cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.rr5q31
title: On-deck seismology: Lessons from InSight for future planetary seismology

description: Before deploying to the surface of Mars, the short-period (SP) seismometer of the InSight mission operated on deck for a total of 48 hours. This dataset can be used to understand how deck-mounted seismometers can be used in future landed missions to Mars, Europa, and other planetary bodies. While operating on deck, the SP seismometer showed signals comparable to the Viking-2 seismometer near 3 Hz where the sensitivity of the Viking instrument peaked. Wind sensitivity showed similar patterns to the Viking instrument, although amplitudes on InSight were $\sim$80\% larger for a given wind velocity. However, during the low wind evening hours the instrument noise levels at frequencies between 0.1 and 1 Hz were comparable to quiet stations on Earth, although deployment to the surface below the Wind and Thermal Shield lowered installation noise by roughly 40 dB in acceleration power. With the observed noise levels and estimated seismicity rates for Mars, detection probability for quakes for a deck-mounted instrument are low enough that up to years of on-deck recordings may be necessary to observe an event. Because the noise is dominated by wind acting on the lander, though, deck-mounted seismometers may be more practical for deployment on airless bodies, and it is important to evaluate the seismicity of the target body and the specific design of the lander. Detection probabilities for operation on Europa reach over 99\% for some proposed seismicity models for a similar duration of operation if noise levels are comparable to low-wind time periods on Mars.
DOI: 10.48577/jpl.spiqjr
title: SWIFT MONITORING OF M51: A 38-DAY SUPER-ORBITAL PERIOD FOR THE PULSAR ULX7 AND A NEW TRANSIENT ULX

description: We present the results from a monitoring campaign made with the Neil Gehrels Swift Observatory of the M51 galaxies, which contain several variable ultraluminous X-ray sources (ULXs). The ongoing campaign started in May 2018, and we report here on ∼ 1.5 years of observations. The campaign, which consists of 105 observations, has a typical cadence of 3–6 days, and has the goal of determining the long-term X-ray variability of the ULXs. Two of the most variable sources were ULX7 and ULX8, both of which are known to be powered by neutron stars that are exceeding their isotropic Eddington luminosities by factors of up to 100. This is further evidence that neutron star powered ULXs are the most variable. Our two main results are, first, that ULX7 exhibits a periodic flux modulation with a period of 38 days varying over a magnitude and a half in flux from peak to trough. Since the orbital period of the system is known to be 2 days, the modulation is super-orbital, which is a near-ubiquitous property of ULX pulsars. Secondly we identify a new transient ULX, M51 XT-1, the onset of which occurred during our campaign, reaching a peak luminosity of ∼ 1040 erg s−1, before gradually fading over the next ∼ 200 days until it slipped below the detection limit of our observations. Combined with the high-quality Swift/XRT lightcurve of the transient, serendipitous observations made with Chandra and XMM-Newton provide insights into the onset and evolution of a likely super-Eddington event.
DOI: 10.48577/jpl.w4qgdm
title: FREQUENCY TUNABLE SURFACE ACOUSTIC WAVE ACTUATORS FOR ADJUSTABLE PITCH DIFFRACTION GRATING

description: Diffraction gratings are commonly used in optical instruments such as in spectrometers, monochromators, and wavelength division multiplexing devices. The diffraction efficiency is directly related to the ratio of the grating spacing or pitch to the wavelength of the light. In a sinusoidal grating (or holographic grating) the efficiency is generally lower than a blazed grating with a saw tooth profile, but the spectral coverage can be broader. To address a large spectral range, advanced spectrometers use a number of diffraction gratings with a fixed pitch. In this paper, we show for the first time, the use of a tunablefrequency surface acoustic wave (SAW) delay line as a broad-band sinusoidal diffraction grating. To tune the frequency, we tune the effective spacing of the interdigitated transducers (IDTs) by applying specific phases to each IDT finger. The prototype SAW grating covers frequency range of 86 MHz to 360 MHz corresponding to optical range of 1.3 μm to 9 μm.
DOI: 10.48577/jpl.wi7kwm
title: Deep-Ultraviolet Raman Spectra of Mars-Relevant Evaporite Minerals under 248.6 nm Excitation

description: We report the first deep-ultraviolet (DUV) Raman spectra for a number of evaporite minerals that are relevant to lacustrine and fluvial environments found on Earth and Mars, and show that DUV Raman can provide detailed information on elemental composition and crystal structure. The minerals included three borates, eight carbonates, and seven sulfates, with each class of mineral exhibited very distinct spectra under 248.6 nm excitation, dominated by the various internal vibrations of the borate, carbonate and sulfate oxyanions. The spectra were found to shifted to lower wavenumbers compared to positions reported in the literature using longer excitation wavelengths. Within each class, mineral end members differing only in their metallic cation could be distinguished by the position of the dominant vibrational mode and the relative intensities of the minor modes, ascribed to the electrostatic impact of the metallic cation on the vibrational behavior of the oxyanion. There was also evidence that DUV Raman can reveal minor metallic components even if they are not apparent in XRD, as two of three calcite (CaCO3) samples exhibited a shoulder on the dominant peak that we assigned to a Mg-rich perturbation. UV absorption by Fe ions was a major factor in determining measurable signal, with Fe-rich minerals exhibiting weak/undetectable spectra. Understanding the spectra of these evaporite minerals will be essential to interpreting and identifying complex mineral samples using this technique, and represents an important addition to the spectral standards library of DUV Raman spectroscopy.
DOI: 10.48577/jpl.2wopuj
title: The causes of sea-level rise since 1900

description: Global-mean sea level has been rising unsteadily since 1900, and the underlying causes are still poorly understood. Here we present a probabilistic framework to reconstruct and budget sea level with independent observations considering their inherent uncertainties. We find that the sum of thermal expansion, ice-mass loss and terrestrial water storage changes is consistent with the trends and multi-decadal variability in observed sea level on both global and basin scales, which we reconstruct from tide-gauge records. Glacier-dominated cryospheric mass loss has caused twice as much sea-level rise as thermal expansion since 1900. Ice mass changes also well explain the high rates typically seen in global sea-level reconstructions during the 1930s, while a sharp increase in water impoundment by man-made reservoirs has been the dominant contributor to lower-than-average rates during the 1970s. The acceleration over the last decades is caused by both thermal expansion and increased Greenland mass loss. No additional large-scale deep ocean warming or Antarctic Ice Sheet mass loss are needed to explain 20th-century changes global-mean sea level. This assessment reconciles the magnitude of observed global-mean sea-level rise since 1900 with the sum of underlying processes.
DOI: 10.48577/jpl.nmwfup
title: Modeling the uncertainties of solar-system ephemerides for robust gravitational-wave searches with pulsar timing arrays

description: The regularity of pulsar emissions becomes apparent once we reference the pulses' times of arrivals to the inertial rest frame of the solar system. It follows that errors in the determination of Earth's position with respect to the solar-system barycenter can appear as a time-correlated bias in pulsar-timing residual time series, affecting the searches for low-frequency gravitational waves performed with pulsar-timing arrays.Indeed, recent array datasets yield different gravitational-wave background upper limits and detection statistics when analyzed with different solar-system ephemerides. Crucially, the ephemerides do not generally provide usable error representations.In this article we describe the motivation, construction, and application of a physical model of solar-system ephemeris uncertainties, which focus on the degrees of freedom (Jupiter's orbital elements) most relevant to gravitational-wave searches with pulsar timing arrays.This model, \textsc{BayesEphem}, was used to derive ephemeris-robust results in NANOGrav's 11-yr stochastic-background search, and it provides a foundation for future searches by NANOGrav and other consortia.The analysis and simulations reported here suggest that ephemeris modeling reduces the gravitational-wave sensitivity of the 11-yr dataset; and that this degeneracy will vanish with improved ephemerides and with the longer pulsar-timing datasets that will become available in the near future.
DOI: 10.48577/jpl.7rtkci
title: Deep Convective Evolution from Shallow Clouds over the Amazon and Congo Rainforests

description: No abstract available.
DOI: 10.48577/jpl.izqzkd
title: Direct semiconductor diode laser system for an optical lattice clock based on neutral strontium for future tests of fundamental physics in space

description: We present the design and the status of an optical lattice clock at NASA’s Jet Propulsion Laboratory based on bosonic 88Sr atoms and its laser system. The design of the clock aims for future sensitive tests of fundamental physics in space. The atomic source employs a two-dimensional magneto-optical trap realized with permanent magnets and a simple dispenser-based atomic oven. This design results in a low system size, weight and power, suppresses thermal atoms in the clock interrogation zone and eliminates hot blackbody radiation in the science cell. The laser system utilizes exclusively direct diode lasers without second harmonic generation to minimize the complexity and power consumption of the overall system. The clock interrogation laser at 698 nm and the laser for the second cooling stage at 689 nm are both locked to the same high finesse optical cavity to further reduce the size of the system. Future paths to system miniaturization are also discussed.
DOI: 10.48577/jpl.uuk3n3
title: LES of the Martian convective boundary layer: Towards developing a new planetary boundary layer scheme

description: The grid resolutions typically employed by atmospheric global circulation and mesoscale models are not sufficiently high to explicitly resolve the turbulence processes within the planetary boundary layer (PBL). Therefore, turbulence fluxes must be fully parameterized in global circulation and mesoscale models using PBL schemes, unlike microscale models, which use the large-eddy simulation (LES) technique to resolve turbulence processes. PBL schemes perform turbulence parameterization using empirical relationships for the mixing length scale. In this study, we provide an LES database for different convective stability conditions to investigate turbulence statistics and derive the first mixing length scale formulation, specifically developed for the Martian convective PBL. The proposed PBL scheme is implemented into MarsWRF multiscale model. its performance is compared to an algebraic PBL scheme currently in use in MarsWRF model. Despite both PBL schemes performed similarly to predict the near-surface meteorological conditions at Gale crater, the presently proposed PBL scheme provided better results in terms of predicting convective boundary layer height with respect to the observational estimations acquired by the radio occultations of Mars Express.
DOI: 10.48577/jpl.vpymoa
title: Gaussian processes for the interpolation and marginalization of waveform error in extreme-mass-ratio-inspiral parameter estimation

description: A number of open problems hinder our present ability to extract scientific information from data that will be gathered by the near-future gravitational-wave mission LISA. Many of these relate to the modeling, detection and characterization of signals from binary inspirals with an extreme $(\lesssim10^{-4})$ component-mass ratio. In this paper, we draw attention to the issue of systematic error in parameter estimation due to the use of fast but approximate waveform models; this is found to be relevant for extreme-mass-ratio inspirals even in the case of waveforms with $\gtrsim90\%$ overlap accuracy and moderate ($\gtrsim30$) signal-to-noise ratios. A scheme that uses Gaussian processes to interpolate and marginalize over waveform error is adapted and investigated as a possible precursor solution to this problem. Several new methodological results are obtained, and the viability of the technique is successfully demonstrated on a three-parameter example in the setting of the LISA Data Challenge.
DOI: 10.48577/jpl.vl1mdw
title: Lyman-alpha polarization intensity mapping

description: We present a formalism that incorporates hydrogen Lyman-alpha (Ly$\alpha$) polarization into the intensity mapping approach. Using the halo model, and \lya emission profiles based on galaxy simulations and observations, we derive auto and cross power spectra for the \lya total intensity, $I$, polarized intensity, $\po$, degree of polarization, $\Pi=\po/I$, and two new quantities, the astrophysical $E$ and $B$ modes of \lya polarization. A characteristic turnover is visible for the one-halo terms of the fiducial power spectra of $\Pi$ and $E$. The position of this feature depends on redshift, and it signals the average size of the halos that dominate the polarization signal at a given time. The impact of varying model parameters depends on the considered polarization quantity, as well as on redshift. Therefore, the comparison of various \lya polarization quantities and redshifts can break degeneracies between competing effects, and can reveal the average shape and extent of the emission profiles, which, in turn, are associated to the physical properties of the cool gas in galaxy halos. Furthermore, measurements of \lya $E$ and $B$ modes can be used as probes of the average degree of anisotropy in the emission and in the distribution of neutral gas in halos across redshifts. Our predicted power spectra, in the multipole range $\sim$ a few times $10^2 \lesssim \ell \lesssim 5\times 10^5$, appear detectable with current technology up to the redshifts of early cosmic reionization, $z\sim 11$. The signal-to-noise ratios reach values as high as $S/N\gtrsim100$ at the one-halo peaks, provided that foreground contamination is known. Contamination from interlopers is expected to be small for the case of polarization, because the interlopers need to also be polarized. Overall, \lya polarization appears as a new intensity mapping probe that boosts the amount of physical information on galaxies and their surroundings retrievable from the observations, most of it not achievable with total emission alone.
DOI: 10.48577/jpl.0echjs
title: Evaluation of Coherent and Incoherent Landslide Detection Methods based on Synthetic Aperture Radar for Rapid Response: A Case Study for Hokkaido Landslide

description: Damage mapping using SAR imagery has been studied for the past decades to support rapid response to natural disasters. Many researches have been developing coherent and incoherent change detection. However, their performances can vary depending on the types of the damages, characteristics of the scatterers and corresponding capability of algorithms. In particular, the coherence-based methods have been well known as promising detector over the urban area and high-coherence region, but still controversial over the low-coherence area as 2019 Hokkaido landslides. In order to understand the characteristics of landslide (damage) detectors for the low-coherence area and find the alternative and complementary method, we designed the coherence difference, coherence normalized difference, log-ratio, intensity correlation difference, and normalized differences of the intensity correlation assuming limited availability of dataset, and also developed the multi-temporal algorithms using the coherence, intensity, and intensity correlation. They are tested and evaluated using multiple polygons extracted from aerial photos. We were able to observe the multi-temporal intensity correlation method has the potential to detect the landslides over the low coherence region and all types of landuses.
DOI: 10.48577/jpl.1zqti7
title: A Survey of Small-Scale Waves and Wave-Like Phenomena in Jupiter’s Atmosphere Detected by JunoCam

description: In the first 20 orbits of the Juno spacecraft around Jupiter, we have identified a variety of wave-like features in images made by its public-outreach camera, JunoCam. Because of Juno’s unprecedented and repeated proximity to Jupiter’s cloud tops during its close approaches, JunoCam has detected more wave structures than any previous surveys. Most of the waves appear in long wave packets, oriented east-west and populated by narrow wave crests. Spacing between crests were measured as small as ~30 km, shorter than any previously measured. Some waves are associated with atmospheric features, but others are not ostensibly associated with any visible cloud phenomena and thus may be generated by dynamical forcing below the visible cloud tops. Some waves also appear to be converging and others appear to be overlapping, possibly at different atmospheric levels. Another type of wave has a series of fronts that appear to be radiating outward from the center of a cyclone. Most of these waves appear within 5° of latitude from the equator, but we have detected waves covering planetocentric latitudes between 20°S and 45°N. The great majority of the waves appear in regions associated with prograde motions of the mean zonal flow. Juno was unable to measure the velocity of wave features to diagnose the wave types due to its close and rapid flybys. However, both by our own upper limits on wave motions and by analogy with previous measurements, we expect that the waves JunoCam detected near the equator are inertia-gravity waves.
DOI: 10.48577/jpl.6b5qdp
title: ISMIP6 Antarctica: a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century

description: TS14Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and assess the mass loss that would contribute to future sea level rise. However, there is 5 currently no consensus on estimates of the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes, forcings employed and initial states of ice sheet models. This study presents results from 21 sets of ice flow model simulations from 13 inter10 national groups focusing on the evolution of the Antarctic ice sheet during the period 2015–2100 as part of the Ice Sheet Model Intercomparison for CMIP6 (ISMIP6). They are forced with outputs from a subset of models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), 15 representative of the spread in climate model results. Simulations of the Antarctic ice sheet contribution to sea level rise in response to increased warming during this period varies between 􀀀7:8 and 30.0 cm of sea level equivalent (SLE) under Representative Concentration Pathway (RCP) 8.5 sce20 nario forcing. These numbers are relative to a control experiment with constant climate conditions and should therefore be added to the mass loss contribution under climate conditions similar to present-day conditions over the same period. The simulated evolution of the West Antarctic ice sheet 25 varies widely among models, with an overall mass loss, up to 18.0 cm SLE, in response to changes in oceanic conditions. East Antarctica mass change varies between 􀀀6:1 and 8.3 cm SLE in the simulations, with a significant increase in surface mass balance outweighing the increased ice dis30 charge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional simulated mass loss of 28mm compared to simulations without ice shelf collapse. The largest sources 35 of uncertainty come from the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 climate models show an addi40 tional mass loss of 0 and 3 cm of SLE compared to simulations done under present-day conditions for the two CMIP5 forcings used and display limited mass gain in East Antarctica
DOI: 10.48577/jpl.m9tqh5
title: Mid-Range Forecasting of Solar-Wind: A Case Study of Building Regression Model with Space Weather Forecast Testbed (SWFT)

description: The Space Weather Forecast Testbed (SWFT) is developed by a team of space weather18 scientists and mathematicians at the University of Southern California (USC) and Jet19 Propulsion Laboratory (JPL) to foster the creation of models for space weather forecast20 by exploration of existing historic data using techniques of machine-learning. As an ex21 ample to demonstrate the potential power of SWFT, we present in this paper a multi22 linear regression based forecast model for solar wind. Solar wind is one of the key drivers23 for numerous physics-based models for space weather including thermosphere and iono24 sphere models. Many attempts have been made to produce forecasts for the solar wind.25 SWFT provides an unified framework for forecast model formulation, training and per26 formance assessment. In particular, the preparation of training and validation data by27 SWFT takes into account of realistic constraints on data latency and forecast lead time.28 In developing a solar wind forecast model, SWFT allows fast exploration of many meta29 parameters such as the list of predictive variables and their time history used in construct30 ing a model. We present the impact of meta-parameter selection, as well as, performance31 relative to existing solar wind forecast models.
DOI: 10.48577/jpl.qztt6m
title: The evolutionary track of H/He envelope in the observed population of sub-Neptunes and Super-Earths planets

description: The observational detection of a localized reduction in the small planet occurrence rate, sometimes termed a “gap”, is an exciting discovery because of the implications for planet evolutionary history. This gap appears to define a transition region in which sub-Neptune planets are believed to have lost their H/He envelope, potentially by photoevaporation or core powered mass loss, and have thus been transformed into bare cores terrestrial planets. Here we investigate the transition between sub-Neptunes and super-Earths by using envelope evolution models of the H/He envelope together with the mass-radius diagram and a photoevaporation model. We find that photoevaporation cannot explain the loss of the H/He envelope if the super-Earths and sub-Neptunes have the same core mass distribution. We explore the possibility that these planets families have different core mass and find that the primordial envelope fractions of the strongly irradiated super-Earths and the sub-Neptunes at an age of 100Myr is $\sim$12$\%$ of their original mass. This agreement suggests that these two groups are part of the same primordial, parent population. Our analysis also shows that sub-Neptunes with R$&lt;$3.5 R$_{\oplus}$ typically lose $\sim$ 70$\%$ of their primordial envelope.