We have used Mars Exploration Rover Opportunity data to investigate the origin and alteration of lithic types along the western rim of Noachian-aged Endeavour crater on Meridiani Planum. Two geologic units are identified along the rim. The Shoemaker formation consists of two types of polymict impact breccia: clast-rich with coarser clasts in upper units; clast-poor with smaller clasts in lower units. Comparison with observations at terrestrial craters show that the lower units represent more distal ejecta from one or more earlier impacts, and the upper units are ejecta from Endeavour crater. Both are mixtures of target rocks of basaltic composition. Subtle compositional differences are caused by differences in post-impact alteration along the crater rim. The lower Shoemaker units and the Matijevic formation represent pre-Endeavour geology, which we equate with the regionally mapped Noachian subdued cratered unit. An alteration style unique to these rocks is formation of Si- and Al-rich vein-like structures crosscutting outcrops, and formation of smectite. Post-Endeavour alteration is dominated by sulfate formation. Rim-crossing fracture zones include regions of alteration that produced Mg-sulfates as a dominant phase, plausibly closely associated in time with the Endeavour impact. Calcium-sulfate vein formation occurred over an extended time period, including pre-Endeavour impact and after the Endeavour rim had been substantially degraded, likely after deposition of the Burns formation that surrounds and embays the rim. Differences in Mg, Ca and Cl concentrations on rock surfaces and interiors indicate mobilization of salts by transient water that has occurred recently and may be ongoing.

Understanding wave propagation in granular sediments is important for subsurface characterization. The presence of fluid and wettability condition result in additional complexities. While it is known that wave propagation in dry granular porous media is dominated by the presence of force chains, their influence in (partially) saturated granular porous media with different wettability conditions remains largely unexplored. To make progress in this direction, we design laboratory experiments by combining core flooding and ultrasonic measurement in glassbead packings that are chemically treated to alternate the wettability. The P- and S-wave velocity-saturation relation and attenuation-saturation relation are obtained from the waveforms for both water- and gas-wetting samples. The results show that there is a transition from an attenuating but stable P-wave pulse at low and moderate saturation to a set of incoherently scattered waves at high saturation. The incoherent scattering in the gas-wetting case is negligibly small, whereas it is more pronounced in the water-wetting case. We conclude that only if water wets the grains, can the liquid enter the grain contacts. These liquid bridges are thought to locally reinforce the force chains and to increase their characteristic length scale. This leads to an increase in P-wave velocity and promotes incoherent scattering since the ratio of dominant wavelength to characteristic length scale decreases. In the gas wetting case, however, the presence of gas prevents the water from direct contact with the glass beads and therefore stops the formation and growth of the liquid bridges within the force chain network.

The dynamical ellipticity of a planet expresses the departure of its mass distribution from spherical symmetry. It enters as a parameter in the description of a planet's precession and nutation, as well as other rotational normal modes. In the case of the Earth, uncertainties in this quantity's history produce an uncertainty in the solutions for the past evolution of the Earth-Moon system. Constraining this history has been a target of interdisciplinary efforts as it represents an astro-geodetic parameter whose variation is shaped by geophysical processes, and whose imprints can be found in the geological signal. We revisit the classical problem of its variation during ice ages, where glacial cycles exerted a varying surface loading that had altered the shape of the geoid. In the framework of glacial isostatic adjustment, and with the help of a recent paleoclimatic proxy of ice volume, we present the evolution of the dynamical ellipticity over the Cenozoic ice ages. We map out the problem in full generality identifying major sensitivities to surface loading and internal variations in parameter space. This constrained evolution is aimed to be used in future astronomical computations of the orbital and insolation quantities of the Earth.

Tsunamis from earthquakes of various magnitudes have affected Cascadia in the past. Simulations of Mw>7.5–9.2 earthquakes constrained by earthquake rupture physics and geodetic locking models show that Mw>8.5 events initiating in the middle segments of the subduction zone can create coastal tsunami amplitudes comparable to those from the largest expected event. The simulations reveal that the concave coastline geometry of the Pacific Northwest coastline focuses tsunami energy between latitudes 44°-45° in Oregon. The possible coastal tsunami amplitudes are largely insensitive to the choice of slip model for a given magnitude. These results are useful for identifying the most hazardous segments of the subduction zone and demonstrate that a worst-case rupture scenario does not uniquely yield the worst-case tsunami scenario at a given location.

Large wildfires generate smoke that greatly compromises air quality over a wide area. Limited studies have suggested that smoke constituents may enter natural water bodies. In an 18-year water monitoring study, we examined whether smoke from distant wildfires had a detectable effect on ion content in a mountain river in an unburned watershed. Significant local wildfire smoke occurred in six years as traced by MODIS satellite data of fires, regional and local atmospheric fine particulate matter (PM2.5), and the amount of potassium (K+) in PM2.5 as a marker of vegetation combustion. Rainwater had elevated K+ and calcium (Ca2+, also associated with wildfire smoke) in smoke years compared to no-smoke years, and was the primary route of atmospheric deposition. Similarly, river water in smoke years had elevated concentrations of K+ and Ca2+, with a higher ratio of K+ to Ca2+ compared to no-smoke years. River concentrations were generally unrelated to river discharge and observed K+ concentrations in smoke and no-smoke years could be accounted for atmospheric deposition. Our study provides early evidence that wildfires affect water quality far beyond the watersheds where they occur. Wildfires are increasing in frequency and extent worldwide, widely distributing vast quantities of smoke containing nutrients, toxins and microbes. Potassium is a routinely-measured water quality parameter that can act as a sentinel of smoke inputs. Further work is needed on the patterns and processes by which wildfire smoke enters water as well as on the consequences for ecosystems and human health.

The Holocene evolution of the Indian Ocean Monsoon (IOM), especially the spatiotemporal nature of its maximum precipitation period, remains controversial. Here we present a high-resolution Holocene IOM rainfall record from the southern Andaman Sea. The local δ18Oseawater values suggest that local maximum rainfall occurred at 10.6-8.6 ka in the southern Andaman Sea. But the sedimentation rate and grain size detailing IOM precipitation in the northern subtropical regions exhibited its highest value at 8.6-5.5 ka. After making further comparisons with other published records for this region, we propose that maximum IOM precipitation exhibited a clearly meridional migration from south to north during the Early Holocene, which was possibly caused the combined influence of the Intertropical Convergence Zone (ITCZ) movement and the El Niño Southern Oscillation (ENSO) activities.

We investigate the synoptic precursors to the Harmattan wind and dust frontogenesis during the high impact Saharan dust outbreak over the Cape Verde Islands on 13 November 2017. We employ multi-scale observations including ship data and Weather Research and Forecasting model Coupled with Chemistry simulations. The analyses indicate that the dust storm was initiated on the leeside of the Saharan Atlas Mountains (SAM) in Algeria on the 10. This dust storm was associated with a double Rossby Wave Break (RWB) linked through non-linear wave reflection. Two successive RWB contributed to the wave amplification over the Eastern North Atlantic Ocean which transported large magnitude potential vorticity air into the North African continent. The resulting coupled pressure surge was associated with cold air advected equatorward over the SAM which organized the strong near-surface wind that ablated the dust. The simulation results indicate that the dust front was initially related to a density current which formed due to the cold airflow over the SAM. The density current then triggered undular bores on the leeside. Each bore perturbed the dust loading and then the subsequent diurnal heating generated differential planetary boundary layer (PBL) turbulence kinetic energy strengthening the dust frontogenesis. Dust became confined behind the cold surge and interacted with the daytime Saharan PBL leading to increased dust loading while the dust front propagated equatorward. Two distinct dust plumes arrived successively at low-levels at Mindelo, Cape Verde Islands; (1) from the coasts of Mauritania and Senegal and (2) from the SAM southern flank.

We report in situ rates of gross oxygen production (GOP), community respiration (R), and net community production (NCP) in the North Pacific Subtropical Gyre derived from mixed layer O/Ar measurements. The measurements were conducted between November 2013 and January 2019 at the site of the Hawaii Ocean Time-series program. Biological O concentration anomalies in the mixed layer showed a consistent diel variation, with values increasing during daytime due to net primary production and decreasing during nighttime due to respiration. In situ mixed layer GOP and R, determined from these variations, co-varied but showed no clear seasonal pattern, averaging 0.9 and 0.8 mmol O m d, respectively. In situ rates of NCP determined from mixed layer O/Ar ranged between -0.7 and 17.6 mmol O m d. Our analyses indicate that at certain times of the year the diapycnal flux of O across the base of the mixed layer may be non-negligible and therefore a fraction of O/Ar-derived NCP may form below the mixed layer. The seasonal climatology of NCP below the mixed layer (down to 150 m) was also estimated using near-monthly changes in dissolved O concentrations. These calculations allowed us to estimate NCP for the entire euphotic zone (0-150 m), which shows pronounced seasonality, with a maximum in May and a minimum in December, when the ecosystem becomes temporarily net heterotrophic. Annual NCP was estimated to be 2.4 ± 0.5 mol O m yr, approximately twice the export of C through sinking particles captured in sediment traps at 150 m.

On 13 November 2017, a strong continental-scale Saharan dust outbreak was observed in satellite imagery over Mindelo, Cape Verde, located about 650 km off the coast of Senegal in West Africa. Horizontal visibility was reduced to 1100 m leading to major disruptions of the local air traffic. Dust mobilization was already observed over the foothills of the Saharan Atlas Mountains at 0600 UTC on 10 November 2019 but did not appear clearly in SEVIRI pink dust images in the subsequent days. In this study, we examined the multi-scale dynamical processes associated with this particular dust storm using ECMWF ERA-Interim reanalysis data, newly performed very-high resolution WRF-CHEM simulations with horizontal grids of 18 km and less, NAAPS aerosol forecast output, ship-based observation dataset from the North Atlantic Expedition MSM 68/2, as well as surface observations, and upper-air soundings from weather stations in North Africa. Our analyses of this storm highlights the following meteorological processes: (1) the event was associated with a typical Harmattan surge, i.e., the post-frontal strengthening of the northerly winds behind an eastward moving cyclone, (2) a series of earlier Rossby Wave Breaking events (RWBs) made the environment favorable for the Harmattan surge, (3) the dust storm was composed of two distinct dust surges, (4) the dust aerosol from the first surge was later mixed with the dust from the second surge while simultaneously propagating south-westward and later westward, (5) the PBL became adiabatic along the leading edge of the leftover cold front between the southern/southeastern flank of the Atlas Mountains and western/northwestern flank of the Hoggar Mountains, and (6) vertical dust mixing then occurred due to very strong surface heating associated with the development of a deep daytime PBL in the region behind the cold front. The results of this research demonstrate that very-high spatial resolution WRF-CHEM model can resolve the dynamical processes and realistically simulate large-scale North African dust storm.

Inverse modelling method named Maximum likelihood Ensemble Filter (MLEF) was used to estimate gridded surface CO fluxes using continuous, flask and Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) data for the years 2009-2011. Here, MLEF coupled with Parametric Chemistry Transport Model (PCTM) driven by Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA2) weather data has been used. Flux estimation was done by solving separate multiplicative biases for photosynthesis, respiration, and air-sea gas exchange fluxes. Hourly land fluxes derived from Simple Biosphere-version 3 (SiB3) model, Takahashi ocean fluxes and Brenkert fossil fuel emissions were used as the prior fluxes. The inversion was carried out by assimilating hourly CO observations, According to this study, North America showed about 60-80% uncertainty reduction while the Asian and European regions showed moderate results with 50-60% uncertainty reduction. Most other land and oceanic regions showed less than 30% uncertainty reduction. The results were mainly compared with well-known CarbonTracker and some parallel inversion studies by considering long-term averages of the estimated fluxes for the TransCom regions. Boreal North America, Temperate North America and Australia showed similar annual averages in each case. Tropical Asia and Europe showed comparable results with all other studies except for the CarbonTracker. The biases were poorly constrained in the regions having few measurement sites like South America, Africa and Eurasian Temperate which showed completely different result with other studies.

Identification of internal structures in an active volcano is mandatory to quantify the physical processes preceding eruptions. We propose a fully unsupervised Bayesian inversion method that uses the point compound dislocation model as a complex source of deformation, to dynamically identify the substructures activated during magma migration. We applied this method at Piton de la Fournaise. Using 7-day moving trends of GNSS data preceding the June 2014 eruption, we compute a total of 15 inversion models of 2.5 million forward problems each, without a priori information. Obtained source shapes (dikes, prolate ellipsoids or pipes) exhibit a global migration from 7-8 km depth to the surface, drawing a “mechanical tomography”? of the plumbing system. Our results allow retrieving geometries compatible with observed eruptive fissures and seismicity distribution, and the retrieved source volume variations made this method a good proxy to anticipate erupted lava in case of no co-eruptive refilling.

A three-dimensional (3-D) hydrodynamic model based on Princeton Ocean Model (POM) and a one-dimensional (1-D) lake model are applied to simulate the thermal structure and circulations of Lake Nam Co (LNC), the second largest lake in Tibet. Results show that POM can well reproduce the seasonal and synoptic variations of the in-situ observed vertical temperature profile, and the spatial distribution of satellite estimated lake surface temperature during May-December 2013. However, without considering the water and energy exchanges related to the lake hydrodynamics, the 1-D model exhibits much more evident biases in the lake thermal evolution. These shortages of the 1-D lake model solutions emphasize that the complex temperature-current interactions must be accounted for investigating the thermodynamics in large lakes over Tibet. From both observation and hydrodynamic simulations, LNC is identified to experience the springtime overturning, warm stratified phase during early-June to mid-November, autumnal overturning, and weak inverse stratified phase since mid-December. The two overturning processes last for about one month and are both related to the thermal bar development, which is controlled by the density-driven convection associated with the radiative heating (surface cooling) in spring (autumn). During the warm stratified phase, the eastern shallow basin is mainly characterized by anticyclonic circulation and bowl-shaped thermocline, while the central deep basin is featured by a cyclonic gyre (eastward currents) and dome-shaped (bowl-shaped) thermocline with the enhancement (weakness) of thermal stratification. The lake circulation during December is basically dominated by a single strong cyclonic gyre in the main lake basin.

The five divisions of NASA’s Science Mission Directorate (SMD) represent a very broad spectrum of academic disciplines, ranging from Astronomy, to Planetary science, to Heliophysics, Earth science, Biology and Physical science with measurement scales ranging from components of atoms to the structure of the entire universe. In addition, the systems that support access to these data range from systems based on formal and broadly accepted OWL ontologies, to those based on current and historical disciplinary metadata standards, to ad-hoc or bespoke systems dating back to NASA’s very earliest missions; all generally developed to support the mission or, more recently, discipline focussed data users. Consequently the access mechanisms, data structures, vocabularies, terms in use, etc. vary widely across the divisions making cross-disciplinary research at best difficult if not impossible. Currently NASA SMD is working to improve support for cross-disciplinary/transdisciplinary research by developing a system that supports discovery across all of SMD’s data products, a model that can be extended to all forms of scientific output including software, tools, models, publications, etc. The core underpinnings of such a system is an information model being developed using the methodology developed by Dr. Peter Fox and Dr. Deborah McGuinness. Here we discuss the model (a knowledge graph), lessons learned along the way, and key findings for other systems attempting to bridge across broad disciplinary challenges.

Juno was inserted into a highly elliptic, polar, orbit about Jupiter on July 4th 2016. Juno’s magnetic field investigation acquires vector measurements of the Jovian magnetic field using a flux gate magnetometer co-located with attitude-sensing star cameras on an optical bench. The optical bench is placed on a boom at the outer extremity of one of Juno’s three solar arrays. The Magnetic Field investigation (MAG) uses measurements of the optical bench inertial attitude provided by the micro Advanced Stellar Compass (µASC) to render accurate vector measurements of the planetary magnetic field. During periJoves, MAG orientation is determined using the spacecraft (SC) attitude combined with transformations between SC and MAG. Substantial pre-launch efforts were expended to maximize the thermal and mechanical stability of the Juno solar arrays and MAG boom. Nevertheless, flight experience demonstrated that the transformation between SC and MAG reference frames varied significantly in response to spacecraft thermal excursions associated with large attitude maneuvers and proximate encounters with Jupiter. This response is monitored by comparing attitudes provided by the MAG investigation’s four CHU’s and the spacecraft attitude. These attitude disturbances are caused by the thermo-elastic flexure of the Juno solar array in response to temperature excursions associated with maneuvers and heating during close passages of Jupiter. In this paper, we investigate these thermal effects and propose a model for compensation of the MAG boom flexure effect.

In their paper, Le mouël et al, (2019) argued that over the past 150 years “most of the variability of surface temperatures could be natural and primarily controlled by the Sun”. We do not agree with their conclusions for several reasons which are (1) a biased interpretation of the Fourier and SSA spectrum, which show no significant co-variability between sunspot amounts and emperature, (2) the small radiative forcing associated with the long-term sunspot variability, and finally the evidence that the slowly-varying components of the temperature and sunspots time-series show opposite trend in the last 30 years.

The Quasi-Biennial Oscillation (QBO) of zonal-mean zonal winds in the tropical stratosphere is a conspicuous feature of the Earth climate. Its influence virtually extends to the whole atmosphere. The QBO is driven by the dissipation of waves generated by deep convection in the tropics. Yet, a significant fraction of these waves have spatial scales that are not explicitly resolved in current climate models, so that the evolution of the QBO in a changing climate still remains unclear. A study by \citeA{Vincent2020} shows that recent long-duration balloon observations, combined with information on the vertical structure of the tropical atmosphere, could contribute to provide significantly improved constraints on wave parameterization in models.

How variations in Earth's orbit pace the glacial-interglacial cycles of the Quaternary are probably one of the greatest mysteries of modern climate science. Supposing coevolution of climate, ice sheets, and carbon cycle over the past 3 million years a current theory cannot explain the observations when it is driven by orbital variations as the only external forcing. Taking advantage of the alkenone paleothermometer in sediment cores sampled in the Tasman Sea floor, we show that the transition of glacial-interglacial periods from 41,000- to 100,000-year that happened during the mid-Pleistocene is not singular. A similar transition involving 10 times longer periods occurred at the hinge of Pliocene-Pleistocene. Referring to the recent theory of gyral Rossby waves we put forward the idea that the climate system preferentially responds to certain orbital variations according to subharmonic modes, which is inherited from the resonant forcing of Rossby waves wrapping around the subtropical gyres.

As the problems humanity faces become ever more obvious and dangerous, the need for interdisciplinary, cross-disciplinary and trans-disciplinary research and solutions becomes ever more apparent. The problems themselves are often intertwined in complex ways - for example the impact of climate change on human health, food & water security, disasters, and so on and how all of these are exacerbated by human population growth and a general lack of recognition that humanity is part of the ecosystem upon which Earthly life depends. Underpinning our ability to understand and solve these complex problems are data of all kinds, more importantly the information that has and continues to be garnered through obtaining and analyzing these and most importantly their inclusion in the larger body of knowledge and ways of knowing that hopefully leads to the wisdom needed to directly address the root causes of each problem. Over the past decades, through involvement in projects on science topics as diverse as quasars and stellar pediatrics, solar physics, social science, and a wide variety of Earth Science topics; where informatics topics such as data management and curation, systems and framework development; and tools and methodologies such as Use Cases, Natural Language Processing, Deep Learning, Knowledge Graphs, Information Models, etc. were included; a number of principles and lessons learned which unite the technical underpinnings of these projects have come to the fore. These will be discussed in this presentation.