bluuebunny/crossref_metadata_2025 huggingface dataset:
The Carnian Pluvial Episode in the Yanyuan Basin (Southwestern China)
Authors: Li Shixin , Zhang Tingshan , Ma Zhiheng , Zeng Jianli , Zhang Xi , Popa Mihai Emilian
Published: February 2023

As one of the hyperthermal events in the Mesozoic, the Carnian Pluvial Episode (CPE) was a global perturbation of the C-cycle and a strong enhancement of the hydrological cycle associated with global warming resulting in significant changes in sedimentary environments from Pangaea to deep water Panthalassa. In this paper, we make research on biostratigraphy, petrology, cyclostratigraphy and geochemistry of the Shemulong Formation in the Yanyuan Basin, at the southwestern of the Yangtze Platform. This strata record the complete deposition of the Carnian stage and preserve the signal of the astronomical orbital period. It also provides good paleontological information which was identified clear biostratigraphic framework. New redox proxies and stable isotopes are analyzed and compare the δ13C data with existing data from other sections of the CPE. In this section, there are at least four terrigenous input pulses which are consisted of sandstone and mudstone, causing the abrupt shutdown of carbonate production during the CPE period. Meanwhile, biodiversity data like bivalves, conodonts and ammonoids in the study area show a major change in abundance and variability during the CPE period. These are also coincident with negative carbon isotope excursions (NCIE), proving the close correspondence between the perturbation of the carbon cycle (and related hyperthermal events occur) and the turnover of depositional systems and ecosystems. Furthermore, we found differences in the recovery of carbonate production after each terrigenous input. The degree of recovery decreases and then increases upwards (bioclastic limestones - oolitic limestones - bioclastic limestones - biostrome - reef mound). It may link to the intensity of the terrigenous input pulse. In summary, this research provides more comparative schemes in the eastern Tethys for the collaborative study of environment biological co-evolution relationship within the CPE interval and is of positive significance for the in-depth understanding of climate and biodiversity changes through hyperthermal intervals in Earth history.AcknowledgementsThis work was supported by the National Natural Science Foundation of China (No. 41972120; 42172129), by the State Key Laboratory of Palaeo-biology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS) (No.173131).
High-precision tropospheric product processing and meteorological application based on GNSS observations from aerial-based highly dynamic platforms
Authors: Zhang Zhenyi , Zhang Weixing , Lou Yidong
Published: February 2023

The Global Navigation Satellite System (GNSS) is an all-weather, high-precision space geodetic technique that can solve positioning results while providing high-precision tropospheric products. Abundant studies have demonstrated the positive impact of traditional ground-based GNSS on numerical weather prediction using data assimilation tools. As tropospheric profile information is promisingly to satisfy the increasing data demand for improving short-range forecast accuracy, it is very important to obtain and assimilate high accuracy, high spatial and temporal resolution, and three-dimensional GNSS tropospheric products. Fortunately, the aerial vehicle market is booming and represented by unmanned aerial vehicle, providing convenient platforms for obtaining richer GNSS tropospheric products at different position and heights. However, there are still some key challenges in processing and assimilating GNSS tropospheric products from such highly dynamic platforms. In our study, we firstly improve the accuracy of aerial-based GNSS tropospheric products up to millimeter level by applying a new data processing method which optimizes the stochastic constraint for GNSS zenith wet delay. Thereafter, we evaluate the impact of those high spatial and temporal tropospheric products on meteorological application by assimilating them into numerical weather models. Experiments are conducted to prove the feasibility of aerial-based GNSS meteorology and point out some topics for further investigation.
Characterization of the social elements involved in socio-environmental conflicts in Mexico.
Authors: González Lezama Mario Alberto , Ramírez Serrato Nelly , Jácome Paz Mariana Patricia , Hernandez Cedeño Isaac , Duquino Rojas Luis Gabriel
Published: February 2023

 Socio-environmental conflicts are the result of an alteration in the natural environment that has repercussions on the interests of the social actors involved. The management of any case depends on the stage of the conflict, the interest in taking advantage of the resource, and the group that takes precedence over the change that this would imply. The environmental factors consist of many climatic, social, and economic variables that result in many types of conflict. For this, so many efforts have already been made to map these incidents at the national and international levels. One such mapping was conducted in the environmental justice atlas, an international compendium of environmental issues. However, little is known about the actors involved in such conflicts. The objective of this work is to identify the resistance actors reported by the Environmental Justice Atlas for Mexico and to search for available information on each of them, as well as the estimated or reported location of their headquarters. The main result was a cartographic mapping of the locations of these actors. The Environmental Justice Atlas registers 151 socio-environmental conflicts in Mexico, in which 485 civil organizations are or were in some way expressing their disagreement or rejection of some projects or megaprojects, while the Mexican government has participated with 171 institutions of the three levels of government, and has been judged and partnered in several of these conflicts; 186 state-owned companies representing the private sector have been identified as the ones responsible for affecting the interests of the actors on the territory and resources of their respective states. From this exercise, it was determined that not all actors have public location information, and even if they do have data, it is difficult to locate them, which could suggest a preference for anonymity when opposing different management of the territory and its resources and the awareness of possible risk in doing so.         
Flaws of scale-aware techniques in convective parameterizations, as discovered in NOAA’s operational convection-allowing modeling systems: an attempt to improve them.
Authors: Grell Georg , Li Haiqin , Freitas Saulo
Published: February 2023

Significant problems in numerical weather prediction modeling systems appear when the horizontal grid-spacing is between 20 km and 1 km and when deep convection is important. These scales are usually termed “Gray Scales”.  Techniques have been developed so that the behavior of the convective parameterization changes with the horizontal grid spacing of the model; such parameterizations are said to become “scale-aware”. Commonly used techniques involve applying a scaling approach to smoothly transition from parameterized to resolved convection. These are similar to an elegantly simple mathematical method originally developed by Arakawa et al. (2011), which scales the convective tendencies in dependence on the convective area fraction. Here we show that the scaling approaches are flawed, since they fail to consider the fact that the impacts of deep convection on those scales are not limited to one grid box, and usually – because of the scaling -- leads to light precipitation covering too much area, as we have previously shown in HRRR simulations. Any scaling approach is especially flawed in areas of light forcing (such as daytime heating) and in the tropics, when the explicit microphysics parameterization is not yet producing precipitation. We will show examples of these problems and discuss possible solutions as applied to NOAA’s new RRFS storm-scale modeling system.
Influence of Drying on Riverine Sediment Biogeochemistry Across the Contiguous United States
Authors: Stegen James , Rod Kenton , Laan Maggi , Delgado Dillman , McKever Sophia , Renteria Lupita , Goldman Amy , Forbes Brieanne , Kaufman Matthew , Garayburu-Caruso Vanessa , Gonzalez Brianna
Published: February 2023

Global change is altering where and when there is enough water for streams to flow. This leads to changes in where and when riverine sediments are inundated with an overlying water column, and affects the associated wet/dry dynamics those sediments experience. Previous work has shown that these changes in inundation and wet/dry dynamics have strong influences over biogeochemical rates, organic matter chemistry, and organismal ecology. For example, a global study of riverbed sediments showed that respiration rates increased up to 66-fold upon rewetting. A current knowledge gap is how respiration rates in re-wetted sediments compare to sediments that are consistently inundated, and what factors govern the effect-size of drying on respiration. To help address this gap we are conducting a manipulative laboratory experiment using sediments from the shallow hyporheic zone (~5cm into the riverbed). The sediments are being crowdsourced from across the contiguous United States to span a broad range of environmental conditions. The experiment has two treatments: one in which sediments are allowed to air dry and another in which sediments are kept inundated. In both cases sediments are constantly shaken to encourage aerobic conditions. After three weeks of these conditions, aerated water is added to both treatments to remove all headspace and oxygen consumption is measured over two hours using custom built oxygen optodes that provide data every two minutes. Results show that in some sites drying and re-wetting has almost no influence over respiration rates, but in other sites drying and re-wetting leads to dramatically lower respiration rates in air dried sediments compared to rates in consistently inundated sediments. These initial outcomes complement previous work showing that while respiration rates following re-wetting may be elevated compared to dry conditions, rates following re-wetting may not be elevated compared to rates in consistently inundated sediments. Combining insights from previous work and the current experiment can, therefore, provide an increasingly holistic understanding of the biogeochemical impacts of changes in where and when streams flow.
Temporal Changes in Deciduous and Coniferous Stemflow Dissolved Organic Matter Composition
Authors: O'Halloran Robyn , Levia Delphis , Guerard Jennifer , Chin Yu-Ping
Published: February 2023

Stemflow is rainwater that runs down the trunk of trees and transport canopy derived dissolved organic matter (DOM) to the forest floor. The chemical composition of stemflow may create hot spots and hot moments of biogeochemical reactivity in the soil and water table. The amount and character of stemflow DOM throughout a 12-month period were analyzed to better understand the effect of phenophases (e.g., leafless, emergence, leafed, senescence for deciduous species and leafed-winter, emergence, leafed-spring/summer, senescence for pine) on tree-derived DOM composition. This study collected stemflow from four major species in the eastern United States, Betula lenta L. (sweet birch), Fagus grandifolia Ehrh. (American beech), Liriodendron tulipifera L. (yellow poplar), and Pinus rigida Mill. (pitch pine), on a monthly basis. A total of 157 samples were analyzed for organic carbon concentration, fluorescence, and light absorbance characteristics. Results from one of the absorbance characterizations, specific ultraviolet absorbance at 254nm, SUVA254, indicated a change in DOM composition throughout the phenophases for the four species. American beech and sweet birch increase in SUVA254 values with the lowest values occurring during emergence with progressively higher values from leafless to leafed and finally senescence phases. Pitch pine’s trend from smallest to largest values follows a different pattern beginning with leafed-winter, then leafed-spring/summer then emergence to senescence. Yellow poplar also demonstrates a different trend with no change occurring between emergence and the leafed phase with those two seasons having the smallest values, then progressively increasing in the leafless phase and then senescence. The fluorescence index (FI) values obtained demonstrate similar phenophase trends as the SUVA254 analysis except for sweet birch. The FI values for sweet birch were highest and identical in emergence and leafed, while FI successively declined between senescence and leafless phenophases. These trends indicate species and season influence sources that alter the quantity and compositional characteristics of DOM, e.g., aromatic content, which varied greatly. We are building a parallel factor analysis (PARAFAC) model based upon the total fluorescence of stemflow DOM to further investigate these changes and provide a more in-depth analysis of its chemical components throughout the different phenophases of these four trees.Funding note: This research was supported by funds from the US National Science Foundation (Award No. GCR-CMMI-1934887).  
Improving the science and practice of hydrological modelling
Authors: Clark Martyn , Knoben Wouter , Tang Guoqiang , van Beusekom Ashley , Arnal Louise , Spiteri Ray
Published: February 2023

Many hydrological modelling groups face similar challenges, with untapped opportunities to share code and concepts across different model development groups. An active community of practice is emerging, where the focus is not so much on developing a community hydrological model, and more on advancing the science and practice of community hydrological modelling. This presentation will summarize our recent efforts to develop open-source models, methods, and datasets to enable process-based hydrological prediction across large geographical domains. This presentation summarizes our recent efforts to advance the science and practice of hydrological modelling, focusing on recent work to (1) develop multi-source probabilistic hydrometeorological forcing datasets on continental and global domains; (2) advance a flexible approach to represent a myriad of physical processes in a unified modelling framework; (3) improve the numerical robustness and efficiency of large-domain terrestrial system model simulations; and (4) develop extensible and reproducible modeling workflows. The presentation will highlight major scientific challenges, future research needs, and some key opportunities for community collaboration.
Constraining temperature variability projections using SMILEs that best represent observed variability
Authors: Maher Nicola , Suarez-Gutierrez Laura , Milinski Sebastian
Published: February 2023

Projecting how temperature variability is likely to change in the future is important for understanding future extreme events. This comes from the fact that such extremes can change due to both changes in the mean climate and its variability. The recent IPCC report found large regions of low model agreement in the change of temperature variability in both December, January, February (DJF) and June, July, August (JJA) when considering 7 Single Model Initial-Condition Large Ensembles (SMILEs). In this study we use the framework described by Suarez-Gutierrez et al, (2021) to constrain future projections of temperature variability by selecting the SMILEs that best represent observed variability. We use 11 SMILEs with CMIP5 and CMIP6 forcing and consider 9 ocean regions and 24 land regions. We then assess, for both DJF and JJA, whether temperature variability projections are constrained by selecting for models capture observed variability in individual regions and seasons. We consider projected changes at various warming levels to account for differences in warming between models and the use of different future scenarios across CMIP5 and 6. We identify MPI-GE and CESM2 as the SMILEs that capture observed variability sufficiently. across most regions (29 & 30 out of 33 in DJF and 28 and 26 in JJA respectively). Whether temperature variability projections are constrained depends on both season and region. For example, in DJF over South East Asia the constraint does not change the already large spread of projections. Conversely, over the Amazon the constraint tells us temperature variability will increase in DJF whereas the entire model archive does not agree on the sign of the change. This method can be used to better constrain our uncertainty in temperature variability projections by selecting SMILEs that best represent observed variability.
Stickiness: A New Variable to Characterize the Temperature and Humidity Contributions toward Extreme Humid Heat
Authors: Ivanovich Catherine , Raymond Colin , Horton Radley , Sobel Adam
Published: February 2023

Extreme values of wet bulb temperature are often used as indicators of heat stress for humans and other animals. However, humid heat extremes are fundamentally compound events, and a given wet bulb temperature can be generated by various combinations of temperature and humidity. Differentiating between extreme humid heat driven by anomalous temperature versus anomalous humidity is essential to identifying these extremes’ distinct physical drivers and preparing for their individual impacts. Extreme dry heat tends to occur due to processes such as blocking events and land surface feedbacks, and it has the potential to prime regions for wildfires and crop damage. In contrast, extreme humid heat depends more on strong moisture fluxes and vertical stability to moist convection, and it poses high risk for human health through its influence over heat stress.Here we explore the variety of combinations of temperature and humidity contributing to heat extremes across the globe. In addition to using traditional metrics, we derive a novel thermodynamic state variable named “stickiness.” Directly analogous to oceanographic spice (which quantifies the relative contributions of temperature and salinity to a given seawater density), stickiness quantifies the relative contributions of temperature and specific humidity to a given wet bulb temperature.Consistent across metrics, we find that extreme humid heat — that is, the occurrence of wet bulb temperatures sufficiently high to impact human health — tends to occur in the presence of anomalously high humidity. Although theoretically humid heat extremes can be achieved at low humidities if temperature is high enough, this tends not to happen in practice. Using stickiness allows for the direct evaluation of the spatial and temporal variability in the temperature- and humidity-dependence of humid heat events, a task that is more complicated and subjective using traditional variables. We identify locations with high variability in stickiness: these include the Persian Gulf, the western United States, and southeast Australia. These locations are key areas where the predictive skill for heat stress-related mortality may improve by considering fluctuations in atmospheric humidity in addition to dry bulb temperature.
MAVEN Observations of Steepened Ultra-Low Frequency Waves in the Upstream Martian Foreshock Region
Authors: Poh Gangkai , Espley Jared , Xu Shaosui , Le Guan , Romanelli Norberto , Halekas Jasper , DiBraccio Gina , Gruesbeck Jacob
Published: February 2023

In this study, we present the analysis of steepened ultra-low frequency (ULF) waves in the foreshock region upstream of Mars’ bow shock observed by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft at Mars. A survey of MAVEN magnetic field and plasma measurements shows quasi-periodic gradual increases followed by a sharp decrease in the magnetic field magnitude (Btotal). Higher frequency waves were also commonly, but not always, observed at the trailing edge of the large-amplitude increase in Btotal. These observations are consistent with the signatures of shocklets observed in the solar wind region upstream of Earth’s and planetary bow shocks. Shocklets are believed to be formed as a result of the steepening of fast magnetosonic waves generated by reflected ions in the quasi-parallel foreshock region. We also performed the minimum variance analysis (MVA) and statistical analysis technique to determine the wave properties (e.g. polarization, wave propagation, amplitude and frequency) of the shocklets and higher frequency waves observed in its trailing edge. Our results showed that these shocklets are left-handed polarized in the spacecraft frame, with mean amplitude δB/B of ~3.5 and time separation between adjacent shocklet events of ~40s. We also analyzed measurements (ions and electrons) from MAVEN’s plasma instruments to investigate the energization process of the particles during the observations of shocklets. We will discuss the possible generation mechanisms for these steepened ultra-low frequency waves at Mars, and any implications for the martian plasma environment downstream of Mars’ bow shock. 
The benefits of Big Data Cooperation from a single research infrastructure viewpoint – ICOS and the ENVRI-hub in EOSC
Authors: Kutsch Werner Leo , Vermeulen Alex , Hellström Margareta
Published: February 2023

The Integrated Carbon Observation System (ICOS), is a distributed European Research Infrastructure which provides high-precision and highly standardised observations from more than 170 stations from three domains: Atmosphere, Ecosystem and Ocean. ICOS covers currently 16 European countries. All ICOS data is made available by the ICOS Carbon Portal, first in near-real time (within 24h when possible), and after further quality control as domain specific annual releases. The data flow follows the Findable, Accessible, Interoperable, Reusable (FAIR) principles.ICOS has been cooperating with other European Environmental Research Infrastructures (the ENVRI Community) since more than a decade. ICOS used the ENVRI Reference Model to set up its data life cycle, developed common metadata and data citation strategies and most recently contributed to the ENVRI-hub within the European Open Science Cloud (EOSC). The ENVRI-hub will be a central gateway to environmental data and services offered by the European environmental research infrastructures. The data offered through the hub will be interoperable across the Earth system disciplines and therefore easy to use for interdisciplinary environmental research. Data will be open and free to use by anyone. Users of the ENVRI-hub will be also able to use the Virtual Research Environments and do their science computing directly inside the hub.The synergies achieved through cooperation within the ENVRI community has saved a lot of resources for ICOS when implementing its data life cycle. Furthermore, it has created common services for scientists working on complex Earth System questions such as climate-biodiversity or climate-air-quality feedbacks.
Thermomechanic control on crustal seismicity along the Andean margin
Authors: Tassara Andres , Riedel Martin , Rioseco Javiera , Echeverria Iñigo
Published: February 2023

Temperature controls the maximum depth of seismicity because it governs the transition between seismogenic brittle deformation at shallow levels to thermally-activated ductile creep at higher depths. We investigate this relationship for the Andean margin of western South America, an archetype of subduction-related active margins that host the largest megathrust earthquakes ever recorded and dense upper plate seismicity associated to crustal faults. We develop our own analytical formulation of the thermal state of the upper plate based on a 1D conductive geotherm with crustal heat production and known temperature at the base of the plate. To the east of the intersection of the subducted slab with the continental lithosphere-asthenosphere boundary (LAB), temperature at the LAB depth is prescribed by an asthenospheric adiabat. To the west of this intersection, temperature along the megathrust is calculated with the analytical expression of England (2018) that depends on the age and subduction velocity of the slab, megathrust friction, thermal conductivity and upper plate heat production. Because the shape of the megathrust and continental LAB for the study region are well constrained with geophysical data (Tassara and Echaurren, 2012), we can extrapolate the 1D approach to 3D and cover the entire margin between the trench and the eastern foreland. We select a preferred set of involved parameters (the preferred thermal model) by fitting a new compilation of surface heat flow measurements. Our results are then compared with the depth of earthquakes recorded along the study region by the catalogue of the Chilean Seismological National Center. For crustal earthquakes (located above the Moho depth), we computed the seismicity cutoff depth (SCD) at each location on a grid as the depth where 90% of the events have hypocentral depths shallower than SCD (for details see Riedel et al. in this meeting). As expected, the spatial distribution of SCD is positively correlated with temperature, although the actual average temperature for a given SCD can be different for different geological regions. This is explained by the dependency of the brittle-ductile transition (BDT) on rock type throughout creep properties of different lithologies, a concept that we use to infer the main rock type implied by the SCD-Temperature relation at each location. Thus, we convert the SCD map and thermal structure in a geological map of the middle-lower crust, which seems to be correlated with the geological structure and geophysical images of the Andean crust.
Examining Atmospheric Dynamical Forcing of Greenland Ice Sheet Surface Mass Loss Within the Context of Arctic Amplification
Authors: Preece Jonathon , Mote Thomas , Wachowicz Lori
Published: February 2023

The current period of Arctic amplification has been characterized by a pronounced reduction in high-latitude snow and ice cover that is reflective of rapidly changing thermodynamic environment. Given this change in the local background conditions, it is not surprising that the Greenland Ice Sheet (GrIS) has undergone drastic surface mass loss since the turn of the century; however, research has shown that the recent acceleration of runoff from the GrIS is strongly linked to a shift in the large-scale atmospheric circulation over the same period that has brought more frequent and intense bouts of summer Greenland blocking. While this atmospheric dynamical change may merely be a manifestation of internal variability, there is growing evidence that widespread changes in surface cover and near-surface thermal gradients under Arctic amplification may favor persistent extremes such as the episodes of Greenland blocking that have encouraged melt of the ice sheet.Here, we explore whether the change in summer atmospheric circulation over Greenland may be a dynamical response to Arctic amplification and attendant snow cover loss. Our results suggests that low North American spring snow cover and a weakened meridional temperature gradient combine to encourage the high-amplitude Omega blocking patterns that we show to have driven the recent trend in summer Greenland blocking. We show that this delayed response to anomalous spring snow cover follows from the snow-hydrological effect, whereby low spring snow cover causes early depletion of soil moisture and anomalously warm surface temperature over eastern North America. The consequent stationary Rossby wave response enforces an anomalous anticyclone, centered over Baffin Bay, that resembles that of high-amplitude Omega blocks and the atmospheric conditions which have promoted melt of the northern GrIS. Together, these results provide evidence that Arctic amplification, and thus anthropogenic climate change, has contributed to recent atmospheric dynamical forcing of GrIS surface mass loss. However, regardless of how strong this link between climate change and atmospheric circulation over Greenland may be, the change in the local thermodynamic environment under Arctic amplification represents a far more robust climate change signal. We also examine the thermodynamic contribution to GrIS surface mass loss using the regional climate model, Modèle Atmosphérique Régional (MAR) associated with blocking circulation. MAR output of surface temperature, meltwater production, and runoff are used to assess the differential impact of blocking events across the ice sheet.
Combined effects of La Niña events and Arctic tropospheric warming on the winter North Pacific storm track
Authors: Zhang Xiang , Wu Bingyi , Ding Shuoyi
Published: February 2023

This study investigates the dominant characteristics of winter Arctic tropospheric thickness (1000–200 hPa), the variations of winter atmospheric circulation in the Northern Hemisphere, and the related winter North Pacific storm track (NPST) variabilities during 1979–2018 under the combined effects of the La Niña events with different periods of Arctic tropospheric thermal conditions. Results show that the leading mode (42.7%) exhibits prominent warm anomalies centered on Greenland and Baffin Bay. The winter Arctic tropospheric thickness experienced a phase shift from a cold period of the Arctic tropospheric temperature in 1979–1999 to the warm period after 2000. During the La Niña events with Arctic tropospheric warm anomalies, a wave train is shown in the mid-high latitudes with alternative anticyclonic, cyclonic, and anticyclonic anomalies over the Ural Mountains, Lake Baikal, and North Pacific, respectively. This atmospheric circulation pattern not only intensifies the linkage between the Arctic and mid-low latitudes but also induces the winter NPST shifting poleward. The possible physical mechanism is attributed to the large-scale circulation change and the local baroclinic energy conversion (BCEC). The enhanced anticyclonic anomaly in the North Pacific alters the climatological mean flow, further influencing the local BCEC through the interaction between the mean flow and eddies. The significantly robust BCEC over the North Pacific possibly induces the poleward shift of winter NPST during the La Niña events under the warm period.
Impactful engagement through games: Examples and experiences from a successful outreach collaboration
Authors: Gallagher Lisa , Maxwell Reed
Published: February 2023

The Integrated GroundWater Modeling Center (IGWMC) is a small research center housed within the High Meadows Environmental Institute at Princeton University. The researchers and students of the IGWMC focus on using field observations, hydrological models, and emerging technologies like machine learning to address important water and climate related issues. The scientists, engineers, and students working in this center also support a mission to develop and promote education and outreach in our community. Much of our outreach focuses on providing fun, social, hands-on activities that are gamified for maximum impact.The IGWMC has an ongoing partnership with the Watershed Institute, an organization in Pennington, New Jersey, that supports a wealth of community focused education, advocacy, and stewardship initiatives. Through the Watershed Institute’s Watershed Academy program for high school students, researchers and students from IGWMC were given the opportunity to host a week-long educational camp, focused on water and climate. During this week, high school students attending engaged with scientists, engineers, graduate students, and undergraduate students to learn about and engage with water and climate topics. We will discuss a collection of gamified activities that have been developed and used for these events along with the impactful experiences had by all.
High-resolution numerical modelling of seasonal volume, heat, and freshwater transport along the Indian coast
Authors: Madkaiker Kunal , Ambarukhana Devendra Rao
Published: February 2023

The Indian subcontinent divides the north Indian Ocean (IO) into Arabian Sea (AS) and the Bay of Bengal (BoB), with different thermohaline properties. Seasonal reversal of winds and equatorial remote forcing due to proximity to equator, influences circulation of these basins. In this study, we numerically modelled the physical characteristics of AS and BoB, using MITgcm with a high spatial resolution of 1/20° (~ 5 km) and 49 vertical levels in a z-coordinate system, on a climatological scale. Temperature, salinity and flow fields were validated with satellite and gridded ARGO datasets. Statistically we established that the model setup simulates the upper ocean features and subsurface circulation in these two basins well.Then, we computed the alongshore volume, heat, and freshwater transport along the coastline of India and eastern Sri Lanka. We observed that the alongshore transport along the eastern coast is stronger with high seasonal variability due to the poleward flowing Western Boundary Current (WBC) and equatorward flowing East Indian Coastal Current (EICC). The west coast transport is influenced by intraseasonal oscillations. We computed the freshwater transport to be an order less than the volume transport. Seasonality of alongshore volume and freshwater transport contradicts each other on the western coast whereas they are in phase on the eastern coast. Then we computed the contribution of freshwater transport in total flow as a percentage of the total volume transport. In the BoB, this is maximum during JJAS season which is limited to the northeastern coast of India, followed by October-November season as it covers the entire east coast. We also observed a weak and narrow freshwater export pathway flowing across the Palk Strait into the Gulf of Mannar. The seasonality of transport and upper ocean salinity highly correlate to each other in this region.Meridional heat transport (MHT) was also computed over AS and BoB. Analysis shows that MHT over AS is stronger than BoB. Both basins act as heat source during summer monsoon and heat sink during winter monsoon. Zonal transport correlates positively with zonal wind whereas meridional transport correlates negatively with meridional wind. Various factors such as wind reversal, Ekman transport and vertical thermal wind shear play a role. Net heat flux positively correlates with total heat transport along the eastern coast of India and southeastern AS. It can be attributed to coastal currents and equatorial forcing which help in advection of heat and thermal ventilation.Understanding the effects of these exchanges on nutrient and carbon transport along the coastal waters via nearshore processes would be aided by further research into these interactions. The high-resolution climatological set-up lays the groundwork for additional research into the physical and biological processes occurring in the Indian coastal seas.
Impact of Agroecological Methods on Aggregate Associated Carbon Fractions
Authors: Kula Casey , Sadeghpour Amir , Keshavarz Afshar Reza
Published: February 2023

Using agroecological methods such as biochar amendments, manure-based fertilizer, and leaving crop residue on field is known to add organic matter and carbon to the soil which in turn can lead to soil health improvement as well as changes in soil physical properties. The previously stated methods were used as treatments as well as a combination of each in a Colorado farm field. Post analysis soil physical tests were run to evaluate the aggregate fractionation, organic matter, water-stability, permanganate oxidizable carbon, and the carbon to nitrogen ratio of each aggregate fraction as well as range of macro- (2mm-6.3mm), meso- (.25mm-2mm), and micro-aggregates (<.25mm).
TomoATT: A Software Package of Adjoint-State Traveltime Tomography for Imaging Subsurface Velocity Heterogeneity and Seismic Anisotropy.
Authors: Chen Jing , Nagaso Masaru , Tong Ping
Published: February 2023

Adjoint-state traveltime tomography (ATT) is a new modality of traveltime tomography for determining subsurface velocity heterogeneity and seismic anisotropy. It formulates the tomographic inverse problem as an eikonal equation-constrained optimization problem solved by the ray-free adjoint-state method. Instead of using the ray-based methods, the theoretical traveltime is predicted by solving the anisotropic eikonal equation in spherical coordinates using the robust grid-based fast sweeping method. The influences of the seismic anisotropy and the Earth’s curvature are taken into account. Besides, the Fréchet derivatives of the objective function with respect to velocity and anisotropy are computed based on the adjoint field obtained by solving the adjoint equation without ray tracing. These two improvements ensure the accuracy of the forward modeling and avoid the potential failure of ray tracing techniques. Meanwhile, compared with wave-equation-based tomography methods, the computational cost of solving eikonal and adjoint equations is drastically cheaper. The usage of the reciprocity principle makes the computation cost nearly independent of the number of earthquakes, enabling the inversion involving massive earthquakes but with moderate computational cost. Due to these advantages, we develop the TomoATT package based on the ATT method, accommodating the tomographic problems on local, regional, and global scales. To be used on high performance computing systems, TomoATT implements a multilevel hybrid parallel algorithm, which utilizes MPI for inter-node parallelization and MPI Shared Memory for intra-node parallelization. The performance on single CPU is also improved using the Single Instruction Multiple Data (SIMD) instructions. This traveltime tomography package has been tested and verified in central California near Parkfield.
3-D Modelling of the Dynamical Mechanisms Driving Continental Intra-Plate Volcanism
Authors: Duvernay Thomas , Davies Rhodri
Published: February 2023

Volcanic provinces within Earth's continents exhibit a wide range of characteristics that reflect the intricate nature of the dynamic interactions at their origin. To improve our understanding of the driving mechanisms at play, we address the generation of intra-plate continental volcanism by modelling the 3-D interaction between an upwelling mantle plume and a thick lithospheric block. We examine scenarios with and without plate motion and assess the spatio-temporal distribution and intensity of produced melts. Our findings demonstrate the critical role of lithospheric thickness in determining the location and volume of plume-driven magmatic provinces. Building on these results obtained using simplified lithospheric structures, we further apply our numerical methodology to simulate the inferred interaction between the Cosgrove plume and eastern Australia during the past 35 Myr. We design the Australian continent using available 3-D lithospheric architecture determined through seismic tomography and impose the inferred plate motion associated with this region. Our models incorporate updated peridotite melting parameterisations to provide quantitative estimates of generated melt volume and composition. We find that plume-driven and shallow edge-driven melting processes, modulated by the lithospheric thickness of the Australian continent, combine to explain the observed volcanic record. Our preliminary results agree well with surface observations and provide further insight into the geodynamics of eastern Australia.
High-frequency microwave satellite radiances data assimilation using NICAM-LETKF in the OSSE framework
Authors: Konduru Rakesh Teja , Liang Jianyu , Miyoshi Takemasa
Published: February 2023

This study investigates the impact of high frequency, such as 3-hourly and 1-hourly satellite microwave radiances, in global atmospheric data assimilation. To understand the impact of such a high-frequency satellite radiances data assimilation, we designed an observing system simulation experiment (OSSE) using the global NICAM-LETKF system at 56 km horizontal resolution. A free run was conducted with the NICAM model and treated as the reference (Nature) for the OSSE experiments. With the NICAM-LETKF system, we conducted five experiments, without data assimilation (NoDA), with only conventional data assimilation but not satellite radiances (NoSat), 6-hourly (6H), 3-hourly (3H), and 1-hourly (1H) satellite clear-sky radiances assimilation. The results showed that satellite microwave radiances assimilation improved the forecast of air temperature and wind over the global ocean compared to NoSat experiments. With the increase in the assimilation frequency of the satellite radiances, the air temperature and winds showed improvement in their representation over the ocean but degraded over land. Over the ocean, microwave radiances assimilation improved the typhoon eyewall wind intensities and its structure for 1H satellite radiances assimilation compared to 6H. These improvements in the wind intensities are prominent during the landfall stage of the typhoon. Forecasting landfall storms' strong winds are essential for disaster prevention and mitigation.
Buoy Observations of Turbulent Mixing in the northwestern subtropical Pacific Ocean
Authors: Lin Hsin-I , Yang Yiing-Jang
Published: February 2023

Strong winds from typhoons decrease sea surface temperatures, and this cooling area is called the cold wake. It is well known that the primary mechanisms causing this phenomenon include turbulent mixing and Ekman pumping that result in the upwelling of cold water in the lower layer. The amplitude of surface cooling is influenced by the typhoon’s moving speed, strength, the radius of the storm, and the pre-typhoon conditions of the upper ocean. The cooling phenomenon affects air-sea interactions, but observing the upper ocean in such an extreme environment is challenging. To understand the physical process of mixing, and to improve the predictions of numerical models, more observations of turbulent mixing are needed. In addition, the passage of eddy also affects the occurrence of background conditions and turbulent mixing. The northwestern subtropical Pacific Ocean is an area where typhoons are prevalent, and eddies often pass through it. Therefore, this is a suitable area to study turbulent mixing when typhoons and eddies pass by.These data were obtained from the surface buoy and the ADCP subsurface moorings located in the northwestern subtropical Pacific Ocean. In September 2022, category 5 typhoon Hinnamnor passed the buoy site during observation period. The upper ocean profiles of temperature and current were obtained, in order to estimate the Richardson numberwhen the typhoon and the cold eddy passed by. The observation results show that the peak value of the probability distribution of the Richardson number was about 3 to 4, and the probability of being less than 0.25 was about 12% at a depth of 20 m before the passage of Typhoon Hinnamnor. When the buoy system was within the 34-knot wind radius (R34) of a typhoon, the peak value of the probability distribution of the Richardson number decreased to slightly smaller than 0.25, and the probability of being less than 0.25 is about 62% at a depth of 20 m. At a depth of 75 m, the probability distribution of the Richardson number did not significantly change within the 34-knot wind radius (R34) of a typhoon,and it was not even close to 0.25. It shows that typhoon-induced turbulent mixing has no effect at this depth. In addition, during the normal period without a cold eddy, the mixed layer was deeper than the depth of 20 m. Marginal instability was evident within the mixed layer, in which the probability distribution of the Richardson number oscillated around 0.25. During the passage of the cold eddy, the upwelling of cold water made the surface mixed layer thinner, and stratification was more stable. Therefore, the cold eddy would prohibit turbulent mixing. The probability distribution of the Richardson number shifted to a larger value. However, the probability distribution of the Richardson number at a depth of 75 m did not change significantly. As a result, the observed cold eddy had no effect on the turbulent mixing at this depth. These results will be presented herein in detail.
Advancing snow modelling across Canada from the Arctic to southern regions
Authors: Richards Agnes , Ouellet Felix , Boisvert-Vigneault Erika , Langlois Alexandre
Published: February 2023

The climate is changing rapidly in the Canadian Arctic and in southern regions in Canada such as the Great Lakes. We adapted the SNOWPACK model from traditional avalanche applications for the Canadian Artic and for two southern regions with moderate (Bay of Quinte, Ontario) to low snowfall (Wigle Creek, Ontario). We developed innovative tools to process large meteorological forcing data and to spatialize output. We also developed a downscaling tool (Outil de Spatialisation de SNOWPACK pour l’Arctique - OSSA) using changes in slope, which refined the spatial resolution of simulations by 45-fold. Our simulations in the Arctic demonstrated that icing events tripled across the Canadian Arctic Archipelago between 1979-2011.  SNOWPACK simulations (1970s to 2020) for the Bay of Quinte focused on changes in snow parameters such as Snow Water Equivalent (SWE), which drives snow melt and flooding. Other parameters such as snow density will also be discussed. Simulations show a substantial change in SWE, especially after 2000. In the region with low snowfall (Wigle Creek), simulations of snow on and off will be presented.We will also illustrate how we advanced SNOWPACK model validation standards though a multi-pronged approach: 1) remote sensing data to validate snow spatial extent, 2) field measurements with sensors to quantify soil temperature feedback, 3) traditional snow pits to validate SWE, and 4) drones to measure snow height and SWE. Finally, we show that validation standards should be adapted to each region based on snowfall and snowmelt. 