cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.dlvelr
title: Satellite Hydrology Observations as Operational Indicators of Forecasted Fire Danger across the Contiguous United States

description: Traditional methods for assessing fire danger often depend on meteorological forecasts, which have reduced reliability after ~10 days. Recent studies have demonstrated long lead-time correlations between pre-fire-season hydrological variables such as soil moisture and later fire occurrence or area burned, yet no potential value of these relationships for operational forecasting have not been studied. Here, we use soil moisture data refined by remote sensing observations of terrestrial water storage from NASA’s GRACE mission and vapor pressure deficit from NASA’s AIRS mission to generate monthly predictions of fire danger at scales commensurate with regional management. We test the viability of predictors within nine US Geographic Area Coordination Centers (GACCs) using regression models specific to each GACC. Results show that the model framework improves interannual wildfire burned area prediction relative to climatology for all GACCs. This demonstrates the importance of hydrological information to extend operational forecast ability into the months preceding wildfire activity.
DOI: 10.48577/jpl.jltw0m
title: A new OCO-2 cloud flagging and rapid retrieval of marine boundary layer cloud properties

description: The Orbiting Carbon Observatory-2 (OCO-2) carries a hyperspectral A-band sensor that can obtain information about cloud geometric thickness (H). The OCO2CLD-LIDAR-AUX product retrieved H with the aid of collocated CALIPSO lidar data to identify suitable clouds and provide a priori cloud-top pressure (Ptop). This collocation is no longer possible since CALIPSO no longer flies in coordination with OCO-2, so here we introduce a new cloud flagging and a priori assignment using only OCO-2 data, restricted to ocean footprints where solar zenith angle &lt; 45°. Firstly, a multi-layer perceptron network was trained to identify liquid clouds over ocean with sufficient optical depth ( &gt; 1) for a valid retrieval, and agreement with MODIS-CALIPSO is 90.0 %. Secondly, we developed a lookup table to simultaneously retrieve cloud , effective radius (re) and Ptop from A-band and CO2 band radiances, with the intention that these will act as the a priori in a future retrieval. Median Ptop difference versus CALIPSO is 12 hPa with interdecile range [-11,87] hPa, substantially better than the MODIS-CALIPSO [-83,81] hPa. The MODIS-OCO-2  difference is 0.8 (-3.8,6.9) and re is -0.3 [-2.8,2.1] m. The  difference is due to optically thick and horizontally heterogeneous cloud scenes. As well as an improved passive Ptop retrieval, this a priori information will allow a purely OCO-2 based Bayesian retrieval of cloud droplet number concentration (Nd). Finally, our cloud flagging procedure may also be useful for future partial column above-cloud CO2 abundance retrievals.
DOI: 10.48577/jpl.7x57c9
title: Determining Space Science Mission Geometry

description: None
DOI: 10.48577/jpl.dm6neg
title: Rise of Great Lakes surface water, sinking of the upper Midwest of the United States, and viscous collapse of the forebulge of the former Laurentide ice sheet

description: Great Lakes water levels rose 0.7–1.2 m from 2013 to 2019, increasing surface water volume by 285 km3. Solid Earth's elastic response to the increased mass load is nearly known: the Great Lakes floor fell 8–22 mm and the adjacent land fell 3–14 mm. Correcting GPS measurements for this predicted elastic loading (1) straightens position-time series, making the evolution of position more nearly a constant velocity and (2) reduces estimates of subsidence rate in Wisconsin, Michigan, and southern Ontario by 0.5–2 mm/yr, improving constraints on postglacial rebound. GPS records Wisconsin and Michigan to have subsided at 1–4 mm/yr. We find this sinking to be produced primarily by viscous collapse of the former Laurentide ice sheet forebulge and secondarily by elastic Great Lakes loading. We infer water on land in the Great Lakes watershed to be total water change observed by GRACE minus Great Lakes surface water smeared by a Gaussian distribution. Water stored on land each year reaches a maximum in March, six months before Great Lakes water levels peak in September. The seasonal oscillation of water on land in the Great Lakes basin, 100 km3 (0.20 m water thickness), is twice that in a hydrology model. In the seasons, groundwater in the Great Lakes watershed increases by 60 km3 (0.12 m) each autumn and winter and decreases by roughly an equivalent amount each spring and summer. In the long term, groundwater volume remained constant from 2004 to 2012 but increased by 50 km3 (0.10 m) from 2013 to 2019.
DOI: 10.48577/jpl.m8fwrk
title: Mars Curiosity Rover Mobility Trends During the First Seven Years

description: NASA's Mars Science Laboratory (MSL) Curiosity rover landed on Mars on August 6, 2012. In the seven years between landing and August 6, 2019 (sol 2488), Curiosity has driven 21,318.5 meters over a variety of terrain types and slopes, employing multiple drive modes with varying amounts of onboard autonomy. Curiosity's drive distances each sol have ranged from its shortest drive of 2.6 centimeters to its longest drive of 142.5 meters, with an average drive distance of 28.9 meters. Real-time human intervention is not possible during Curiosity's drives due to the latency in uplinking commands and downlinking telemetry. Instead, the operations team relies on Curiosity's fault protection software to keep the rover safe during drives. During its first seven years on Mars, Curiosity has attempted 738 drives. While 622 drives ran to completion, 116 drives were prevented or stopped early by Curiosity's fault protection software. The primary risks to mobility success have been wheel damage, wheel entrapment, progressive wheel sinkage, and the potential for hardware or cable failures that result in an inability to command one or more steer or drive actuators. In this paper, we describe Curiosity's mobility subsystem, mobility trends over the first 21.3 kilometers of the mission, operational aspects of mobility fault protection, risks to continued mobility success, and risk mitigation strategies.
DOI: 10.48577/jpl.iu8yzd
title: GPU-accelerated massive black hole binary parameter estimation with LISA

description: The Laser Interferometer Space Antenna (LISA) is slated for launch in the early 2030s. A main target of the mission is massive black hole binaries that have an expected detection rate of _ 20 yr􀀀1. We present a parameter estimation analysis for a variety of massive black hole binaries. This analysis is performed with a graphics processing unit (GPU) implementation comprising the PhenomHM waveform with higher-order harmonic modes and aligned spins; a fast frequency-domain LISA detector response function; and a GPU-native likelihood computation. The computational performance achieved with the GPU is shown to be 500 times greater than with a similar CPU implementation, which allows us to analyze full noise-infused injections at a realistic Fourier bin width for the LISA mission in a tractable and e_cient amount of time. With these fast likelihood computations, we study the e_ect of adding aligned spins to an analysis with higher-order modes by testing di_erent con_gurations of spins in the injection, as well as the e_ect of varied and _xed spins during sampling. Within these tests, we examine three di_erent binaries with varying mass ratios, redshifts, sky locations, and detector-frame total masses ranging over three orders of magnitude. We discuss varied correlations between the total masses and mass ratios; unique spin posteriors for the larger mass binaries; and the constraints on parameters when _xing spins during sampling, allowing us to compare to previous analyses that did not include aligned spins
DOI: 10.48577/jpl.zto508
title: Frequency-modulated diode laser frequency combs at 2 m wavelength

description: Chip-scale electrically pumped optical frequency combs (OFCs) are expected to play a fundamental role in applications ranging from telecommunications to optical sensing. To date, however, the availability of such sources around 2 um was scarce. Here, we present a frequency modulated (FM) OFC operating around 2060 nm of wavelength exploiting the inherent gain nonlinearity of single-section GaSb quantum well diode lasers. A 2 mm long device operating as a self-starting comb outputs 50 mW of optical power over 10 nm of bandwidth while consuming &lt;1 W of electrical power. Using the Shifted Wave Interference Fourier Transform Spectroscopy (SWIFTS) technique, we characterize the generated frequency-modulated waveform, and demonstrate a linearly chirped phase relationship among the entire emission optical bandwidth. Furthermore, by compensating for the linear chirp using a single mode optical fiber with opposite dispersion, 10 ps-long optical pulses are generated. The high frequency stability of the devices with 19.3~GHz repetition rates allows us to perform mode-resolved free-running dual-comb spectroscopy.
DOI: 10.48577/jpl.0gjsgs
title: An Eye on the Storm: Integrating a Wealth of Data for Quickly Advancing the Physical Understanding and Forecasting of Tropical Cyclones

description: Tropical cyclones (TCs) are among the most destructive natural phenomena with huge societal and economic impact. They form and evolve as the result of complex multi-scale processes and non-linear interactions. Even today the understanding and modeling of these processes is still lacking.A major goal of NASA is to bring the wealth of satellite and airborne observations to bear on addressing the unresolved scientific questions and improving our forecast models. Despite their significant amount, these observations are still underutilized in hurricane research and operations, due to the complexity associated with finding and bringing together semi-coincident and semi-contemporaneous multi-parameter data that are needed to describe the multiscale TC processes. Such data are traditionally archived in different formats, with different spatio-temporal resolution, across multiple databases, and hosted by various agencies. To address this shortcoming, NASA supported the development of the JPL Tropical Cyclone Information System (TCIS) - a Data Analytic Framework that integrates model forecasts with multiparameter satellite and airborne observations, providing interactive visualization and on-line analysis tools. TCIS supports interrogation of a large number of atmospheric and ocean variables, allowing for quick investigation of the structure of the tropical storms and their environments.This paper provides an overview of the TCIS’s components and features. It also summarizes recent pilot studies, providing examples how the TCIS has inspired new research, helping to increase our understanding of TCs.The goal is to encourage more users to take full advantage of the novel capabilities. TCIS allows atmospheric scientists to focus on new ideas and concepts rather than painstakingly gathering data scattered over several agencies.
DOI: 10.48577/jpl.3ryjpo
title: Increasing the space-time resolution of mapped sea surface height from altimetry

description: We present a new mapping methodology to improve the resolution of gridded sea surface height (SSH) using along-track multi-satellite measurements, and apply it in the California Current system. This is motivated by the upcoming Surface Water and Ocean Topography (SWOT) satellite mission, which will provide novel high-resolution wide-swath measurements of SSH. The calibration/validation of SWOT in the California Current requires independent observations of fine-scale 2D SSH variability. Currently, the best gridded SSH product for the region is AVISO’s global dataset, based on optimal interpolation (OI). Our new method is based on 2-dimensional variational analysis (2DVAR) and we address some limitations of the AVISO OI global parameterization that restrict the resolution. Key improvements are: (1) use of a background field incorporating mesoscale information, as opposed to a long-term mean field; (2) optimized regional parameters; and (3) a representation error term in the observational error covariance matrix to account for the spread of measurements in time. Using a suite of independent remote and in situ observations, we show that 2DVAR delivers a higher-resolution SSH field that captures finer-scale mesoscale ocean circulation in the California Current region, at the expense of an increase in noise.
DOI: 10.48577/jpl.1f8vdn
title: WISEA J041451.67−585456.7 and WISEA J181006.18−101000.5: The First Extreme T-type Subdwarfs?

description: We present the discovery of WISEA J041451.67−585456.7 and WISEA J181006.18−101000.5, two low-temperature (1200-1400 K), high proper motion T-type subdwarfs. Both objects were discovered via their high proper motion (&gt;0.5′′yr−1) and confirmed as brown dwarfs with follow-up near-infrared spectroscopy. Their spectra and near-infrared colors are unique amongst known brown dwarfs, with some colors consistent with L-type brown dwarfs and other colors resembling those of the latest-type T dwarfs. While no forward model consistently reproduces the features seen in their near-infrared spectra, the closest matches suggest very low metallicities ([Fe/H] ≤ -1), making these objects likely the first examples of extreme subdwarfs of the T spectral class (esdT). WISEA J041451.67−585456.7 and WISEA J181006.18−101000.5 are found to be part of a small population of objects that occupy the “substellar transition zone”, and have the lowest masses and effective temperatures of all objects in this group.
DOI: 10.48577/jpl.6nsgup
title: MEMS Deformable Mirror Development for High-Contrast Imaging I: Miniaturized, Flight-Capable Control Electronics

description: Deformable mirrors (DMs) are a critical technology to enable coronagraphic direct imaging of exoplanets with current and future ground- and space-based telescopes as well as future mission concepts, such as the Habitable Exoplanet Observatory (HabEx) and the Large UV/Optical/IR Surveyor (LUVOIR). The latter concepts aim to image a diversity of exoplanet types ranging from gas giants to Earth analogs, which requires large actuator count, ﬁne surface height resolution (10 pm), and driving electronics that are radiation resilient and have low mass and volume. In this paper, we present the design and testing of a ﬂight-capable, miniaturized DM controller. We achieved contrasts on the order of 5×10−9 on a coronagraph test bed in a vacuum chamber in the High Contrast Imaging Testbed (HCIT) facility at NASA’s Jet Propulsion Laboratory (JPL) demonstrating that the electronics are capable of meeting the requirements of coronagraph instruments on future space telescopes. We also report on functionality testing on-board the high-altitude balloon experiment “Planetary Imaging Concept Testbed Using a Recoverable Experiment - Coronagraph (PICTURE-C),” which aims to directly image debris disks and exozodiacal dust around nearby stars. The controller is designed for the Boston Micromachines Corporation Kilo-DM and is readily scalable to larger DM formats. The three main components of the system (the DM, driving electronics, and mechanical and heat management) are designed to be compact and have low-power consumption to enable its use not only on exoplanet missions, but also in a wide-range of applications that require precision optical systems, such as direct line-of-sight laser communications. The controller is capable of handling 1,024 actuators with 220 V maximum dynamic range, 16-bit resolution,14-bit accuracy, and operating at up to 1kHz frequency. The system ﬁts in a 10×10×5 cm3 volume, weighs less than 0.5 kg, and consumes less than 8 W. We have developed a turnkey solution reducing the risk for future missions, lowering their cost by signiﬁcantly reducing volume, weight, and power consumption of the wavefront control hardware.
DOI: 10.48577/jpl.cyxicv
title: ECOSTRESS: NASA’s next generation mission to measure evapotranspiration from the International Space Station

description: The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) was launched to the International Space Station on June 29, 2018. The primary science focus of ECOSTRESS is centered on evapotranspiration (ET), which is produced as level-3 (L3) latent heat flux (LE) data products. These data are generated from the level-2 land surface temperature and emissivity product (L2_LSTE), in conjunction with ancillary surface and atmospheric data. Here, we provide the first validation (Stage 1, preliminary) of the global ECOSTRESS clear-sky ET product (L3_ET_PT-JPL, version 6.0) against LE measurements at 82 eddy covariance sites around the world. Overall, the ECOSTRESS ET product performs well against the site measurements (clear-sky instantaneous/time of overpass: r2 = 0.88; overall bias = 8%; normalized RMSE = 6%). ET uncertainty was generally consistent across climate zones, biome types, and times of day (ECOSTRESS samples the diurnal cycle), though temperate sites are over-represented. The 70 m high spatial resolution of ECOSTRESS improved correlations by 85%, and RMSE by 62%, relative to 1 km pixels. This paper serves as a reference for the ECOSTRESS L3 ET accuracy and Stage 1 validation status for subsequent science that follows using these data.
DOI: 10.48577/jpl.wkcj25
title: Competing effects of soil fertility and toxicity on tropical greening

description: Tropical forests are expected to green up with increasing atmospheric CO2 concentrations, but primary productivity may be limited by soil nutrient availability. However, rarely have canopy-scale measurements been assessed against soil measurements in the tropics. Here, we sought to assess remotely sensed canopy greenness against steep soil nutrient gradients across 50 1-ha mature forest plots in Panama. Contrary to expectations, increases in in situ extractable soil phosphorus (P) and base cations (K, Mg) corresponded to declines in remotely sensed mean annual canopy greenness (r2 = 0.77 – 0.85; p &lt; 0.1), controlling for precipitation. The reason for this inverse relationship appears to be that litterfall also increased with increasing soil P and cation availability (r2 = 0.88 – 0.98; p &lt; 0.1), resulting in a decline in greenness with increasing annual litterfall (r2 = 0.94; p &lt; 0.1). As such, greater soil nutrient availability corresponded to greater leaf turnover, resulting in decreased greenness. However, these decreases in greenness with increasing soil P and cations were countered by increases in greenness with increasing soil nitrogen (N) (r2 = 0.14; p &lt; 0.1), which had no significant relationship with litterfall, likely reflecting a direct effect of soil N on leaf chlorophyll content, but not on litterfall rates. In addition, greenness increased with extractable soil aluminum (Al) (r2 = 0.97; p &lt; 0.1), but Al had no significant relationship with litterfall, suggesting a physiological adaptation of plants to high levels of toxic metals. Thus, spatial gradients in canopy greenness are not necessarily positive indicators of soil nutrient scarcity. Using a novel remote sensing index of canopy greenness limitation, we assessed how observed greenness compares with potential greenness. We found a strong relationship with soil N only (r2 = 0.65; p &lt; 0.1), suggesting that tropical canopy greenness in Panama is predominantly limited by soil N, even if plant productivity (e.g., litterfall) responds to rock-derived nutrients. Moreover, greenness limitation was also significantly correlated with fine root biomass and soil carbon stocks (r2 = 0.62 – 0.71; p &lt; 0.1), suggesting a feedback from soil N to canopy greenness to soil carbon storage. Overall, these data point to the potential utility of a remote sensing product for assessing belowground properties in tropical ecosystems.
DOI: 10.48577/jpl.7jneus
title: A new methodology for observation-based parameterization developme

description: We develop a methodology for identification of candidate observables that best constrain therepresentation of the most uncertain processes in physical parameterizations. This methodologyconsists of the three steps: (i) identifying processes that significantly impact parameterization results,(ii) identifying observables that best constrain the influential processes, and (iii) investigatingthe sensitivity of the parameterization results to the measurement error and vertical resolution ofthe constraining observables. This new methodology is applied to the Jet Propulsion Laboratorystochastic multi-plume Eddy-Diffusivity/Mass-Flux (JPL-EDMF) parameterization for two casestudies representing non-precipitating marine stratocumulus and marine shallow convection. Wefind that the most uncertain processes in the JPL-EDMF model are related to the representationof lateral entrainment for convective plumes and parameterization of mixing length scale for theeddy-diffusivity part of the model. The results show a strong interaction between these uncertainprocesses. Measurements of the water vapor profile for shallow convection and of the cloud coverprofile for the stratocumulus case are among those measurements that best constrain the uncertainJPL-EDMF processes. The interdependence of the required vertical resolution and error characteristicsof the observational system are shown. If the observations are associated with larger error,their vertical resolution has to be finer and vice versa. For example, it was found that for the shallowconvection case, the measurement of water vapor with a vertical resolution of 20 m and error of4 g kg􀀀1, or with a vertical resolution of 200 m and error of 2 g kg􀀀1 provide similar constraintfor the model parameters. We suggest that the methodology presented here and the results hereinprovide an objective basis for defining requirements for future observing systems such as futuresatellite missions to observe clouds and the planetary boundary layer.
DOI: 10.48577/jpl.lhvhgo
title: Draft Genome Sequences of Bacillus glennii V44-8, Bacillus saganii V47-23a, Bacillus sp. V59.32b, Bacillus sp. MER_TA_151, and Paenibacillus sp. MER_111, Isolated from cleanrooms where the Viking and Mars Exploration Rover spacecraft were assembled.

description: National Aeronautics and Space Administration (NASA) strives to monitor the total microbial burden of spacecraft as a means for minimizing forward contamination: the inadvertent transfer of viable microorganisms to extraterrestrial environments. Here, we report the draft genome sequences of species Bacillus glennii V44-8, Bacillus saganii V47-23a, and potential novel Bacillus sp. V59.32b (isolated from the Viking spacecraft assembly cleanroom) and genomic sequences of potential novel species Bacillus sp. MER_TA_151 and Paenibacillus sp. MER_111 (isolated from the Mars Exploration Rover (MER) assembly cleanroom).
DOI: 10.48577/jpl.y3ywpd
title: Three-to-Six-Day Air-Sea Oscillation in Models and Observations

description: Analysis of coupled ocean-atmosphere numerical simulations revealed a widespread oscillation of Sea Surface Temperature (SST) and surface wind anomalies with a cyclic nature characterized by a period of three to six days. Similar oscillations were also found in buoy data at different locations around the globe and in an atmospheric reanalysis, albeit the oscillations were noisier and stronger in the observations and they were weaker and longer-period in the atmospheric reanalysis. These oscillations did not, however, develop in an atmosphere-only simulation, suggesting the importance of ocean-atmosphere coupling for simulating this phenomenon. We propose a mechanism for this interaction involving a feedback between SST and surface wind.