bluuebunny/crossref_metadata_2025 huggingface dataset:
Two Decades of Satellite Observations: Sensible-Heat Polynya Variability at Pine Island Glacier, West Antarctica
Authors: Savidge Elena , Snow Tasha , Siegfried Matthew R.
Published: March 2024

Thermodynamically maintained open ocean areas surrounded by sea ice, or sensible-heat polynyas, are linked to key ice-sheet processes, such as ice-shelf basal melt and ice-shelf fracture, when they occur near ice-shelf fronts. However, the lack of detailed multi-year records of polynya variability pose a barrier to assessing the potential interconnectivity between polynya and frontal dynamics. Here, we present the first multi-decadal record (2000–2022) of polynya area at Pine Island Glacier (PIG) from thermal and optical satellite imagery. We found that although polynya area was highly variable, there were consistencies in the timing of polynya maximal extent, and opening and closing. Furthermore, we found that the largest polynya (269 km2) in our record occurred at PIG’s western margin just 68 days before iceberg B-27 calved, suggesting that polynya size and position may influence rifting dynamics. We suspect that large sensible-heat polynyas have the potential to reduce both ice-shelf buttressing (via reduced landfast ice) and shear margin dynamics (via reduced contact with slower marginal ice), which may lead to structural instability and eventually contribute to calving. Our new dataset provides a pathway to assess coevolving polynya and frontal dynamics, demonstrating the importance of building long-term records of polynya variability across the continent.
Spatio-temporal variation of reference evapotranspiration and its contributing factors over the Indian subcontinent under historic and future climate change
Authors: Varghese Femin C , Mitra Subhasis
Published: March 2024

The estimation of reference evapotranspiration (ETo) holds significant importance for the hydrological cycle, necessitating an extensive understanding of the various climate variables and their influence on ETo variability. This study aims to examine spatio-temporal variations in Penman Monteith based ETo estimations and the factors contributing to their changes over the Indian subcontinent in the historic and future climate change. Using climate variables from the ERA5 reanalysis and CMIP6 simulations this study focuses on the changes in ETo across different aridity zones in the study area. Further, the partial least squares (PLS) regression was employed to determine the relative contribution of different climate variables on ETo trends. Results show that the majority (70%) of the areas in the subcontinent exhibited decreasing ETo trends in the historical past. Zonal analysis of ETo trends revealed all zones except the humid zone exhibited a significant decreasing trend for ETo. Contribution analysis shows that, across the study area, temperature and radiation are the most significant factors influencing ETo, followed by wind speed and relative humidity. Further, temperature and ETo were found to be having opposing tendencies, highlighting an “evapotranspiration paradox” that encompasses the majority of the study area. CMIP6 simulations show that ETo is projected to increase significantly across the Indian subcontinent, especially in the semi-arid and arid regions with temperature and radiation being the dominant factor contributing to increases in ETo.
Development of an online O2-CO2 soil profile probe for flux estimations
Authors: Maier Martin , Osterholt Laurin , Levintal Elad
Published: March 2024

Reliable and accurate measurements of gas fluxes between soil and atmosphere are fundamental to calculate global greenhouse gas budgets. Chamber methods and the eddy covariance method are the most often used methods to measure soil-atmosphere gas fluxes. The gradient method can provide additional information about the localization of gas production within the soil profile. Using this approach gas fluxes in the soil profile are calculated by multiplication of the vertical concentration gradient of a gas in the soil by the effective gas diffusion coefficient of the soil. Technical progress in the field of small gas sensors has made it possible to integrate online CO2 sensors into soil gas profile monitoring systems, which greatly facilitates soil CO2 monitoring. While soil CO2 fluxes have been widely studied during the last decade, the “forgotten half” of this respiratory flux, the counter wise flux of atmospheric oxygen (O2) into the soil is rarely investigated, although it is known that O2 availability is the key for many soil processes.Our objective was to develop and test a soil gas profile probe for online CO2 and O2 measurements with high temporal resolution that allows (1) soil–atmosphere flux estimation and (2) estimation of soil respiration profiles for both CO2 and O2 including (3) the apparent respiratory coefficient (CO2 efflux divided by O2 influx).We developed a multilevel O2-CO2 profile probe with small build-in online sensors in multiple depths. The design was based on a modified version of a recently developed CO2 profile probe (Osterholt and Maier, 2020, Osterholt et al 2023). The probe consists of one 3D print segment per depth each containing one small NDIR CO2 and one O2 sensor. Extensive laboratory tests with different O2 sensors were necessary to exclude, or identify and quantify, possible biases in the O2 measurements due to expected environmental changes during field measurements (such as barometric pressure, soil temperature and relative humidity). The segments can be combined to probes of different length. For the installation of the sampler a hole has to be drilled, into which the sampler is inserted. We present first results from laboratory experiments and a field experiment, focusing on methodological issues and the technical performance of the measuring system.Acknowledgements: This research was supported by the German Research Foundation (DFG, MA 5826/4‑1 project number: 535470615)Osterholt, L. and Maier, M.: Development of an in-situ CO­2 gradient sampler, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7272, https://doi.org/10.5194/egusphere-egu2020-7272,  2020.Osterholt, L.; Kolbe, S.; Maier, M. (2022): A differential CO2 profile probe approach for field measurements of soil gas transport and soil respiration #. In J. Plant Nutr. Soil Sci. 185 (2), pp. 282–296. DOI: 10.1002/jpln.202100155.
Improving Multi-model Ensembles of Climate Projections through Time Variability Correction and Ensemble Dependence Transformation
Authors: Shao Yawen , Bishop Craig , Abramowitz Gab , Hobeichi Sanaa
Published: March 2024

The uncertainty of future climate change is typically estimated by a collection of models from various climate institutions. The Ensemble Dependence Transformation (EDT) method has proven effective in producing ensembles with means that lie closer to the verifying observations and with variances that match the variance of the observations about the ensemble mean. However, EDT does not specifically address temporal variability and persistence attributes within individual models. This limitation can potentially be addressed by the Time Variability Correction (TVC) method, designed to quantify, and correct model variability errors across differing time scales.In this study, we test and compare four approaches: 1) TVC only; 2) EDT only; 3) TE: Applying TVC to individual models first, followed by EDT; 4) ETE: Applying EDT to obtain the time-varying mean series, using TVC to correct the EDT-transformed series, and applying EDT again to TVC post-processed model series. These methods are employed to post-process 26 CMIP6 (Coupled Model Intercomparison Project Phase 6) daily mean temperature projections across Australia under a model-as-truth setup.We evaluate the results using verification metrics for assessing both individual models and multi-model ensembles. Findings indicate that, overall, ETE performs better in improving individual model statistics, including variance and lag correlations relative to the time-varying ensemble mean. Additionally, ETE enhances ensemble statistics, notably ensemble standard deviation (ESD) during both in-sample historical and out-of-sample projection periods. TE is particularly effective at improving root mean squared difference (RMSD) between ensemble mean and observations, along with continuous ranked probability skill score (CRPSS).
Novel environmental big data grid integration and interoperability model
Authors: Zhu Daoye , He Yuhong , Moore Kent
Published: March 2024

Currently, effectively managing, retrieving, and applying environmental big data (EBD) presents a considerable challenge owing to the abundant influx of heterogeneous, fragmented, and real-time information. The existing network domain name system lacks the spatial attribute mining necessary for handling EBD, while the geographic region name system proves inadequate in achieving EBD interoperability. EBD integration faces challenges arising from diverse sources and formats. Interoperability gaps hinder seamless collaboration among systems, impacting the efficiency of data analysis.To address the need for unified organization of EBD, precise man-machine collaborative spatial cognition, and EBD interoperability, this paper introduces the EBD grid region name model based on the GeoSOT global subdivision grid framework (EGRN-GeoSOT). EGRN-GeoSOT effectively manages location identification codes from various sources, ensuring the independence of location identification while facilitating correlation, seamless integration, and spatial interoperability of EBD. The model comprises the grid integration method of EBD (GIGE) and the grid interoperability method of EBD (GIOE), providing an approach to enhance the organization and interoperability of diverse environmental datasets. By discretizing the Earth's surface into a uniform grid, GIGE enables standardized geospatial referencing, simplifying data integration from various sources. The integration process involves the aggregation of disparate environmental data types, including satellite imagery, sensor readings, and climate model outputs. GIGE creates a unified representation of the environment, allowing for a comprehensive understanding of complex interactions and patterns. GIOE ensures interoperability by providing a common spatial language, facilitating the fusion of heterogeneous environmental datasets. The multi-scale characteristic of GeoSOT allows for scalable adaptability to emerging environmental monitoring needs.EGRN-GeoSOT establishes a standardized framework that enhances integration, promotes interoperability, and empowers collaborative environmental analysis. To verify the feasibility and retrieval efficiency of EGRN-GeoSOT, Oracle and PostgreSQL databases were combined and the retrieval efficiency and database capacity were compared with the corresponding spatial databases, Oracle Spatial and PostgreSQL + PostGIS, respectively. The experimental results showed that EGRN-GeoSOT not only ensures a reasonable capacity consumption of the database but also has higher retrieval efficiency for EBD.
Windstorm risk assessment in the Netherlands: Evaluation of statistical dependencies between hazard and damage data
Authors: Fonseca Cerda Maria del Socorro , Haer Toon , de Moel Hans , Aerts Jeroen , Botzen Wouter , Koks Elco , van Ederen Daan
Published: March 2024

Extreme windstorms pose significant societal and economic challenges, ranking among the costliest natural disasters in Europe. This study addresses the complex task of quantifying windstorm impacts, with a specific focus on the Netherlands. Despite their substantial economic cost, windstorm risks in the Netherlands have been underexplored in dedicated regional studies. Existing large-scale investigations often rely on hazard-loss relationships derived from data from other European countries. We aim to enhance the accuracy of windstorm risk assessment by utilizing not only higher-resolution hazard data but also higher-resolution Dutch damage data. Our methodology involves analyzing high-resolution data to identify hazard variables that best correlate with losses. This is done by leveraging post-disaster loss data from a private Dutch insurance company. In particular, we use the aggregated losses per postal code 4 area, which delivers a nuanced understanding of the spatial distribution of losses. Simultaneously, we account for hazard intensities using the wind climatology data from KNMI North Sea Wind (KNW). This data is derived from 40 years (1979-2019) of ERA-Interim re-analyzed data and downscaled to a higher resolution (2.5 x 2.5 km) tailored specifically for the Netherlands. Through statistical analysis, the study aims to determine the most suitable hazard components for a regional windstorm damage assessment model. This approach aims to move beyond the conventional use of daily maxima wind speed or gust speed by evaluating the appropriateness of hazard variables concerning observed losses. This meticulous integration of proprietary loss records and refined wind climatology enables developing new spatial windstorm hazard maps and a high-resolution windstorm risk database, which provide a solid basis for risk assessment.
Numerical Investigation of High Impact Foehn storm in February 1925 using WRF and PALM models.
Authors: Shastri Renuka Prakash , Brönnimann Stefan , Stucki Peter
Published: March 2024

One of the most hazardous windstorms was observed in Switzerland on February 15, 1925. The storm is categorized as a 'High-impact Foehn Storm' that affected all Foehn regions of Switzerland. All communities, stables, and houses were wholly or partially damaged in the canton of Glarus. In previous work, the Weather Research and Forecasting Model (WRF) was used for downscaling the storm from the Twentieth Century Reanalysis (20CRv2) down to a grid width of 3 km. While many storm features were realistically simulated, wind speeds in the Glarus Valley, where most damage occurred, remained well below the expected values. Here, we go one step further by using a Large-Eddy Simulation model (LES) to analyze whether high gust peaks would occur at the bottom of the valley. For this, the PArallelized Large-eddy simulation Model (PALMv6.0) is coupled to WRFv4.1.2. In the first stage, WRFv4.1.2 was downscaled to a resolution of 1x1 km2 by using the "Twentieth Century Reanalysis" (20CRv3) as a boundary condition. Three nested domains with resolutions 25km, 5 km, and 1 km were set up for the simulation experiment. The second stage involves downscaling PALMv6.0 to a resolution of 20 m by using the output of WRFv4.1.2 as a boundary condition. The simulation shows strong winds between Netstal and Näfels on Earth's surface. Peak gusts of 40 m/s and more hit the valley floor south of Näfels. Strong turbulence fields reaching the ground at high velocities are observed in the central valley in the south-north direction. The simulation shows good agreement with the damage described, and the simulated peak gusts easily reach the measured maxima of extreme storms. Being able to realistically simulate the local characteristics of a Foehn storm that occurred a century back opens a new window to quantitative analyses of past extremes and their impacts.
Magnitude estimation of Paleo-moonquakes from boulder tracks in Finsen crater
Authors: Tao Sha , Shi Yaolin , Zhu Bojing
Published: March 2024

High-resolution images taken by the Lunar Reconnaissance Orbiter show the existence of many boulder tracks within the Finsen crater. Current research suggests that shallow moonquakes and meteorite impacts are likely to be the cause of boulder falls. Based on a simplified model, we simulate the rolling process of the boulder along the slope when the lunar surface shakes and provide the critical PGA (peak ground acceleration) required for the boulder to start rolling under different conditions. The results show that boulders may roll down slopes within one or more cycles under strong ground shaking. The critical PGA of seismic waves required for a boulder to conduct slope rolling is related to the size of the boulder, the slope at the initial location, the dominant period of the seismic wave, and the ratio of horizontal and vertical peak ground accelerations. Except for rolling against the slope, in some cases, boulders may jump and roll downhill. Using the high-resolution images taken by the LRO to determine how the boulders rolled downhill, we can then estimate the lower limit of the magnitude of moonquakes in the region under different conditions. Finally, we provide a preliminary estimation of the lower limit of the paleo-moonquakes magnitude in the Finsen Crater.
Lithological influence on bedrock incision and transience: Insights from the Aparados da Serra Escarpment, southeast Brazil
Authors: Haag Maurício , Schoenbohm Lindsay , Jess Scott , Augusto Sommer Carlos , Endrizzi Gabriel
Published: March 2024

Bedrock strength is widely regarded to exert major control over fluvial incision and landscape evolution. Despite that, quantifying lithological effects on natural landscapes has been extremely difficult due to limited continuous exposure at a watershed scale, especially in vegetated environments. Recent numerical models emphasize the pivotal role of rock strength in steering long-term landscape evolution, causing deviations from steady-state conditions, the formation of knickpoints, and biased erosion records. Situated along the southeast coast of Brazil, the Aparados da Serra Escarpment (lat. 28–29°S) represents a prominent geomorphological feature (>1,500 m asl) in the passive margin section of South America. Marked by a sequence of relatively weak sedimentary units overlain by relatively strong volcanic rocks, the escarpment exhibits gradual changes in the strong/weak ratio along its length due to a regional south-dipping contact. The well-constrained stratigraphy (stacked sedimentary and volcanic rocks), climatic conditions (uniform rainfall and temperature), and tectonic setting (regionally uniform and low uplift rates) make this region an ideal laboratory for investigating the influence of rock strength on river profiles. This study conducts a comprehensive series of in-situ rock strength measurements at closely spaced intervals (15 m vertical intervals between each site) along three sections across the escarpment (Rocinha at 28.8°S, Rio do Rastro at 28.4°S, and Corvo Branco at 28.0°S), covering a total escarpment segment > 100 km along strike and providing near-continuous exposure from sea level to 1,500 m asl. To this end, we perform detailed mapping along each section and use a Schmidt hammer type N to record the compressive strength of each lithological unit in the area. In addition, we also record the weathering state and fracture spacing for each site, allowing us to build the first continuous rock strength suite for a major geomorphological feature. Our resulting dataset (> 200 sites with > 30 measurements for each site) allows us to examine a long-postulated but rarely documented relationship between rock strength and bedrock channel steepness. Comparative analysis of normalized river steepness (Ksn) from adjacent watersheds (
The CUISINES 2024 menu: Updates and progress on a large exoplanet model intercomparison framework
Authors: Fauchez Thomas , Sohl Linda , Chaverot Guillaume , Christie Duncan , Deitrick Russell , Haqq-Misra Jacob , Harman Sonny , Iro Nicolas , Tsigaridis Kostas , Villanueva Geronimo
Published: March 2024

The exoplanet community possesses an incredible variety of models to match the astronomical diversity of exoplanets. Those models are used to either predict or interpret exoplanet data. However, contrary to Earth science, we have no existing ground truth to validate those models. Meanwhile, we would still learn a lot from benchmarking exoplanet models together to increase the robustness in our data prediction and interpretation, to identify bugs and to highlight model features that would require additional developments.The Climates Using Interactive Suites of Intercomparisons Nested for Exoplanet Studies (CUISINES) Working Group of NASA’s Nexus for Exoplanet Systems Science (NExSS) supports a systematized approach to evaluating the performance of exoplanet models, and provides here a framework for conducting community-organized exoplanet Model Intercomparison Projects (exoMIPs). The CUISINES framework adapts Earth climate community practices specifically for the needs of the exoplanet researchers, encompassing a range of model types, planetary targets, and parameter space studies. In this presentation, we will give updates on the various exoMIPs and we will provide insights on our findings to make an exoplanet model intercomparison a success on short and long timescales.
Study on the impact and adaptation strategies of climate change on infrastructure in coastal communities.
Authors: Chuang Mo-Hsiung , Lin Shyue-Yen , Ma Kuo-Chen , Ku Cheng-Yu
Published: March 2024

This study aims to explore the assessment of landslide hazards and adaptation faced by coastal communities under the impact of climate change. Considering the influence of climate change leading to increased frequency of extreme weather events, particularly heavy rainfall, which significantly affects the stability of hill slopes, this research will establish a shallow landslide susceptibility model for extreme rainfall events. This model can comprehensively solve the unsaturated transient Richard's equation and utilize the resultant pore water pressure along with the formula for the safety factor of unsaturated slope stability to construct a comprehensive regional landslide susceptibility analysis module. The module will generate distribution maps depicting the potential for slope collapses during extreme rainfall events. Through this analysis module, the study intends to predict collapse grids influenced by climate change and use Geographic Information Systems to create collapse susceptibility maps. We will overlay these maps with key infrastructure of coastal communities, including emergency response units, to understand the impact of landslide disasters on the infrastructure, emergency response capabilities during disasters, and post-disaster recovery capabilities of coastal communities. Furthermore, the study will explore the impact and adaptation strategies of climate change on infrastructure in coastal communities.
Does more frequent Very Short-Range Forecast provide more useful information?
Authors: Son Joohyung , Kim Jongseong , Kim Seongjin
Published: March 2024

The Very Short-Range Forecast (VSRF) for precipitation from the Korea Meteorological Administration (KMA) is released every 10 minutes, providing forecasts for the next 6 hours at 10-minute intervals. However, when the forecast is provided to the public, it is updated at 10-minute interval, but only provides up to 6 hours at every hour. Consequently, from the public's perspective, forecasts for specific times may change every 10 minutes. While this allows users to access the latest updates, it also poses a challenge in terms of reduced reliability due to constantly changing predictions.This study aims to assess the prediction performance and variability between forecasts released at 10-minute intervals and those at 1-hour intervals. We evaluated with the Very Short-Range Forecast numerical model KLAPS in VSRF and seek to determine which approach offers more valuable information from the public's standpoint. The assessment focuses on two distinct types of precipitation. The first involves convective showers, which sporadically appear over short durations, driven by atmospheric instability during the Korean Peninsula's summer. The second relates to systematic precipitation associated with a frontal boundary accompanying a medium-scale low-pressure system. For convective showers, the 1-hour interval exhibits better performance and continuity, particularly as the forecast time extends. In the case of systematic precipitation, the 1-hour interval remains superior, though the skill is not as prominent as with convective showers. This highlights that an abundance of information doesn't always equate to high-quality information.
Just another Tasman Sea marine heatwave?
Authors: Holbrook Neil
Published: March 2024

Through late November and early December 2023, a severe category marine heatwave (MHW) was detected moving southwards off the east coast of Tasmania, Australia. The MHW was characterised by offshore sea surface temperature anomalies ~4oC above climatological values embedded within and around large anticyclonic eddies with warm anomalies to >1000m depth. Given the deleterious impacts from previous MHWs on marine ecosystems, fisheries, and aquaculture in the region, serious concerns were raised. To advise and prepare stakeholders, a series of online briefings was given by physical, biogeochemical, fisheries, and social scientists on the current and likely evolving environmental conditions associated with the MHW. So, how unusual was this event? Was it successfully forecast? Was it expected from our knowledge of large-scale modes of climate variability and their teleconnections? This presentation will discuss the characteristics, evolution – both forecast and projected – and emerging impacts of the November-December 2023 Tasman Sea MHW. It will be argued that the characteristics of this event mirror expectations from anthropogenic climate change, and that initialised seasonal SST forecasts were little different from expectations under climate change projections and trend persistence.
Energy transfer of imbalanced Alfvénic turbulence in the heliosphere
Authors: Yang Liping , He Jiansen , Verscharen Daniel , Li Hui , Bowen Trevor A. , Bale Stuart D. , Wu Honghong , Li Wenya , Wang Ying , Zhang Lei , Feng Xueshang , Wu Ziqi
Published: March 2024

Imbalanced Alfvénic turbulence is a universal process playing a crucial role in energy transfer in space, astrophysical, and laboratory plasmas. A funda-mental and long-lasting question about the imbalanced Alfvénic turbulence is how and through which mechanism the energy transfers between scales. Here, we show that the energy transfer of imbalanced Alfvénic turbulence is completed by coherent interactions between Alfvén waves and co-propagating anomalous fluctuations. These anomalous fluctuations are generated by nonlinear couplings instead of linear reflection. We also reveal that the energy transfer of the waves and the anomalous ﬂuctuations is carried out mainly through local-scale and large-scale nonlinear interactions, respectively, responsible for their bifurcated power-law spectra. This work unveils the energy transfer physics of imbalanced Alfvénic turbulence, and advances the understanding of imbalanced Alfvénic turbulence observed by Parker Solar Probe in the inner heliosphere.
Ocean Response to Typhoon Mangkhut (2018) on a Continental Slope in the South China Sea
Authors: Zhang Han
Published: March 2024

Typhoon is a synoptic phenomenon that has significant impact on ocean. Mooring observations of nearly the full water column on the continental slope in the South China Sea revealed the ocean's response to Typhoon Mangkhut (2018). Mangkhut induced sea surface cooling ∼4°C that was biased to the right side of its track, which recovered with an e-folding time after approximately 1 week.  Mangkhut was a relatively fast-moving typhoon and caused a fast near-inertial response throughout the entire depth in its lee. The typhoon-induced upper ocean (deep-water) near-inertial current velocities were >1.5 m/s (∼0.08 m/s), with an e-folding time of approximately a week (2 weeks) and frequency of 1.04f (1.08f, where f is the local inertial frequency). The near-inertial currents were near-circular polarized in the upper ocean and near-rectilinear polarized with the main axis in the across-slope direction in deep water. The deep-water near-inertial waves amplified the vertical excursions of isotherms from ∼120 to ∼200 m, reduced the stratification, elevated vertical current shears, and enhanced turbulent dissipation rate, especially during 14–17 September when the effects of near-inertial waves and diurnal spring tides overlapped. A net cooling ∼0.15°C and salinity increase ∼0.05 psu were observed in the deep ocean after Mangkhut. Typhoon-induced near-inertial waves correspond to the intensification of southwestward along-slope mean near-bottom currents. This study indicates the immediate influence of typhoon in deep-water and contribute to the bottom mixing on the continental slope.
Massive changes in marine sedimentation rates during the Carnian Pluvial Episode (Late Triassic)
Authors: Dal Corso Jacopo , Sun Yadong , Kemp David B.
Published: March 2024

The Carnian is marked by major environmental changes, including multiple carbon-cycle perturbations, global warming and enhanced hydrological cycling that have been linked to the effects of the emplacement of Wrangellia large igneous province. The environmental perturbations occurred in an interval of about 1–2 Myr between the Julian 2 and the base of the Tuvalian 2. This interval is named Carnian Pluvial Episode (CPE). The widespread and pronounced sedimentological changes observed in marine sedimentary records, which abruptly shift towards mainly siliciclastic deposition, point to general higher continental runoff during the CPE. However, quantification of actual changes in sediment flux to marine basins is still lacking. We calculated changes in linear and relative sedimentation rates in Carnian well age-constrained marine successions. During the Julian 2, the lithological changes are coupled to increases of up to ca. 3000% in relative sedimentation rates in the marine sequences of Western Tethys and Panthalassa, and to slight decreases (< -100%) in sedimentation rates in successions of Eastern Tethys. Sedimentation rates then decrease in the Tuvalian 1 in all the successions. The higher siliciclastic delivery to the basins is likely the result of the interplay of higher precipitation and continental runoff under conditions of higher atmospheric pCO2, eustatic sea-level changes and local depositional contraints, which could all be relatable to the effects of volcanic gases emissions from Wrangellia large igneous province.
Improving All-sky Simulations of Typhoon Cloud/Rain Band Structures of NOAA-20 CrIS Window Channel Observations
Authors: Niu Zeyi
Published: March 2024

The Cross-track Infrared Sounder (CrIS) observations (O) contributed greatly to numerical weather prediction. Further contribution depends on the success of all-sky data assimilation, which requires a method to produce realistic cloud/rain band structures from background fields (i. e., 6-h forecasts), and to remove large biases of all-sky simulation of brightness temperature in the presence of clouds. In this study, CrIS all-sky simulations of brightness temperatures at an arbitrarily selected window channel within Typhoon Hinnamnor (2022) are investigated. The 3-km Weather Research and Forecasting model with three microphysics schemes were used to produce 6-h background forecasts (B). The O−B statistic deviate greatly from Gaussian distribution with large biases in either water clouds, or thin ice clouds, or thick ice clouds within Typhoon Hinnamnor. By developing a linear regression function of three all-sky simulations of brightness temperature from 6-h forecasts with three microphysics schemes, the O−B statistics approximate a Gaussian normal distribution in water clouds, thin ice clouds and thick ice clouds. Taking the regression function that is established by a training dataset to combine 6-h background forecasts at later times, the cloud/rain band structures compared much more favorably with CrIS observations than those from an individual microphysics, and the O−B biases are significantly reduced. The work in this study to quantify and remove biases in background fields of brightness temperature and generating realistic typhoon cloud/rain band structures in background fields will allow a better description of center position, intensity and size to improve typhoon forecasts.
The Nature and the response characteristics of the Roo Rise to subduction zone in the eastern Indian Ocean
Authors: Ran Weimin , Lu Yintao , Jiang Tao , Liu Hong , Shang Luning
Published: March 2024

The Sunda arc convergent plate subduction tectonic system in Southeast Asia is one of the most active convergent plate boundary zones in the world. Early studies suggest that the Sunda arc subduction system is mainly characterized by subducted accretionary plate margin and typical accretionary prism forearc uplift landform. The latest research found that the Roo Rise, the most eastern section of the Christmas Island Seamount Province in the Wharton Basin of the eastern Indian Ocean, has reached the Java Trench region with plate movement. Compared with the “normal” oceanic crust subduction process in other regions of the Sunda arc, the Roo Rise “Uplift” structure triggered different subduction geological processes in the Sunda arc system. Combined with previous research results, the nature of Roo Rise are comprehensively summarized and understood, including the lithology and chronological origin, and the deep subduction structure characteristics of the “Rise-Trench” area. To further enhance the understanding of the early forearc subduction erosion process, including local accretionary prism front edge collision “concave”, differential uplift of forearc uplift, the compression and narrowing of the forearc basin. We discuss the response characteristics of the backarc basin to the new subduction tectonic framework of “Rise-Trench-Arc-Basin” by using two-dimensional multichannel seismic data interpretation for the first time. At present, a new stage of compressional tectonic movement is taking place in the backarc Kendeng-Madura strait basin. We believe that the characteristics of the shallow compressional anticline are the direct tectonic deformation response in the backarc basin under the new “vertical orthogonal fast and high angle” subduction structure framework formed by the Roo Rise.
Modulation of Ocean Temperature Structure and Heat Content by Tropical Cyclones
Authors: Zhang Han
Published: March 2024

The ocean temperature response to tropical cyclones (TCs) is important for TC development, local air–sea interactions, and the global air–sea heat budget and transport. As TCs and ocean temperature structures are changing in the recent decades, it is worthy to study their contribution on ocean heat uptake. The modulation of the upper ocean temperature structure after TCs were studied at the observation stations in the northern South China Sea. The upper ocean temperature and heat response to the TCs mainly depend on the combined effect of mixing and vertical advection. Mixing cooled the sea surface and warmed the subsurface, while upwelling (downwelling) reduced (increased) the subsurface warm anomaly and cooled (warmed) the deeper ocean. An ideal parameterization that depends on only the nondimensional mixing depth (HE), non-dimensional transition layer thickness (HT), and nondimensional upwelling depth (HU) was able to roughly reproduce sea surface temperature (SST) and upper ocean heat change. After TCs, the subsurface heat anomalies moved into the deeper ocean. The air–sea surface heat flux contributed little to the upper ocean temperature anomaly during the TC forcing stage and did not recover the surface ocean back to pre-TC conditions more than one and a half months after the TC. This work shows how upper ocean temperature and heat content varies by a TC, indicating that TC-induced mixing modulates the warm surface water into the subsurface, and TC-induced advection further modulates the warm water into the deeper ocean and influences the local and global ocean heat budget.
Stacking Machine Learning Models Empowered High Time-height Resolved Ozone Profiling from Ground to the Stratopause Based on MAX-DOAS Observation
Authors: Zhang Sanbao , Wang Shanshan , Zhu Jian , Xue Ruibin , Jiang Zhiwen , Gu Chuanqi , Yan Yuhao , Zhou Bin
Published: March 2024

Ozone (O3) profiles are crucial for comprehending the intricate interplay among O3 sources, sinks, and transport. However, conventional O3 monitoring approaches often suffer from limitations such as low spatiotemporal resolution, high cost, and cumbersome procedures. Here, we propose a novel approach that combines Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) and machine learning (ML) technology. This approach allows the retrieval of O3 profiles with exceptionally high temporal resolution at the minute level and vertical resolution reaching the hundred meters scale. The ML models are trained using parameters obtained from radiative transfer modeling, MAX-DOAS observations, and reanalysis dataset. To enhance the accuracy of retrieving O3, we employ a stacking approach in constructing ML models. The retrieved MAX-DOAS O3 profiles are compared to data from in-situ instrument, lidar, and satellite observation, demonstrating a high level of consistency. The total error of this approach is estimated to be within 25%. On balance, this study is the first ground-based passive remote sensing of high time-height resolved O3 distribution from ground to the stratopause (0-60 km). It opens up new avenues for enhancing our comprehension of O3 dynamics in atmospheric environments. Moreover, the cost-effective and portable MAX-DOAS combined with this versatile profiling approach enables the potential for stereoscopic observations of various trace gases across multiple platforms.This work has been supported by Sino-German Mobility Program (M-0509), National Natural Science Foundation of China (grant number 42075097, 22176037, 42375089, 22376030).
A multiple-parameter regularization approach for filtering monthly GRACE/GRACE-FO gravity models
Authors: Ji Kunpu , Shen Yunzhong , Zhang Lin , Chen Qiujie , Lou Lizhi , Yao Lianbi
Published: March 2024

The Gravity Recovery and Climate Experiment (GRACE) and its subsequent GRACE Follow-On (GRACE-FO) missions have been instrumental in monitoring Earth’s mass changes through time-variable gravity field models. However, these models suffer from high-frequency noise and significant north-south striping (NSS) noise. The most widely used spectral filter for addressing these issues is the decorrelation and denoising kernel (DDK) filter, utilized by official processing agencies. The key operation of DDK filtering is to regularize the normal equation built by the Level-1b data. However, the regularization parameter used in original DDK filters is empirically determined by the signal-to-noise ratios and remains unchanged across all months. This is improper due to the heterogeneity of the monthly covariance matrix. Additionally, a single regularization parameter may not effectively address the ill-posedness of the inversion equation. For this reason, we propose a multiple-parameter regularization approach for filtering GRACE gravity field models, with regularization parameters determined by minimizing the mean squared error (MSE) for each month. The proposed method is used to process the ITSG-Grace2018 and ITSG-Grace_operational Level-2 spherical harmonic coefficients with degree/order 96 from April 2002 to December 2022. The results show that our method produces the filtered mass anomalies, global trend, and annual signal amplitudes that align better with three mascon solutions (CSR, JPL, and GSFC) compared to DDK filters and ordinary Tikhonov regularization with a single regularization parameter. In some typical areas with significant signals, our approach retains more detailed characteristics in filtered signals compared to DDK filters and ordinary Tikhonov regularization. Repeated simulations demonstrate that the filtered signals by our approach are closer to the simulated true signals than those by other methods.
Rainfall accumulation as a driver of higher Leptospirosis risk in northern South America
Authors: Builes-Jaramillo Alejandro , Arias-Monsalve Clara Susana , Valencia Juliana , Florian Carolina , Salas Hernán D.
Published: March 2024

Rainfall accumulation during wet seasons in Northern South America can be enhanced during La Niña ENSO phases.  Leptospirosis is a zoonotic waterborne disease that affects humans, domestic animals, and wildlife associated with occupational and recreational water activities, natural disasters, and socioeconomic conditions for which rainfall plays a key role in its transmission. We analyzed the incidence of leptospirosis, and relative risk of changes on the incidence of the disease due to rainfall accumulation in Northern Colombia during the period 2007-2021. The rainfall accumulation analysis was done for 7, 14 and 21 days based on the periods of incubation of the disease, biology of transmission, and thresholds of rainfall accumulation above the mean values. We found a statistically significant association between excess rainfall and leptospirosis at different lags for cities in Northern Colombia (Barranquilla, Santa Marta, Cartagena) and the levels of accumulated rainfall exceedance associated with leptospirosis were specific for each city. Our findings give insight into the association between leptospirosis and excess accumulated rainfall and provide climate services and local health authorities with tools to act on and prevent this important zoonotic disease.
Near-real-time monitoring of fossil CH4 emission from fossil fuel activities
Authors: Dou Xinyu , Ciais Philippe , Lin Xin , Liu Zhu , Song Xuanren , Wu Qingyang
Published: March 2024

Methane emissions stemming from coal, oil, and natural gas production and conveyance constitute a large component of anthropogenic methane emissions, and a priority for mitigation in the Glasgow declaration. We delineate near-real-time fossil-fuel derived CH₄ emissions constrained by atmospheric observations, spanning from 2019 to 2022, characterized by a temporal resolution of 8-days, a spatial resolution of 10 km and a separation between oil, gas and coal emissions. Through a comprehensive synthesis of observations from nested satellite-based inversion models over ultra-emitters sites, high emission extraction basins and the globe, we have identified that fossil CH4 emissions stemming exceed the United Nations Framework Convention on Climate Change (UNFCCC) global estimates by a notable margin of 5%-16% (4~12 million metric tons of methane per year). When factoring in the societal costs of methane, our analysis reveals an additional burden of 17 to 51 billion US dollars, indicating that the true extent of climate damage may be far greater than previously acknowledged. This fiscal impact, borne by communities and economies worldwide, accentuates the imperative of integrating near-real-time and fine-grained methane monitoring into climate action strategies. Our findings advocate for the immediate and prioritized rectification of methane emission inventories to reflect the true scale of emissions, thereby bolstering the global response to the climate crisis and reducing the financial and environmental toll on society.
Reprocessing of the ocean bottom seismic data of the TYDE experiment using modern techniques.
Authors: Calò Marco , Gamez Lindoro José Antonio , Di Luccio Francesca , Bernal Manzanilla Karina
Published: March 2024

During the TYrrhenian Deep-sea Experiment (TYDE) 14 Ocean Bottom stations were deployed in the period December 2000-May 2001 on the southern Tyrrhenian seafloor around the Aeolian islands All the stations were equipped with Hydrophones (OBH) and six of them with 3-component geophones (OBS). This experiment represented one of the first and most important passive ocean bottom data acquisition ever realized in southern Tyrrhenian and the records were mainly used to perform receiver functions, modeling of the seismic velocity field, and detect and locate seismicity.In this work we present a reprocessing of these old data using modern techniques of analysis to improve the quality of the signals and extract more information of what has been already published.We show the workflow used for cleaning the records together with Machine Learning approaches to improve the detection of small events and the application of methods that were not common at that time, such as the Ambient Noise analyses. Work supported by the “Pianeta Dinamico” call, 2023–2025 CAVEAT
QFuego-Patagonia: a comprehensive glacier-related dataset for Patagonia and Tierra del Fuego, South America
Authors: Farías-Barahona David , Schaefer Marius , Braun Matthias , Peña Valentina , Hernández Jorge ,   Team QFuego-Patagonia
Published: March 2024

Patagonia and Tierra del Fuego (Fuego-Patagonia 45°S to 56°S) comprise large ice fields known as Northern Patagonia Icefield (NPI) and Southern Patagonia Icefield (SPI), as well as other significant glacierized areas such as the Cordillera Darwin (CD), the Isla Santa Inés, Hoste, and hundreds of smaller glaciers. In total, this ice coverage adds up to an approximate area of 22,000 km2, accounting for about 80% of South America's total.
Throughout the 20th century, much of the knowledge about these glaciers was based on in-situ measurements and data extracted from emerging remote sensing techniques. These efforts were primarily undertaken by scientists from Argentina, Chile, Germany, the United States, France, Japan, and the United Kingdom, as well as the ongoing contributions of government institutions in Chile and Argentina.
Due to increased access to new and more precise satellites, optical and radar sensors, geophysical methods, meteorological instruments, and the sophistication of numerical models in the present century, knowledge about glaciers in Patagonia has significantly expanded. In recent decades, there have been regular updates on changes in area, elevation, surface speeds, determination of thickness in more locations, etc. In this work, we present a comprehensive dataset of the glaciers of Patagonia and Tierra del Fuego (QFuego-Patagonia) consolidated in a Geographic Information System (GIS), which will be made available to the community. This database includes elevation changes, GPR measurements, subglacial topography modeling, as well as time series of surface velocities, among others, which serve as the basis for modeling and projecting the future of Patagonian glaciers. We also announce the new QFuego-Patagonia web portal, where some of the data presented here will be available to the scientific community (https://qfuego-patagonia.org/).
Investigation of Plasma Composition and Small-Scale Density Irregularities on a Non-circular and Non-Sun-Synchronous Polar Low-Earth-Orbit (LEO) Satellite: Swarm-E e-POP Observations in the F-region and Topside Ionosphere-Thermosphere
Authors: Yau Andrew , Foss Victoria , Howarth Andrew , Kastyak-Ibrahim Marzena , White Andrew
Published: March 2024

The Swarm-E/Enhanced Polar Outflow Probe (e-POP) is in an elliptic (non-circular) and non-Sun-synchronous polar orbit (81° inclination, 325 km perigee × 1500 km initial apogee). This gives the satellite a unique vantage point among LEO satellites for observing plasma and related space weather processes in the topside ionosphere and thermosphere, especially the altitude variations of specific physical phenomena. The imaging and rapid-scanning ion mass spectrometer (IRM) on Swarm E combines the technique of ion time-of-flight (TOF), hemispherical electrostatic analysis, and 2D positional ion detection (imaging) to resolve the mass-per-charge (M/q), energy-per-charge (E/q), and incident direction of each detected ion, and to simultaneously measure the incident plasma current at high (1-ms) cadence. Data acquired over the 8-year period from launch (September 2013) to December 2021 has enabled the quantitative investigation of several important magnetosphere-ionosphere-thermosphere (MIT) coupling processes and the altitude distributions and variations of the resulting plasma composition, structure, and dynamics in the F-region and topside ionosphere-thermosphere. These include the effects of atmospheric photoelectrons on spacecraft charging, molecular and nitrogen (N+) ion enhancements in the active-time auroral ionosphere, and decameter-scale structures in equatorial plasma bubbles, for example. We present an overview of investigations of the long- (solar-cycle time scale) and short-term (down to substorm time scale) variations of the various observed features and associated phenomena in the context of their impact on MIT coupling.