• Issue
    Volume 43, Issue 7
    3005-3588
    16 April 2016

Issue Information

Free Access

Issue Information

  • Pages: 3005-3008
  • First Published: 27 April 2016

Research Letters

Space Sciences

Free Access

Formation of energetic electron butterfly distributions by magnetosonic waves via Landau resonance

  • Pages: 3009-3016
  • First Published: 06 March 2016
Key Points

  • Electron butterfly distributions of ~100 keV are quickly formed in the radiation belts
  • Electron butterfly distributions are observed in direct association with magnetosonic waves
  • Numerical simulations produce butterfly distributions similar to the observations

Free Access

Relativistic electron microbursts and variations in trapped MeV electron fluxes during the 8–9 October 2012 storm: SAMPEX and Van Allen Probes observations

  • Pages: 3017-3025
  • First Published: 06 March 2016
Key Points

  • Balance between MeV electron acceleration and loss by chorus is investigated
  • Microburst precipitations well coincides with large increase in MeV electron fluxes
  • MeV electron acceleration by chorus is much efficient than microburst losses

Free Access

Electromagnetic disturbances observed near the dip region ahead of dipolarization front

  • Pages: 3026-3034
  • First Published: 16 March 2016
Key Points

  • Magnetosonic waves are observed near the dip region ahead of dipolarization front
  • This wave is generated by ion perpendicular velocity distribution
  • This type of ion distribution could be formed by the reflected ions ahead of DF

Free Access

Subsolar magnetopause observation and kinetic simulation of a tripolar guide magnetic field perturbation consistent with a magnetic island

  • Pages: 3035-3041
  • First Published: 25 March 2016
Key Points

  • First observation of a tripolar guide field perturbation at Earth's magnetopause
  • Observation is consistent with asymmetric Hall magnetic fields between two X lines
  • Symmetric-like magnetopause conditions and a guide field are likely required for its development

Free Access

Electron butterfly distribution modulation by magnetosonic waves

  • Pages: 3051-3059
  • First Published: 21 March 2016
Key Points

  • Unlike Berstein-mode waves, the observed waves are not bound by neighboring harmonics of the proton gyrofrequency
  • Electron pitch angle distribution is modulated by the magnetosonic wave intensity
  • Bounce resonance with magnetosonic waves is the mechanism behind our event's electron pitch angle distribution as shown by our simulation

Planets

Free Access

A revised surface age for the North Polar Layered Deposits of Mars

  • Pages: 3060-3068
  • First Published: 23 March 2016
Key Points

  • Using a new crater production function for current Mars, the NPLD surface age is closer to ~1.5 kyr
  • Accounting for ice target strength suggests that crater model ages are overestimates
  • The north polar deposit on Mars is being resurfaced faster than previously calculated

Free Access

LADEE/LDEX observations of lunar pickup ion distribution and variability

  • Pages: 3069-3077
  • First Published: 22 March 2016
Key Points

  • LDEX observes lunar exospheric pickup ions through integrator channel at high time/spatial resolution
  • Ion production scale height of 100 km, peak near 0800 LT, and linear dependence on solar wind flux
  • Comparison to model suggests Ar+ and CO+ as dominant ion species, with possible contribution from Al+

Free Access

Topographic roughness of the northern high latitudes of Mercury from MESSENGER Laser Altimeter data

  • Pages: 3078-3087
  • First Published: 24 March 2016
Key Points

  • Topographic roughness of the northern hemisphere of Mercury is mapped using MLA data
  • There is a distinctive dichotomy in roughness between smooth plains and intercrater and heavily cratered regions
  • Surface roughness is mainly controlled by density and shape of impact craters

Free Access

Solid-state photochemistry as a formation mechanism for Titan's stratospheric C4N2 ice clouds

  • Pages: 3088-3094
  • First Published: 22 March 2016
Key Points

  • C4N2 ice clouds in Titan's stratosphere form via solid-state photochemistry
  • This alternate ice formation mechanism explains the apparent state of nonequilibrium between C4N2 vapor and ice
  • Increased dilution in the ice mixture shifts the C4N2 ice emission feature to larger wavenumbers

Free Access

Comparison of the Martian thermospheric density and temperature from IUVS/MAVEN data and general circulation modeling

  • Pages: 3095-3104
  • First Published: 04 April 2016
Key Points

  • Observed CO2 density and temperature agree well with model predictions
  • Sensitivity of temperature and density on physical parameters is explored
  • Longitudinal disturbances represent a stationary imprint of topography in the thermosphere

Solid Earth

Free Access

Weathering resistance of carbonate fault mirrors promotes rupture localization

  • Pages: 3105-3111
  • First Published: 18 March 2016
Key Points

  • Some fault surfaces are covered by nanoparticle layers that form fault mirrors
  • We show that nanoparticle layers on carbonate fault mirrors are resistant to chemical dissolution
  • Low reactivity of nanoparticle layers could retard fault healing and promote fault localization

Free Access

Exchangeable cation composition of the smectite-rich plate boundary fault at the Japan Trench

  • Pages: 3112-3119
  • First Published: 18 March 2016
Key Points

  • Exchangeable cation composition of smectite-rich fault gouge was examined by wet chemical analysis
  • Na+ to Mg2+ exchange reaction might have progressed in the slip zone during the earthquake
  • Cation exchange reaction may be intimately linked to physical aspect of smectite-bearing faults

Free Access

Active tectonics west of New Zealand's Alpine Fault: South Westland Fault Zone activity shows Australian Plate instability

  • Pages: 3120-3125
  • First Published: 18 March 2016
Key Points

  • Newly observed thrust faulting shows the South Westland Fault Zone (SFWZ) is an active seismogenic structure
  • Large but infrequent earthquakes (at least Mw 6.8) with the most recent rupture post −12.1 ± 1.7 ka based on OSL dating
  • Intra-Australian Plate faulting shows that key structures remain uncharacterized in areas with rainforest cover

Free Access

Subsidence along the Atlantic Coast of North America: Insights from GPS and late Holocene relative sea level data

  • Pages: 3126-3133
  • First Published: 17 March 2016
Key Points

  • Late Holocene RSL rise rates are compared to GPS vertical rates along the Atlantic Coast of North America
  • Holocene RSL data are used to separate long-term GIA-induced displacement from the modern rate
  • Differences between geologic and GPS rates occur in areas of excessive groundwater extraction

Free Access

Mapping 3D fault geometry in earthquakes using high-resolution topography: Examples from the 2010 El Mayor-Cucapah (Mexico) and 2013 Balochistan (Pakistan) earthquakes

  • Pages: 3134-3142
  • First Published: 11 March 2016
Key Points

  • High-resolution topography provides a new means of mapping 3-D fault geometry
  • The proposed method is complimentary to the field measurements of fault dip
  • From the fault geometry, we find variations in dip at the endpoint of the Hoshab rupture

Free Access

Uppermost mantle structure beneath eastern China and its surroundings from Pn and Sn tomography

  • Pages: 3143-3149
  • First Published: 14 March 2016
Key Points

  • Vp and Vs upper mantle wave speeds for eastern China and its surroundings
  • Larger amplitudes of P velocity anomalies than S velocity anomalies
  • Rapid changes of physical properties in the uppermost mantle in depth

Free Access

Ice mass loss in Greenland, the Gulf of Alaska, and the Canadian Archipelago: Seasonal cycles and decadal trends

  • Pages: 3150-3159
  • First Published: 10 March 2016
Key Points

  • In 2013 ice mass trends on and around Greenland diverged significantly from the long-term average
  • The positive mass deviation over Greenland reached nearly 500 Gt by 2015
  • Greenland and Canadian ice mass losses continue to accelerate while Alaskan loss has remained steady

Free Access

Coseismic and early postseismic deformation due to the 25 April 2015, Mw 7.8 Gorkha, Nepal, earthquake from InSAR and GPS measurements

  • Pages: 3160-3168
  • First Published: 18 March 2016
Key Points

  • Coseismic and early postseismic observations of Mw 7.8 Gorkha, Nepal, earthquake are presented
  • The postseismic surface uplift and subsidence is found to be opposite to that of coseismic motion
  • An afterslip occurred mainly toward downdip and eastward of the coseismic slip asperity

Open Access

Postseismic gravity change after the 2006–2007 great earthquake doublet and constraints on the asthenosphere structure in the central Kuril Islands

  • Pages: 3169-3177
  • First Published: 23 March 2016
Key Points

  • The viscoelastic relaxation caused gravity change larger than the coseismic change
  • The low Maxwell viscosity of 1018 Pa s in the asthenosphere is responsible for the gravity change
  • The result emphasizes the importance of viscoelastic relaxation in regional tectonic deformation

Free Access

W phase source inversion using high-rate regional GPS data for large earthquakes

  • Pages: 3178-3185
  • First Published: 18 March 2016
Key Points

  • Fast and reliable calculation of the moment tensor
  • Use of seismogeodesy as a powerful tool for tsunami early warning
  • Reducing time for tsunami early warning purposes

Free Access

Comparing source inversion techniques for GPS-based local tsunami forecasting: A case study for the April 2014 M8.1 Iquique, Chile, earthquake

  • Pages: 3186-3192
  • First Published: 21 March 2016
Key Points

  • The three inversion approaches give similar first-order rupture parameters while depth, strike, dip, and rake angles show great differences
  • Despite large differences in far-field tsunami propagation, forecasting along the coast would be surprisingly similar for all three models
  • Regional and national near-field TEWS should build their own source inversion strategies based on corresponding tectonic settings

Free Access

Ice cap melting and low-viscosity crustal root explain the narrow geodetic uplift of the Western Alps

  • Pages: 3193-3200
  • First Published: 30 March 2016
Key Points

  • Explanation for the geodetic uplift of the Alps
  • Revisit the relation between deglaciation and uplift
  • Pointing out the key role of rheology on strain

Free Access

Lithospheric fault and kinematic decoupling of the Apennines system across the Pollino range

  • Pages: 3201-3207
  • First Published: 08 March 2016
Key Points

  • A huge set of receiver functions is used to define a lithospheric fault at the Ionian slab edge
  • The fault decouples the deformation of Apennines (delamination) from Calabrian forearc (retreat)
  • The fault segments the normal fault system within the 60 km long Pollino seismic gap

Free Access

Heat transport in the Hadean mantle: From heat pipes to plates

  • Pages: 3208-3214
  • First Published: 14 April 2016
Key Points

  • The extraction of melt by volcanic heat pipes reduces lithospheric basal slopes and stresses
  • As volcanism wanes, conduction through the lithosphere dominates and plates can break
  • At high heat flow, plate tectonics is suppressed by heat pipes

Free Access

Small post-perovskite patches at the base of lower mantle primordial reservoirs: Insights from 2-D numerical modeling and implications for ULVZs

  • Pages: 3215-3225
  • First Published: 21 March 2016
Key Points

  • We identify three types of distributions of pPv anomalies relative to large primordial reservoirs
  • We identify two types of pPv patches within large primordial reservoirs
  • Iron-rich pPv patches within large primordial reservoirs may explain observations of ULVZs

Free Access

Frequency, pressure, and strain dependence of nonlinear elasticity in Berea Sandstone

  • Pages: 3226-3236
  • First Published: 22 March 2016
Key Points

  • We study the frequency dependence of nonlinear elasticity in Berea sandstone
  • We find different frequency dependence behavior among the harmonic content
  • These findings will ultimately help in better relating the nonlinear elastic behavior to rock microstructure

Free Access

Extracting ocean-generated tidal magnetic signals from Swarm data through satellite gradiometry

  • Pages: 3237-3245
  • First Published: 27 March 2016
Key Points

  • Oceanic M2 tidal magnetic signal extracted from only 20.5 months of Swarm data compared to >3.5 years of CHAMP data
  • Swarm gradiometry allows for extraction from higher-altitude data compared to CHAMP
  • Swarm gradiometry allows for extraction during more magnetically disturbed times compared to CHAMP

Free Access

Evidence of a shallow persistent magmatic reservoir from joint inversion of gravity and ground deformation data: The 25–26 October 2013 Etna lava fountaining event

  • Pages: 3246-3253
  • First Published: 28 March 2016
Key Points

  • Gravity and deformation signatures of the 26 October 2013 Mount Etna lava fountain
  • Integrated finite element-based inversion of gravity and GPS data
  • Inference on a highly compressible volatile-rich magma in the magmatic reservoir

Free Access

An aseismic slip transient on the North Anatolian Fault

  • Pages: 3254-3262
  • First Published: 28 March 2016
Key Points

  • A 1 month transient event (Mw 5.3) has been detected by high temporal resolution InSAR time series along the North Anatolian Fault
  • A Bayesian inversion constrains the depth (between 0 and 3 km), the length (8 km), and the peak slip (2 cm) of this transient event
  • A need for a revision of the current mechanical model of this segment is highlighted

Open Access

An empirically based steady state friction law and implications for fault stability

  • Pages: 3263-3271
  • First Published: 30 March 2016
Key Points

  • We describe fault evolution over the entire seismic cycle
  • We describe fault stability over a wide range of experimental (and natural) conditions
  • We account for the diversity of slip events observed at laboratory (and natural) scale

Free Access

First airborne samples of a volcanic plume for δ13C of CO2 determinations

  • Pages: 3272-3279
  • First Published: 30 March 2016
Key Points

  • Airborne sampling of volcanic plumes for carbon isotopes
  • New data for remote Kanaga volcano in Western Aleutians
  • Mantle source identified for carbon in this volcano and this part of the arc

Hydrology and Land Surface Studies

Free Access

Quantifying the signature of sediment composition on the topologic and dynamic complexity of river delta channel networks and inferences toward delta classification

  • Pages: 3280-3287
  • First Published: 18 March 2016
Key Points

  • Sediment composition leaves a distinct signature on delta channel network complexity
  • As deltas evolve and reach steady state, complexity also achieves steady state
  • A TopoDynamic complexity space offers potential for process inference and delta classification

Open Access

Multiscale structure of meanders

  • Pages: 3288-3297
  • First Published: 16 March 2016
Key Points

  • A novel method objectively quantifies the shape of nonstationary meanders over all spatial scales
  • A tree made from the wavelet transform (WT) of curvature captures the spatial structure of meanders
  • The WT at the submeander scale results in two simple shape parameters: fattening and skewing

Free Access

Isotopic evidence for lateral flow and diffusive transport, but not sublimation, in a sloped seasonal snowpack, Idaho, USA

  • Pages: 3298-3306
  • First Published: 18 March 2016
Key Points

  • Large event-specific isotopic steps are preserved throughout most of the winter and early spring
  • Advection via sublimation and pervasive flow is minimal, while isotope diffusivity is ~10E−10 m2/s
  • Melt channels and progressive loss of isotopically distinct upper layers indicate lateral flow

Free Access

Trend and uncertainty in spatial-temporal patterns of hydrological droughts in the Amazon basin

  • Pages: 3307-3316
  • First Published: 21 March 2016
Key Points

  • Spatial-temporal patterns of hydrological droughts derived from limited data in the Amazon basin
  • Droughts in northern and southern subbasins differ in trends and association to climatic indices
  • Trend toward more intense droughts in southern subbasins is linked to Atlantic Ocean anomalies

Free Access

Demonstrating soil moisture remote sensing with observations from the UK TechDemoSat-1 satellite mission

  • Pages: 3317-3324
  • First Published: 25 March 2016
Key Points

  • The first observations that spaceborne GNSS-R can sense soil moisture are shown
  • GNSS-R signals respond to the same land features consistently over time
  • Soil moisture could be estimated at short temporal scales if effects from roughness and vegetation are removed

Free Access

Canopy and physiological controls of GPP during drought and heat wave

  • Pages: 3325-3333
  • First Published: 30 March 2016
Key Points

  • Forest and nonforest ecosystems have different responses to water stress
  • Relative changes in VIs can spatially track GPP decline for the entire drought period
  • GPP anomaly can be temporally tracked by VIs for nonforest and VPD for forest

Free Access

Mangrove pore water exchange across a latitudinal gradient

  • Pages: 3334-3341
  • First Published: 01 April 2016
Key Points

  • Mangrove pore water exchange was equivalent to one third of global annual river discharge
  • These exchange rates have implications for coastal nutrient, carbon, and greenhouse gas cycling
  • Mangroves play a disproportionately large role in coastal hydrological cycles

Cryosphere

Free Access

Organization of ice flow by localized regions of elevated geothermal heat flux

  • Pages: 3342-3350
  • First Published: 21 March 2016
Key Points

  • Localized regions of elevated geothermal heat flux may organize ice flow in regions of relatively slow ice flow
  • Fast-flowing glaciers are unaffected by localized elevated geothermal heat flux
  • Improved estimates of fine-scale geothermal heat flux are needed to assess possible impacts on ice dynamics and mass budget estimates

Oceans

Free Access

The impact of groundwater depletion on spatial variations in sea level change during the past century

  • Pages: 3351-3359
  • First Published: 17 March 2016
Key Points

  • Groundwater depletion elevates average sea level but also deforms the solid Earth and sea surfaces, causing spatial variations in sea level
  • Models predict depressed sea level in western North America and southern Asia, where groundwater loss is most significant
  • Groundwater depletion has slowed sea level rise in California and India by ~0.4 mm/yr since 1930, consistent with tide gauge observations

Open Access

Intense submesoscale upwelling in anticyclonic eddies

  • Pages: 3360-3369
  • First Published: 09 March 2016
Key Points

  • High-resolution simulations show intense submesoscale upwelling in anticyclones
  • The upwelling can drive a large increase in biological productivity
  • The cause is symmetric instability that is not included in current nutrient budgets

Free Access

A new characterization of the turbulent diapycnal diffusivities of mass and momentum in the ocean

  • Pages: 3370-3379
  • First Published: 12 March 2016
Key Points

  • The first multiparameter parameterizations of mixing efficiency and turbulent Prandtl number are proposed
  • Global maps of mixing efficiency suggest local estimates that may be grossly different from the canonical value of 0.2
  • Estimates of diapycnal diffusivity need to be reassessed based on the generalized-Osborn formula

Free Access

Nonlinearities in patterns of long-term ocean warming

  • Pages: 3380-3388
  • First Published: 12 March 2016
Key Points

  • Response time scales and regions of ocean heat uptake depend nonlinearly on the forcing level
  • Global thermal expansion does not scale linearly with the surface temperature anomaly
  • Reasons are forcing dependent circulation responses and the nonlinear equation of state

Free Access

Long-term variability of surface nutrient concentrations in the North Pacific

  • Pages: 3389-3397
  • First Published: 21 March 2016
Key Points

  • Surface nutrient concentrations in the North Pacific are optimally interpolated
  • The PDO- and NPGO- related nutrient variability are presented
  • Phosphate and silicate trends are negative, but nitrate shows no trend

Free Access

Origin and fate of surface drift in the oceanic convergence zones of the eastern Pacific

  • Pages: 3398-3405
  • First Published: 24 March 2016
Key Points

  • Lagrangian circulation associated with the large-scale surface convergence zones in the eastern Pacific
  • Highlighting escape pathways from the center of the convergence zones, with short meridional scales
  • Importance of eddy-like variability in structuring the large-scale circulation in a Lagrangian framework

Open Access

Eddy-driven recirculation of Atlantic Water in Fram Strait

  • Pages: 3406-3414
  • First Published: 24 March 2016
Key Points

  • Seasonally varying eddy-mean flow interaction controls recirculation of Atlantic Water in Fram Strait
  • The bulk recirculation occurs in a cyclonic gyre around the Molloy Hole at 80 degrees north
  • A colder westward current south of 79 degrees north relates to the Greenland Sea Gyre, not removing Atlantic Water from the slope current

Free Access

Empirical algorithms to estimate water column pH in the Southern Ocean

  • Pages: 3415-3422
  • First Published: 28 March 2016
Key Points

  • Algorithms are developed for estimation of pH from biogeochemical floats in the Southern Ocean
  • The pH algorithms can also be used to adjust pH sensor data on biogeochemical floats
  • The seasonal cycle in surface pH ranges from 0.05 to 0.08 for the study region

Free Access

Swell dissipation from 10 years of Envisat advanced synthetic aperture radar in wave mode

  • Pages: 3423-3430
  • First Published: 24 March 2016
Key Points

  • Swells are systematically tracked using synthetic aperture radar from the Envisat mission
  • A robust range of the swell dissipation is calculated and can be used to constrain air-sea fluxes
  • Swell dissipation is weakly related to its steepness and wind speed weighted by the direction

Free Access

Assessing the impact of satellite-based observations in sea surface temperature trends

  • Pages: 3431-3437
  • First Published: 30 March 2016
Key Points

  • SST trend in the past decade is as large as that in the past 34 years
  • SST trends do not reduce significantly when satellite-based observations are included
  • The biases of satellite observations should be corrected

Climate

Free Access
Highlight

Emergence of heat extremes attributable to anthropogenic influences

  • Pages: 3438-3443
  • First Published: 07 March 2016
Key Points

  • We identify when the first attribution of heat extremes to anthropogenic climate change is possible
  • Earliest attribution to anthropogenic influences in the 1930s globally and the 1980s in many regions
  • Aerosol-induced cooling delayed emergence of the anthropogenic signal in Northern Hemisphere regions

Free Access

Detecting cross-equatorial wind change as a fingerprint of climate response to anthropogenic aerosol forcing

  • Pages: 3444-3450
  • First Published: 21 March 2016
Key Points

  • A model-observation synergy is developed to identify the anthropogenic aerosol-induced climate change
  • Cross-equatorial antisymmetric pattern is a fingerprint of aerosol forcing
  • Zonal mean cross-equatorial energy transport theory is validated observationally

Free Access

Investigating the seasonal predictability of significant wave height in the West Pacific and Indian Oceans

  • Pages: 3451-3458
  • First Published: 29 March 2016
Key Points

  • Seasonal predictability of significant wave height in the Indo-Pacific Ocean is investigated
  • There is potential for predicting wave height with several months lead time during boreal summers
  • ENSO has a nonlinear influence on the number of extreme significant wave height events

Free Access
Highlight

Predictability of the recent slowdown and subsequent recovery of large-scale surface warming using statistical methods

  • Pages: 3459-3467
  • First Published: 18 March 2016
Key Points

  • The recent slowdown in surface warming likely was not predictable using statistical methods
  • The Pacific Multidecadal Oscillation does not appear to exhibit any predictability
  • The Atlantic Multidecadal Oscillation does appear to exhibit some predictability

Free Access

Evolution of moisture transport to the western U.S. during the last deglaciation

  • Pages: 3468-3477
  • First Published: 29 March 2016
Key Points

  • Waning continental ice sheet weakened atmospheric pressure centers driving evolution of Pacific winter storm track from sinuous to zonal
  • Variations in meltwater flux to the Atlantic modulated storm track intensity via atmosphere-ocean teleconnections
  • Dynamics inferred from modeling results are broadly consistent with speleothem records from the region

Atmospheric Science

Free Access

The combined influences of autumnal snow and sea ice on Northern Hemisphere winters

  • Pages: 3478-3485
  • First Published: 24 February 2016
Key Points

  • Considering snow cover and sea ice together creates more skillful subseasonal forecasts
  • Sea ice and snow cover influences on winter weather share a common mechanism but differ in timing
  • The Arctic has a detectable influence on midlatitude weather in present and likely future climates

Free Access

Comparing GOSAT observations of localized CO2 enhancements by large emitters with inventory-based estimates

  • Pages: 3486-3493
  • First Published: 09 March 2016
Key Points

  • GOSAT estimated CO2 abundance due to large emitters compared to inventory-based estimate
  • Observed and inventory-based CO2 abundance agree well over global and subcontinental scales
  • Observation-model discrepancy (22%) over East Asia is close to uncertainty in emission inventory

Open Access

The stratospheric pathway for Arctic impacts on midlatitude climate

  • Pages: 3494-3501
  • First Published: 21 March 2016
Key Points

  • Stratospheric dynamics is crucial for Arctic sea ice and midlatitude climate linkage
  • Reduced stratospheric wave mean flow interaction much alters the sea ice impacts on the surface
  • Representation of the whole stratosphere is indispensable for realistic climate predictions

Free Access

A method for independent validation of surface fluxes from atmospheric inversion: Application to CO2

  • Pages: 3502-3508
  • First Published: 15 February 2016
Key Points

  • Validating fluxes from an atmospheric inversion is challenging
  • The method projects changes of observable state errors to flux differences
  • The posterior flux is more accurate than the prior where fluxes contribute to CO2 error reduction

Free Access

Effect of climate change on surface ozone over North America, Europe, and East Asia

  • Pages: 3509-3518
  • First Published: 21 March 2016
Key Points

  • Climate change increases surface ozone in polluted regions and decreases surface ozone in nearby and cleaner regions
  • Surface ozone increases are largest at high percentiles even with constant biogenic emissions
  • Air quality extremes become more hazardous under future climate warming

Free Access

Generation and backreaction of spontaneously emitted inertia-gravity waves

  • Pages: 3519-3525
  • First Published: 24 March 2016
Key Points

  • Maximum wave vertical velocity is proportional to the resolution
  • The energy extracted by the waves is weakly sensitive to the resolution
  • The dipole loses at most 0.2% energy per day to inertia-gravity waves

Free Access

On the infrasound detected from the 2013 and 2016 DPRK's underground nuclear tests

  • Pages: 3526-3533
  • First Published: 22 March 2016
Key Points

  • Underground nuclear tests by the DPRK have generated observable atmospheric infrasound
  • During the 2013 and 2016 tests, the stratospheric waveguide was in a very different state
  • We hypothesize that the 2016 test took place at least 1.5 times deeper than the 2013 test

Atmospheric Science (ASC)

Free Access

The role of the sea on the flash floods events over Liguria (northwestern Italy)

  • Pages: 3534-3542
  • First Published: 22 March 2016
Key Points

  • The role of SST initial field in numerical simulations of flash floods in Liguria (Italy) is shown
  • Quantitative precipitation forecast is strongly sensitive to small-scale SST inhomogeneities
  • The operational use of fully atmosphere-ocean coupled modeling systems is strongly encouraged

Atmospheric Science

Free Access

Lagrangian temperature and vertical velocity fluctuations due to gravity waves in the lower stratosphere

  • Pages: 3543-3553
  • First Published: 22 March 2016
Key Points

  • Long-duration balloon observations are used to characterize Lagrangian temperature fluctuations
  • Intrinsic frequency spectra and PDFs are derived for temperature and cooling rates
  • A parameterization of gravity wave temperature fluctuations in the lower stratosphere is developed

Free Access

Energetic particle precipitation: A major driver of the ozone budget in the Antarctic upper stratosphere

  • Pages: 3554-3562
  • First Published: 29 March 2016
Key Points

  • Evaluation of the EPP-induced O3 variability on long time scales
  • EPP causes an average upper stratospheric O3 depletion of about 10–15% on a monthly basis
  • Discrimination between EPP and solar irradiance effects on ozone

Free Access
Highlight

Volcanic lightning and plume behavior reveal evolving hazards during the April 2015 eruption of Calbuco volcano, Chile

  • Pages: 3563-3571
  • First Published: 11 March 2016
Key Points

  • New approach to quantify eruptive processes combining lightning and umbrella expansion rates from the 2015 Calbuco eruption
  • Formation of hazardous pyroclastic density currents signaled by a sharp increase in proximal lightning and slower upwind plume expansion
  • Observations and modeling suggest that ice formation above 10 km controlled the propagation of volcanic lightning downwind

Free Access

Tropical cloud buoyancy is the same in a world with or without ice

  • Pages: 3572-3579
  • First Published: 27 March 2016
Key Points

  • Clouds do not have higher buoyancies in a world with fusion than in a world without it
  • Preexisting theories for cloud buoyancy do not predict systematically higher buoyancies in a world with ice
  • The large reservoir of CAPE in the upper troposphere is not due to the latent heat of fusion

Free Access

Ice nucleation activity of diesel soot particles at cirrus relevant temperature conditions: Effects of hydration, secondary organics coating, soot morphology, and coagulation

  • Pages: 3580-3588
  • First Published: 30 March 2016
Key Points

  • Ice nucleating ability of fresh soot particles is similar to hydrated and compact particles
  • Organic-coated particles required homogeneous freezing threshold conditions
  • Soot particles with aqueous organics nucleated ice via immersion freezing mechanism