A new augmented Ensemble of Data Assimilations (EDA) technique to estimate background error covariances (B-matrix) has been developed for the Copernicus European Regional Re-Analysis (CERRA). The B-matrix is modelled on a bi-Fourier limited area model. Background errors are assumed isotropic, homogeneous and non-separable. Linearised geostrophic and hydrostatic balances are incorporated as multivariate relationships, coupling vorticity and geopotential extended to mass-wind and specific humidity fields via the f-plane approximation. The B-matrix is estimated by a new 10-member CERRA-EDA system, temporally tethered to real-time meteorological situations. The EDA forecast differences comprise two main pools: seasonal and daily. The seasonal component is pre-prepared at reanalysis-resolution (5.5km). The new augmentation governs real-time mixture of winter and summer differences. The daily component is an 11km moving 2.5 day average. B-matrix re-estimation occurs every 2 days, with a fixed split of 80-20\% seasonal-daily. We consider a case study to illustrate the potential of CERRA-EDA to estimate weather regime change. The most influential factors are temporal evolution of spatial observation coverage, and varying the seasonal-daily split. Background error statistics, improvements in analysis and forecast skill scores and overall assimilation system performance are shown and discussed.

A key benefit to the scientific community of a pathfinder to 542 AU is calibration data for an array of instruments on a flagship probe to interstellar space. There are fundamental processes and parameters of the near interstellar medium, whose estimated range of values could be greatly narrowed by in-situ sampling from a fast and small mission. By selecting an angle relative to the sun, plane of the ecliptic and a scientifically interesting target (such as Trappist-1), it is possible to perform initial optical measurements from the Solar Gravitational Lens (SGL) focal region on the same pathfinder. Doing so provides a basic set of data for larger follow-on missions to observe that (and other) solar systems in greater detail. By combining the datasets from 2 solar cycles (22 years) of space weather monitoring satellites, Voyager 1 and other deep space probes, the Practical Interplanetary Propulsion (PIP) Study constructed a radial profile for the solar wind ranging from 1 AU through the foreshock at 83 AU, to a notional heliopause at 123 AU, and the near interstellar medium out to 1,800 AU. The resulting matrix of plasma parameters was applied to a trajectory model “seed code,” to test flight paths for future probes. This paper presents an example pathfinder, consisting of a cubesat bus equipped with a Wind Rider propulsion system and radioisotope power system (RPS). A brief description of those subsystems and how they interact with the solar wind or interstellar medium is included. Trajectory simulation results estimate the trip time from 1 to 542 AU near the plane of the ecliptic takes 6.9 years. Adding a compact imaging instrument enables the probe to sample data from the vantage point of the Trappist-1 SGL, as well as PickUp Ions (PUI) for a 1 year science campaign. Total pathfinder mission time after launch is less than 8 years. A set of policy-making recommendations for enabling such small precursor-type missions is provided in the conclusions, as well as ways to extend the mission to communicate from 1,000 AU to 1,800 AU. Alternatively, a method to gradually decelerate to a near stop at the end of the mission, using the Wind Rider to drag against the interstellar plasma, is also included.

The overturn of mantle cumulates following the crystallization of the lunar magma ocean – particularly the sinking of ilmenite-bearing cumulates (IBC) – provides an explanation for several aspects of the Moon’s evolution. However, the growth of a stagnant lid due to the temperature dependence of the viscosity tends to prevent IBC from sinking. Here, we investigate the dynamics of the overturn based on a composition-dependent rheology coupling diffusion and dislocation creep of major lunar mantle minerals via three alternative mixing models: isostrain, isostress and Minimized Power Geometric (MPG). The pre-overturn structure is obtained from a fractional crystallization model of the lunar magma ocean, which predicts the formation of a 36-km-thick IBC layer. The possibility of overturning this layer strongly depends on the choice of the rheological mixing model. The isostress model allows for a rapid and complete overturn, while the isostrain and the experiment-based MPG models do not allow IBC to sink. If IBC started sinking and mixing with the underlying mantle during magma ocean solidification, IBC could be initially distributed across a layer with a thickness of up to 150 km, whose partial overturn is always possible, independent of the rheological model. These results highlight the importance of improving rheological models for relevant lunar materials. In all cases, the overturn occurs via small-scale instabilities.

The Brewer-Dobson Circulation (BDC) determines the distribution of long-lived trac- ers in the stratosphere; therefore, their changes can be used to diagnose changes in the BDC. We evaluate decadal (2005-2018) trends of nitrous oxide (N2O) in two versions of the Whole Atmosphere Chemistry-Climate Model (WACCM) by comparing them with measurements from four Fourier transform infrared (FTIR) ground-based instruments, the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS), and with a chemistry-transport model (CTM) driven by four different reanalyses. The limited sensitivity of the FTIR instruments can hide negative N2O trends in the mid-stratosphere because of the large increase in the lowermost stratosphere. When applying ACE-FTS measurement sampling on model datasets, the reanalyses from the European Centre for Medium Range Weather Forecast (ECMWF) compare best with ACE-FTS, but the N2O trends are consistently exaggerated. The N2O trends obtained with WACCM disagree with those obtained from ACE-FTS, but the new WACCM version performs better than the previous above the Southern Hemisphere in the stratosphere. Model sensitivity tests show that the decadal N2O trends reflect changes in the stratospheric transport. We further investigate the N2 O Transformed Eulerian Mean (TEM) budget in WACCM and in the CTM simulation driven by the latest ECMWF reanalysis. The TEM analysis shows that enhanced advection affects the stratospheric N2O trends in the Tropics. While no ideal observational dataset currently exists, this model study of N2O trends still provides new insights about the BDC and its changes because of the contribution from relevant sensitivity tests and the TEM analysis.

The spatiotemporal evolution of droughts in the Congo River Basin (CRB) from 1981–2018 was investigated using the Standardised Precipitation Index (SPI) and Standardised Precipitation–Evapotranspiration Index (SPEI) to assess the roles of precipitation and potential evapotranspiration. The results confirmed a notable trend toward drier conditions, particularly in parts of the northern and central basin, as well as in the south of the CRB, which was associated with increases in potential evapotranspiration and declining rainfall. Global outputs of the Lagrangian model FLEXPART were used to model air masses over four important climatological regions considered to be the main sources of precipitation in the CRB, and their contributions to precipitation over the basin were computed. These analyses confirmed that moisture in the CRB is ~60% self-sourced; African lands were the next greatest contributor, followed by the Indian and Atlantic Oceans. It was found that a reduction in contributions of the sources prevailed during 53 meteorological drought episodes that affected the CRB during the study period and it could be inferred that a reduction in moisture supplied from the Atlantic and Indian Oceans played an important role in the onset of drought episodes. It was also observed that the contribution of moisture from all sources to the CRB decreased during the study period, especially over the northern half of the basin, where the main humid forest of the CRB is located, confirming the importance of water transport and local hydroclimatological dynamics on the hydrological conditions, ecosystems, and local communities of the CRB.

Passive Aquatic Listeners (PALs) have been increasingly deployed to collect minute-scale surface oceanic rainfall and wind information, with a sampling area similar to the spaceborne sensor footprints. This provides an unprecedented opportunity to validate satellite precipitation products over oceans. This study evaluates the Global Precipitation Climatology Project (GPCP) daily products, including the widely-used GPCP v1.3 and the newly released GPCP v3.2, over oceans using 58 PALs as references. The study shows that the GPCP performance depends on time scale, region, and rainfall intensity. The two versions of GPCP perform similarly at multi-year and monthly scales, while GPCP v3.2 shows substantial improvements in representing rain occurrence and rain intensity at daily scale. The results also highlight the challenge of precipitation measurement over certain regions such as the tropical Northeastern Pacific and extratropical North Pacific, where both versions of the GPCP products perform similarly but exhibit noticeable differences compared to PAL observations.

Antarctica has been proposed as the dominant source of the meltwater that entered the oceans during Meltwater Pulse 1b (MWP1b) that occurred approximately 11,500 years ago. The deglaciation of heavily glaciated fjords off the coast of Antarctica at approximately this time has provided support for this hypothesis. Further support for this scenario was provided by the fact that the highly non-monotonic relative sea level histories recorded at sites on the coast of Scotland, which had been heavily glaciated at last glacial maximum, could be explained by the inter-hemispheric sea level teleconnection associated with a significant deglaciation of Antarctic ice sheets at this time. That the magnitude of grounded ice loss from Antarctica at MWP1b time was adequate to provide the necessary RSL rise along the coast of Scotland has not been demonstrated. Furthermore, there exist implicit suggestions to the effect that a significant contribution to MWP1b must have also been delivered to the oceans by the abrupt northern hemisphere warming that occurred at the end of the Younger Dryas (YD) cold reversal, which also occurred approximately 11,500 years ago. This warming event occurred due to the rapid intensification of the Atlantic Meridional Overturning Circulation (AMOC) when it recovered after the YD. We present a fingerprinting analysis of the contribution of all major ice sheets to MWP1b using the ICE7G_NA (VM7) model of ice loading history and find that the best agreement between calculated sea level curves and observations is obtained with a minimal Antarctic contribution.

The ESA-NASA Multi-mission Algorithm and Analysis Platform (MAAP) is a platform designed to meet the need of the international scientific community to collaborate on the generation and analysis of increasingly massive datasets from space-based, airborne, and field observations for aboveground terrestrial carbon dynamics. The MAAP is an open-source, cloud-based platform that distinguishes itself from other science platforms by being agnostic to any science disciplines and allows scientists to write, develop, and execute their own algorithms in shared workspaces that are tailored to their specific area of research. We present an overview of the capabilities of the Pilot implementation of MAAP. Users can explore and visualize ESA and NASA data that is ingested in the MAAP data catalog, develop and test algorithms to generate new datasets and act upon existing ones, launch matured algorithms as large-scale processing jobs, and analyze the results. This allows scientists to follow the entire scientific process within the platform, from the conception of a hypothesis to the creation of scientific results in a version-controlled and reproducible environment. Users can document their process, collaborate with other users, and share algorithms and datasets. We will conclude with an outlook on the features that the next phase of development will bring to the platform.

Carbonate melts have been proposed to exist in the lower mantle, but their interaction with other lower mantle melt compositions is poorly understood. To understand miscibility in the carbonate-silicate-metal melt system, we simulate endmember, binary, and ternary melt mixtures and study how their Gibbs free energies of mixing evolve with pressure. We find that carbonate-metal and carbonate-silicate melts have miscibility gaps that close with increasing pressure, while silicate-metal melts are immiscible at all lower-mantle pressures. Extending this analysis to the core-mantle boundary, we suggest three miscible melt fields near the endmember carbonate, silicate, and iron melt compositions. Analysis of the densities of these miscible melt compositions indicates that some carbonate-rich and some silicate-rich melt compositions are gravitationally stable at the core-mantle boundary and could be candidate compositions to explain ultra-low velocity zones. Additionally, we evaluate the speciation of an example immiscible melt composition at various pressures throughout the mantle and identify reduced carbon species that would be expected to form in the melt. Our analysis reveals that a majority of Earth's carbon could have been transported to the core during core-mantle differentiation and that much of Earth's carbon may be stored in the deep interior today.

Heatwaves are an accustomed extreme event of the Australian climate and cause catastrophic impacts on human health, agriculture, and urban and natural systems. Heatwaves are measured by various metrics developed for the employment of different impact-based studies. We have analysed the trends in Australia-wide heatwave metrics (frequency, duration, intensity, number, cumulative magnitude, timing, and season duration) across 69 extended summer seasons (i.e., from Nov-1951 to Mar-2020). Our findings not only emphasise that heatwaves are becoming hotter, longer, and more frequent, but also signify that they are occurring with excess heat, commencing much earlier, and expanding their season over many parts of Australia in recent decades. We also investigated the heatwave and severe heatwave trends at a local city-scale using two different observational products (AWAP gridded dataset and ACORN_SATV2 station data) over selected time periods (1911 to 2019, 1911-64, and 1964-2019). Results suggest that heatwave trends are different amongst the two datasets. However, the results highlight that the severe heatwave cumulative magnitude and their season duration has been increasing significantly in recent decades over the southern coastal cities of Australia (like Melbourne and Adelaide). The climatological mean of the most heatwave and severe heatwave metrics is substantially higher in recent decades compared to earlier periods across all the cities considered. The findings of our study have significant implications for the development of advanced heatwave planning and adaptation strategies.

Coastal wetlands provide a wealth of ecosystem services, including improved water quality, protection from storm surges, and wildlife habitat. Louisiana’s wetlands, however, are threatened by development, pollution, and relative sea level rise (RSLR)—the combination of sea level rise and subsidence rates. Despite widespread wetland loss, areas such as the Wax Lake and Atchafalaya river deltas are in fact growing due to their sediment loads, resulting in a complex of both degradation and aggradation along the Louisiana coast. In order to understand and model how coastal wetlands are responding to RSLR, there is a need for improved vegetation mapping, biomass estimation, and landscape-scale study of accretionary processes. AVIRIS-NG offers high spatial and spectral resolution data that can be integrated with external datasets—including from in situ measurements, monitoring stations, and other remote sensing platforms—to study these distributions and processes. Spectra derived from AVIRIS-NG imagery were used to parameterize Multiple Endmember Spectral Mixture Analysis (MESMA) for mapping vegetation functional types in addition to partial least squares regression (PLSR) models for plant aboveground biomass (AGB). The historical Landsat record complemented this analysis by deriving maps of change in wetland health and sediment availability through time. Each of these remotely sensed parameters were investigated to determine their combined relationship to Louisiana’s coastal accretion rates. In quantifying landscape-scale processes that impact wetland accretion, this research aids the assessment of coastal resiliency in the face of sea level rise. Further, the investigated imaging spectroscopy methods pertaining to vegetation mapping, biomass estimation, and accretionary modeling will inform future studies under the global Surface Biology and Geology mission.

Carbon fluxes from agroecosystems contribute to the variability in the carbon cycle and atmospheric [CO2]. In this study, we used the Integrated Science Assessment Model (ISAM) equipped with a spring wheat module to study carbon fluxes and their variability in spring wheat agroecosystems of India. First, ISAM was run in the site-scale mode to simulate the Gross Primary Production (GPP), Total Ecosystem Respiration (TER), and Net Ecosystem Production (NEP) over an experimental spring wheat site in the north India. Comparison with flux-tower observations showed that the spring wheat module in ISAM can match the observed flux patterns better than generic crop models. Next, regional-scale runs were conducted to simulate carbon fluxes across the country for the 1980-2016 period. Results showed that the fluxes vary widely, primarily due to variations in planting dates across regions. Fluxes peak earlier in the eastern and central parts of the country, where the crops are planted earlier. All fluxes show statistically significant increasing trends (p<.01) during the study period. The GPP, Net Primary Production (NPP), Autotrophic respiration (Ra), and Heterotrophic Respiration (Rh) increased at 1.272, 0.945, 0.579, 0.328, and 0.366 TgC/yr2, respectively. Numerical experiments were conducted to study how natural forcings like changing temperature and [CO2] and agricultural management practices like nitrogen fertilization and water availability could contribute to the increasing trends. The experiments revealed that increasing [CO2], nitrogen fertilization, and water added through irrigation contributed to the increase of carbon fluxes, with nitrogen fertilization having the strongest effect.

The Lightning Imaging Sensor (LIS) was launched to the International Space Station (ISS) in February 2017, detecting optical signatures of lightning with storm-scale horizontal resolution during both day and night. ISS LIS data are available beginning 1 March 2017. Millisecond timing allows detailed intercalibration and validation with other spaceborne and ground-based lightning sensors. Initial comparisons with those other sensors suggest flash detection efficiency around 60% (diurnal variability of 51-75%), false alarm rate under 5%, timing accuracy better than 2 ms, and horizontal location accuracy around 3 km. The spatially uniform flash detection capability of ISS LIS from low-Earth orbit allows assessment of spatially varying flash detection efficiency for other sensors and networks, particularly the Geostationary Lightning Mappers. ISS LIS provides research data suitable for investigations of lightning physics, climatology, thunderstorm processes, and atmospheric composition, as well as realtime lightning data for operational forecasting and aviation weather interests. ISS LIS enables enrichment and extension of the long-term global climatology of lightning from space, and is the only recent platform that extends the global record to higher latitudes (± 55). The global spatial distribution of lightning from ISS LIS is broadly similar to previous datasets, with globally averaged seasonal/annual flash rates about 5-10% lower. This difference is likely due to reduced flash detection efficiency that will be mitigated in future ISS LIS data processing, as well as the shorter ISS LIS period of record. The expected land/ocean contrast in the diurnal variability of global lightning is also observed.

In high-pH ($\text{pH}>10$) fluids that have participated in low-temperature ($<150\,^{\circ}\text{C}$) serpentinization, the dominant form of C is often methane (CH$_{4}$), but the origin of this CH$_{4}$ is uncertain. To assess CH$_{4}$ origin during low-temperature serpentinization, we pumped fluids from aquifers within the Samail Ophiolite, Oman. We determined fluid chemical compositions, analyzed taxonomic profiles of fluid-hosted microbial communities, and measured isotopic compositions of hydrocarbon gases. We found that 16S rRNA gene sequences affiliated with methanogens were widespread in the aquifer. We measured clumped isotopologue ($^{13}$CH$_{3}$D and $^{12}$CH$_{2}$D$_{2}$) relative abundances less than equilibrium, consistent with substantial microbial CH$_{4}$ production. Further, we observed an inverse relationship between dissolved inorganic C concentrations and $\delta^{13}\text{C}_{\text{CH}_{4}}$ across fluids bearing microbiological evidence of methanogenic activity, suggesting that the apparent C isotope effect of microbial methanogenesis is modulated by C availability. A second source of CH$_{4}$ is evidenced by the presence of CH$_{4}$-bearing fluid inclusions in the Samail Ophiolite and our measurement of high $\delta^{13}\text{C}$ values of ethane and propane, which are similar to those reported in studies of CH$_{4}$-rich inclusions in rocks from the oceanic lithosphere. In addition, we observed 16S rRNA gene sequences affiliated with aerobic methanotrophs and, in lower abundance, anaerobic methanotrophs, indicating that microbial consumption of CH$_{4}$ in the ophiolite may further enrich CH$_{4}$ in $^{13}$C. We conclude that substantial microbial CH$_{4}$ is produced under varying degrees of C limitation and mixes with abiotic CH$_{4}$ released from fluid inclusions. This study lends insight into the functioning of microbial ecosystems supported by water/rock reactions.

Ground-based observations of shock aurora, which is an aurora related to geomagnetic sudden commencement (SC), have mainly been limited to the dayside. On 26 February 2023, right after the SC onset at 19:24 UT, ground-based all-sky cameras and a wide-angle camera detected shock aurora at 21 MLT in the auroral zone. For this aurora, three different emissions are detected instead of the previously known two emissions: intensification of a pre-existing arc (19:25 UT), red diffuse aurora (19:28 UT), and a second, green discrete arc (19:31 UT). The relative location of these emissions differs from the dayside cases where the first and last types are not distinguished. Geomagnetic data under this aurora indicates a significant difference in the anti-sunward propagation velocity between the secondary discrete arc and the related field-aligned current.

Crawford and Flaxman impact data that have been attributed to the Eocene, and were published at the turn of the millenium, have been reinterpreted in the light of a visible crater structure in the Barossa area of the Adelaide hills. New considerations include apparent iron meteorite fragments and proposed iron melt, around the Angaston area. At the focus, 300 m north of the junction of Lambtail Corner Rd and Hutton Vale Rd Angaston, a central uplift is present, 50 m above local lows. Until this report, geological studies in this exact area had not deduced an inclusive geological history, as besides the Stockwell and Kitchener faults no other faults are present to account for these hills. In the 1960’s, it was documented that immediately underlying a massive heamatite deposit at Breakneck Hill Rd West is kunkar, which not only underlays but occasionally penetrates the heamatite. Kunkar above the haematite also contains and surrounds isolated iron nodules. Haematite iron deposits do not exist within 25 km, except on these hills, as far as documented. Magnetite iron fragments found above ground nearby are smooth, magnetic, and dark, with 5 mm fusion crust, and are candidates for representing meteorite dispersal fragments. Weathered pieces of putative H chondrite occur alongside the smoothed and fusion crusted pieces. These contain 1 mm presumed Ni-Fe inclusons and 0.l mm inclusions of the same type. On the basis of these observations, it is proposed that the bolide may have been iron-rich, and that vaporisation was incomplete. Determination of the form of target rocks, and the relationship of Kurianda to Crawford and Flaxman will follow, under a model whereby the incident meteor may have been of the “rubble pile” type, breaking up upon entry to the atmosphere.

Aerosols acting as cloud condensation nuclei (CCN) play a fundamental role in droplet formation and cloud development in the atmosphere. Several studies have focused on the representation of aerosol-cloud interactions to improve cloud parametrizations and deep moist convection representation in numerical models. However, the effect of aerosol concentration on mixed-phase clouds is complex as it can not be directly measured and it is far from being fully understood. Then, observation of CCN distributions, variability, and exploration of possible sources can help go deeper into the effects of aerosols on cloud and precipitation processes. From October 2018 to April 2019, Cloud, Aerosol, and Complex Terrain Interactions field campaign (CACTI) took place in central Argentina. An ARM-DOE Mobility Facility was installed in Villa Yacanto, Cordoba to understand the processes affecting orographic deep convective initiation in the region. CCNs in situ observations from a Mobile Aerosol Observation System were analyzed. Amazon biomass burning is one of the known sources of aerosols in central and northern Argentina however during CACTI measurement period low rate emissions were observed from this source. Then, local aerosol source regions were investigated by backward trajectories with lagrangian dispersion model FLEXPART to determine their possible interaction with extreme precipitation events.

In long-established cities such as Detroit, MI, stormwater runoff from impervious surfaces (roads, roofs, etc.) is combined with sanitary waste and piped beneath the city to a wastewater treatment plant. These engineered methods of water management, termed gray infrastructure, currently dominate management practices but have drawbacks due to issues of cost, capacity, reliability, and maintenance requirements. In addition, combined sewer systems in cities like Detroit can become overwhelmed during extreme storm events, requiring the diversion of untreated sewage into local bodies of water. In a world of growing urbanization and intensifying storm events, the development of innovative approaches to stormwater management is expected to play a large role in mitigating negative environmental impacts from polluted urban runoff and flooding. The eco-friendly counterpart of gray infrastructure, known as green infrastructure (green roofs, rain gardens, bioswales, etc.), is an integrated approach to stormwater management that utilizes decentralized infiltration systems to mimic the natural processes of water filtration and deceleration. Correspondingly, our research focuses on a bioswale that was retrofitted into the center island of a previously designed parking lot in the post-industrial urban ecosystem of Detroit. The main goals of our work are to: 1) quantify potential pollutant removal, 2) quantify runoff infiltration capacity, and 3) provide qualitative insight into best management practices for future bioswale retrofits. We collected soil samples from 2 depths (30 and 45 cm) at 9 points from the bioswale for characterization (pH, organic matter, electric conductivity, and texture). We also collected and analyzed undisturbed soil cores with and without added metal contaminants common to Detroit and with a surface addition of biochar to test infiltration and determine the potential of increased contaminant sorption. The results will allow us to advance with an improved design and methodology and convey a strong argument for the expansion of bioswales and other forms of green infrastructure across the greater Detroit area, potentially leading to a more robust system of controlling stormwater that brings aesthetics, health, and a wide array of ecosystem services to a redeveloping concrete jungle.