Analyses of Lunar Laser Ranging data show that the spin‐symmetry axis of the Moon is ahead of its expected Cassini state by an angle of 𝜙p = 0.27 arcsec. This indicates the presence of one or more dissipation mechanisms acting on the lunar rotation. A combination of solid‐body tides and viscous core‐mantle coupling have been proposed in previous studies. Here, we investigate whether viscoelastic deformation

The dates of the transition between winter and summer (W2S) and between summer and winter (S2W) regional-scale atmospheric regimes have been defined using daily weather types above and around the Caribbean basin from 1979 to 2017. The uncertainties due to either the use of two different reanalyses (i.e., NCEP-DOE and ERA-Interim) or the parametrization used for the definition of the transition dates

This study investigates how teleconnections linking tropical rainfall anomalies and wintertime circulation in the northern extra-tropics are represented in historical simulations for the period 1950–2010 run by partners of the EU-funded PRIMAVERA project, following the HighResMIP protocol of CMIP6. The analysis focusses on teleconnections from the western/central Indian Ocean in mid-winter and from

We present a power spectral analysis of two narrow annular regions near Jupiter's South Pole derived from data acquired by the Jovian Infrared Auroral Mapper instrument onboard NASA's Juno mission. In particular, our analysis focuses on the data set acquired by the Jovian Infrared Auroral Mapper M‐band imager (hereafter IMG‐M) that probes Jupiter's thermal emission in a spectral window centered at

The frequency and intensity of extreme hydrological events (droughts and floods) have been increasing over the past few decades, which has been posing a threat to water security and agriculture production. Thus, projecting the future evolution of hydrological extremes plays a crucial role in sustainable water management and agriculture development in a changing climate. In this study, we develop the

A new 1.5 meter diameter impact crater was discovered on Mars only ~40 km from the InSight lander. Context camera images constrained its formation between February 21 and April 6, 2019; follow‐up HiRISE images resolved the crater. During this time period, three seismic events were identified in InSight data. We derive expected seismic signal characteristics and use them to evaluate each of the seismic

This study investigates the influences of internal climate variability (ICV) on Eurasian spring (March–May) surface air temperature (SAT) trends based on a 30-member ensemble of the Community Earth System Model version 1 (CESM1) from 1979 to 2014. The SAT trends over the mid-high latitude Eurasia vary considerably among individual simulations, indicating a large impact of ICV on SAT trends at regional

Extraordinarily frequent and long-lasting snowstorms affected China in January 2008, causing extensive social and economic damages. The potential predictability of such extreme events on the sub-seasonal timescale has been evaluated using results from the hindcast experiments by the Beijing Climate Center Climate System Model. The spatial distribution of precipitation during the period can be successfully

How much and fast the Earth is warming in response to increasing greenhouse gas concentrations is one of the fundamental questions in climate science. Here we investigate the role that different modes of climate variability play in modulating the temperature response. We show evidence for a robust statistical relationship between global warming rate variations and Atlantic Multidecadal Variability

The first EOF mode (EOF1) of summer storm track activity over the North Atlantic is characterized by a dipole structure, with negative storm track anomalies over the south coast of Greenland extending northeast across Iceland to the Norwegian Sea and positive anomalies over coastal western Europe. This study shows that a significant interdecadal change in the North Atlantic storm track during boreal

Convection-permitting climate models have shown superior performance in simulating important aspects of the precipitation climate including extremes and also to give partly different climate change signals compared to coarser-scale models. Here, we present the first long-term (1998–2018) simulation with a regional convection-permitting climate model for Fenno-Scandinavia. We use the HARMONIE-Climate

Near‐Earth asteroid (101955) Bennu is an active asteroid experiencing mass loss in the form of ejection events emitting up to hundreds of millimeter‐ to centimeter‐scale particles. The close proximity of the Origins, Spectral Interpretations, Resource Identification, and Security–Regolith Explorer (OSIRIS‐REx) spacecraft enabled monitoring of particles for a 10‐month period encompassing Bennu’s perihelion

Comprehensive analysis of remote sensing data used to select the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) landing site correctly predicted the atmospheric temperature and pressure profile during entry and descent, the safe landing surface, and the geologic setting of the site. The smooth plains upon which the InSight landing site is located, were accurately

We analyze the trajectories of 313 particles seen in the near‐Bennu environment between December 2018 and September 2019. Of these, 65% follow sub‐orbital trajectories, 20% undergo more than one orbital revolution around the asteroid, and 15% directly escape on hyperbolic trajectories. The median lifetime of these particles is ~6 h. The trajectories are sensitive to Bennu's gravitational field, which

Laplace‐like resonances among Ganymede, Europa, and Io may have once led Ganymede to have an eccentricity (presently e  = 0.0013) as high as ~0.07 (Showman & Malhotra, 1997, https://doi.org/10.1006/icar.1996.5669). While diurnal stresses at Ganymede today are small (less than 10 kPa), a previous period of higher eccentricity may have allowed for an order of magnitude increase in the diurnal tidal stresses

Recent studies suggest that the wintertime North Pacific eddy-driven jet stream will strengthen and extend eastward in response to Arctic sea ice loss. Using output from the Polar Amplification Model Intercomparison Project we examine the mean change of the North Pacific wintertime zonal winds, and use cluster analysis to explore the change in sub-seasonal, wintertime variability in zonal winds between

The major physiographic “smooth plains” units on Mercury are dominantly composed of volcanic deposits that have been deformed by horizontal compressive stresses. An open issue is whether these features formed by stresses induced by global contraction, bending stresses due to volcanic loading, or some combination of both. In this study, we model the surface expression of 12 shortening structures within

Increasing precipitation on the Antarctic Ice Sheet (AIS) in a warming climate has the potential to partially mitigate Antarctica’s contribution to sea level rise. We show that a simple, physically motivated change to the shallow convective cloud phase in the Community Earth System Model (CESM)—improving a long-standing bias in shortwave cloud forcing over the Southern Ocean—leads to an enhanced response

We examine the weakening of the Atlantic Meridional Overturning Circulation (AMOC) in response to increasing CO\(_2\) at different horizontal resolutions in a state-of-the-art climate model and in a small ensemble of models with differing resolutions. There is a strong influence of the ocean mean state on the AMOC weakening: models with a more saline western subpolar gyre have a greater formation of

In 2015, the New Horizons spacecraft flew past Pluto and its moon Charon, providing the first clear look at Charon's surface. New Horizons images revealed an ancient surface, a large, intricate canyon system, and many fractures, among other geologic features. Here, we assess whether tidal stresses played a significant role in the formation of Charon's tensile fractures. Although presently in a circular

The semi-arid African Sahel region is highly sensitive to changes in monsoon precipitation, as much of the region’s workforce is employed in the agricultural industry (Hamro-Drotz and Programme 2011). Thus, studying the response of rainfall and aridity in this region to radiative perturbations is a matter of pressing humanitarian relevance. In addition, there is evidence to suggest that spatially asymmetric

Planetary impact events eject large volumes of surface material. Crater excavation processes are difficult to study, and in particular the details of individual ejecta fragments are not well understood. A related, enduring issue in planetary mapping is whether a given crater resulted from a primary impact (asteroid or comet) or instead is a secondary crater created by an ejecta fragment. With mapping

The chronology of the moons of Saturn, especially Titan, has been limited by a lack of strong constraints on the cratering rate, low number statistics for small‐N counts of large‐diameter craters, and uncertainty about whether impactors are mostly heliocentric impactors orbiting the Sun or planetocentric impactors orbiting Saturn itself. Here, I propose to address these three problems. Instead of looking

We construct a simple cloud model for a Venus general circulation model (GCM), which includes condensable gases of H2O and H2SO4 vapors, and condensation, evaporation, and sedimentation of sulfuric acid cloud particles. The zonally averaged mass loading of the cloud reproduced in the model takes its maximum and minimum in high and middle latitudes, respectively. This latitudinal distribution is consistent

Most of the organics detected on Mars so far are aliphatic and aromatic organo‐chlorine compounds. The smallest were first identified by the thermal treatment of the solid samples by Viking in 1976; although at the time, they were attributed to contamination. Since 2012, a larger variety of structures have been identified by the Sample Analysis at Mars experiment aboard the Curiosity rover. Evidence

Planetary radar has provided a growing number of data sets on the inner planets and near‐Earth and main belt asteroid populations in the solar system. Physical interpretation of radar data for inference of surface properties requires constraints on the constitutive parameters of the material making up a given surface. In this study, the complex permittivity of seven minerals as a function of frequency

Ozone in the upper troposphere–lower stratosphere (UTLS) is primarily regulated by tropospheric dynamics. Understanding mechanisms driving ozone variability at the UTLS is crucial to evaluate the transport of mass to and from the lower stratosphere. The El Niño-Southern Oscillation (ENSO) is the primary coupled mode acting on interannual timescales modulating tropospheric circulation worldwide. ENSO

Monsoon intra-seasonal oscillation (MISO) represents a quasi-periodic occurrence of rainfall spells over India during summer monsoon (June–September) associated with large-scale circulation and convection. The connection of MISO with the hydrological cycle has been explored in this study through stable oxygen (δ18O) and hydrogen isotope ratios (δD) in rainwater samples collected from two stations located

Mars atmospheric pressure variations induce ground displacements through elastic deformations. The various sensors of the InSight mission were designed in order to be able to understand and correct for these ground deformations induced by atmospheric effects. Particular efforts were made, on one hand, to avoid direct pressure and wind effects on the seismometer and, on the other hand, to have a high

A large parameter-perturbed ensemble (PPE) of the Met Office climate model is used to explore the relationship between radiative feedbacks and the present-day simulation of the associated physical processes. We highlight three tropical regimes (deep convection over ocean and land, and marine stratocumulus) in which the same set of processes drives the present-day simulation of clouds and their feedbacks

No abstract is available for this article.

Basaltic lava flows are common on the surface of the Earth and other terrestrial bodies. However, inflation—including a combination of initially rapid molten core thickening and gradual crustal growth—must be accounted for to enable accurate reconstructions of eruption parameters from observed lava flow morphologies. The shape of an inflated lava flow can change significantly over time. Therefore,

Noise prediction from streamlined bodies such as wind turbine blades can be predicted accurately using CFD computations that use spatio-temporal turbulence models at the expense of high computational power. In this work, empirical methods proposed from BPM, Grosveld and Lowson are used to compute numerically to analyse the influence of rotor solidity factor on broadband trailing edge noise from a 2 MW

Global dust storms are the most thermodynamically significant dust events on Mars. The most recent of these events occurred in 2018. Although it was monitored by several spacecraft in orbit and on the surface, many questions remain regarding its onset, expansion and decay. Here, we model the 2018 event with the National Aeronautics and Space Administration (NASA) Ames Mars Global Climate Model in order

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

An amendment to this paper has been published and can be accessed via the original article.

he Curiosity rover’s exploration of rocks and soils in Gale crater has provided diverse geochemical and mineralogical datasets, underscoring the complex geological history of the region. We report the crystalline, clay mineral, and amorphous phase distributions of four Gale crater rocks from an 80‐meter stratigraphic interval. The mineralogy of the four samples is strongly influenced by aqueous alteration

Aeolian megaripples, with five to fifty meter spacing are abundant on the surface of Mars. These features were repeatedly targeted by high‐resolution orbital images, but they have never been observed to move. Thus, aeolian megaripples (especially the bright‐toned ones often referred as Transverse Aeolian Ridges ‐ TARs) have been interpreted as relict features of a past climate. In this report, we show

Geochemical results are presented from Curiosity’s exploration of Vera Rubin ridge (VRR), in addition to the full chemostratigraphy of the predominantly lacustrine mudstone Murray formation up to and including VRR. VRR is a prominent ridge flanking Aeolis Mons (informally Mt. Sharp), the central mound in Gale crater, Mars, and was a key area of interest for the Mars Science Laboratory mission. ChemCam

Sulfur‐water chemistry plays an important role in the middle atmosphere of Venus. Ground based observations have found that simultaneously observed SO2 and H2O at ~64 km vary with time and are temporally anti‐correlated. To understand these observations, we explore the sulfur‐water chemical system using a one‐dimensional chemistry‐diffusion model. We find that SO2 and H2O mixing ratios above the clouds

New results (Grassi et al., 2020) from analysis of Juno Jovian Infrared Auroral Mapper (JIRAM) 4‐5 μm observations provide updated latitudinal abundance profiles and measurements of the spatial distribution of H2O, NH3, PH3, GeH4, and AsH3 in Jupiter's troposphere near the 3‐5 bar level. The observed compositional variations provide new constraints on processes shaping chemical abundances in the cloud‐forming

The asymmetric gravity field measured by the Juno spacecraft has allowed the estimation of the depth of Jupiter's zonal jets, showing that the winds extend approximately 3000 km beneath the cloud level. This estimate was based on an analysis using a combination of all measured odd gravity harmonics, J3, J5, J7, and J9, but the wind profile's dependence on each of them separately has yet to be investigated

Recent planetary data and geophysical modelling suggest that hydrothermal activity is ongoing under the ice crust of Enceladus, one of Saturn's moons. According to these models, hydrothermal flow in the porous, rocky core of the satellite is driven by tidal deformation that induces dissipation and volumetric internal heating. Despite the effort in the modelling of Enceladus' interior, systematic understanding‐‐‐and

Vera Rubin ridge (VRR) is an erosion‐resistant feature on the northwestern slope of Mount Sharp in Gale crater, Mars, and orbital visible/short‐wave infrared measurements indicate it contains red‐colored hematite. The Mars Science Laboratory Curiosity rover performed an extensive campaign on VRR to study its mineralogy, geochemistry, and sedimentology to determine the depositional and diagenetic history

One of the most mysterious lunar features discovered during the Apollo era was Ina, a ~2 × 3‐km depression composed of bleb‐like mounds surrounded by hummocky and blocky terrains. Subsequent studies identified dozens of similar features in lunar maria, describing them as Irregular Mare Patches (IMPs). Due to the unusual and complex characteristics of IMPs, their specific formation mechanism is debated

The Cassini state equilibrium associated with the precession of the Moon predicts that the mantle, fluid core, and solid inner core precess at different angles. We present estimates of the dissipation from viscous friction associated with the differential precession at the core‐mantle boundary (CMB), Q c m b , and at the inner core boundary (ICB), Q i c b , as a function of the evolving lunar orbit

The rate of warming of the Arctic surface temperature has exceeded that of the global surface temperature in recent decades. However, the underlying process and causes of the long-term warming remain uncertain. In this paper, we explored the factors underlying variation in Arctic mean surface temperature anomalies (AMTA) using a piecewise linear model for 1920–2018. This analysis indicated that the

For the first time, we analyze 2.2 km UK Met Office Unified Model convection-permitting model (CPM) projections for a pan-European domain. These new simulations represent a major increase in domain size, allowing us to examine the benefits of CPMs across a range of European climates. We find a change to the seasonality of extreme precipitation with warming. In particular, there is a relatively muted

The response of the North Pacific storm track to the mesoscale sea surface temperature (SST) in winter is investigated via a global high-resolution atmospheric model. A simulation forced by eddy-resolving SST is compared with a simulation in which the mesoscale SST is filtered out. The results show that removing the mesoscale SST could greatly influence the storm track in the free atmosphere, with

Determining how global dust storms originate and develop is one of the major challenges of Martian meteorology. We model the 2018 global dust storm using the Ensemble Mars Atmosphere Reanalysis System (EMARS), combining satellite observations with a Mars global climate model via data assimilation. A reanalysis is a valuable data set for this investigation because it is anchored to the real Martian

The lunar opposition effect is the increase of brightness on the lunar surface when the phase angle approaches 0°, which is caused mainly by shadow‐hiding and coherent backscattering. However, the contribution of coherent backscattering is not yet well established. This study analyzes the contribution of coherent backscattering to the opposition effect using the correlation between the contribution

In response to the high demand for more skillful climate forecasts at the seasonal timescale, innovative climate prediction systems are developed with improved physics and increased spatial resolution. Alongside the model development process, seasonal predictions need to be evaluated on past years to provide robust information on the forecast performance. This work presents the quality assessment of

The lunar floor‐fractured crater Gassendi and surrounding area were examined with high‐resolution Lunar Reconnaissance Orbiter imagery and other remote‐sensing data to characterize and understand the volcanic processes in the southwestern region of the Moon. This study was selected because the Gassendi region exhibits a variety of volcanic features (e.g., cryptomaria deposits, pyroclastic deposits

A high‐angular momentum giant impact with the Earth can produce a Moon with a silicate isotopic composition nearly identical to that of Earth's mantle, consistent with observations of terrestrial and lunar rocks. However, such an event requires subsequent angular momentum removal for consistency with the current Earth‐Moon system. The early Moon may have been captured into the evection resonance, occurring

Moisture sources and pathways over the Limpopo River Basin (LRB) in southern Africa were identified using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model applied to NCEP II (2.5° × 2.5°) reanalysis data for 1981–2016. The 10-day air parcel backward trajectories were produced for the extended wet season (October–April) as well as the early and late summer. Analysis of a 36-year

The Madden Julian oscillation (MJO) has a systematic influence on the state of the extratropical atmosphere. The physical mechanism involves teleconnections from tropical deep convective heat sources through wave propagation. MJO heating resembles a propagating dipole that cycles through phases on a timescale similar to the response timescale. This complicates the attribution of the response to a well

The impact of climate change on Sahel precipitation suffers from large uncertainties and is strongly model-dependent. In this study, we analyse sources of inter-model spread in Sahel precipitation change by decomposing precipitation into its dynamic and thermodynamic terms, using a large set of climate model simulations. Results highlight that model uncertainty is mostly related to the response of

Large Eddy Simulations are carried out to analyze flow past flat plate in different configurations and inclinations. A thin flat plate is considered at three inclination angles (α = 30°, 60° and 90°) and three aspect ratios (AR = 0.5, 2 and 5). The Reynolds number based on the free stream velocity and chord length of the plate at different inclination angles varies between 75,000 to 150,000. An increase

Hydrothermal high sanidine and specular hematite are found within ferric‐rich and grey‐colored cemented basaltic breccia occurring within horizontal, weathering‐resistant strata exposed in an erosional gully of the Pu’u Poliahu cinder cone in the summit region of Maunakea volcano (Hawai’i). The cone was extensively altered by hydrothermal, acid‐sulfate fluids at temperatures up to ~400 °C, and, within

The NASA Curiosity rover’s ChemCam instrument suite has detected boron in calcium‐sulfate‐filled fractures throughout the sedimentary strata of Gale crater including Vera Rubin ridge (VRR). The presence of elevated B concentration provides insights into Martian subsurface aqueous processes. In this study we extend the dataset of B in Ca‐sulfate veins across Gale crater, comparing the detection frequency