framework in introductory-level general education courses on water and environmental policy, advanced professional-level courses on hydrology and environmental science, art and animation studios, and graduate-level landscape architecture courses. Our contribution to the CBPR framework ensures that research and learning objectives are met while ensuring equity and inclusivity throughout the project for all involved.