cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.3xq8hb
title: The End of Galaxy Surveys

description: For nearly a century, imaging and spectroscopic surveys of galaxies have given us information about the contents of the universe and the galaxies themselves. This paper attempts to define the logical endpoint of such surveys by defining not the next galaxy survey, but the final galaxy survey at NIR wavelengths; this would be the galaxy survey that exhausts the information content useful for addressing extant questions. As we show in the paper, such a survey would require incredible advancements in a number of technologies (e.g., telescope apertures, detector properties, pixel count, orbit, and data transmission) and the final details depend on the as yet poorly constrained properties of the earliest galaxies (including their intrinsic brightness and redshift of formation). As such, the details and requirements of the last galaxy surveys are not well defined. However, using an standard exposure time calculator, we define nominal surveys for extracting the useful information for three science cases: dark energy cosmology, galaxy evolution, and supernovae. We show the scaling relations that trade off sky background, telescope aperture, and focal plane size to allow for a survey of a given depth over a given area. We find that for optimistic assumptions, a telescope pf 280m with a marginally resolved focal plane of 20 deg$^2$ operating at L2 and observing at in a single band at $\sim2\mu$m could potentially exhaust the cosmological information content of galaxies in a 10 year survey. For galaxy evolution (making use of gravitational lensing to magnify the earliest galaxies) and SN the same telescope would suffice. We discuss the technological advances that would be needed for such a telescope and a technological advance (placing telescopes $\sim$ 1 AU outside the plane of the Solar System) that could reduce the sky background by a factor of $\sim50$, significantly reducing the required telescope aperture. While the final galaxy survey remains well outside of our technical reach today, we present scaling relations that show how we can progress toward the goal of day exhausting the information content encoded in the shapes, positions, and colors of galaxies.
DOI: 10.48577/jpl.uvxw5w
title: A Simplified Framework for High-Resolution Urban Vegetation Classification with Optical Imagery in the Los Angeles Megacity

description: High spatial resolution maps of Los Angeles, California are needed to capture the heterogeneity of urban land cover while spanning the regional domain used in carbon and water cycle models. We present a simplified framework for developing a high spatial resolution map of urban vegetation cover in the Southern California Air Basin (SoCAB) with publicly available satellite imagery. This method uses Sentinel-2 (10–60 m × 10–60 m) and National Agriculture Imagery Program (NAIP) (0.6 m x 0.6 m) optical imagery to classify urban and non-urban areas of impervious surface, tree, grass, shrub, bare soil/non-photosynthetic vegetation, and water. Our approach was designed for Los Angeles, a geographically complex megacity characterized by diverse Mediterranean land cover and a mix of high-rise buildings and topographic features that produce strong shadow effects. We show that a combined NAIP and Sentinel-2 classification reduces misclassified shadow pixels and resolves spatially heterogeneous vegetation gradients across urban and non-urban regions in SoCAB at 0.6–10 m resolution with 85% overall accuracy and 88% weighted overall accuracy. Results from this study will enable long-term monitoring of land cover change associated with urbanization and quantification of biospheric contributions to carbon and water cycling in cities.
DOI: 10.48577/jpl.9vzk3j
title: A metamorphic origin for Europa's ocean

description: Europa likely contains an iron-rich core. In order for it to have formed, temperatures within Europa reached ≳ 1250 K. At that temperature, accreted chondritic minerals---e.g., carbonates and phyllosilicates---would partially devolatilize. Here, we compute the amounts and compositions of exsolved volatiles. We find that volatiles released from the interior would have carried solutes (including redox-sensitive species), and generated the entirety of Europa's ocean and likely an early CO2 atmosphere. No late delivery of cometary water was necessary. Contrasting with prior work, we find CO2 could be the most abundant solute in the ocean, followed by Ca^2+, SO4^2-, and HCO3^-. However, gypsum precipitation from the seafloor to the ice shell decreases the dissolved S/Cl ratio, such that Cl &gt; S at the shallowest depths, consistent with the recent inference of endogenous chlorides at Europa's surface. Gypsum would form a 3--10 km thick sedimentary layer at the seafloor. The Europa Clipper mission will be able to test these predictions.
DOI: 10.48577/jpl.ce2izv
title: Extreme outliers in lower stratospheric water vapor over North America observed by MLS: Relation to overshooting convection diagnosed from colocated Aqua-MODIS data

description: Convectively injected water vapor (H2O) in the North American (NA) summer lower17most stratosphere results in significant outliers in the 100-hPa H2O measurements from18 the Aura Microwave Limb Sounder (MLS). MLS statistics from 15 years confirm that19 the NA region contains over 60% of global 100-hPa H2O&gt; 12 ppmv, despite having only20 ∼ 1.8% of all MLS observations. A profile sampled in August 2019 stands out, with H2O = 26.3 ppmv,21 far exceeding the prior record and the median ∼ 4.5 ppmv abundance in NA. This par22ticular outlier is associated with a large overshooting convective event (OCE) that spanned23 multiple US states and persisted for several hours. Colocation of the MLS data over NA24 with cloud observations from Aqua’s Moderate Resolution Imaging Spectroradiometer25 reveals the unique character of this case, as only 2.3% of MLS profiles are as close to an26 OCE and only 0.024% of OCEs cover as large an area within a 500 km perimeter of a27 profile.
DOI: 10.48577/jpl.k3brmu
title: Scaling Behavior of a Turbulent Kinetic Energy Closure Scheme for the Stably Stratified Atmosphere: A Steady-State Analysis

description: We present a turbulent kinetic energy (TKE) closure scheme for the stablystratified atmosphere in which the mixing lengths for momentum andheat are not parameterized in the same manner. The key difference is that,while the mixing length for heat tends towards the stability independent mixinglength for momentum in neutrally stratified conditions, it tends towardsone based on the Brunt–V¨ais¨al¨a time scale and square root of the TKE inthe limit of large stability. This enables a unique steady-state solution forTKE to be obtained, which we demonstrate would otherwise be impossibleif the mixing lengths were the same. Despite the model’s relative simplicity,it is shown to perform reasonably well with observational data from the1999 Cooperative Atmosphere-Surface Exchange Study (CASES-99) usingcommonly employed model constants. Analyzing the scaling behavior of thenon-dimensional velocity and potential temperature gradients, or of the stability(correction) functions, reveals that for large stability the present modelscales in the same manner as the first-order operational scheme of Viterboet al. (Quart. J. Roy. Meteor. Soc. 125, 2401–2426, 1999). Alternatively,it appears as a blend of two cases of the TKE closure scheme of Baas etal. (Bound.-Layer Meteor. 127, 17–36, 2008). Critically, because a uniquesteady-state TKE can be obtained, the present model avoids the non-physicalbehavior identified in one of the cases of Baas et al. (2008).
DOI: 10.48577/jpl.xgpj6r
title: Efficient Starshade Retargeting Architecture Using Chemical Propulsion

description: NASA is studying a possible starshade flying in formation with the Nancy Grace Roman Space Tele- scope (Roman). The starshade would perform weeks-long translational retargeting maneuvers between target stars. A retargeting architecture is introduced that is based on chemical propulsion and does not require ground tracking or interactions with the telescope during the retargeting cruise. Feasibility is demonstrated through a covariance analysis of the starshade-telescope relative position over several weeks using realistic sensor and actuator assumptions. Performance is sufficient for Roman to reacquire the starshade after retargeting and the architecture is shown to also be applicable to other mission concepts such as the Habitable Exoplanet Observatory (HabEx). Results are verified through high-fidelity simulations, and driving sources of uncertainty are identified to confirm the robustness of the approach
DOI: 10.48577/jpl.um4x5z
title: The ECCO-Darwin Data-assimilative Global Ocean Biogeochemistry Model: Estimates of Seasonal to Multi-decadal Surface Ocean pCO2 and Air-sea CO2 Flux

description: Quantifying variability in the ocean carbon sink remains problematic due to sparse observations and spatiotemporal variability in surface ocean pCO2. To address this challenge, we have updated and improved ECCO-Darwin, a global ocean biogeochemistry model that assimilates both physical and biogeochemical observations. The model consists of an adjoint-based ocean circulation estimate from the Estimating the Circulation and Climate of the Ocean (ECCO) consortium and an ecosystem model developed by the Massachusetts Institute of Technology Darwin Project. In addition to the data-constrained ECCO physics, a Green’s Function approach is used to optimize the biogeochemistry by adjusting initial conditions and six biogeochemical parameters. Over seasonal to multi-decadal timescales (1995–2017), ECCO-Darwin exhibits broad-scale consistency with observed surface ocean pCO2 and air-sea CO2 flux reconstructions in most biomes, particularly in the subtropical and equatorial regions. The largest differences between CO2 uptake occur in subpolar, seasonally-stratified biomes, where ECCO-Darwin results in stronger winter uptake. Compared to the Global Carbon Project OBMs, ECCO-Darwin has a time-mean, global-ocean CO2 sink (2.47 ± 0.50 Pg C year-1) and interannual variability that are more consistent with interpolation-based products. Compared to interpolation-based methods, ECCO-Darwin is less sensitive to sparse and irregularly-sampled observations. Thus, ECCO-Darwin provides a basis for identifying and predicting the consequences of natural and anthropogenic perturbations to the ocean carbon cycle, as well as the climate-related sensitivity of marine ecosystems. Our study further highlights the importance of physically-consistent, property-conserving reconstructions, as are provided by ECCO, for ocean biogeochemistry studies.
DOI: 10.48577/jpl.vxvy9q
title: Exploring the factors controlling the error characteristics of the Surface Water and Ocean Topography mission discharge estimates

description: The Surface Water and Ocean Topography (SWOT) satellite mission will measure river width, water surface elevation, and slope for rivers wider than 50-100 m. SWOT observations will enable estimation of river discharge using e.g. the Manning-Strickler flow law, complementing the in-situ network of streamgages – if unobserved flow law parameters such as the friction coefficient and river bathymetry can be adequately estimated. Several discharge inversion algorithms designed to compute flow law parameters have been proposed, but to date, a systematic assessment of factors controlling algorithm performance has not been conducted. Here, we assess performance of five discharge inversion algorithms developed for SWOT; algorithm inputs include synthetic SWOT observations produced using hydraulic models, and an a priori estimate of mean annual flow (Qwbm). Considering daily sampling without SWOT measurement error, 4/5 algorithms estimated discharge with median normalized root mean square errors below 60% and correlation coefficient above 0.94, despite high Qwbm biases, which after normalization showed a median value of 46% and ranged from 0.3% to 887%. We find that prior accuracy was an important control on algorithm performance, but algorithm estimates generally improved on the prior. We show for the first time that accuracy and frequency of remote sensing observations are less important than the accuracy of the prior Qwbm, hydraulic variability among reaches, and flow law accuracy, in governing discharge algorithm performance. This study lays the groundwork to develop predictive power of algorithm performance, and thus map global distribution of expected SWOT discharge accuracy.
DOI: 10.48577/jpl.yb7wzs
title: Planning the coverage of planets under geometrical constraints

description: Scheduling the coverage of a planet by scientific instruments on board spacecrafts under observational constraints is central in a significant number of current and future missions for the exploration of the solar system. In this paper, we describe the components and algorithms of a software used to study early-phase mission design or to schedule daily operations of currently in-flight spacecraft. The scheduling problem at hand is usually a large combinatorial problem of which we give a formal model. A discretization process is described and several ordering algorithms are designed and compared. Experiments show that high-quality schedules can be produced by approaches combining reasoning about rolling, coverage and priorities.
DOI: 10.48577/jpl.cp5o2l
title: Solar geoengineering may not prevent strong warming from direct effects of CO2 on stratocumulus cloud cover

description: Discussions of countering global warming with solar geoengineering assume that warming owing to rising greenhouse gas concentrations can be compensated by artificially reducing the amount of sunlight Earth absorbs. However, here we show that solar geoengineering may not be fail-safe to prevent global warming because CO\textsubscript{2} has direct effects on cloud cover: it reduces cloud cover by modulating the longwave radiative cooling within the atmosphere, which is not mitigated by solar geoengineering. We use idealized high-resolution simulations of clouds to show that under a sustained solar geoengineering scenario, the direct CO\textsubscript{2} effects gradually thin subtropical stratocumulus clouds and may eventually lead to their loss at concentrations above 1700~ppm. Because stratocumulus clouds cover large swaths of subtropical oceans and cool Earth by reflecting incident sunlight, their loss would trigger strong (about 5~K) global warming. Thus, the results highlight that, at least in this extreme and idealized scenario, solar geoengineering may be incapable of countering greenhouse-gas driven global warming.
DOI: 10.48577/jpl.vcdkxo
title: An Improved Perturbation Pressure Closure in the Extended EDMF Framework

description: The extended eddy-diffusivity mass-flux (EDMF) framework is developed as a unified parameterization for all subgrid-scale turbulence and convection in global climate models. The prognostic equations for vertical momentum and turbulence kinetic energy (TKE) in the EDMF framework require a consistent closure formulation for perturbation pressure, which has long been a challenge in convective parameterizations. This work derives an analytical solution for the perturbation pressure from idealized 2-D and 3-D rising bubbles. The derivation leads to a new closure, which combines modified pressure drag and virtual mass effects with a new momentum advection term. This momentum advection is an important source at the lower half of the thermal bubble and at cloud base levels in convective systems. It represents the essential physics of the perturbation pressure, that is, to ensure the 3D non-divergent properties of the flow. Moreover, the new formulation modifies the pressure drag to be inversely proportional to updraft depth. This is found to significantly improve simulations of the diurnal cycle of deep convection, without compromising the simulation of shallow convection, and thus is a key step towards a unified scheme. By assuming that the pressure only re-distributes TKE between subdomains, rather than doing work on the grid mean, the velocity pressure-gradient correlation closure is obtained from the perturbation pressure closure. This novel pressure closure is implemented in the extended EDMF, which successfully simulates a rising bubble test case in a single column model.
DOI: 10.6084/m9.figshare.23968212.v1
title: <b>Information Warfare in the Russia-Ukraine War</b>

description: The dataset contains comments extracted from the Weibo accounts of both the Ukrainian embassy and the Russian embassy. These comments cover the time period from February 20 to March 20 in 2022 and the period from February 20 to March 20 in 2023.
DOI: 10.48577/jpl.bzldzz
title: TESS Reveals HD 118203 b to be a Transiting Planet

description: The exoplanet HD 118203 b, orbiting a bright (V = 8.05) host star, was discovered using the radial velocity method by da Silva et al., but was not previously known to transit. Transiting Exoplanet Survey Satellite (TESS) photometry has revealed that this planet transits its host star. Nine planetary transits were observed by TESS, allowing us to measure the radius of the planet to be 1.136 RJ, and to calculate the planet mass to be 2.166 MJ. The host star is slightly evolved with an effective temperature of Teff = 5683 K and a surface gravity of log g = 3.889. With an orbital period of 6.134985 days and an eccentricity of 0.314 ± 0.017, the planet occupies a transitional regime between circularized hot Jupiters and more dynamically active planets at longer orbital periods. The host star is among the 10 brightest known to have transiting giant planets, providing opportunities for both planetary atmospheric and asteroseismic studies.
DOI: 10.48577/jpl.fynnxh
title: Deposition of PFAS 'forever chemicals' on Mt. Everest

description: Mt. Everest, one of the most coveted climbing mountains on earth, also contains the highest altitude chemical contamination on land. We analyzed meltwater and snow samples from the Khumbu Glacier for "forever chemicals" per- and polyfluoroalkyl substances (PFAS) for the first time. Our research team utilized solid-phase extraction (SPE) and liquid chromatography/tandem mass spectrometry in an LC/MS/MS to identify pollutants sampled from Everest Base Camp, Camp 1, Camp 2, and Everest Balcony. From the 14 PFAS compounds tested using the EPA Method 537.1, we found PFOS, PFOA, and PFHxA in Mt. Everest snow and meltwater. The highest concentrations found were 34.5 ng/L and 18.7 ng/L at Base Camp and Camp 2, respectively; however, PFAS species were also found within one order of magnitude in all sampling sites with detection, suggesting a ubiquitous presence on the mountain. The relatively high levels of PFAS in the near environment indicate loss from the gear used by trekkers, as the concentrations are higher than background levels from atmospheric deposition. While providing only a one-season fingerprint for pollutants on Mt. Everest these are the highest PFAS samples ever retrieved, with concentrations indicating the need for further sampling to determine human health risk.
DOI: 10.48577/jpl.quvqao
title: The CARMENES search for exoplanets around M dwarfs - LP 714-47 b (TOI 442.01): populating the Neptune desert

description: We report the discovery of a Neptune-like planet (LP 714-47 b, mb = 30.8 ± 1.5 M⊕ , Rb = 4.7 ± 0.3 R⊕ ) located in the “hot Nep- tune desert.” The confirmation of the TESS Object of Interest (TOI 442.01) was achieved with radial-velocity follow-up using CARMENES, ESPRESSO, Keck/HIRES, iSHELL, and PFS, as well as from photometric data using TESS, Spitzer, and ground- based photometry from MuSCAT2, TRAPPIST-South, MONET-South, the George Mason University telescope, the Las Cumbres Observatory Global Telescope network, the El Sauce telescope, the TÜB ̇ITAK National Observatory, the University of Louisville Manner Telescope, and WASP-South. We also present high-spatial resolution adaptive optics imaging with the Gemini Near-Infrared Imager. The low uncertainty in the mass and radius determination place LP 714-47 b among the physically well characterised plan- ets, allowing for a meaningful comparison with planet structure models. The host star LP 714-47 is a slowly rotating early M dwarf (Teff = 3950 ± 51 K) with a mass of 0.59 ±0.02 M⊙ and a radius of 0.58 ±0.02 R⊙. From long-term photometric monitoring and spec- troscopic activity indicators, we determine a stellar rotation period of about 33 d. The stellar activity is also manifested as correlated noise in the radial velocity data. In the power spectrum of the radial velocity data we detect a second signal with a period of 16 days in addition to the 4-day signal of the planet. This could be a harmonic of the stellar rotation period or the signal of a second planet. It may be possible to tell the difference after more TESS data and radial-velocity data are obtained.
DOI: 10.48577/jpl.dt8kmp
title: Titan's Interior structure and dynamics after the Cassini/Huygens mission

description: The Cassini-Huygens mission that explored the Saturn system during the period 2004-2017, revolutionized our understanding of Titan, the only known moon with a dense atmosphere and the only body, besides Earth, with surface liquids. Its predominantly nitrogen atmosphere also contains a few percent of methane that is photolyzed on short geological timescales to form ethane and more complex organic molecules, and 40Ar, the decay product of 40K. The presence of these two compounds argue for the interior-surface exchange processes. Here we review the information that constrains Titan’s interior structure. Gravity and orbital data suggest that Titan is an ocean world, which implies differentiation into a hydrosphere and a rocky core. The mass and gravity data complemented by equations of state constrain the ocean density and composition as well as the hydrosphere thickness. We present end-member models, review the dynamics of each layer, and discuss the global evolution consistent with orbital data.