• Issue
    Volume 49, Issue 19
    16 October 2022

Issue Information

Free Access

Issue Information

  • First Published: 29 September 2022

Research Letter

Planets

Open Access

Morphology of Extreme and Far Ultraviolet Martian Airglow Emissions Observed by the EMUS Instrument on Board the Emirates Mars Mission

  • First Published: 22 September 2022
Key Points

  • First continuous observations of extreme ultraviolet (EUV) and far ultraviolet (FUV) dayglow on Mars

  • Most of the EUV and FUV emissions observations show variations related to season and solar forcing

  • Emirates Mars ultraviolet spectrograph observations are in agreement with the Hopkins ultraviolet telescope observations during solar minimum

Climate

Free Access

Observed Changes in Daily Precipitation Intensity in the United States

  • First Published: 27 September 2022
Key Points

  • We find consistent shifts from lower to higher daily precipitation intensities, particularly in the central and eastern United States

  • All contiguous United States domains show significant changes in their distributions of precipitation intensity from 1951–1980 to 1991–2020

  • Mean and standard deviation of wet day precipitation intensities increase for nearly all domains in the central and eastern United States

Space Sciences

Free Access

Dynamic Jovian Magnetosphere Responses to Enhanced Solar Wind Ram Pressure: Implications for Auroral Activities

  • First Published: 21 September 2022
Key Points

  • High resolution global magnetohydrodynamics model of Jovian magnetosphere that can reproduce the radial density profile of Jovian magnetosphere is conducted

  • Hemispheric field-aligned currents (FACs) and Alfvénic power (AP) exhibit non-linear responses during solar wind compression (SWC)

  • The responses of both FAC and AP to SWC shows agreement with many auroral observations

Oceans

Open Access

Ventilation Changes Drive Orbital-Scale Deoxygenation Trends in the Late Cretaceous Ocean

  • First Published: 27 September 2022
Key Points

  • Small orbitally induced changes in ventilation produce large-scale modification of O2 distribution in the late Cretaceous ocean

  • Deoxygenation is strongly enhanced in already poorly oxygenated basins such as the proto-Atlantic ocean

  • Variations in deoxygenation strength occurs at all orbital frequency albeit with different amplitude

Hydrology and Land Surface Studies

Open Access

Evaluation of Extreme Soil Moisture Conditions During the 2020 Sahel Floods and Implications for Disease Outbreaks

  • First Published: 01 October 2022
Key Points

  • Above-normal precipitation of up to 600 mm locally led to flooding in the African Sahel during the 2020 growing season (June-October)

  • Precipitation and surface soil moisture data indicate that this event was among the most extreme in the region in recent decades

  • This event is linked with disease outbreaks, and soil moisture is potentially a better indicator of outbreak risk than precipitation alone

Climate

Open Access

Ningaloo Niño/Niña in CMIP6 Models: Characteristics, Mechanisms, and Climate Impacts

  • First Published: 19 September 2022
Key Points

  • Coupled Model Intercomparison Project Phase 6 (CMIP6) ensemble mean simulation of Ningaloo Niño/Niña captures the observations despite the substantial inter-model spread

  • Inter-model magnitude spread is due to different performances in both the El Niño-Southern Oscillation teleconnections and the coastal Bjerknes feedback

  • The CMIP6 models are skillful in reproducing the regional climate impacts of Ningaloo Niño/Niña

Free Access

Accelerated Transition Between Dry and Wet Periods in a Warming Climate

  • First Published: 03 October 2022
Key Points

  • Approximately three-fifths (59%) of global land area are projected to experience accelerated transition between dry and wet periods

  • Southern Asia suffers the most from severe transition between dry and wet periods

  • Enhanced precipitation and potential evapotranspiration variabilities contribute to the accelerated dry-to-wet transitions

Atmospheric Science

Open Access

Ionic Charge Emission Into Fog From a Remotely Piloted Aircraft

  • First Published: 03 September 2022
Key Points

  • First example of an instrumented uncrewed aerial vehicle used to release charge for fog modification

  • Unipolar charge release into fog is followed by fog reflectivity increases

  • Observations consistent with charge-induced droplet size distribution changes

Climate

Free Access

Recognizing the Role of Tropical Seaways in Modulating the Pacific Circulation

  • First Published: 29 September 2022
Key Points

  • The co-effects of opening of two tropical seaways on the Pacific circulation are investigated with climate model

  • Shallow opening of tropical seaways can generate an active Pacific meridional overturning circulation, whilst a deeper condition can not

  • The stepwise closure of the tropical seaways can provide similar-to-record patterns of zonal sea surface temperature gradients

Cryosphere

Open Access

Sensitivity of Sea Ice Growth to Snow Properties in Opposing Regions of the Weddell Sea in Late Summer

  • First Published: 22 September 2022
Key Points

  • High fraction of melt-freeze forms causes significant higher snow densities in the northwestern than in the eastern Weddell Sea

  • Lower thermal conductivity of snow in the eastern Weddell Sea than previously assumed results in significantly reduced potential bottom sea ice growth

  • In the northwestern Weddell Sea, the substantial amount of snow ice leads to additional thermodynamic ice growth at the ice bottom

Climate

Open Access

Heat Stress During Arba’een Foot-Pilgrimage (World’s Largest Gathering) Projected to Reach “Dangerous” Levels Due To Climate Change

  • First Published: 21 September 2022
Key Points

  • Future climate change will likely increase the frequency and intensity of heatwaves during Arba'een at Shiite holy sites in Iraq

  • An increase in mugginess (measured by wet-bulb temperature) is more pronounced at night than during the day in a warmer climate

  • We project a rise in consecutive occurrences of hot days and nights, which could threaten human health during the Arba'een event

Hydrology and Land Surface Studies

Free Access

Evaluation of IMERG Over CONUS Complex Terrain Using Environmental Variables

  • First Published: 22 September 2022
Key Points

  • Conditional analysis of Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (IMERG) using environmental parameters is conducted over mountainous terrain

  • The hypothesis of “Does IMERG-Final quantification performance over complex terrain depend on orographically forced upward motion (w) and horizontal moisture flux convergence (Q) environmental parameters” proven to be correct

  • Satellite-based precipitation product algorithms should incorporate environmental parameters to improve or adjust Level-2 or Level-3 estimates over complex terrain

Atmospheric Science

Open Access

Compton Camera Imaging of a Gamma-Ray Glow From a Thunderstorm

  • First Published: 29 September 2022
Key Points

  • Gamma-ray glows were observed in a mountainous area 25 km from the Japan Sea and 410 m above sea level on 14 January 2022, during winter

  • One of the glows suggested two enhanced concentrations in gamma-ray images, which was taken for the first time with a Compton camera

  • The first successful gamma-ray imaging provides a new means of investigating radiation beam pattern of gamma-ray glows in thunderclouds

Open Access

Tracking the 2022 Hunga Tonga-Hunga Ha'apai Aerosol Cloud in the Upper and Middle Stratosphere Using Space-Based Observations

  • First Published: 29 September 2022
Key Points

  • Ozone Monitoring and Profiler Suite measured the Hunga Tonga aerosol layer in the upper stratosphere at altitudes up to 50 km, and tracked it above 36 km for 2.5 months

  • This eruption resulted in the highest stratospheric aerosol optical depth since Pinatubo in 1991

  • Within weeks, parts of the volcanic cloud reached the Southern Hemisphere pole, and by April, it also reached the Northern Hemisphere pole

Free Access

Meridional Propagation of Carbon Dioxide (CO2) Growth Rate and Flux Anomalies From the Tropics Due to ENSO

  • First Published: 20 September 2022
Key Points

  • El Niño Southern Oscillation (ENSO) events strongly influence tropical land carbon dioxide (CO2) flux variability, and global CO2 variability both at surface and upper atmosphere

  • Asymmetrical meridional propagation of the ENSO-CO2 flux signal is imprinted on CO2 growth rate near the surface

  • The terrestrial biosphere fluxes and fire induced emissions from the tropical southern hemisphere show dominant CO2 flux variability

Solid Earth

Open Access

Crystal Shape Control on the Repacking and Jamming of Crystal-Rich Mushes

  • First Published: 22 September 2022
Key Points

  • We identify two coexisting modes of mush deformation: a short-range (continuous) and a long-range (stochastic) granular repacking

  • The relative contribution of these two modes of deformation depends on crystal shape

  • Force chain disruptions can lead to a reduction of the overall resistance to melt extraction

Climate

Free Access

Future Hurricanes Will Increase Palm Abundance and Decrease Aboveground Biomass in a Tropical Forest

  • First Published: 01 October 2022
Key Points

  • Future hurricanes will alter forest composition and decrease aboveground biomass accumulation

  • Predicted temperature and CO2 changes will have smaller effects on forest composition than future hurricane disturbances

  • Predicted temperature and CO2 changes cannot compensate for the biomass loss due to intense and frequent hurricane disturbances

Space Sciences

Open Access

Energy Flux Through the Magnetopause During Flux Transfer Events in Hybrid-Vlasov 2D Simulations

  • First Published: 29 September 2022
Key Points

  • Energy transfer through the magnetopause experiences spatiotemporal variations under steady solar wind driving

  • Energy flux within flux transfer events (FTEs) has an inward and outward component between the FTE leading and trailing edges on the dayside

  • On the nightside, FTEs provide a significant energy injection to the magnetosphere

Solid Earth

Open Access

Evolution of Pulverized Fault Zone Rocks by Dynamic Tensile Loading During Successive Earthquakes

  • First Published: 22 September 2022
Key Points

  • Fracture density increases and fragment size decreases during each successive tensile loading event

  • Tensile pulverization of crystalline rock does not require high strain rates and can be produced tens of meters from large faults

  • Finely pulverized rock may represent the accumulation of damage by successive earthquakes over thousands to millions of years

Space Sciences

Open Access

Geospace Concussion: Global Reversal of Ionospheric Vertical Plasma Drift in Response to a Sudden Commencement

  • First Published: 21 September 2022
Key Points

  • Dayside ionospheric plasma undergoes a transient motion from downward to upward during a sudden commencement (SC)

  • Both observations and simulations show that the reversed vertical drift is a global response of the ionosphere to the SC

  • The transient response is caused by a reversal of induced zonal electric field during the SC

Climate

Open Access

The Role of the North Atlantic Oscillation for Projections of Winter Mean Precipitation in Europe

  • First Published: 29 September 2022
Key Points

  • The North Atlantic Oscillation (NAO) explains half of model spread in southern European winter precipitation change by 2080–2099 for RCP8.5

  • Extreme positive NAO winters may increase in frequency in future by up to 35%, due to mean NAO change, but there is large model uncertainty

  • Extreme positive NAO winters have more severe future precipitation impacts, with implications for resilience to this type of extreme season

Solid Earth

Open Access

Collision-Induced Subduction Polarity Reversal Explains the Crustal Structure of Northern Borneo: New Results From Virtual Deep Seismic Sounding (VDSS)

  • First Published: 03 October 2022
Key Points

  • Crustal thickness map of northern Borneo obtained from Virtual Deep Seismic Sounding

  • Evidence of crustal thinning indicates Sulu Sea extension propagated into northern Borneo during the late Miocene

  • Variations in crustal thickness consistent with subduction polarity reversal induced by continent-continent collision

Atmospheric Science

Open Access

The Dependence of Tropical Cyclone Pressure Tendency on Size

  • First Published: 01 October 2022
Key Points

  • A new analytical model for tropical central pressure tendency is developed and tested against observations

  • The new model predicts an inverse size-dependence of both intensification and decay rates of tropical cyclones

  • The model predictions are supported by analyses of historical best track size and central pressure estimates

Solid Earth

Open Access

Monitoring Seismic Velocity Changes Across the San Jacinto Fault Using Train-Generated Seismic Tremors

  • First Published: 21 September 2022
Key Points

  • We extract stable station-station body-wave correlation functions using seismic energy generated by freight trains

  • We perform 10-year seismic velocity monitoring around the San Jacinto Fault and observe a 2-month-long velocity perturbation in 2014

  • We interpret this velocity change as caused by a previously unreported slow-slip event at the southern edge of the Anza seismic gap

Cryosphere

Open Access

Calibrated Mass Loss Predictions for the Greenland Ice Sheet

  • First Published: 29 September 2022
Key Points

  • Credible predictions of glacier mass loss need to be conditioned on observations

  • We present a two-stage Bayesian calibration to condition ensemble predictions on observations

  • Conditioning on observations of surface speeds and cumulative mass loss corrects bias and reduces the credibility interval

Oceans

Open Access

Climate and Anthropogenic Controls of Seaweed Expansions in the East China Sea and Yellow Sea

  • First Published: 16 September 2022
Key Points

  • Multi-sensor satellite data show significant and near-synchronized expansions of Sargassum horneri and Ulva prolifera in the past 38 years

  • Ocean warming appears to be a main factor behind the recent expansions of S. horneri because of its physiological requirement

  • Ocean warming may also play a role in U. prolifera expansions, but the effect appears confounded by human mitigation efforts

Solid Earth

Free Access

Acoustic Wave Velocities of Ferrous-Bearing MgSiO3 Glass up to 158 GPa With Implications for Dense Silicate Melts at the Base of the Earth's Mantle

  • First Published: 29 June 2022
Key Points

  • We have conducted the acoustic wave velocity measurements of Fe2+-bearing MgSiO3 glass up to 158 GPa

  • The change in trend of the VS profile, likely induced by the structural transition in Si-O coordination number, is observed around 106 GPa

  • Our data show the substitution of 12 mol% Fe in MgSiO3 glass decreases the VS by ∼5.5%

Open Access

Predicting Future Laboratory Fault Friction Through Deep Learning Transformer Models

  • First Published: 27 September 2022
Key Points

  • The limits of deep learning models are explored for predicting the future frictional behavior of laboratory earthquake slip

  • A deep learning transformer model is applied to acoustic emissions broadcast from the laboratory fault to predict future frictional state

  • Acoustic emissions are found to carry information for predicting future fault friction and imminence of failure

Oceans

Open Access

Glacial Ice Melting Stimulates Heterotrophic Prokaryotes Production on the Getz Ice Shelf in the Amundsen Sea, Antarctica

  • First Published: 22 September 2022
Key Points

  • Unlike the sea-ice melting system, enhanced bacterial production (BP) in the eastern Getz Ice Shelf (GtzIS) was uncoupled with phytoplankton biomass

  • Dissolved organic carbon in glacier meltwater likely stimulates BP on the eastern GtzIS

  • Warming-induced glacial melting may weaken carbon sequestration in the Antarctic Ocean by stimulating heterotrophic bacterial metabolism

Climate

Free Access

Contrasting Climatic Trends of Atmospheric River Occurrences Over East Asia

  • First Published: 01 October 2022
Key Points

  • The mean annual occurrences of atmospheric rivers (ARs) show increases in low latitudes but decreases in high latitudes over East Asia

  • The “dipole” pattern of long-term AR trends is associated with contrasting dynamic and thermodynamic responses

  • Such changes in annual AR occurrences contribute to the “Southern-Flood Northern-Drought” precipitation pattern over eastern China

Free Access

Lengthening Dry Spells Intensify Summer Heatwaves

  • First Published: 03 October 2022
Key Points

  • The average dry spell (DSL) length has increased by 0.46 day/decade over the global continents since the 1970s

  • The robust and widespread relationships between the average DSL length and heatwave duration and severity were found

  • The shortening average DSL length associated with heatwaves indicated an enhancing coupling process between DSL and heatwaves

Free Access

The Unprecedented Character of California's 20th Century Enhanced Hydroclimatic Variability in a 600-Year Context

  • First Published: 01 October 2022
Key Points

  • California's hydroclimate shows enhanced variability caused by increasingly wet extremes during the 20th century

  • Tree-ring based hydroclimate reconstructions suggest that this statewide configuration has not been seen in the past 600 years

  • The 16th century shows enhanced hydroclimate variability driven by an increase in the magnitude of dry extremes, rather than wet extremes

Solid Earth

Open Access

Imaging the Absorbing Feeding and Eruptive Pathways of Deception Island, Antarctica

  • First Published: 29 September 2022
Key Points

  • High absorption detects deep eruptive pathways from the caldera center to its rim

  • Absorption imaging reconstructs shallow pathways of hazardous materials

  • Seismic absorption is sensitive to thermal anomalies at depth

Planets

Open Access

Spatio-Temporal Structure of Far Ultraviolet Martian Dayglow Observed by EMM-EMUS

  • First Published: 11 August 2022
Key Points

  • Variations in the ultraviolet dayglow from the Martian thermosphere with local time (LT) and emission viewing angle are characterized

  • Asymmetry in the dayglow between dawn and dusk varies by emission from +15.4% to −12.3% in response to transport and temperature

  • Patches of significant dayglow brightness increase are observed that appear to result from changes in composition and photoelectron flux

Atmospheric Science

Free Access

Tropospheric Expansion Under Global Warming Reduces Tropical Lower Stratospheric Ozone

  • First Published: 27 September 2022
Key Points

  • Global warming reduces ozone in the tropical lower stratosphere, an effect typically attributed to strengthening stratospheric upwelling

  • Yet, global warming also deepens the troposphere, which erodes the ozone layer and reduces transport of ozone into the lower stratosphere

  • Along with strengthening upwelling, tropospheric expansion contributes at leading order to reductions in tropical lower stratospheric ozone

Oceans

Free Access

Multidecadal Regime Shifts in North Pacific Subtropical Mode Water Formation in a Coupled Atmosphere-Ocean-Sea Ice Model

  • First Published: 01 October 2022
Key Points

  • Driving mechanisms for the North Pacific subtropical mode water formation exhibit a regime shift with a periodicity of about 50–70 years

  • Multidecadal regime shifts are associated with meridional and zonal shifts in the Aleutian Low (AL)

  • Position shift of the AL affects the variability of the local air-sea flux and remotely driven oceanic dynamics

Atmospheric Science

Free Access

Effects of Different Types of Aerosols on Deep Convective Clouds and Anvil Cirrus

  • First Published: 20 September 2022
Key Points

  • The height and amount of Cloud-Aerosol Lidar with Orthogonal Polarization-identified deep convective clouds and anvil cirrus first increase and then level off with aerosol increase

  • Marine aerosols start to decrease cloud top height when aerosol optical depth is relatively smaller than continental aerosols

  • With increased aerosol loadings, deep convective clouds have a decreased cloud optical depth (COD) while anvils have an increased COD. One exception is for smoke

Oceans

Open Access

Tropical Instability Waves and Wind-Forced Cross-Equatorial Flow in the Central Atlantic Ocean

  • First Published: 12 September 2022
Key Points

  • Composites of Tropical Instability Waves at 0°N, 23°W show a surface (subsurface) velocity maximum during northward (southward) phases

  • Meridional wind stress forces a seasonally-varying, shallow cross-equatorial overturning cell-the Equatorial Roll

  • The superposition of Tropical Instability Waves and Equatorial Roll causes asymmetric mixing during north- and southward phases

Solid Earth

Free Access

Mountain Rivers Reveal the Earthquake Hazard of Geologic Faults in Silicon Valley

  • First Published: 12 September 2022
Key Points

  • The topographic structure of mountain rivers can be inverted for long-term slip-and moment accrual-rates along relief-generating faults

  • Thrust faults along the western side of Silicon Valley have the potential for generating a Mw = 6.9 earthquake every 250–300 years

  • This approach may be deployed more broadly to evaluate seismic hazard in regions with limited geological and geophysical information

Open Access

Inherited Heterogeneities Can Control Viscous Subduction Zone Deformation of Carbonates at Seismogenic Depths

  • First Published: 03 October 2022
Key Points

  • Carbonate sediments and veins are common in subduction zone input sequences and are typically underthrust near the plate interface

  • Underthrust carbonates deform faster by dynamic recrystallization and dissolution-precipitation processes at lower temperature than quartz

  • Grain-scale heterogeneities localize shear strain in calcite veins by promoting viscous deformation at seismogenic zone temperatures

Climate

Free Access

Cloud and Surface Albedo Feedbacks Reshape 21st Century Warming in Successive Generations of An Earth System Model

  • First Published: 20 September 2022
Key Points

  • Higher equilibrium climate sensitivity, from more positive cloud feedbacks, only slightly increases 21st century transient warming

  • Cloud and surface albedo feedbacks redistribute warming from the middle and high northern latitudes to lower latitudes

  • These warming pattern differences result from feedback differences, not CMIP5 to CMIP6 forcing scenario differences

Atmospheric Science

Open Access

Microphysical Differences in the Concentric Eyewalls of Typhoon Lekima (2019)

  • First Published: 06 October 2022
Key Points

  • Different polarimetric radar signatures were present in the concentric eyewalls of Typhoon Lekima (2019)

  • Large drops are produced dominantly by the warm-cloud (cold-cloud) processes in the outer (inner) eyewall

  • Different dynamical structures in the concentric eyewalls of Lekima are responsible for the variation in their microphysics

Space Sciences

Open Access

A Realistic Projection of Climate Change in the Upper Atmosphere Into the 21st Century

  • First Published: 23 September 2022
Key Points

  • The first realistic projection of climate change in the upper atmosphere (100–500 km altitude) for 2015–2070 is presented

  • The predicted global mean cooling and decline in thermosphere density for 2015–2070 are about twice as strong as for the past

  • The largest changes in the ionosphere are expected in the region of ∼50°S–20°N and ∼90°–0°W

Cryosphere

Free Access

Greenland Interannual Ice Mass Variations Detected by GRACE Time-Variable Gravity

  • First Published: 29 September 2022
Key Points

  • Greenland interannual mass variations are correlated with the Pacific Decadal Oscillation

  • We report an East-West Coastal Dipole related to the North Atlantic Oscillation

  • The contribution of the Atlantic Multidecadal Oscillation is also captured

Atmospheric Science

Open Access

Signature of the Contemporary Southwestern North American Megadrought in Mesopause Region Wave Activity

  • First Published: 06 October 2022
Key Points

  • Gravity waves were measured in the mesopause region before and during the current Southwestern North American megadrought

  • Wave-driven temperature variance during the drought decreased by 28% and changed from primarily semiannual to primarily annual variations

  • Decreased wave activity may be related to the summer and winter precipitation deficits during the ongoing megadrought

Hydrology and Land Surface Studies

Free Access

Causes of Missing Snowmelt Following Drought

  • First Published: 27 September 2022
Key Points

  • At 15 watersheds in the Sierra Nevada, the root-zone storage deficit explains anomalously low streamflow from snowpack following drought

  • Median error in 2021 predictions is reduced from 60% to 20% by including the deficit in the forecasting model

  • Future drought-related perturbations to runoff could be assessed using root-zone storage deficits inferred from distributed hydrologic data

Commentary

Solid Earth

Free Access

Earthquake Focal Mechanisms as a Stress Meter of Active Volcanoes

  • First Published: 01 October 2022
Key Points

  • Zhan et al. (2022) assessed the stress state of an active volcano from temporal changes of focal mechanisms during its unrest

  • A quantitative assessment of temporal changes of focal mechanisms allows us to use them as a stress meter

  • Combining focal mechanisms with other geophysical measurements yields more precise estimates of the stress state of active volcanoes

Research Letter

Hydrology and Land Surface Studies

Open Access

Correcting Systematic Bias in Climate Model Simulations in the Time-Frequency Domain

  • First Published: 19 September 2022
Key Points

  • Systematic biases exist in the magnitude and frequency of climate events simulated by the models

  • A continuous wavelet transform-based method for identifying and correcting biases in the time-frequency domain is presented

  • Time series of Niño 3.4 sea surface temperature and Arctic sea-ice extent is used to demonstrate the usefulness of the approach

Atmospheric Science

Free Access

Revisiting Cloud Radiative Heating and the Southern Annular Mode

  • First Published: 27 September 2022
Key Points

  • Poleward shifts of the Southern Hemisphere extratropical jet stream change atmospheric cloud radiative heating through two key mechanisms

  • The fraction of low clouds that are exposed to space increases equatorward of the mean jet latitude, enhancing local radiative cooling

  • Clouds in extratropical cyclones shift poleward, causing radiative heating anomalies throughout the troposphere

Space Sciences

Free Access

Direct Evidence for Auroral Kilometric Radiation Propagation Into Radiation Belts Based on Arase Spacecraft and Van Allen Probe B

  • First Published: 29 September 2022
Key Points

  • A unique auroral kilometric radiation (AKR) event is reported simultaneously by Arase satellite and Van Allen Probes during 19-month observations

  • Simulations show that more AKR for 350 kHz pass the locations of two satellites, consistent with observations

  • AKR raypaths are highly dependent on wave frequency, initial wave normal angles and azimuthal angles

Atmospheric Science

Open Access

Stratospheric Balloon Observations of Infrasound Waves From the 15 January 2022 Hunga Eruption, Tonga

  • First Published: 27 September 2022
Key Points

  • Comparison between balloon-borne and ground-based observations of infrasound waves triggered by the January 2022 Hunga eruption

  • Eruption sequence from infrasound in broad agreement with plume top height evolution

  • Benchmark for long-range monitoring of infrasound from large explosive sources using stratospheric balloon observations

Space Sciences

Open Access

Soft X-Ray Imaging of Magnetopause Reconnection Outflows Under Low Plasma-β Solar Wind Conditions

  • First Published: 27 September 2022
Key Points

  • Global magnetospheric magnetohydrodynamic modeling of soft X-ray emission is examined under low-temperature solar wind conditions

  • Soft X-ray emission by the solar wind charge-exchange process is expected to be very bright around the dayside reconnection region

  • X-ray map can reflect plasma jets under cold solar wind allowing visualization of the reconnection region as observed in the solar corona

Commentary

Climate

Open Access

Blowing Hot and Cold: Glacier Microclimate can Help Understand Impacts of Climate Change on Forests Communities

  • First Published: 06 October 2022
Key Points

  • Current rates of global warming are expected to double within decades, at a much faster pace than what most ecosystems experienced over several millennia

  • Fast warming threathens ecosystems as elevational ranges at which species occur will need to shift to be able to respond to changes in their thermal niches

  • Using the rainforest of La Perouse Glacier as a “natural laboratory,” Gaglioti et al. (2022, https://doi.org/10.1029/2022GL098574) analyze effects of past and anticipated future climate change

Research Letter

Climate

Free Access

A 10-Year Thundersnow Climatology Over China

  • First Published: 29 September 2022
Key Points

  • A 10-year climatology of thundersnow in China was revealed for the first time

  • The high-frequency areas of thundersnow are mainly located in the Tibetan Plateau and northeastern China

  • Thundersnow is significantly influenced by the Arctic Oscillation and associated with the anomalous western North Pacific anticyclone

Free Access

Influence of the Tropical Indian Ocean Tripole on Summertime Cold Extremes Over Central Siberia

  • First Published: 29 September 2022
Key Points

  • Summertime cold extremes in Central Siberia are closely associated with the Indian Ocean tripole (IOT) pattern

  • Anomalous upper-level geopotential height over Central Siberia inhibits local cold extremes

  • Asian continent meridional teleconnection plays an atmospheric bridge between IOT and Central Siberia cold extremes

Open Access

The Contribution of Climate Change to Increasing Extreme Ocean Warming Around Japan

  • First Published: 15 September 2022
Key Points

  • The contribution of climate change to discrete extreme ocean warming (EOW) from January 1982 through July 2022 around Japan is estimated

  • The occurrence chance of EOW is generally higher in southern Japan, more than doubled since 2000 due to climate change

  • Limiting global warming from 2°C to 1.5°C sharply reduces the possibility of normal climate exceeding record warm ocean surface

Commentary

Climate

Free Access

An Energetic Perspective on the Holocene North American Monsoon

  • First Published: 22 September 2022
Key Point

  • The strength North American Monsoon tracks changes in the position of the midlatitude westerlies over the Holocene

Research Letter

Atmospheric Science

Free Access

Impact of the Latitude of Stratospheric Aerosol Injection on the Southern Annular Mode

  • First Published: 16 September 2022
Key Points

  • Stratospheric Aerosol Injection (SAI) impacts the Southern Annular Mode (SAM), and the response is strongly sensitive to the latitude of SAI

  • Injections in the Northern Hemisphere drive positive SAM response and injections in the Southern Hemisphere drive negative SAM response

  • Meridional extent of lower stratospheric aerosol heating likely an important contributor to the sensitivity to injection latitude

Free Access

Inconsistent Frequency Trends Between Hourly and Daily Precipitation During Warm Season in Mainland of China

  • First Published: 29 September 2022
Key Points

  • Observed inconsistent frequency trend between daily and hourly precipitation causes “more hours in 1 day, but fewer days” rainfall feature

  • Models show opposite rainfall feature and miss broad increase of extreme precipitation amount (PA) rate in total PA, especially hourly scale

  • Both CMIP6 and observations show frequency and intensity changes dominated the total PA trend at hourly and daily time scales, respectively

Climate

Free Access

Seasonal-Interannual Predictions of Summer Precipitation Over the Tibetan Plateau in North American Multimodel Ensemble

  • First Published: 06 October 2022
Key Points

  • Dynamical prediction skills of the summer precipitation over Tibetan Plateau (TP) are regionally dependent in North-American Multi-Model Ensemble, with higher skill in the southwestern TP

  • Ability of the models in reproducing the Pacific Sea surface temperature-precipitation relation is highly responsible for the southwest-TP prediction skills

  • Prediction skills vary with the observational data sets and their mean tends to provide the highest skill scores over the southwestern TP

Solid Earth

Open Access

Preferential Formation of Chlorite Over Talc During Si-Metasomatism of Ultramafic Rocks in Subduction Zones

  • First Published: 21 September 2022
Key Points

  • Limited talc formation by Si-metasomatism of ultramafic rocks in subduction zones

  • Chlorite formation is likely pervasive at the slab-mantle interface

  • Preferential formation of chlorite has wide-ranging chemical and physical implications for subduction zone processes

Atmospheric Science

Free Access

Rapidly Changing Emissions Drove Substantial Surface and Tropospheric Ozone Increases Over Southeast Asia

  • First Published: 29 September 2022
Key Points

  • Surface and tropospheric ozone has risen significantly over Southeast Asia from 2005 to 2016

  • NOx emission trends underestimated over Peninsular Southeast Asia but overestimated over Maritime Continents in inventories

  • Growing anthropogenic emissions drove large surface ozone increases over Peninsular Southeast Asia

Hydrology and Land Surface Studies

Open Access

The Influence of Magnetic Minerals on Induced Polarization Measurements in Sedimentary Rocks

  • First Published: 15 September 2022
Key Points

  • Only 38% (at most) of the variation in the induced polarization (IP) signal is predictable from pore geometrical descriptors (PGD)

  • The magnetic susceptibility, a parameter unrelated to PGD, exerts a stronger influence on IP data

  • Using magnetic susceptibility to constrain variations in the specific capacitance improves IP models from pore descriptors

Atmospheric Science

Free Access

Observations and Impacts of Long-Range Transported Wildfire Smoke on Air Quality Across New York State During July 2021

  • First Published: 27 September 2022
Key Points

  • A long-range transported wildfire smoke event significantly enhanced PM2.5 across New York State in July 2021

  • Multi-platform observations are used to understand the details of the event

  • A lidar network can help to monitor smoke event, assess impacts on surface PM2.5, aid satellite measurements and improve forecasting models

Climate

Open Access

Ocean Heat Uptake Efficiency Increase Since 1970

  • First Published: 29 September 2022
Key Points

  • Ocean heat uptake efficiency (OHUE) change is estimated from ocean heat content and global mean surface temperature records

  • There is a >99% probability that ocean heat uptake efficiency increased over the past five decades

  • OHUE was on average 0.58 ± 0.08 W/m2K over this period and increased during it by 0.19 ± 0.04 W/m2K

Solid Earth

Free Access

New Early Permian Paleomagnetic and Geochronological Data From the Xilinhot–Songliao Block and Their Implications for the Relationship Between the Paleo-Asian Ocean and the Paleo-Tethys Ocean

  • First Published: 27 September 2022
Key Points

  • The Xilinhot–Songliao Block (XSB) was located at ∼19.3°N on the northern margin of the East Paleo-Tethys Ocean (EPTO) at 285 Ma

  • The northern boundary of the EPTO tectonic domain extended to the southern margin of the XSB

  • The Hegenshan Ocean between the XSB and Mongolia Block was the main ocean basin of the eastern Paleo-Asian Ocean at 285 Ma

Climate

Free Access

A North Atlantic Warming Hole Without Ocean Circulation

  • First Published: 23 September 2022
Key Points

  • A warming hole appears in a slab ocean model, weaker in absolute magnitude than the observed, but close after removing the global average

  • The warming hole is driven by intensified surface westerlies in response to external forcings that lead to cooling via turbulent heat flux

  • A novel methodology is developed to identify compensating effects of damping by sea surface temperature and the rise of greenhouse gases

Space Sciences

Free Access

Resonant Generation of an Alfvén Wave by a Substorm Injected Electron Cloud: A Van Allen Probe Case Study

  • First Published: 19 September 2022
Key Points

  • The resonant generation of an Alfvén wave by energetic electrons is observed

  • The observed wave is the fundamental harmonic, propagating eastward with azimuthal wave number of about 110–115

  • The wave was generated through the gradient instability and interacted with electrons via the drift resonance

Free Access

Unraveling the Formation Region and Frequency of Chorus Spectral Gaps

  • First Published: 15 September 2022
Key Points

  • Chorus spectral gaps are formed near the equatorial source region where parallel and anti-parallel emissions are interleaved

  • Landau resonance causes electron parallel acceleration and phase space density isotropization around half electron Alfven velocity, which increases with latitudes

  • Chorus spectral gaps are usually found below 0.5 fce due to electron anisotropy reduction caused by Landau resonance at high latitudes

Solid Earth

Open Access

Non-Isotropic Contraction and Expansion of Samples in Diamond Anvil Cells: Implications for Thermal Conductivity at the Core-Mantle Boundary

  • First Published: 27 September 2022
Key Points

  • Samples in diamond anvil cell experiments contract and expand in a strongly non-isotropic fashion upon compression and decompression

  • Experimental reports on iron conductivity at high pressure contain errors due to the assumption of isotropic contraction or expansion

  • Accurate in situ determination of sample geometry is necessary for thermal and electrical conductivity measurements at high pressure

Space Sciences

Open Access

2D Reconstruction of Magnetotail Electron Diffusion Region Measured by MMS

  • First Published: 27 September 2022
Key Points

  • The fluctuating measurements are consistent with a 2D reconnecting geometry, permitting a detailed spacecraft trajectory to be determined

  • The Magnetospheric Multiscale Mission data is projected onto a 2D spatial domain, revealing the fine-scale structure of the electron diffusion region (EDR)

  • The EDR includes profiles with strong gradients in fields and flows, consistent with those observed in a matched 2D kinetic simulation