cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.npoegg
title: Extending the Atmospheric River Concept to Aerosols: Climate and Air Quality Impacts

description: (ARs) construct to analyze aerosol atmospheric rivers(AARs) and consider their impacts. More specifically, our study is the first to develop anobjective global algorithm for detecting AARs, develop a climatology of AARs, show theircontributions to major global aerosol transport pathways, and illustrate how AAR events candrive extreme cases of poor air quality conditions. Our methodology and analysis separatelyaccount for dust (DU), carbonaceous (CA, accounting for organic and black carbon separatelywhere appropriate), sea salt (SS) and sulfate (SU) aerosols. For each of these aerosol species,there are long-range regional transport pathways with AARs accounting for a sizable fraction(40-80%) of the annual total transport in relatively few events (20-40 AAR days/year). Theclimatological results show that DU AARs mostly originate from desert areas, SS AARs aremostly present over the oceanic regions, whereas CA AARs are more frequent over theNorthern Hemisphere and often extend from tropical forests. This study also highlights theimportance of the source-receptor relationships between the emission sources and AARdrivenair quality impacts over the receptor regions. Examples include a CA AAR over SouthAmerica that impacted visibility and air quality over São Paulo as well as a recent DU AARover the tropical Atlantic, the so-called “Godzilla” dust storm, that increased the aerosoloptical thickness measured at an AERONET station in Tallahassee, Florida from 0.2 to 1.4.
DOI: 10.48577/jpl.r1hrsg
title: Assessment of Forest Biomass Estimation from Dry and Wet SAR Acquisitions Collected during the 2019 UAVSAR AM-PM Campaign in Southeastern United~States

description: Forest above-ground biomass (AGB) estimation from SAR backscatter is affected by varying imaging and environmental conditions.~This paper quantifies and compares the performance of forest biomass estimation from L-band SAR backscatter measured selectively under dry and wet conditions during the 2019 AM-PM NASA airborne campaign.~Seven Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) images acquired between June and October 2019 over a temperate deciduous forest in Southeastern United States with varying moisture and precipitation conditions are examined in conjunction with LIDAR and field measurements. Biomass~is estimated by fitting a 3-parameter modified Water Cloud Model (WCM) to radiometric terrain corrected SAR backscatter. Our experiment is designed to quantify the biomass estimation errors when biomass models are calibrated and validated on varying acquisition conditions (dry or wet). Multi-temporal~estimation strategies are also evaluated and compared with single-acquisition estimation approaches.~As~an outcome, the experiment shows that the WCM model calibrated and validated on single acquisitions adapts to different soil moisture conditions with RMSD up to 18.7 Mg/ha.~The AGB estimation performance, however, decreases with RMSD upwards of 30~Mg/ha when the model is cross-validated on moisture and precipitation conditions different than the calibration conditions. Results confirm that calibrating the model over the multi-temporal data using averaged backscatter or weighted combinations of individual AGB estimates, improves the biomass estimation accuracy up to about 20\% at L-band. This study helps design biomass cal/val procedures and biomass estimation algorithms for dense time-series to be collected by low-frequency radar missions such as NASA-ISRO SAR (NISAR) and BIOMASS.
DOI: 10.48577/jpl.ev2gvo
title: Mycorrhizal distributions impact global patterns of carbon and nutrient cycling

description: Most tree species predominantly associate with a single type of mycorrhizal fungi. Because of the principle differences in mycorrhizal associations, they can differentially affect plant nutrient acquisition and biogeochemical cycling. Here, we use the updated carbon-nitrogen economics within the Community Land Model version 5 (CLM5) to evaluate the impact of mycorrhizal association on the global nitrogen and carbon cycles. Different spatial distributions of plant mycorrhizal associations lead to clear differences in present day Net Primary Productivity by up to 345  21 TgCyr-1, owing to the impacts of different symbioses on carbon costs of nitrogen acquisition (4.3% more costly than those originally proposed on average). Simulated global NPP increased throughout the 21st century by 20%, while the carbon costs of nitrogen acquisition have increased at a faster rate by 50%. This suggests that nutrient acquisition will increasingly demand a higher portion of assimilated carbon to support the same productivity.
DOI: 10.48577/jpl.ne72ov
title: Flying Commercial Satellite Technology to a Metal World in the Asteroid Belt

description: IEEE Spectrum Magazine article doesn't have an abstract or introduction. Please see the article file.
DOI: 10.48577/jpl.hexd8z
title: Observational constraints on the response of high-latitude northern forests to warming

description: 31 Since the 1960s, carbon cycling in the high-latitude northern forest (HLNF) has experienced32 dramatic changes: most of the forest is greening and net carbon uptake from the atmosphere has33 increased. During the same time period, the CO2 seasonal cycle amplitude (SCA) has increased by34 ~50% or more. Disentangling complex processes that drive these changes has been challenging.35 In this study, we substitute spatial sensitivity to temperature for time to quantify the impact of36 temperature increase on Gross Primary Production (GPP), total ecosystem respiration (TER), the37 fraction of Photosynthetic Active Radiation (fPAR), and the resulted contribution of these changes38 in amplifying the CO2 SCA over the HLNF since 1960s. We use the spatial heterogeneity of GPP39 inferred from solar-induced chlorophyll Fluorescence in combination with net ecosystem40 exchange (NEE) inferred from column CO2 observations made between 2015 and 2017 from41 NASA’s Orbiting Carbon Observatory -2. We find that three quarters of the spatial variations in42 GPP can be explained by the spatial variation in the growing season mean temperature (GSMT).43 The long term hindcast captures both the magnitude and spatial variability of the trends in observed44 fPAR. We estimate that between 1960 and 2010, the increase in GSMT enhanced both GPP and45 the SCA of NEE by ~20%. The calculated enhancement of NEE due to increase in GSMT46 contributes 56–72% of the trend in the CO2 SCA at high latitudes, much larger than simulations47 by most biogeochemical models.
DOI: 10.48577/jpl.hujacv
title: Beyond Ecosystem Modeling: A Roadmap to Community Cyberinfrastructure for Ecological Data-Model Integration

description: In an era of rapid global change, our ability to understand and predict Earth's natural systems is lagging behind our ability to monitor and measure changes in the biosphere. Bottlenecks to informing models with observations have reduced our capacity to fully exploit the growing volume and variety of available data. Here, we take a critical look at the information infrastructure that connects ecosystem modeling and measurement efforts, and propose a roadmap to community cyberinfrastructure development that can reduce the divisions between empirical research and modeling and accelerate the pace of discovery. A new era of data‐model integration requires investment in accessible, scalable, transparent tools that integrate the expertise of the whole community, including both modelers and empiricists. This roadmap focuses on five key opportunities for community tools: the underlying foundationsof community cyberinfrastructure; data ingest; calibration of models to data; model‐data benchmarking; and data assimilation and ecological forecasting. This community‐driven approach is key to meeting the pressing needs of science and society in the 21st century.
DOI: 10.48577/jpl.na1kan
title: The TESS Objects of Interest Catalog from the TESS Prime Mission

description: We present 2241 exoplanet candidates identified with data from the Transiting Exoplanet Survey Satellite (TESS) during its two-year prime mission. We list these candidates in the TESS Objects of Interest (TOI) Catalog, which includes both new planet candidates found by TESS and previously- known planets recovered by TESS observations. We describe the process used to identify TOIs and investigate the characteristics of the new planet candidates, and discuss some notable TESS planet discoveries. The TOI Catalog includes an unprecedented number of small planet candidates around nearby bright stars, which are well-suited for detailed follow-up observations. The TESS data products for the Prime Mission (Sectors 1–26), including the TOI Catalog, light curves, full-frame images, and target pixel files, are publicly available on the Mikulski Archive for Space Telescopes.
DOI: 10.48577/jpl.au2uux
title: Application of topological data analysis to comparing aerosol optical depth map

description: Topological data analysis (TDA) combines concepts from algebraic topology, machine learning, statistics, and data science that allows us to study data in terms of their latent shape properties. Despite the of TDA in a broad range of applications, from neuroscience to power systems to finance, the utility of TDA in the Earth Science applications is yet untapped. The current study aims to offer a new direction to analysis of multi-resolution Earth science data using the concept of data shape and the associated intrinsic topological data characteristics. In particular, we develop a new topological approach for multi-resolution data matching and evaluation of the associated impact of spatial scale on the derived conclusions. We illustrate the proposed new methodology in application to the aerosol optical depth (AOD) datasets from the Goddard Earth Observing System, Version 5 (GEOS-5) model over the Middle East. Our results show that contrary to the existing approaches, TDA allows for systematic and reliable comparison of spatial patterns from various observational and model datasets without regridding the datasets into common grids.
DOI: 10.48577/jpl.ilyr5t
title: The Origins Survey Spectrometer (OSS): revealing the hearts of distant galaxies and forming planetary systems with far-IR spectroscopy.

description: Abstract. The Origins Survey Spectrometer (OSS) is a multi-purpose far-IR spectrograph for Origins. Operating at the photon background limit, OSS covers the 25 to 588 micron wavelength range instantaneously at a resolving power (R) of 300 using six logarithmically-spaced grating modules. Each module couples at least 30 and up to 100 spatial beams simultaneously, enabling true (3D) spectral mapping. In addition, OSS provides two high-resolution modes. The first inserts a long-path Fourier-transform interferometer (FTS) into a portion of the incoming light in advance of the grating backends, enabling R up to 43,000 x [λ/112 μm], while preserving the grating-based sensitivity for line detection. The second incorporates a scanning etalon in series with the FTS to provide R up to 300,000 for the 100–200 μm range.
DOI: 10.48577/jpl.lcg6rr
title: Pluto in Glory: Discovery of its Huge Opposition Surge

description: Observations of the Pluto Charon system were captured with the Palomar High Angular Resolution Observer (PHARO) adaptive optics system on the 200-inch Hale telescope during the historically small solar phase angles in 2018-2019. Both objects exhibit large opposition surges of ~30-35% in the last half degree of solar phase angle, which is larger than that observed for icy moons and other Kuiper Belt Objects. The size of the surge may be due to a unique surface texture caused by ongoing geologic processes or active volatile transport. These observations enable accurate determination of Pluto’s geometric albedo in the JHK filter system, which we find to be 0.84±0.04, 0.59±0.05, and 0.40±0.04 for Pluto, respectively, and 0.68±0.03 for Charon in the J-filter.
DOI: 10.48577/jpl.yhjtbp
title: Astrodynamics Committee Highlights for 2020

description: Spacecraft flybys again enabled and enhanced a variety of scientific missions throughout the year. Of particular interest were missions performing tours in the Inner Solar System. Parker Solar Probe completed three solar encounter phases this year; performing a Venus flyby along the way. The flyby was preceded by an activity to image comet NEOWISE, a target of much interest from observers during the year. In turn, BepiColombo, the ESA-JAXA low-thrust mission to Mercury, was observed by astronomers as it performed its Earth flyby on its seven-year tour towards the innermost planet. Joining them was ESA’s Solar Orbiter, launched in February. It will use gravity assists from Venus to raise its inclination with respect to the ecliptic to enable observations of the Sun’s polar regions. On its way to its first Venus encounter in December, Solar Orbiter passed through the ion and dust tails of Comet C/2019 Y4 (ATLAS) during late May and early June.
DOI: 10.48577/jpl.hwwgbl
title: Radiation Test Results for ISSI 1 Gb DDR2

description: ISSI IS46DR16640B and IS46DR81280B DDR2 1Gb devices are studied for radiation effects. Special emphasis is placed on understanding the device-level behavior and recovery of various error modes. An overview of all identified key radiation degradation and disruptions are provided. This includes TID and SEE. Key results are presented for standard SBU, MBU, SEFI, stuck bits, and TID performance. For the case of device-level disruptions (such as SEFIs that cause the device to stop responding), recovery requirements are explored to assist users in recovering operation without power-cycling. Power cycling was not necessary for any observed SEFI mode. The established ratio of SEFIs that may require power cycle to all SEFIs is below 0.0037. SEFIs are seen to have controller-dependent signatures with some controller architectures suppressing some, or all, of the erroneous data delivered during a SEFI.
DOI: 10.48577/jpl.pggamz
title: Rapid reconfiguration of the Greenland Ice Sheet margin

description: The Greenland Ice Sheet has lost mass at an accelerating rate over the last two decades, but limits of early remote sensing restricted examination of localized change at an ice-sheet-wide scale. We use satellite-derived ice-sheet surface velocities, glacier terminus advance/retreat, and surface elevation-change data spanning ~1985-2015 to explore local characteristics of what is now a rapid reconfiguration of the ice sheet coastal margin. Widespread glacier terminus retreat is a more consistent climate response indicator than surface velocities, though local velocity patterns provide indicators of ice flow reconfiguration, including narrowing zones of fast-flow, ice flow rerouting, and outlet abandonment. The implications of this observed rapid reconfiguration are wide-ranging, and likely include alteration of subglacial hydrology, iceberg discharge, liquid freshwater flux, potential nutrient and sediment flux, and mass flux. Without detailed observations of earlier deglaciations and with present limits on ice-sheet model capabilities, these observational records provide an important analogue for past deglaciation and for projecting future ice loss.
DOI: 10.48577/jpl.1extnj
title: The Full Extent of El Niño’s Precipitation Influence on the United States and the Americas: The Sub-Optimality of the Niño 3.4 SST Index

description: Key features of El Niño’s influence on North American winter precipitation are well-known but we show that this influence has, hitherto, been sub-optimally characterized in winter, and especially in fall and spring. The sub-optimality has arisen from the historical over-reliance on regressions on the Niño 3.4 SST index – a widely used marker of El Niño variability. We show that El Niño’s full influence is obtained from assembling the regressions on the spatiotemporal modes constituting El Niño variability, rather than from regressions on an SST index keyed just to its mature phase (Niño 3.4 index). The notably different influence of central and eastern Pacific El Niños on Eastern Seaboard is documented. The full influence of El Niño on North American precipitation is shown to be substantially larger than previously recognized and pronounced not just in northern winter but even in fall and spring – enhancing prospects for year-round seasonal prediction.
DOI: 10.48577/jpl.s2z4c2
title: Destination Jezero Crater: Landing Site of the Mars 2020 Perseverance Rover

description: On February 18, 2021, NASA’s Mars 2020 Perseverance rover will hurtle through the martian atmosphere at nearly 1000 miles per hour toward its landing site at Jezero crater. Once Perseverance has reached its destination on the surface of Mars, attention will turn to the intriguing deposits within and around this ancient crater that may answer one of the most fundamental and enduring mysteries of the universe: Was there ever life beyond Earth?
DOI: 10.48577/jpl.0sh5fu
title: Bookshelf Kinematics and the Effect of Dilatation on Fault Zone Inelastic Deformation: Examples from Optical Image Correlation Measurements of the 2019 Ridgecrest Earthquake Sequence

description: The 2019 Ridgecrest earthquake sequence initiated on July 4th by a series of foreshocks, including a Mw 6.4 event, that culminated a day later with the Mw 7.1 mainshock and resulted in rupture of a set of cross-faults. Here we use sub-pixel correlation of optical satellite imagery to measure the displacement, finite strain and rotation of the near-field coseismic deformation to understand the kinematics of strain release along the surface ruptures. We find the average off-fault deformation along the mainshock rupture is 34% and is significantly higher along the foreshock rupture (56%) suggesting it is a less structurally developed fault system. Measurements of the 2D dilatational strain along the mainshock rupture show a correlation between the degree of fault extension and contraction with the width of inelastic strain, and wider fault zones under extension than shear. Measurements of the vorticity along the main, dextral rupture show that conjugate sinistral faults are embedded within zones of large clockwise rotations caused by two mechanisms i) the transition of strain beyond the tips of dextral faults and ii) bookshelf kinematics. These rotations and bookshelf slip can explain why faults of different shear senses do not intersect one another and the occurrence of pervasive and mechanically unfavorable cross-faulting in this region. Understanding the causes for the variation of fault-zone widths along surface ruptures has importance for reducing the epistemic uncertainty of probabilistic models of distributed rupture that will in turn provide more precise estimates of the hazard distributed rupture poses to nearby infrastructure.
DOI: 10.48577/jpl.6bwifw
title: Sampling Accelerated Micron Scale Ice Particles with a Quadrupole Ion Trap Mass Spectrometer

description: The Enceladus plume is a target of astrobiological interest in planetary science since it may carry signs of extraterrestrial life entrapped in ice grains formed from the subsurface ocean of this moon of Saturn. Fly-by mission concepts have been proposed to perform close investigations of the plume, including detailed in-situ measurements of chemical composition with a new generation of mass spectrometer instrumentation. Such a scenario involves high-velocity collisions (typically around 5 km/s or higher) of the instrument with the encountered ice grains. Post-impact processes may include molecular fragmentation, impact ionization, and various subsequent chemical reactions that could alter the original material prior to analysis. In order to simulate Enceladus plume fly-through conditions, we are developing an ice grain accelerator and have coupled it to the Quadrupole Ion Trap Mass Spectrometer (QITMS) developed for flight applications. Our experimental setup enables the creation and acceleration of ice particles with well-defined size, charge, and velocity, which are subsequently directed into the QITMS, where they impact the surface of the mass analyzer and the analysis of post-impact, volatilized molecules takes place. In this work, we performed mass spectral analysis of ice grains of ca. 1.3 µm in diameter, accelerated and impacted at velocities up to 1000 m/s, with an upgrade of the accelerator in progress that will enable velocities up to 5000 m/s. We report the first observations of ice grain impacts measured by the QITMS, which were recorded as brief increases in the abundance of water molecules detected within the instrument.
DOI: 10.48577/jpl.faiifc
title: Sensing Horizontally Oriented Frozen Particles with Polarimetric Radio Occultations aboard PAZ: Validation Using GMI Coincident Observations and Cloudsat a-Priori Information

description: The sensitivity of PAZ’s Polarimetric Radio Occultation observations to horizontally oriented frozen particles is as- sessed using coincident measurements from the Global Pre-5 cipitation Mission (GPM) core satellite’s radiometer (GMI) and ancillary information from Cloudsat. The difference be- tween the horizontal and vertical polarization of the GMI ob- served radiances at 166 GHz, indicative of horizontally ori- ented particles, is compared with the PAZ differential phase10 shift observations. A clear positive trend is observed, ex- hibiting a good correlation between the two observations. The radiometer absolute observations and polarization dif- ferences are then used to build a look up table of ice water content vertical profiles, using coincident observations be-15 tween GPM and Cloudsat. The vertical profiles of ice water content, along with the information of the radiometric po- larization differences and some simple assumptions are used to simulate the expected PAZ differential phase shift obser- vations. The validation with the PAZ and GPM coincident20 measurements shows a high correlation between the simu- lated and observed differential phase shift, therefore proving the sensitivity of polarimetric radio occultations to horizon- tally oriented frozen particles. These results demonstrate that polarimetric radio occultations can not only sense the precip-25 itation near the surface (original goal of the mission), but also the frozen particles near and well above the freezing level, providing additional detail of the cloud vertical structure.