cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.48577/jpl.5muzmf
title: The HITRAN2020 molecular spectroscopic database

description: The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables, including partition sums, that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the interveningyears).All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition ranges from updating a few lines of specic molecules to complete replacements of the lists and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increasedsubstantially, often featuring sub-percent uncertainties. Broadening parameters associated with the water vapor's ambient pressure were introduced to HITRAN for the first time and are available now for several molecules. The HITRAN2020 edition will continue taking advantage of the relational structure and thecient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition.
DOI: 10.48577/jpl.lj6myb
title: Seasonal Estimates and Uncertainties of Snow Accumulation from CloudSat Precipitation Retrievals

description: CloudSat is often the only measurement of snowfall rate available at high latitudes, making it a valuable tool for understanding snow climatology. The capability of CloudSat to provide information on seasonal and subseasonal time scales, however, has yet to be explored. In this study, we use subsampled reanalysis estimates to predict the uncertainties of CloudSat snow water equivalent (SWE) accumulation measurements at various space and time resolutions. An idealized/simulated subsampling model predicts that CloudSat may provide seasonal SWE estimates with median percent errors below 50% at spatial scales as small as 2 2. By converting these predictions to percent differences, we can evaluate CloudSat snowfall accumulations against a blend of gridded SWE measurements during frozen time periods. Our predictions are in good agreement with results. The 25th, 50th, and 75th percentiles of the percent differences between the two measurements all match predicted values within eight percentage points. We interpret these results to suggest that CloudSat snowfall estimates are in sufficient agreement with other, thoroughly vetted, gridded SWE products. This implies that CloudSat may provide useful estimates of snow accumulation over remote regions within seasonal time scales.
DOI: 10.48577/jpl.pzkdoy
title: Large metasurface-based optical concentrators for infrared photodetectors

description: We demonstrate large metasurface-based optical concentrators utilizing a modular design. In this approach each metasurface module comprising the optical concentrator is designed individually, thus reducing the required computational resources and improving the design versatility. Each module has an off-axis focal point, and this point is located in between the module center and the intended detector center. This reduces the necessary deflection angle, thus improving the concentrator design. We designed, fabricated and tested 300-$\mu$m-diameter metasurface-based optical concentrators operating in the 3-5 $\mu$m mid-wavelength infrared range. These optical concentrators are fabricated on a gallium antimonide substrate, which can be used for epitaxial growth of infrared detectors. This allows future monolithic integration of these concentrators with detectors epitaxially grown on the front side of the substrate, and concentrator fabricated on the backside. The optical concentrators enhanced the measured optical intensity at the intended detector position up to a factor of $6.4$, in the future this will improve the signal-to-noise ratio of detectors and increase their operating temperature.
DOI: 10.48577/jpl.vfnyg2
title: Characteristics, origins, and biosignature preservation potential of carbonate-bearing rocks within and outside of Jezero crater

description: Jezero crater, an ancient lake basin that is the landing site of the Mars 2020 Perseverance rover, contains a carbonate-bearing rock unit termed the margin fractured unit. Some of the carbonates in these rocks may have formed in a fluviolacustrine environment and therefore could preserve biosignatures of paleolake-inhabiting lifeforms. Here we evaluate whether these margin fractured unit carbonates formed as authigenic precipitates in a fluviolacustrine environment or via alteration of primary minerals by groundwater. We integrate thermal inertia measurements from the Thermal Emission Imaging System (THEMIS), spectral analyses from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), examination of stratigraphic relationships in Jezero crater using High Resolution Science Experiment (HiRISE) and Context Camera (CTX) images and digital elevation models. We also compare the Jezero crater results to observations from the Curiosity rover in Gale crater. We find that margin fractured bedrock with the deepest visible-to-near-infrared carbonate absorptions also has exceptionally high thermal inertia and thickness relative to other carbonate-bearing units in Jezero crater, consistent with enhanced cementation and crystallization by groundwater. Our results indicate that it is equally likely that carbonates in Jezero crater formed via alteration of primary minerals by alkaline groundwater rather than as authigenic precipitates in a fluviolacustrine environment. Jezero crater may have hosted ancient subsurface habitable environments related to these groundwaters, where life-sustaining redox energy was generated by water-rock interactions. The Mars 2020 Perseverance rover could encounter biosignatures preserved from this carbonate-forming environment, whether it was fluviolacustrine or in the subsurface.
DOI: 10.48577/jpl.jx7c35
title: The effects of heavy precipitation on Polarimetric Radio Occultation (PRO) bending angle observations

description: Following the successful launch of the Spanish PAZmission the proof of concept experiment “RadioOccultation and Heavy Precipitation with PAZ (ROHP-PAZ)” started operating in May 2018.The ROHP-PAZ observations demonstrated that precise measurements of the phase differencebetween horizontal and vertical polarizations from GNSS L-band signals are sensitive to orientedhydrometeors along the ray paths. While this differential phase shift measurement on the timedomain has proven very useful, the regular RO intermediate products from different polarizedchannels, such as bending angle and phase retrievals on the domain of impact parameter, have neverbeen exploited. In this research, we studied the characteristics of polarimetric phase and bendingangle difference retrieved by the radio-holographic (RH) method to mitigate atmospheric multipatheffect and to explore their use in data assimilation. To validate RH approach in polarimetricretrievals, we performed end-to-end simulations where the hydrometeors are modeled by theeffective refractivity with different horizontal extents. The simulation results show that the strongprecipitation (&gt;15mm/hr) with 40 km horizontal extent can be detected with the retrieved bendingangle shift. The calibration process on the impact parameter domain has also been developedto extract the differential phase and bending angle shift. Statistics from the actual PAZ data alsosuggests that the retrieved RH polarimetric phase shift is approximately proportional to the rain-rateat a ratio of 0.02 `rad/(mm/hr).
DOI: 10.48577/jpl.y6rsm6
title: Intraseasonal Sea-Level Variability in the Persian Gulf

description: Satellite observations are used to establish the dominant magnitudes, scales, and mechanismsof intraseasonal variability in ocean dynamic sea level () in the Persian Gulf over 2002–2015.Empirical orthogonal function (EOF) analysis applied to altimetry data reveals a basin-wide, singlesignedintraseasonal fluctuation that contributes importantly to variance in the Persian Gulf atmonthly to decadal timescales. An EOF analysis of Gravity Recovery and Climate Experiment(GRACE) observations over the same period returns a similar large-scale mode of intraseasonalvariability, suggesting that the basin-wide intraseasonal variation has a predominantly barotropicnature. A linear barotropic theory is developed to interpret the data. The theory representsPersian-Gulf-average () in terms of local freshwater flux, barometric pressure, and wind stressforcing, as well as at the boundary in the Gulf of Oman. The theory is tested using a multiplelinear regression with these freshwater flux, barometric pressure, wind stress, and boundary quantities as input, and as output. The regression explains 70%9% (95% confidence interval)of the intraseasonal variance. Numerical values of regression coefficients computed empiricallyfrom the data are consistent with theoretical expectations from first principles. Results point toa substantial non-isostatic response to surface loading. The Gulf of Oman boundary conditionshows lagged correlation with upstream along the Indian Subcontinent, Maritime Continent,and equatorial Indian Ocean, suggesting a large-scale Indian-Ocean influence on intraseasonal variation mediated by coastal and equatorial waves, and hinting at potential predictability. Thisstudy highlights the value of GRACE for understanding sea level in an understudied marginal sea.
DOI: 10.48577/jpl.jnkqkf
title: Disentanglement of energetic internal gravity waves and small-scale frontal dynamics

description: Oceanic fronts with lateral scales less than 20 km are now known to be one of the ma48jor contributors to the vertical heat uxes in the global ocean, which emphasizes their49 potential impact on Earth's climate. However, frontal dynamics with time scales less than50 one day, whose contribution to vertical heat uxes is thought to be signicant, are ob51scured by energetic internal gravity waves. In this study, we address this critical issue52 by disentangling IGWs and frontal dynamics using an approach based on characteris53tic scales of vertical variability. Results using a numerical model with very high-resolution,54 conrm that it is possible to recover frontal dynamics at short time scales and the as55sociated intense vertical velocities and vertical heat uxes. This opens up new perspec56tives for a more accurate estimation of the vertical exchanges of any tracers between the57 surface and the ocean interior.
DOI: 10.48577/jpl.wkfbxl
title: Planck Galactic Cold Clumps at High Galactic Latitude-A Study with CO Lines

description: Gas at high Galactic latitude is a relatively little-noticed component of the interstellar medium. In an effort to address this, forty-one Planck Galactic Cold Clumps at high Galactic latitude (HGal; |b| &gt; 25◦) 42 43 were observed with 12CO, 13CO and C18O J=1-0 lines, using the Purple Mountain Observatory 13.7-m telescope. 12CO (1-0) and 13CO (1-0) emission was detected in all clumps while C18O (1-0) emission was only seen in sixteen clumps. The highest and average latitude for sources detected in this survey are −71.43◦ and 37.8◦, respectively. Fifty-one velocity components were obtained and then each component was identified as a single clump. Thirty-three clumps were further mapped and 54 dense cores were extracted. The emission lines of the cores were studied and the average excitation temperature Tex of 12CO is 10.3 K. The average line width of thermal velocity dispersion and non-thermal velocity dispersion are 0.19 km s−1 and 0.46 km s−1 respectively, suggesting that these cores are dominated by turbulence. Distances of the HGal clumps given by Gaia dust reddening are about 200 pc. The ratio X13/X18 is significantly higher than that in the solar neighborhood, implying that HGal gas has a different star formation history compared to the gas in the Galactic disk. HGal cores with sizes from 0.01-0.1 pc show no notable Larson’s relation and the turbulence remains supersonic until the scale smaller than 0.1 pc. None of the HGal cores which bear masses from 0.01-1 M⊙ are gravitationally bound and are all confined with outer pressure.
DOI: 10.48577/jpl.zlvcdf
title: Evolution of Acyl Peroxynitrates (PANs) in wildfire smoke plumes detected by the Cross-Track Infrared Sounder (CrIS) over the western U.S. during summer 2018.

description: We use new peroxyacetyl nitrate (PAN) observations from the Cross-Track Infrared Sounder (CrIS) on the Suomi National Polar-orbiting Partnership satellite to investigate PAN over the western U.S. during the summer 2018 North American wildfire season. This period coincides with the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN). When combined with favorable background conditions, the resolution and sensitivity of CrIS is sufficient to observe PAN production in plumes. CrIS PAN normalized excess mixing ratios (NEMRs) in the Pole Creek Fire increase from 0.2% to 0.4% within 3-4 hours of physical aging, consistent with NEMRs calculated from WE-CAN observations. CrIS is also able to detect PAN and CO enhancements in plumes that have been transported hours to days downwind. On average for the study period, 24-56% of PAN in the free troposphere during the afternoon over the western U.S. can be attributed to fires.
DOI: 10.48577/jpl.1cvfka
title: Interpretation of the Precipitation Structure Contained in Polarimetric Radio Occultation Profiles Using Passive Microwave Satellite Observations

description: Observationally, a major source of uncertainty in evaluation of climate models arises from the difficulty in obtaining globally distributed, fine scale profiles of temperature, pressure and water vapor, that probe through convective precipitating clouds, from the boundary layer to the upper levels of the free troposphere. In this manuscript, a two-year analysis of data from the Radio Occultations through Heavy Precipitation (ROHP) polarimetric RO demonstration mission onboard the Spanish PAZ spacecraft is presented. ROHP measures the difference in the differential propagation phase delay (Δ𝜙) between two orthogonal polarization receive states that is induced from the presence of non-spherically shaped hydrometeors along the Global Navigation Satellite System (GNSS) propagation path, complementing the standard RO thermodynamicprofile. Since Df is a net path-accumulated depolarization and does not resolve the precipitationstructure along the propagation path, orbital coincidences between ROHP and the GlobalPrecipitation Measurement (GPM) constellation passive MW radiometers are identified toprovides three-dimensional precipitation context to the RO thermodynamic profile. Passive MWderived precipitation profiles are used to simulate the Δ𝜙 along the ROHP propagation paths.Comparison between the simulated and observed Δ𝜙 are indicative of the ability of ROHP to detectthreshold levels of ray path-averaged condensed water content, as well as to suggest possibleinferences on the average ice phase hydrometeor non-sphericity. The use of the polarimetric RO vertical structure is demonstrated as a means to condition the lower tropospheric humidity by the top-most height of the associated convective cloud structure.
DOI: 10.48577/jpl.lrzldg
title: Variational Bayesian Independent Component Analysis for InSAR Displacement Time-series with Application to Central California, USA

description: The exploitation of ever increasing Interferometric Synthetic Aperture Radar (InSAR)16 datasets to monitor the Earth’s surface deformation is an important goal of today’s geodesy.17 In this study our observations consist of deformations along the Line-Of-Sight (LOS) di18 rection of the satellite. Our observations are the result of the combination of a multi19 tude of sources (either volcano-tectonic or non-tectonic deformation). In most cases, we20 are facing a Blind Source Separation (BSS) problem. Natural approaches to tackle BSS21 problems are multivariate statistical techniques that attempt to decompose the dataset22 into a limited number of statistically independent sources, under the assumption that23 the different physical mechanisms contributing to the observations have independent foot24 prints in space and/or time. We show the capabilities of a variational Bayesian Indepen25 dent Component Analysis (vbICA) algorithm in dealing with synthetic InSAR time se26 ries and compare it to the commonly used FastICA algorithm. We explore the effective27 ness of the spatial and temporal mode decompositions. We apply vbICA on data rela28 tive to the San Joaquin Valley (SJV) and the Central San Andreas Fault (CSAF), Cal29 ifornia, spanning the time range 2015/03/01-2019/07/14. The proposed approach likely30 isolates the contribution of shallow and deep aquifers to the surface deformation as well31 as the elastic and inelastic deformation. We present a 1-dimensional compaction esti32 mation of the elastic and inelastic storage coefficients adopting a formalism that takes33 into account the last century water level history. Concerning the CSAF, the algorithm34 helps separating tectonic loading from seasonal behavior concentrated in the Quaternary35 sediments of the Salinas Valley.
DOI: 10.48577/jpl.wufxwy
title: Changes of South-Central Pacific Large-scale Environment Associated with Hydrometeors-Radiation-Circulation Interactions in a Coupled GCM

description: A common deficiency in coupled atmosphere-ocean models is the lack of stratocumulus 27 clouds near the west coasts of continents and shallow cumulus clouds over the trade wind regions. 28 In this study, we examine the changes of large-scale trade wind environment associated with 29 hydrometeors-radiation-circulation interactions, focusing over the south-central Pacific, by 30 carrying out experiments with falling ice (snow) radiative effects (FIREs) on or off using the 31 CESM1-CAM5 coupled model. We found that experiment with FIREs off (NOS) tends to have 32 too-warm (0.3—0.9 K) sea surface temperature (SST) over the east half of the Pacific, weaker 33 surface wind stress over the northeast side but stronger stress over the southwest side of the study 34 domain, lower-tropospheric wind fields with a cyclonic-like wind pattern that is similar to surface 35 wind stress, and weaker subsidence over the northeast side against observations/reanalysis data 36 and experiment with FIREs on (SON). The cyclonic-like wind pattern for changes between NOS 37 and SON causes stronger moisture convergence, accompanied with horizontal warm advection, 38 horizontal moist advection, and stronger effective ascending motion over the northeast side of the 39 study domain, building large-scale environmental conditions to facilitate middle- and high-clouds 40 instead of shallow cumulus clouds in nature. This large-scale environment in conjunction with the 41 warmer SSTs may be also responsible for the lacking of the stratocumulus clouds near the coast 42 of America. Remaining biases in SON such as the double intertropical convergence zone and 43 parameterization deficiencies may also prevent a more realistic simulation of trade wind clouds 44 and their associated large-scale environments.
DOI: 10.48577/jpl.ih61ea
title: Spectral Fidelity of Earth's Terrestrial and Aquatic Ecosystems

description: The Surface Biology and Geology (SBG) investigation aspires to create global maps of spectral surface reflectance and emissivity at a cadence of 16 days or better. For the first time these spectroscopic maps will have coverage to address global system-level questions about Earth's geology, cryosphere and ecosystems. The revolutionary potential poses a commensurate challenge: creating contiguous maps free from regional biases induced by atmosphere, geometry, or inversion error. To this end, high spectroscopic precision with uniform spectral response and stable spectral calibration will be crucial. This study quantifies the impact of spectral fidelity on SBG's aquatic and terrestrial ecosystem objectives. We find that contemporary algorithms for ecosystem trait retrieval demand better fidelity and uniformity than that of historical missions. Spectroscopic nonuniformities that have previously been considered acceptable can cause systematic errors larger than the instrument noise and of the same order as the variability SBG aims to measure. Moreover, their impact on atmospheric correction can induce climate-dependent systematic errors that thwart comparisons between ecosystems. These results underscore the importance of spectral uniformity in SBG sensor design.
DOI: 10.48577/jpl.lthn6b
title: Long-term observations of upper-tropospheric cloud ice from the MLS

description: Upper tropospheric cloud ice varies across different timescales and plays an important role in regulating Earth’s climate, but knowledge of the abundances and the variability of cloud ice has been limited for decades. The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument onboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) provides an unprecedented record of cloud ice measurements since its launch in April 2006. However, CALIPSO has left the A-Train in September 2018 and entered the C-Train orbit which follows a slightly different ground track with a different local crossing time. This orbit change challenges the continuation of a long-term record of cloud ice since ice is subject to stronger diurnal cycle. Fortunately, the Aura Microwave Limb Sounder (MLS), still as a member of the A-Train, has a consistent local crossing time and has measured high quality radiance since launch in 2004, and will probably continue beyond 2024. We present the use of MLS 640-GHz cloud-induced radiance (Tcir) to build a robust upper tropospheric partial ice water path (pIWP) product due to its high dynamical range to different sizes of ice particles. The MLS rebuilt pIWP, which extends nearly two decades, captures the spatial and temporal variabilities of upper tropospheric cloud ice that CALIOP is capable of measuring. This provides valuable alternative for studying the upper tropospheric cloud ice and possibly provides a more consistent input to climate studies.