cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.tdjeor
title: Quantifying spread in spatio-temporal changes of upper-ocean heat 1 content estimates: 2 an internationally coordinated comparison

description: The Earth system is accumulating energy due to human-induced activities. More than 90% of this energy has been stored in the ocean as heat since 1970, with ~64% of that in the upper 700 m. Differences in upper ocean heat content anomaly (OHCA) estimates, however, exist. Here, we evaluate spread in upper OHCA estimates arising from choices in instrumental bias corrections and mapping methods, in addition to theeffect of using a common ocean mask. The same dataset was mapped by six research groups for 1970–2008, with six instrumental bias corrections applied to expendable bathythermograph (XBT) data. We find that use of a common ocean mask may impact estimation of global OHCA by 2–13%. Uncertainty due to mapping method dominatesover XBT bias correction at a global scale and is largest in the Indian Ocean and in the eddy-rich and frontal regions of all basins. Uncertainty due to XBT bias correction is largest in the Pacific Ocean within 30°N–30°S. In both mapping and XBT cases,spread is higher since the 1990s. Important differences in spatial trends among mapping methods are found in the well-observed Northwest Atlantic and the poorly observed Southern Ocean. Although our results cannot identify the best mapping or bias correction schemes, they identify where and when greater uncertainties exist, and so where further refinements may yield the largest improvements. Our results highlightthe need for a future international coordination to evaluate performance of existing mapping methods.
DOI: 10.48577/jpl.0r7ccj
title: A linear relationship between vertical velocity and condensation processes in deep convection

description: Vertical velocities and microphysical processes within deep convection are intricately linked, having wide-ranging impacts on water and mass vertical transport, severe weather, extreme precipitation, and the global circulation. The goal of this research is to investigate the functional form of the relationship between vertical velocity, w, and microphysical processes that convert water vapor into condensed water, M, in deep convection. We examine an ensemble of high-resolution simulations spanning a range of tropical and midlatitude environments, a variety of convective organizational modes, and different model platforms and microphysics schemes. The results demonstrate that the relationship between w and M is robustly linear, with the slope of the linear fit being primarily a function of temperature and secondarily a function of supersaturation. The R2 of the linear fit is generally above 0.6 except near the freezing and homogeneous freezing levels. The linear fit is examined both as a function of local in-cloud temperature and environmental temperature. The results for in-cloud temperature are more consistent across the simulation suite, although environmental temperatures are more useful when considering potential observational applications. The linear relationship between w and M is substituted into the condensate tendency equation and rearranged to form a diagnostic equation for w. The performance of the diagnostic equation is tested in several simulations, and it is found to diagnose the storm-scale updraft speeds to within 1 m s-1 throughout the upper half of the clouds. Potential applications of the linear relationship between w and M and the diagnostic w equation are discussed.
DOI: 10.48577/jpl.hh8gpv
title: A Nitrogen-Rich Atmosphere on Ancient Mars Indicated by Isotopic Evolution

description: Nitrogen's isotopic ratio was the first indicator of substantial atmospheric evolution on Mars and its value has been recently measured with high precision. Loss to space in the sputtering and photochemical processes would have enriched the heavy isotope more than observed, and previous models proposed a massive, multi-bar early \ce{CO2} atmosphere or large recent volcanic outgassing as mitigations. A common feature of these models is that the atmospheric nitrogen has been in a steady state -- loss to space balances outgassing -- from $\sim3$ billion years ago. Here we show a previously unknown family of evolutionary solutions that explain the size and isotopic composition of Mars nitrogen. In this family of ``dynamical'' solutions, the nitrogen is almost never in a steady state, and its partial pressure gradually descends to the present-day value over the past 4 billion years. The dynamical solutions do not require a multi-bar early \ce{CO2} atmosphere and are fully consistent with the amount of volcanic outgassing indicated by both geologic mapping and the atmospheric $^{36}$Ar/$^{38}$Ar ratio. Monte Carlo simulations that include the dynamical solutions indicate that the pressure of \ce{N2} at 3.8 billion years ago was 60 -- 740 mbar (90\% confidence), with 310 mbar being the median value and the spread mostly due to the uncertainty in the sputtering loss rate. Nitrogen thus likely contributed substantially to the warming and the formation of sustained surface melting on early Mars.
DOI: 10.48577/jpl.xmntoi
title: Assessing Planetary Complexity and Potential Agnostic Biosignatures using Epsilon Machines

description: We present a new approach to exoplanet characterization using tech-niques from complexity science, with potential applications to biosig-nature detection. This agnostic method makes use of the temporalvariability of light reected or emitted from a planet. We use a tech-nique known as epsilon machine reconstruction to compute the statisticalcomplexity, a measure of the minimal model size for time series data.We demonstrate that statistical complexity is an e ective measure ofthe complexity of planetary features. Increasing levels of qualitativeplanetary complexity correlate with increases in statistical complexityand Shannon entropy, demonstrating that our approach can identifyplanets with the richest dynamics. We also compare Earth time serieswith Jupiter data, and nd that for the three wavelengths consid-ered, Earth's average complexity and entropy rate are approximately 50% and 43% higher than Jupiter's, respectively. The majority ofschemes for the detection of extraterrestrial life rely upon biochemicalsignatures and planetary context. However, it is increasingly recog-nized that extraterrestrial life could be very di erent to life on Earth.Under the hypothesis that there is a correlation between the pres-ence of a biosphere and observable planetary complexity, our techniqueo ers an agnostic and quantitative method for the measurement thereof.
DOI: 10.48577/jpl.zrievu
title: A Visual Analytics Framework for Distributed Data Analysis Systems

description: This paper proposes a visual analytics frameworkthat addresses the complex user interactions required througha command-line interface to run analyses in distributed dataanalysis systems. The visual analytics framework facilitates theuser to manage access to the distributed servers, incorporate datafrom the source, run data-driven analysis, monitor the progress,and explore the result using interactive visualizations. We providea user interface embedded with generalized functionalities andaccess protocols and integrate it with a distributed analysissystem. To demonstrate our proof of concept, we present two usecases from the earth science and Sustainable Human BuildingEcosystem research domain.
DOI: 10.48577/jpl.afr2ix
title: On the controlling factors for globally extreme humid heat

description: Humid heat presents a major societal challenge through its impacts on human health, energy demand, and economic productivity, underlined by the projected emergence of conditions beyond human tolerance. However, systematic assessment of what drives the most extreme humid heat worldwide has been lacking. Here, we investigate factors determining the location and magnitude of humid-heat extremes, framing our analysis around the four regions with the highest values: the southern Persian Gulf, north-central Pakistan, eastern South Asia, and the western Amazon. We find that strong boundary-layer moisture fluxes, together with stability that inhibits moist convection, explain well the timing and location of near-surface humid-heat extremes. These favorable conditions are achieved through regionally distinct factors, including shallow sea breezes in the Persian Gulf and large-scale subsidence in eastern South Asia. Our results demonstrate some of the principal controls on the most intense humid heat, both globally and for particular regions and heat events.
DOI: 10.48577/jpl.gxdyp9
title: Geomorphological Patterns of Remotely Sensed Methane Hot Spots in the Mackenzie Delta, Canada

description: We studied geomorphological controls on methane (CH4) hotspots in the Mackenzie Delta region in northern Canada using airborne imaging spectroscopy collected as part of the Arctic Boreal Vulnerability Experiment (ABoVE). Methane emissions hotspots were retrieved at ~25 m2 spatial resolution from a ~10,000 km2 AVIRIS-NG survey of the Mackenzie Delta acquired 31 July – 3 August 2017. Separating the region into the permafrost plateau and the lowland delta, we refined the domain wide power law of CH4 enhancements detected as a function of distance to standing water in different ecoregions. We further studied the spatial decay of the distance to water relationship as a function of land cover across the Delta. We show that geomorphology exerts a strong control on the spatial patterns of emissions at regional to sub-regional scales: compared to methane hotspots detected in the upland, we find that methane hotspots detected in the lowland have a more gradual power law curve indicating a weaker spatial decay with respect to distance from water. Spatial decay of CH4 hotspots in uplands is more than 2.5 times stronger than in lowlands, which is due to differences in topography and geomorphological influence on hydrology. We demonstrate that while the observed spatial distributions of CH4 follow expected trends in lowlands and uplands, these quantitatively complement knowledge from conventional wetland and freshwater CH4 mapping and modelling.
DOI: 10.48577/jpl.ewynxu
title: Advances in the application and utility of subseasonal-to-seasonal predictions

description: The subseasonal-to-seasonal (S2S) predictive timescale, encompassing lead times ranging from 2 weeks to a season, is at the frontier of forecasting science. Forecasts on this timescale provide opportunities for enhanced application-focused capabilities to complement existing weather and climate services and products. There is, however, a ‘knowledge-value’ gap, where a lack of evidence and awareness of the potential socio-economic benefits of S2S forecasts limits their wider uptake. To address this gap, here we present the first global community effort at summarizing relevant applications of S2S forecasts to guide further decision-making and support the continued development of S2S forecasts and related services. Focusing on 12 sectoral case studies spanning public health, agriculture, water resource management, renewable energy and utilities, and emergency management and response, we draw on recent advancements to explore their application and utility. These case studies mark a significant step forward in moving from potential to actual S2S forecasting applications. We show that by placing user needs at the forefront of S2S forecast development – demonstrating both skill and utility across sectors – this dialogue can be used to help promote and accelerate the awareness, value and co-generation of S2S forecasts. We also highlight that while S2S forecasts are increasingly gaining interest among users, incorporating probabilistic S2S forecasts into existing decision-making operations is not trivial. Nevertheless, S2S forecasting represents a significant opportunity to generate useful, usable and actionable forecast applications for and with users that will increasingly unlock the potential of this forecasting timescale.
DOI: 10.48577/jpl.guc9ut
title: Mirror-Assisted Self-Injection Locking of Laser to Whispering-Gallery-Mode Microresonator

description: Self-injection locking is a dynamic phenomenon which provides passive stabilization of a laser emission frequency via resonant optical feedback. The stabilization coefficient depends on the level of the feedback and quality factor of the external resonant structure creating the feedback. A conventional self-injection locked laser (SIL) based on a dielectric cavity involves barely tunable resonant Rayleigh scattering (RRS). In this work we study theoretically a scheme of a SIL via a high-Q microresonator with drop-port coupled mirror, in which optical feedback level is optimally adjusted by tuning the drop-port mirror coupling. We show that the additional reflector can improve the laser stabilization and power handling efficiency if compared with the classic RRS-based scheme.
DOI: 10.48577/jpl.powedu
title: Genomic characterization of Parengyodontium torokii sp. nov., a biofilm-forming fungus isolated from Mars 2020 assembly facility

description: A fungal strain (FJII-L10-SW-P1) was isolated from the Mars 2020 spacecraft assembly facility and exhibited biofilm formation on spacecraft-qualified Teflon surfaces. The reconstruction of a five loci gene tree (ITS, LSU, SSU, RPB1 &2, and TEF1) using multi-locus sequence typing (MLST) analyses of the strain FJII-L10-SW-P1 supported a close relationship to other known Parengyodontium album subclade 3 isolates while being phylogenetically distinct from subclade 1 strains. The zig-zag rachides morphology of the conidiogenous cells and spindle-shaped conidia were the distinct morphological characteristics of the P. album subclade 3 strains. The MLST data and morphological analysis supported the conclusion that the P. album subclade 3 strains could be classified as a new species of the genus Parengyodontium and clustered in the family Cordycipitaceae. The name Parengyodontium torokii sp. nov. is proposed to accommodate the strain, with FJII-L10-SW-P1T as the holotype. The genome of the FJII-L10-SW-P1T strain was sequenced, annotated, and the secondary metabolite clusters were identified. Genes predicted to be responsible for biofilm formation and adhesion to surfaces were identified. Homology-based assignment of gene ontologies to the predicted proteome of P. torokii revealed the presence of gene clusters responsible for synthesizing several metabolic compounds, including a cytochalasin that was also verified using traditional metabolomic analysis.
DOI: 10.48577/jpl.6vqbek
title: A repeating fast radio burst source in a globular cluster

description: Fast radio bursts (FRBs) are exceptionally luminous flashes of unknown physical origin,reaching us from other galaxies1. Most FRBs have only ever been seen once, while othersflash repeatedly, though sporadically2,3. Many models invoke magnetically powered neutronstars (magnetars) as the engines producing FRB emission4,5. Recently, CHIME/FRB announcedthe discovery6 of the repeating FRB 20200120E, coming from the direction of thenearby grand design spiral galaxy M81. Four potential counterparts at other observing wavelengthswere identified6 but no definitive association with these sources, or M81, could bemade. Here we report an extremely precise localisation of FRB 20200120E, which allows us toassociate it with a globular cluster (GC) in the M81 galactic system and to place it 2 pc offsetfrom optical center of light of the GC. This confirms6 that FRB 20200120E is 40 times closerthan any other known extragalactic FRB. Because such GCs host old stellar populations, thisassociation strongly challenges FRB models that invoke young magnetars formed in a corecollapsesupernova as powering FRB emission. We propose, instead, that FRB 20200120Eis a highly magnetised neutron star formed via either accretion-induced collapse of a whitedwarf or via merger of compact stars in a binary system7. Alternative scenarios involvingcompact binary systems, efficiently formed inside globular clusters, could also be responsiblefor the observed bursts.
DOI: 10.48577/jpl.tfjeuu
title: Navigating stellar wobbles for imaging with the solar gravitational lens

description: The solar gravitational lens (SGL) offers unique capabilities for direct high-resolution imaging of faint, distant objects, such as exoplanets. For that purpose, in the near future, a spacecraft carrying a meter-class telescope with a solar coronagraph would be placed in the focal region of the SGL. That region begins at ~547~astronomical units from the Sun and occupies the immediate vicinity of the target-specific primary optical axis -- the line that connects the center of the target and that of the Sun. Clearly, this axis is not at rest. It undergoes complex motion as the exoplanet orbits its host star, as that star moves with respect to the Sun, and even as the Sun itself moves with respect to the solar system's barycenter due to the gravitational pull of planets in our solar system. Although less prominent, other motions exist. An image of an extended object is projected by the SGL into an image plane and moves within that plane, responding to the motion of the optical axis. To sample the image, a telescope must always be on the move, following the projection, with precise knowledge of its own position with respect to the image. We consider the dominant motions that determine the position of the focal line as a function of time. We evaluate the needed navigational capability for the telescope to conduct a multiyear exoplanet imaging mission in the focal region for the SGL. We show that even in a rather conservative case, when an Earth-like exoplanet is in our immediate stellar neighborhood at ~10 light years, the motion of the image is characterized by a small total acceleration that is driven primarily by the orbital motion of the exoplanet (estimated to be at the level of 6 um/s^2, decreasing inversely with distance to a target) and by the reflex motion of our Sun (target independent, staying at ~0.2 um/s^2). Such a small acceleration can be maintained for the entire ~10-year duration of a prospective imaging mission with modern electric micropropulsion systems. We conclude that the required navigation in the SGL's focal region, although complex, can be accurately modeled and is achievable with realistic, available propulsion technology.
DOI: 10.48577/jpl.pubcjd
title: Thrust Faulting as the Origin of the Dorsa on the trailing hemisphere of Enceladus

description: Several large ridges, termed dorsa, stand over 800 m above their surroundings in a region centered on the trailing hemisphere of Saturn’s icy moon Enceladus. In map view, these dorsa are linear to curvilinear, 20 km to more than 50 km long, and display nearorthogonal trends. They cross-cut (are younger than) most other geological features in the region. High-resolution limb profiles show the dorsa to be asymmetric in cross-sectioned profile and 5–6 km in width, and high-resolution images show striations along their crests. The structure and morphology of the dorsa suggest they are thrust blocks, possibly analogous to lobate scarps or wrinkle-ridges found on the terrestrial planets. The low slopes of their backlimbs and steeper forelimbs, suggest the dorsa were formed as wrinkle ridges or lobate scarps overlying thrust faults that penetrate 1-4 km deep to a detachment, most likely at the brittle-ductile transition (BDT). Their near-orthogonal trends are consistent with biaxial horizontal shortening. These relationships suggest that the central trailing hemisphere was recently subjected to a relatively high heat flow at the time that deformation occurred.
DOI: 10.48577/jpl.wjsbnh
title: GEOSCAN: Global Earth Observation using Swarm of Coordinated Autonomous Nanosats

description: The climate crisis we are facing calls for significant improvements in our understanding of natural phenomena, with clouds being identified as a dominant source of uncertainty. To this end, the emerging field of 3D computed cloud tomography (CCT) aims to more precisely characterize clouds by utilizing multi-dimensional imaging to reconstruct their outer and inner structure. In this paper, we propose a future Earth observation mission concept, driven by the needs of CCT, that operates constellation of NanoSats to provide multi-angular, spectrally-resolved, spatial and temporal scientific measurements of natural atmospheric phenomena. Our proposed mission, GEOSCAN, will on-board active steering capability to rapidly reconfigure networked swarm of autonomous Nanosats to track evolving phenomena of interest, on-demand, in real-time. We present the structure of the GEOSCAN constellation and discuss details of the mission concept from both science and engineering perspectives. On the science side, we outline the types of remote Earth observation measurements that GEOSCAN enables beyond the state-of-the-art, and how such measurements translate to improvements in CCT that can lead to reduction in uncertainty of the global climate models (GCMs). From the engineering side, we investigate feasibility of the concept starting from hardware components of the NanoSat that form the basis of the constellation. In particular, we focus on the active steering capability of the GEOSCAN with algorithmic approaches that enable coordination from new software. We identify technology gaps that need to be bridged and discuss other aspects of the mission that require in-depth analysis to further mature the concept.
DOI: 10.48577/jpl.6ya30i
title: Reduction in meridional heat export contributes to recent Indian Ocean warming

description: Since 2000, the Indian Ocean has warmed more rapidly than the Atlantic or Pacific. Air-sea fluxes alone cannot explain the rapid Indian Ocean warming, which has so far been linked to an increase in temperature transport into the basin through the Indonesian Throughflow (ITF). Here, we investigate the role that the heat transport out of the basin at 36◦S plays in the warming. Adding the heat transport out of the basin to the ITF temperature transport into the basin, we calculate the decadal mean Indian Ocean heat budget over the 2010s. We find that heat convergence increased within the Indian Ocean over 2000-2019. The heat convergence over the 2010s is the same order as the warming rate, and thus the net air-sea fluxes are near zero. This is a significant change from previous analyses using trans-basin hydrographic sections from 1987, 2002, and 2009, which all found divergences of heat. A two year time series shows that seasonal aliasing is not responsible for the decadal change. The anomalous ocean heat convergence over the 2010s compared to previous estimates is due to changes in ocean currents at both the southern boundary (33%) and the ITF (67%). We hypothesize that the changes at the southern boundary are linked to an observed broadening of the Agulhas Current, implying that temperature and velocity data at the western boundary are crucial to constrain heat budget changes.
DOI: 10.48577/jpl.teugom
title: Using Ensemble Data Assimilation to Explore the Environmental Controls on the Initiation and Predictability of Moist Convection

description: Atmospheric deep moist convection has emerged as one of the most challenging topics for numerical weather prediction, due to its chaotic process of development and multi-scale physical interactions. This study examines the dynamics and predictability of a weakly organized linear convective system using convection permitting EnKF analysis and forecasts with assimilating all-sky satellite radiances from a water vapor sensitive band of the Advanced Baseline Imager on GOES-16. The case chosen occurred over the Gulf of Mexico on 11 June 2017 during the NASA Convective Processes Experiment (CPEX) field campaign.