cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.ypta7j
title: Draft genome sequences of Aspergillus and Penicillium species isolated from the International Space Station and Crew Resupply Vehicle Capsule

description: The draft whole-genome sequences (WGS) of 30 fungal strains isolated from the International Space Station and belonging to Penicillium and Aspergillus genera were assembled. The WGS will allow for detailed genomic characterization to determine the possible applications and importance for space and biotechnological industries.
DOI: 10.48577/jpl.ech7dm
title: Characterizing methane emission hotspots from thawing permafrost

description: Methane (CH4) emissions from climate-sensitive ecosystems within the northern permafrost region represent a potentially large but highly uncertain source, with current estimates spanning a factor of seven (11 – 75 Tg CH4 yr-1). Accelerating permafrost thaw threatens significant increases in pan-Arctic CH4 emissions, amplifying the permafrost carbon feedback. We used airborne imaging spectroscopy with meter-scale spatial resolution and broad coverage to identify a previously undiscovered CH4 emission hotspot adjacent to a thermokarst lake in interior Alaska. Hotspot emissions were confined to &lt; 1% of the 10 ha lake study area. Ground-based chamber measurements confirmed average daily fluxes from the hotspot of 1,170 mg CH4 m-2 d-1, with extreme daily maxima up to 24,200 mg CH4 m-2 d-1. Ground-based geophysical measurements revealed thawed permafrost directly beneath the CH4 hotspot, extending to a depth of ~15 m, indicating that the intense CH4 emissions likely originated from recently thawed permafrost. Hotspot emissions accounted for ~40% of total diffusive CH4 emissions from the lake study site. Combining study site findings with hotspot statistics from our 70,000 km2 airborne survey across Alaska and northwestern Canada, we estimate that pan-Arctic terrestrial thermokarst hotspots currently emit 1.1 (0.1 – 5.2) Tg CH4 yr-1, or roughly 4% of the annual pan-Arctic wetland budget from just 0.01% of the northern permafrost land area. Our results suggest that significant proportions of pan-Arctic CH4 emissions originate from disproportionately small areas of previously undetermined thermokarst emissions hotspots, and that pan-Arctic CH4 emissions may increase non-linearly as thermokarst processes increase under a warming climate
DOI: 10.48577/jpl.lgyt4w
title: Aboveground biomass distributions and vegetation composition changes in Louisiana’s Wax Lake Delta

description: The Wax Lake Delta (WLD) is an actively prograding delta in the Mississippi River Delta Plain that is otherwise experiencing widespread degradation and submergence of its coastal wetlands. The WLD is actively accumulating mineral and organic sediment that increases soil surface elevation, changing emergent wetland communities as the young delta develops. There is uncertainty in how the dynamics of community composition respond to net changes in soil elevation and determine aboveground biomass and carbon storage. This study utilizes high resolution imaging spectrometer data captured on October 17, 2016, to map the delta’s dominant vegetation species and wetland types. We validated this vegetation map (overall accuracy = 77.62%, Kappa = 0.72) and compared it with a published species map that used WorldView-2 data collected five years earlier on October 16, 2011. This allowed us to map changes resulting from five years of delta development to determine changes in wetland forest species (Salix nigra), two dominant herbaceous wetland species (Colocasia esculenta and Polygonum punctatum), and various grass species. Results show an increase in C. esculenta and a marginal increase in forested wetlands (S. nigra). C. esculenta’s expansion occurred largely from the delta island heads toward the fringes into wetland area previously occupied by P. punctatum, which saw a corresponding decline. Additionally, this study leveraged these species distributions with a published aboveground biomass (AGB) dataset to examine the dominant plant types’ growth patterns across elevational gradients. We characterized variability in AGB by marsh platform elevation and across different elevational zones categorized by hydroperiod, or hydrogeomorphic zones. We found that the herbaceous plant species peak in AGB in the low intertidal zone and decrease with elevation before increasing slightly in the higher elevations, consistent with previous field-based mesocosm experiments for C. esculenta. With vegetation distributions, succession, and growth patterns in the WLD characterized, this study may inform future restoration efforts throughout the Mississippi River Delta Plain regarding the changing vegetation composition that may emerge following changes in surface elevation with sediment deposition.
DOI: 10.48577/jpl.79upje
title: Physical and Chemical Structure of the Disk and Envelope of the Class 0/I protostar L1527

description: Sub-millimeter spectral line and continuum emission from the protoplanetary disks and envelopes of protostars are powerful probes of their structure, chemistry, and dynamics. Here we present a benchmark study of our modeling code, RadChemT, that for the first time uses a chemical model to reproduce ALMA C18O (2-1) and CARMA 12CO (1-0), and N2H+ (1-0) observations of L1527, that allow us to distinguish the disk, the infalling envelope and outflow of this Class 0/I protostar. RadChemT combines dynamics, radiative transfer, gas chemistry and gas-grain reactions to generate models which can be directly compared with observations for individual protostars. Rather than individually fit abundances to a large number of free parameters, we aim to best match the spectral line maps by (i) adopting a physical model based on density structure and luminosity derived primarily from previous work that fit SED and 2D imaging data, updating it to include a narrow jet detected in CARMA and ALMA data near (≤ 75au) the protostar, and then (ii) computing the resulting astrochemical abundances for 292 chemical species. Our model reproduces the C18O and N2H+ line strengths within a factor of 3.0; this is encouraging considering the pronounced abundance variation (factor &gt; 103) between the outflow shell and CO snowline region near the midplane. Further, our modeling confirms suggestions regarding the anti- correlation between N2H+ and the CO snowline between 400 au to 2,000 au from the central star. Our modeling tools represent a new and powerful capability with which to exploit the richness of spectral line imaging provided by modern submillimeter interferometers.
DOI: 10.48577/jpl.ebxcpg
title: Surface texture optimization of Ti-6Al-4V AM-built components for biomedical applications

description: Additive Manufacturing (AM) is gaining traction in the production of medical devices due to its ability to generate patient-matched parts with irregular geometries and/or dimensions designed for a specific patient's anatomy. Nevertheless, AM-built parts have the inherent characteristic of as-printed rough surfaces, packed with surface and near-surface defects. Common surface defects found on AM surfaces are partially melted/sintered powder, v-notches, remnants of melt pools (fish scaling), and remaining support structures, all of which can cause undesirable effects. For example, deep valleys on the surface can be a host of corrosion sites associated with fretting, crevice corrosion, and pitting corrosion. Partially attached/sintered powder at the surface causes cleanliness problems on the component if not eliminated during post-processing, and loose powder can leach out of the component once it is fully implanted. Likewise, the presence of high surface roughness and deep notches compromises the mechanical properties of the as-built components and can lead to detrimental effects especially on fatigue properties. Moreover, the sub-surface porosity often found near the surface caused by non-optimized process parameters on the hatching and contour scans can reduced the components' performance. One way to improve the mechanical performace of AM-built medical components to meet industry standards is to improve their as-printed surfaces. However, due to the complexity of some AM-built parts, traditional surface finishing methods cannot be considered. This paper will review and discuss the surface features associated with early fatigue failures on AM-built components, and surface finishing techniques that can be employed to overcome these challenges. The surface texture improvement via a combination of surface finishing methods was studied on Ti-6Al-4V built by powder bed fusion. Tensile strength and high cycle fatigue experiments were performed at different surface finishing levels to understand the implications of the surface texture on the mechanical performance of the AM-built Ti-6Al-4V components.
DOI: 10.48577/jpl.t0rdos
title: The Enceladus Orbilander Mission Concept: Balancing Return and Resources in the Searth for Life

description: Enceladus' long-lived plume of ice grains and water vapor makes accessing oceanic material readily achievable from orbit (around Saturn or Enceladus) and from the moon's surface. In preparation for the National Academies of Sciences, Engineering and Medicine 2023-2032 Planetary Science and Astrobiology Decadal Survey, we investigated four architectures capable of collecting and analyzing plume material from orbit and/or on the surface to answer the most pressing science questions at Enceladus: Is the subsurface ocean inhabited? Why or why not? Trades specific to those four architectures were studied to allow an evaluation of the science return with respect to investment. The team found that Orbilander, a mission concept that would first orbit and then land on Enceladus, represented the best balance. Orbilander was thus studied at a higher fidelity, including more detailed science operations plan during both orbital and landed phases, landign site characterization and selection analyses, and landing procedures. The Orbilander mission concept demonstrates that scientifically compelling but resource conscious Flagship-class missions can be executed in the next decade to search for life at Enceladus.
DOI: 10.48577/jpl.kpdery
title: Quantitative, compositional analysis of trace amino acids in icy moon analogues with a microcapillary electrophoresis laser-induced fluorescence detection system

description: Enceladus’s jet activity, Europa’s putative plume activity, and the evidence supporting global subsurface oceans have made them high-priority targets for future NASA missions. In situ analysis of organic molecules in the jets/plumes or subsurface oceans of these icy moons would provide relevant, detailed information on formation, habitability, and on-going planetary processes of celestial bodies and could provide the first evidence of the potential for extant life beyond Earth. Microcapillary electrophoresis with laser-induced fluorescence (µCE-LIF) enables highly-sensitive, automated, quantitative, compositional analysis of organic molecule monomers and short polymers and can achieve a sub-parts-per-trillion limit of detection. Portable Mars Organic Analyzer prototypes have been built and field tested and the Enceladus Organic Analyzer and Microfabricated Organic Analyzer for Biosignatures prototypes are under development as potential instruments for missions to Enceladus or Europa. Here, high-resolution separations of amino acids contained within icy moon analogue solutions of sulfuric acid, carbonic acid, sodium carbonate, and magnesium sulfate were obtained using a benchtop µCE-LIF system. Separations were improved by dilution, pH regulation, and chelation of cations with EDTA. Also, a sample taken from Champagne Geyser, a CO2-driven geyser at Chaffin Ranch, Utah, was analyzed for amino acids and found to contain leucine, valine, serine, alanine, and glycine. Alanine and glycine were quantified via a standard curve at 80.1 ± 0.8 µM and 900 ± 100 nM, respectively. This work represents a significant step forward for the liquid-based µCE-LIF analysis of small organic molecules and biopolymers for future space missions to icy bodies like Enceladus and Europa.
DOI: 10.48577/jpl.qeyhlb
title: The Double Asteroid Redirection Test (DART): Planetary Defense Investigations and Requirements

description: The Double Asteroid Redirection Test (DART) is a kinetic impactor mission, designed to demonstrate that mitigation technique on (65803) Didymos I Dimorphos, the secondary of the (65803) Didymos system. DART has four Level-1 Requirements to meet in order to declare mission success: (1) impacting Dimorphos in September–October 2022, (2) causing at least a 73-second change in its binary orbit period via the impact, (3) measuring the change in binary period to an uncertainty of 7.3 seconds or less, and (4) measuring the momentum transfer efficiency (of the impact and characterizing the resulting effects of the impact. The data necessary to achieve these requirements will be obtained and analyzed by the DART Investigation Team. We discuss the rationales for the data to be gathered, the analyses to be undertaken, and how mission success will be achieved.
DOI: 10.48577/jpl.psaa5g
title: Successes and challenges of factor analysis/target transformation application to visible-to-near-infrared hyperspectral data

description: We designed a laboratory visible-to-near-infrared (VNIR) hyperspectral experiment to test the effectiveness of factor analysis/target transformation for detecting minerals mixed with Mars Global Simulant-1 (MGS-1). The purpose of this experiment is to test for true positive, true negative, false positive, and false negative results from application of factor analysis/target transformation methods and determine the parameters that dictate good versus bad algorithm performance. Gypsum, calcite, montmorillonite, nontronite, and kaolinite were each mixed with MGS-1 at abundances of 1%, 2.5%, 5%, 10%, 20%, and 50%. The mixtures were placed in 2.5×2.5×1 cm sample trays and imaged using a Headwall Imaging Spectrometer with a spectral range of 0.9-2.6 µm, 8.98 nm spectral sampling, and 0.34 mm/pixel spatial resolution. These images include thousands to tens of thousands of hyperspectral pixels covering each individual mixture tray. Full-image factor analysis/target transformation (FA/TT) and Dynamic Aperture Factor Analysis/Target Transformation (DAFA/TT) were applied to these data to detect the minerals mixed with MGS-1. The results demonstrate that factor analysis/target transformation is prone to both false positive and false negative detections, but in certain applications—including DAFA/TT—it can be useful for highlighting spectrally interesting areas in hyperspectral images for follow-up investigation. The results presented here demonstrate that applications of factor analysis/target transformation to VNIR hyperspectral datasets should be used to highlight small outcrops and/or weak spectral signals in pixels for follow-up investigation. This emphasizes the need for supporting evidence to be obtained—in addition to factor analysis/target transformation—before interpretations of planetary surface processes should be made.
DOI: 10.48577/jpl.rbkcrg
title: ECOSTRESS and CIMIS: A Comparison of Potential and Reference Evapotranspiration in Riverside County, California

description: The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) provides remotely-sensed estimates of plant water use, demand, and stress at 70 m spatial resolution every 1–5 days, sampling across the diurnal cycle. This study, in partnership with an operational water management institution, the Eastern Municipal Water District (EMWD) in Southern California, was conducted to evaluate estimates of evapotranspiration under ideal conditions where water is not limited. EMWD regularly uses a ground-based network of reference evapotranspiration (ETo) estimates from the California Irrigation Management Information System (CIMIS), yet there are gaps in spatial coverage and questions of spatial representativeness and consistency. Space-based potential evapotranspiration (PET) estimates, such as those from ECOSTRESS, provide consistent spatial coverage. We compared ECOSTRESS ETo (estimated from PET) to CIMIS ETo at five CIMIS sites in Riverside County, California from July 2018–June 2020. We found strong correlations between CIMIS ETo and ECOSTRESS ETo across all five sites (R2 = 0.89, root mean square error (RMSE) = 0.11 mm hr−1). Both CIMIS and ECOSTRESS ETo captured similar seasonal patterns through the study period as well as diurnal variability. There were site-specific differences in the relationship between ECOSTRESS AND CIMIS, in part due to spatial heterogeneity around the station site. Consequently, careful examination of landscapes surrounding CIMIS sites must be considered in comparisons. These results indicate that ECOSTRESS successfully retrieves PET that is comparable to ground-based reference ET, highlighting the potential for providing observation-driven guidance for irrigation management across spatial scales.
DOI: 10.48577/jpl.ssrbxp
title: An Assessment of Regional ICESat-2 Sea Level Trends

description: Global sea level rise is an important indicator of ongoing climate change and well observed by satellite radar altimetry. However, observations from conventional altimetry degrade at the coast where regional sea level changes can deviate from open ocean sea level changes. Tide gauges have historically filled this gap, providing important measurements of coastal sea level, but nevertheless undersampling dynamic coastal environments. With the launch of the laser altimeter onboard ICESat-2 in 2018, new high-resolution observations of ice, land, and ocean elevations are available. Here we assess the potential benefits of sea level measured by ICESat-2 by comparing to observations from Jason-3 and hourly tide gauges. We find agreement in the linear rates computed from the independent data sources. The recent La Niña is clearly evident in ICESat-2 observations, as well as small-scale features. By demonstrating the quality of the ICESat-2-measured sea level, we provide support for integrating it into the existing suite of sea-level observations. As the time-series lengthens in the coming years, it can serve as an important tool for coastal communities addressing ongoing sea-level rise.
DOI: 10.48577/jpl.pfedev
title: Improvements in cloud and water vapor simulations over the tropical oceans in CMIP6 compared to CMIP5

description: Clouds and water vapor are among the most difficult quantities for global climate models to simulate because they are affected by physical processes that operate over scales unresolved by current climate models. We use NASA satellite data to assess the representation of clouds and water vapor structures in 27 climate models that participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6). Each model is assigned numerical scores based on its performance in simulating spatial mean, variance and pattern correlation of multi-year mean clouds and water vapor structures in lower, middle, and upper troposphere and near the tropopause over tropical oceans. We find measurable improvements in CMIP6 models relative to CMIP5 models for both clouds and water vapor. The differences between models and satellite observations and the spread across the models are reduced. In addition, we find that the models’ equilibrium climate sensitivity (ECS) is correlated with overall performance scores for both CMIP5 and CMIP6 models, with a weaker correlation in CMIP6, suggesting that the models that capture better tropical clouds and water vapor distributions tend to have higher ECS. The physical processes responsible for the apparent correlation between ECS and model performance score warrant further study.
DOI: 10.48577/jpl.t6m3rv
title: The Surface Energy Budget at Gale Crater during the first 2500 sols of the Mars Science Laboratory mission

description: We use in situ environmental measurements by the Mars Science Laboratory (MSL) mission to obtain the surface energy budget (SEB) across Curiosity’s traverse during the first 2500 sols of the mission. This includes values of the downwelling shortwave solar radiation, the upwelling solar radiation reflected by the surface, the downwelling longwave radiation from the atmosphere, the upwelling longwave radiation emitted by the surface, the sensible heat flux associated with turbulent motions, and the latent heat flux associated with water phase changes. We then analyze their temporal variation on different timescales and relate this to the mechanisms causing these variations. Through its Rover Environmental Monitoring Station, MSL allows for a more accurate determination of the SEB than its predecessors on Mars. Moreover, the unprecedented duration, cadence and frequency of MSL environmental observations allow for analyses of the SEB from diurnal to interannual timescales. The results presented in this article can be used to evaluate the consistency with predictions from atmospheric numerical models, to validate aerosol radiative properties under a range of dust conditions, to understand the energy available for solar-powered missions, and to enable comparisons with measurements of the SEB by the Perseverance rover at Jezero crater.
DOI: 10.48577/jpl.xyhogh
title: CYGNSS Ocean Surface Wind Validation in the Tropics

description: Surface wind plays a crucial role in many local/regional weather and climate processes,26 especially through the exchanges of energy, mass and momentum across the Earth’s surface.27 However, there is a lack of consistent observations with continuous coverage over the global28 tropical ocean. To fill this gap, the NASA Cyclone Global Navigation Satellite System29 (CYGNSS) mission was launched in December 2016, consisting of a constellation of eight small30 spacecrafts that remotely sense near surface wind speed over the tropical and sub-tropical oceans31 with relatively high sampling rates both temporally and spatially. This current study uses data32 obtained from the Tropical Moored Buoy Arrays to quantitatively characterize and validate the33 CYGNSS derived winds over the tropical Indian, Pacific, and Atlantic Oceans. The validation34 results show that the uncertainty in CYGNSS wind speed, as compared with these tropical buoy35 data, is less than 2 m s-1 root mean squared difference, meeting the NASA science mission36 Level-1 uncertainty requirement for wind speeds below 20 m s-1. The quality of the CYGNSS wind is further assessed under different precipitation conditions, and in convective cold-pool38 events, identified using buoy rain and temperature data. Results show that CYGNSS winds39 compare fairly well with buoy observations in the presence of rain, though at low wind speeds40 the presence of rain appears to cause a slight positive wind speed bias in the CYGNSS data. The41 comparison indicates the potential utility of the CYGNSS surface wind product, which in turn42 may help to unravel the complexities of air-sea interaction in regions that are relatively under43sampled by other observing platforms.
DOI: 10.48577/jpl.ptyf88
title: Open science: Open data, open models, ...and open publications?

description: This commentary explores the challenges and opportunities associated with a possible transition of Water Resources Research to a publication model where all articles are freely available upon publication (“Gold” open access). It provides a review of the status of open access publishing models, a summary of community input, and a path forward for AGU leadership. The decision to flip to open access is framed by a mix of finances and values. On the one hand, the challenge is to define who pays, and how, and what can we do to improve the affordability of publishing. On the other hand, the challenge is to increase the extent to which science is open and accessible. The next steps for the community include an incisive analysis of the financial feasibility of different cost models, and weighing this financial feasibility against the desire to advance open science.