We present a near surface air temperature (NSAT) fused data product over the contiguous United States using Level 2 data from the Atmospheric Infrared Sounder (AIRS), on the Aqua satellite, and the Cross-track Infrared Microwave Sounding Suite (CrIMSS), on the Suomi National Polar-orbiting Partnership (SNPP) satellite. We create the fused product using Spatial Statistical Data Fusion (SSDF), a procedure for fusing multiple datasets by modeling spatial dependence in the data, along with ground station data from NOAA’s Integrated Surface Database (ISD) which is used to estimate bias and variance in the input satellite datasets. Our fused NSAT product is produced twice daily and on a 0.25-degree latitude-longitude grid. We provide detailed validation using withheld ISD data and comparison with ERA5-Land reanalysis. The fused gridded product has no missing data; has improved accuracy and precision relative to the input satellite datasets, and comparable accuracy and precision to ERA5-Land; and includes improved uncertainty estimates. Over the domain of our study, the fused product decreases daytime bias magnitude by 1.7 K and 0.5 K, nighttime bias magnitude by 1.5 K and 0.2 K, and overall RMSE by 35% and 15% relative to the AIRS and CrIMSS input datasets, respectively. Our method is computationally fast and generalizable, capable of data fusion from multiple datasets estimating the same quantity. Finally, because our product reduces bias, it produces long-term datasets across multi-instrument remote sensing records with improved bias stationarity, even as individual missions and their data records begin and end.

Free alternate bars are large-scale, downstream-migrating bedforms characterized by an alternating sequence of three-dimensional depositional fronts and scour holes that frequently develop in rivers as the result of an intrinsic instability of the erodible bed. Theoretical models based on two-dimensional shallow water and Exner equations have been successfully employed to capture the bar instability phenomenon, and to estimate bar properties such as height, wavelength and migration rate. However, the mathematical complexity of the problem hampered the understanding of the key physical mechanisms that sustain bar formation. To fill this gap, we considered a simplified version of the equations, based on neglecting the deformation of the free surface, which allows us to: (i) provide the first complete explanation of the bar formation mechanism as the result of a simple bond between variations of the water weight and flow acceleration; (ii) derive a simplified, physically based formula for predicting bar formation in a river reach, depending on channel width-to-depth ratio, Shields number and relative submergence. Comparison with an unprecedented large set of laboratory experiments reveals that our simplified formula appropriately predicts alternate bar formation in a wide range of conditions. Noteworthy, the hypothesis of negligible free surface effect also implies that bar formation is fully independent of the Froude number. We show that this intriguing property is intimately related to the three-dimensional nature of river bars, which allows for a gentle lateral deviation of the flow without significant deformation of the water surface.

Groundwater fluoride is the major cause of the endemic fluorosis. Global fluorosis data indicate that that granitic aquifer which fractures controlled hydrology is highly susceptible to contaminate groundwater with high fluoride. Till date there has not been any sincere effort to understand the type of granitic aquifer based on the different type of the granites and their fluoride content. The present paper assesses the different types of granites and their fluoride content. Dissolution of fluoride from these rock types are the major source of high fluoride contamination in the groundwater. The granitic aquifers are also dominated by fracture control hydrology which enhances the chances of rock water interaction and dissolution of fluoride. The mineralogy of the rocks is also favorable due to the presence of biotite and muscovite which are found to have high affinity to donate fluoride during rock water interaction as shown by the following equation. KAl2[AlSi3O10]F2+2OH- = KAl2[AlSi3O10]OH-+2F- (Muscovite) KMg3[AlSi3O10] F2+2 OH- = KMg3[AlSi3O10]OH-+2F- (Biotite) Delineation of the type of aquifer and the geochemistry of the granitic rocks needs to assess to understand the geogenic causes of fluoride in the granitic aquifer along with the water chemistry (pH>8) which enhances the rate of dissolution of fluoride during rock water interaction. Further estimation can be made by the application pf isotopic data particularly 18O, 2H, 3H, 34S isotope which can quantitatively estimate the sources of fluoride and contribution from different sources as well as rock water interaction time.

The Beaufort Sea High is a high-pressure system located in the Beaufort Sea and influences ocean circulation in the western Arctic known as the Beaufort Gyre. Wrangel Island, located in the western Chukchi Sea, typically experiences easterly sea ice motion due to the Beaufort Gyre. We find that under these climatological conditions, moving ice is blocked by the island and piles up on its eastern side, while ice on its western side continues to drift. This results in an ice thickness dipole across the island. A reversal in the sense of the oceanic and atmospheric circulation across the western Arctic results in a dipole with the opposing sign. We find the dipole is present throughout the year and is strongest in January when the ice thickness difference is approximately 1m. During the spring, it is associated with the transient opening of a polynya to the west of the island. The dipole is the result of opposing ice divergence and convergence across the western Arctic and may impact ocean circulation and ecosystems within the Chukchi Sea.

Observations of atmospheric neutral density and associated dynamics within the lower thermosphere has been a challenge to the atmospheric science and space community due to its inaccessibility to balloon-borne or orbital in situ instruments. We present a methodology to study the latitudinal and temporal variation of neutral density in this region through a simultaneous campaign at geographically distinct high-power large-aperture (HPLA) radar facilities to observe meteor trajectories. These meteors are formed by meteoroids entering the Earth’s atmosphere; the deceleration they undergo due to atmospheric drag provides a source of information to determine the neutral density of the atmosphere at altitudes of 80 to 140 km. Through the measurement of meteor head echo trajectories using specialized radar waveforms and signal processing to enhance the range resolution, combined with novel statistical techniques to account for the distribution of meteoroid properties, the temporal evolution of atmospheric neutral density from 70 to 140 km can be characterized with sub-km altitude resolution. Initial results will be presented from the first of four observation campaigns planned during the 2019-2021 period using the HPLA radar sites at Jicamarca, Millstone Hill, and Resolute Bay, which span equatorial to polar latitudes at similar longitude. The simultaneous measurements across facilities complements other measurements of atmospheric composition and structure at similar altitudes to provide improved identification of latitudinal coupling and forcing from lower altitudes into the magnetosphere-ionosphere-thermosphere (MIT) system.

Various teaching methods including classroom lectures, physical experiments, and field excursions are useful for students to learn and understand the basic concepts of geography and earth sciences. However, due to constraints in the current curriculum of geographic education in Japanese schools, physical experiments and field excursions are rarely conducted, and classroom lectures tend to focus on memorizing some technical terms. This environment is not ideal for teaching processes and mechanisms of geographic phenomena. High-frequency, high-definition topographic data obtained using a TLS (Terrestrial Laser Scanner) and SfM-MVS photogrammetry with a UAS (Unmanned Aerial System) have become popular in geoscience. Those surveying approaches allow us to directly monitor rapidly changing landforms, while we can also use the obtained data to visualize geographic phenomena by various methods and materials including 3D print models, 3D virtual models, pictures, videos, and virtual/mixed reality. Here we explore the use of high-frequency, high-definition topographic data for educating geographic thinking. We arranged and conducted experimental teaching classes for elementary school students. First, we showed two 3D print models of the same sea cliff for years 2015 and 2017 constructed form high-definition topographic data. When students touched the two models, they were able to feel topographic changes due to erosion and sedimentation effectively. Furthermore, after exploring the 3D print models, many students were able to imagine how the sea cliff would change in the future. Next, we showed two images of fluvial deposits along a river segment in the area where the students live for July 2017 and September 2017. Then, they were able to imagine the transportation force of river flow. They also understood that the river flows typically in quiet but becomes powerful at high flow to move more sediment, and it might cause a disaster. Such visualized and touchable learning materials derived from high-frequency, high-definition topographic data enable students to enhance their geographic imagination of landforms, which are familiar to them but unexpectedly changing, at appropriate spatial and time scales.

Sea ice production within polynyas, an outcome of the atmosphere - ice - ocean interaction, is a major source of dense water and hence key to the global overturning circulation, but is poorly quantified over open-ocean polynyas. Using the two recent extensive open-ocean polynyas within the wider Maud Rise region of the Weddell Sea in 2016 and 2017, we here explore the surface ice energy budget and estimate their ice production based on satellite retrievals, in-situ hydrographic observations, and the Japanese 55-year Reanalysis (JRA55). We find that the oceanic heat flux amounts to 36.1 and 30.7 W m-2 within the 2016 and 2017 polynyas, respectively. We find that the 2017 open-ocean polynya produced nearly 200 km3 of new sea ice, which is comparable to the production in the largest Antarctic coastal polynyas. Finally, we find that ice production is highly correlated with the 2 m air temperature and wind speed, which affect the turbulent fluxes. It is also highly sensitive to uncertainties in the atmospheric air temperature and mixed layer depth, which urgently need to be better monitored at high latitudes.

We examine the wave coupling efficiency of solar wind to magnetospheric fluctuations in the ULF frequency range using an advanced full-wave simulation code, Petra-M. Earth’s magnetic field is tilted to the ecliptic plane; thus, compressional wave sources can be incident over a wide range of magnetic latitudes. When compressional waves are incident at a low latitude, very little wave power can reach the inner magnetosphere. On the other hand, waves incident from a high latitude source can propagate efficiently into the inner magnetosphere and reach the ground near the cusp region. The mode-conversion and polarization reversal at the crossover plays a critical role in compressional wave propagation. The mode-converted linearly polarized electromagnetic ion cyclotron waves also occur at the Alfvén and ion-ion hybrid resonances. Therefore, the results suggest that solar wind compression can drive the linearly polarized EMIC waves, and the wave occurrence can have seasonal and diurnal dependence.

On 14 October 2023, an annular eclipse took place between 1503 UT and 2055 UT. It affected both North and South America. In this study, we used multiple ground-based and space-borne instruments, and we analysed ionospheric, thermospheric, magnetic and electrodynamic responses to this eclipse. In the vertical total electron content (VTEC) maps, at mid-latitudes, we observed a 40% depletion shortly after the Moon's shadow arrival. When the eclipse reached the low latitude region and the northern crest of the equatorial anomaly, we observed only 20-25% VTEC decrease in the vicinity of the eclipse path. However, after the Moon shadow crossed the magnetic equator, the low-latitude VTEC depletion reached 40%. The latter can be explained by the eclipse weakening the equatorial electric fields and, consequently, the equatorial fountain. In the topside VTEC and in the in-situ electron density measurements from Swarm B and C satellites we observed 40-50% decrease over the area affected by the eclipse. In the thermosphere, the eclipse produced a noticeable drop in the neutral mass density (7-18%) at 490-510 km of altitude, and changed the thermospheric composition in the vicinity of the eclipse path by 25-35%. Finally, the eclipse also clearly affected the geomagnetic field, especially at low and equatorial latitudes. Shortly after the umbra's arrival, we observed a clear decline in the total intensity F and the horizontal component H at all equatorial stations in South America. Whereas, in the variations of the vertical magnetic component Z no common pattern was observed during the eclipse. Key points:  the eclipse caused 40% depletion in total electron content, and it produced 40-50% decrease in electron density in the topside ionosphere  satellites show 7 to 20% decrease in the neutral mass density and 25-35% change in the thermospheric composition due to the eclipse  magnetic measurements show a clear decrease in the total intensity and horizontal component at low latitudes during the eclipse

During summer, the Southern Ocean is largely unaffected by anthropogenic emissions, which makes this region an ideal place to investigate marine natural aerosol sources and processes. A better understanding of natural aerosol is key to constrain the preindustrial aerosol state and reduce the aerosol radiative forcing uncertainty in global climate models. We report the concentrations of gaseous sulfuric acid, iodic acid, and methanesulfonic acid (MSA) together with a characterization of new particle formation (NPF) events over a large stretch of the Southern Ocean. Measurements were conducted on board the Russian icebreaker Akademik Tryoshnikov from January to March 2017. Iodic acid is characterized by a particular diurnal cycle with reduced concentration around noon, suggesting a lower formation yield when solar irradiance is higher. Gaseous MSA does not have a diurnal cycle and measured concentrations in gas and condensed phase are compatible with this species being primarily produced via heterogeneous oxidation of dimethyl sulfide and subsequent partitioning into the gas phase. We also found that NPF in the boundary layer is mainly driven by sulfuric acid but it occurred very rarely over the vast geographical area probed and did not contribute to the CCN budget in a directly observable manner. Despite the near absence of NPF events in the boundary layer, Aitken mode particles were frequently measured, supporting the hypothesis of a free tropospheric source. Iodic acid and MSA were not found to participate in nucleation, however, MSA may contribute to aerosol growth via heterogeneous formation in the aqueous phase.

While rising global temperatures have altered global drought risk and are projected to continue to change large-scale hydroclimate, it has proved difficult to detect the influence of warming on drought-relevant variables at regional scales. In addition to the inherent difficulty in identifying signals in noisy data, detection and attribution studies generally rely on general circulation models, which may fail to accurately capture the characteristics of naturally forced and internal hydroclimate variability. Here, we use a long tree-ring based paleoclimate record of drought to estimate pre-industrial variability in the Palmer Drought Severity Index (PDSI), a commonly used metric of drought risk. Using a Bayesian framework, we estimate the temporal and spatial characteristics of hydroclimate variability prior to 1850. We assess whether observed twenty-first century PDSI is compatible with this pre-industrial variability or is better explained by a forced response that depends on global mean temperature. Our ressults suggest that global warming likely contributed to dry PDSI in Eastern Europe, the Mediterranean, and Arctic Russia and to wet PDSI in Northern Europe, East-central Asia, and Tibet.

A fundamental quantity in tropical dynamics is the ‘convective mass flux’, which measures the upwards mass flux in tropical convection. Changes in convective mass flux under warming are an important, and uncertain, aspect of climate change. Here we build off recent work linking changes in mass flux to the clear-sky energy budget to show that convective mass fluxes decrease along isotherms at around 3-5 % K-1 under warming. We show that this constraint holds throughout the free-troposphere and across a hierarchy of models; from idealized radiative-convective equilibrium simulations to CMIP6 models. This decrease in convective mass flux with warming is driven by a stabilization of the lapse rate and can be captured with a simple analytical model. We also revisit previous work by Held and Soden (2006), who proposed a scaling for changes in the convective mass flux at cloud-base with warming. We show that the Held and Soden scaling does not capture inter-model spread in cloud-base mass flux changes under warming in cloud-resolving models. Altogether, this work provides a quantitative constraint on changes in convective mass flux throughout the troposphere which can be derived from first principles, and which is verified across a hierarchy of models.

This study investigates the effects of using high resolution surface load change grids when modeling elastic crusted deformation at ANET-POLENET Global Navigation Satellite System (GNSS) sites in the Amundsen Sea Embayment (ASE), Antarctica. We create sub-kilometer resolution surface change grids from 1143 digital elevation models (DEMs) derived from stereo optical imagery. We model elastic deformation at grid resolutions between 0.32 and 6 km. We find that grid resolutions of 6 km are appropriate to characterize elastic deformation at the ANET-POLENET sites within the ASE, as each GNSS site is more than 5 km from sites of major mass loss. Our experiments reveal that for localities where major mass change is occur within 5 km, such as at grounding zones and shear margins, the effects of surface load grid resolution within elastic models may be large and finer scale resolutions (less than 0.32 km) should be used.

With the increasing volume of data generated in agriculture, developing guidelines for appropriate data sharing and management is essential. Founded in 2015, the AgBioData Consortium aims to identify the current major issues in data curation and management and ensure more Findable, Accessible, Interoperable, and Reusable (FAIR) data. In 2021 we received funding from the National Science Foundation for a Research Coordination Network grant, whose main goals are: (1) make recommendations and implementation plans for FAIR data in agriculture; (2) expand the AgBioData network by recruiting key stakeholders in agricultural research; (3) provide educational material to train researchers on FAIR data sharing; and (4) develop a roadmap for a sustainable genomic, genetic and breeding (GGB) Database Ecosystem. We have started by launching nine working groups covering different aspects of data management in agriculture and recruitment. We also plan new groups focused on sharing and archiving new types of data, such as those generated with high-throughput phenotyping platforms. As plant phenomics becomes a major part of agriculture, we foresee opportunities to collectively identify best data management practices in current and future phenomics repositories to ensure that phenomics data is FAIR from the start. We are welcoming new members with expertise in the field. If you are interested in joining, please visit our website (https://www.agbiodata.org).

The Filchner-Ronne Ice Shelf (FRIS) is characterized by moderate basal melt rates due to the near-freezing waters that dominate the wide southern Weddell Sea continental shelf. We revisited the region in austral summer 2018 with detailed hydrographic and noble gas surveys along FRIS. The FRIS front was characterized by High Salinity Shelf Water (HSSW) in Ronne Depression, Ice Shelf Water (ISW) on its eastern flank and an inflow of modified Warm Deep Water (mWDW) entering through Central Trough. Filchner Trough was dominated by Ronne HSSW-sourced ISW, likely forced by a recently intensified circulation beneath FRIS due to enhanced sea ice production in the Ronne polynya since 2015. Glacial meltwater fractions and tracer-based water mass dating indicate two separate ISW outflow cores, one hugging the Berkner slope after a two-year travel time, and the other located in the central Filchner Trough following a ~six year-long transit through the FRIS cavity. Historical measurements indicate the presence of two distinct modes, in which water masses in Filchner Trough were dominated by either Ronne HSSW-derived ISW (Ronne-mode) or more locally-derived Berkner-HSSW (Berkner-mode). While the dominance of these modes has alternated on interannual time scales, ocean densities in Filchner Trough have remained remarkably stable since the first surveys in 1980. Indeed, geostrophic velocities indicated outflowing ISW-cores along the trough’s western flank and onto Berkner Bank, which suggests that Ronne-ISW preconditions Berkner-HSSW production. The negligible density difference between Berkner- and Ronne-mode waters indicates that each contribute cold dense shelf waters to protect FRIS against inflowing mWDW.

The LASP Interactive Solar IRradiance Datacenter (LISIRD), lasp.colorado.edu/lisird, is a website where researchers can discover, visualize, and download solar data from a variety of space missions, instruments, models, and laboratories. LISIRD focuses on making heliophysics research as effortless as possible by making solar data openly available and easy to analyze through an intuitive user interface, detailed metadata, interactive plotting capabilities, and a catalog of over 75 datasets. This poster will discuss how LISIRD currently demonstrates, and aspires to better comply with, the TRUST Principles (Transparency, Responsibility, User Community, Sustainability, and Technology). Topics will include metadata efforts to improve dataset transparency, usability testing to further understand the needs of user communities, and how we designed our current technology stack to make development and maintenance easier and more sustainable.

Cyclostratigraphy’s near 100% success rate in statistical cycle identification suggests confirmation bias; absence of cyclicity is not regarded as a possible outcome. Vaughan et al 2011 (VBS) showed that the usual methods of estimating confidence levels (CLs) admit numerous false cycle detections, but in subsequent debate it is asserted that the corrections recommended by VBS do not apply in cyclostratigraphy because they lead to rejection of the expected orbital periods. Is there a deeper problem? VBS particularly criticised universal failure to correct CLs for the unavoidably multiple nature of significance tests of power spectra. However, the multiple-test problem is compounded by assumptions of unlimited freedom to vary procedures to allow for properties of individual datasets. Statistical analysis in cyclostratigraphy operates in a large variable-space, both of target hypotheses (many orbital cycles and combinations thereof), and of procedures (many pre- and syn-processing options). Each of the many data-contingent choices made before and during spectral analysis and significance-testing implies the existence of alternatives: in effect, the reported analysis is only one of many. Given that multiple experiments will eventually achieve a positive result purely by chance, unadjusted significance thresholds will result in large numbers of spurious cycle identifications, a possible explanation for observed success rates. Additional multiplicity is implied by the practice of treating CLs as a guide, rather than as a definitive signal:noise discriminator; treating CLs as movable (or even optional) negates the concept that the particular dataset is just one realisation of many permitted by the noise model; without pre-selection of a CL the statistics are meaningless. Suggestions for practical improvements include: better hypothesis formulation (with attention to the prior probability of signal preservation in an unreliable recording medium); more care in discriminating between the exploratory (hypothesis-setting) and confirmatory (hypothesis-testing) modes of data analysis; advance definition of analytical protocols; and publication of all results whether positive or negative. Reference: Vaughan et al 2011: doi:10.1029/2011PA002195.

Nudging is a ubiquitous capability of numerical weather and climate models that is widely used in a variety of applications (e.g. crude data assimilation, “intelligent’ interpolation between analysis times, constraining flow in tracer advection/diffusion simulations). Here, the focus is on the momentum nudging tendencies themselves, rather than the atmospheric state that results from application of the method. The initial intent was to interpret these tendencies as a quantitative estimation of model error (net parameterization error in particular). However, it was found that nudging tendencies depend strongly on the nudging time scale chosen, which is the primary result presented here. Reducing the nudging time scale reduces the difference between the model state and the target state, but much less so than the reduction in the nudging time scale, resulting in increased nudging tendencies. The dynamical core, in particular, appears to increasingly oppose nudging tendencies as the nudging time scale is reduced. These results suggest nudging tendencies cannot be quantitatively interpreted as model error. Still, nudging tendencies do contain some information on model errors and/or missing physical processes and still might be useful in model development and tuning, even if only qualitatively.