• Issue

    Geophysical Research Letters: Volume 40, Issue 11

    2479-2877
    16 June 2013
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Regular Articles

Space Sciences

Free Access

Saturn's magnetospheric refresh rate

A. M. Rymer,  D. G. Mitchell,  T. W. Hill,  E. A. Kronberg,  N. Krupp,  C. M. Jackman, 
  • Pages: 2479-2483
  • First Published: 03 May 2013
Key Points

  • Saturn has a magnetospheric frequency close to the planet's rotation rate
  • We confirm that Jupiter's natural refresh rate is 2-3 days
  • This result is relevant to the ongoing mystery of periodic phenomena at Saturn

Free Access

SAMI3 simulation of plasmasphere refilling

J. Krall,  J. D. Huba, 
  • Pages: 2484-2488
  • First Published: 11 April 2013
Key Points

  • Refilling is simulated with E x B drifts in all three dimensions
  • Because of corotation, diurnal variations are strong at fixed local time
  • The quiet-time plasmasphere morphology repeats daily

Free Access

Field-aligned current reconfiguration and magnetospheric response to an impulse in the interplanetary magnetic field BY component

V. Wilder,  S. Eriksson,  H. Korth,  J. B. H. Baker,  M. R. Hairston,  C. Heinselman,  B. J. Anderson, 
  • Pages: 2489-2494
  • First Published: 25 April 2013
Key Points

  • An impulse in IMF By drives fast flows in the high latitude ionosphere
  • The peak dawn-side FAC strength occurs 1.25 hours after the impulse
  • The FAC strength correlates well with solar wind MA and SYM-H

Free Access

An indication of the existence of a solar wind strahl at 10 AU

A. P. Walsh,  C. S. Arridge,  A. Masters,  G. R. Lewis,  A. N. Fazakerley,  G. H. Jones,  C. J. Owen,  A. J. Coates, 
  • Pages: 2495-2499
  • First Published: 03 May 2013
Key Points

  • First observations of suprathermal solar wind electrons outside 5AU
  • Unexpected presence of a distinct strahl component to the distribution
  • This implies pitch angle scattering rates decrease with heliocentric distance

Free Access

Dynamics and distribution of nano-dust particles in the inner solar system

A. Juhász,  M. Horányi, 
  • Pages: 2500-2504
  • First Published: 06 May 2013
Key Points

  • The acceleration of nano-dust to near solar wind speed is calculated
  • The intermittent nature of the observations can be due to the IMF configuration
  • Observations do not allow conclusions about the origin of these particles

Free Access

Oscillatory flow braking in the magnetotail: THEMIS statistics

Evgeny V. Panov,  Marina V. Kubyshkina,  Rumi Nakamura,  Wolfgang Baumjohann,  Vassilis Angelopoulos,  Victor A. Sergeev,  Anatoli A. Petrukovich, 
  • Pages: 2505-2510
  • First Published: 25 March 2013
Key Points

  • Damped oscillatory flow in the plasma sheet is caused by oscillating flux tube
  • Oscillation period can be reliably estimated using MHD theory
  • Group parameters of the damped oscillatory flows are given

Free Access

Observation of multiple sub-cavities adjacent to single separatrix

Rongsheng Wang,  Aimin Du,  Rumi Nakamura,  Quanming Lu,  Yuri V. Khotyaintsev,  Martin Volwerk,  Tielong Zhang,  E. A. Kronberg,  P. W. Daly,  Andrew N. Fazakerley, 
  • Pages: 2511-2517
  • First Published: 07 May 2013
Key Points

  • Multiple sub-cavities adjacent to the separatrix
  • Electron acceleration in the separatrix
  • Unipolar parallel and oscillating perpendicular electric field in the separatrix

Free Access

Discriminating the tectonic and non-tectonic contributions in the ionospheric signature of the 2011, Mw7.1, dip-slip Van earthquake, Eastern Turkey

Lucie M. Rolland,  Mathilde Vergnolle,  Jean-Mathieu Nocquet,  Anthony Sladen,  Jean-Xavier Dessa,  Farokh Tavakoli,  Hamid Reza Nankali,  Frédéric Cappa, 
  • Pages: 2518-2522
  • First Published: 10 May 2013
Key Points

  • New near-source coseismic ionospheric observations using GPS and GLONASS
  • Signals carry information on the seismic rupture slip mode
  • Initial polarity and amplitude distributions explained using a full 3D modeling

Free Access

Longitudinal and day-to-day variability in the ionosphere from lower atmosphere tidal forcing

Tzu-Wei Fang,  Rashid Akmaev,  Tim Fuller-Rowell,  Fei Wu,  Naomi Maruyama,  George Millward, 
  • Pages: 2523-2528
  • First Published: 13 May 2013
Key Points

  • Ionospheric variability is simulated by a coupled atmosphere-ionosphere model
  • Ionospheric longitudinal variations are driven by the non-migrating tides
  • Lower atmosphere tidal forcing can cause about half of the diurnal variability

Planets

Free Access

Intensities of the Martian N2 electron-impact excited dayglow emissions

Jane L. Fox,  Nicholas E. F. Hać, 
  • Pages: 2529-2533
  • First Published: 01 April 2013
Key Points

  • We have computed the intensities of 15 band systems of N2 on Mars
  • The intensities of the VK emissions agree with SPICAM limb profiles
  • Our calculations do not require that the mixing ratio of N2 be reduced

Free Access

Does folding accommodate Europa's contractional strain? The effect of surface temperature on fold formation in ice lithospheres

Michael T. Bland,  William B. McKinnon, 
  • Pages: 2534-2538
  • First Published: 01 May 2013
Key Points

  • Fold growth rates are a strong function of surface temperature
  • Folding requires larger strains at Europan equatorial temperatures
  • Passive shortening during contraction helps explain Europa's strain imbalance

Free Access

Limb imaging of the Venus O2 visible nightglow with the Venus Monitoring Camera

A. García Muñoz,  R. Hueso,  A. Sánchez-Lavega,  W. J. Markiewicz,  D. V. Titov,  O. Witasse,  A. Opitz, 
  • Pages: 2539-2543
  • First Published: 14 May 2013
Key Points

  • The Venus O2 visible nightglow is investigated for over 4 years with VMC
  • The O2 visible nightglow is brighter near the equator and faints polewards
  • The evidence from VMC and VIRTIS suggests that the two emissions correlate

Solid Earth

Free Access
Highlight

Electrical resistivity tomography revealing the internal structure of monogenetic volcanoes

Stéphanie Barde-Cabusson,  Xavier Bolós,  Dario Pedrazzi,  Raul Lovera,  Guillem Serra,  Joan Martí,  Albert Casas, 
  • Pages: 2544-2549
  • First Published: 08 May 2013
Key Points

  • Electrical resistivity tomography was performed on monogenetic volcanoes
  • The eruptive conduit of a Strombolian cone was identified
  • ERT imaging contributes in volcanic forecasting by the identification of hazards

Free Access

Arc magma compositions controlled by linked thermal and chemical gradients above the subducting slab

Sebastian F. L. Watt,  David M. Pyle,  Tamsin A. Mather,  José A. Naranjo, 
  • Pages: 2550-2556
  • First Published: 29 April 2013
Key Points

  • Mafic arc rocks preserve a systematic down-slab magma chemical gradient
  • This reflects increasing dominance of hydrous melts in the slab flux
  • This change, over a few km, is a first-order control on melt chemistry

Free Access

Observations of core-mantle boundary Stoneley modes

Paula Koelemeijer,  Arwen Deuss,  Jeroen Ritsema, 
  • Pages: 2557-2561
  • First Published: 01 May 2013
Key Points

  • We present CMB Stoneley mode splitting function measurements
  • The CMB Stoneley mode splitting correlates well with diffracted body wave data
  • Our measurements allow to constrain density variations in the lowermost mantle

Free Access

The 2011 M = 9.0 Tohoku oki earthquake more than doubled the probability of large shocks beneath Tokyo

Shinji Toda,  Ross S. Stein, 
  • Pages: 2562-2566
  • First Published: 02 May 2013
Key Points

  • Tokyo seismicity rate jumped 10-fold even though the M9 shock struck 200 km away
  • The data can be explained by stress triggering, permitting a 5-yr M>7 forecast
  • Capturing highly time-dependent hazard is critical to megacities near megaquakes

Free Access

Monitoring deformation at the Geysers Geothermal Field, California using C-band and X-band interferometric synthetic aperture radar

D. W. Vasco,  Jonny Rutqvist,  Alessandro Ferretti,  Alessio Rucci,  Fernando Bellotti,  Patrick Dobson,  Curtis Oldenburg,  Julio Garcia,  Mark Walters,  Craig Hartline, 
  • Pages: 2567-2572
  • First Published: 07 March 2013
Key Points

  • X-band data provides improved coverage of deformation at The Geysers
  • The C-band deformation rate agrees with past estimates
  • The estimates are supported by modeling

Free Access

Using hydroacoustic stations as water column seismometers

Selda Yildiz,  Karim Sabra,  LeRoy M. Dorman,  W. A. Kuperman, 
  • Pages: 2573-2578
  • First Published: 21 March 2013
Key Points

  • We show how to convert pressure data to vector seismic data

Free Access

Constraints on the composition of the Aleutian arc lower crust from VP/VS

Donna J. Shillington,  Harm J. A. Van Avendonk,  Mark D. Behn,  Peter B. Kelemen,  Oliver Jagoutz, 
  • Pages: 2579-2584
  • First Published: 20 March 2013
Key Points

  • VP/VS ratio estimated for Aleutian lower crust from along-arc refraction line
  • Results indicate abundant clinopyroxenite, consistent with geochemistry
  • Alpha quartz is an important control on crustal velocities in arcs

Free Access

Convergence of the frequency-size distribution of global earthquakes

Andrew F. Bell,  Mark Naylor,  Ian G. Main, 
  • Pages: 2585-2589
  • First Published: 28 March 2013
Key Points

  • The tail of the global frequency-magnitude distribution is poorly constrained
  • Convergence properties are inconsistent with an unbounded GR distribution
  • The global catalogue is a mix of superposed randomly-sampled regional catalogues

Free Access

Linking permeability to crack density evolution in thermally stressed rocks under cyclic loading

I. Faoro,  S. Vinciguerra,  C. Marone,  D. Elsworth,  A. Schubnel, 
  • Pages: 2590-2595
  • First Published: 02 April 2013
Key Points

  • Identification of 3 regimes of permeability approaching failure
  • Identification of the role of cooling rates on crack geometry and connectivity
  • Prediction of the coupled permeability and microcrack network evolution

Free Access

Stress tensor changes related to fluid injection at The Geysers geothermal field, California

Patricia Martínez-Garzón,  Marco Bohnhoff,  Grzegorz Kwiatek,  Georg Dresen, 
  • Pages: 2596-2601
  • First Published: 03 April 2013
Key Points

  • Fluid injection causes local temporal variations of the stress field orientation
  • Long-term fluid extraction results in changes of the stress regime with depth
  • Stress inversion applied to microseismicity improves reservoir characterization

Free Access

California foreshock sequences suggest aseismic triggering process

Xiaowei Chen,  Peter M. Shearer, 
  • Pages: 2602-2607
  • First Published: 03 April 2013
Key Points

  • Foreshocks are triggered by aseismic process which may trigger the mainshocks
  • Foreshocks are less energetic than aftershock and background seismicity
  • The stress drop history suggests similarity between foreshocks and swarms

Free Access

Active blind thrusts beneath the Tokyo metropolitan area: Seismic hazards and inversion tectonics

Tatsuya Ishiyama,  Hiroshi Sato,  Naoko Kato,  Toshio Nakayama,  Susumu Abe, 
  • Pages: 2608-2612
  • First Published: 19 April 2013
Key Points

  • Blind thrust structures in Tokyo were imaged in deep seismic profiles
  • Fault activity was estimated by shallow seismic profile and borehole transect
  • Low slip rates pose a problem on infrequent but devastating seismic hazards

Free Access

Characterization of fluid flow in a shear band in porous rock using neutron radiography

Stephen A Hall, 
  • Pages: 2613-2618
  • First Published: 03 May 2013
Key Points

  • Fluid flow into sandstone is tracked by neutron radiography and image analyses
  • Measurements of local water imbibition rates are made in a shear band
  • Comparison is made of flow and 3D strain fields (from digital image correlation)

Free Access

Effects of pore fluid pressure on slip behaviors: An experimental study

A. Ougier-Simonin,  W. Zhu, 
  • Pages: 2619-2624
  • First Published: 09 May 2013
Key Points

  • A new experimental setup is designed to investigate pore pressure effect on slip
  • Excess pore pressure can induce slip instability on an otherwise creeping fault
  • Deformation mechanisms that control such different behaviors are identified

Free Access

Rapid ice melting drives Earth's pole to the east

J. L. Chen,  C. R. Wilson,  J. C. Ries,  B. D. Tapley, 
  • Pages: 2625-2630
  • First Published: 13 May 2013
Key Points

  • First explained the abrupt departure of the mean pole position in recent years.
  • Polar motion provides constraints to study of ice melting and sea level rise.
  • Polar motion is useful in bridging the gap between GRACE and follow-on missions.

Free Access

Assessing the potential improvement in short-term earthquake forecasts from incorporation of GPS data

Ting Wang,  Jiancang Zhuang,  Teruyuki Kato,  Mark Bebbington, 
  • Pages: 2631-2635
  • First Published: 14 May 2013
Key Points

  • Anomalies in GPS data are extracted and show short-term precursory information
  • These GPS signals are not caused by the earthquakes
  • GPS data can be used to augment probability models for earthquake forecasting

Free Access

Azimuthal anisotropy at Valhall: The Helmholtz equation approach

Aurélien Mordret,  Nikolai M. Shapiro,  Satish Singh,  Philippe Roux,  Jean-Paul Montagner,  Olav. I. Barkved, 
  • Pages: 2636-2641
  • First Published: 06 April 2013
Key Points

  • Seismic interferometry is applied to passive data from an industrial network
  • 6 hours of data are sufficient to measure seismic anisotropy
  • We demonstrate that the azimuthal anisotropy is dominated by the 2psi term

Free Access

The role of hydrous phases in the formation of trench parallel anisotropy: Evidence from Rayleigh waves in Cascadia

Lara S. Wagner,  Matthew J. Fouch,  David E. James,  Maureen D. Long, 
  • Pages: 2642-2646
  • First Published: 02 May 2013
Key Points

  • Cascadia exhibits trench parallel anisotropy in Rayleigh wave phase velocities
  • Rayleigh wave depth constraints show this anisotropy at 50 -110 km depth
  • Most likely cause is the presence of hydrous phases in or just above the slab

Free Access

Effects of continental configuration on mantle heat loss

C. M. Cooper,  L.-N. Moresi,  A. Lenardic, 
  • Pages: 2647-2651
  • First Published: 09 May 2013
Key Points

  • When distributed, continents can cause flow patterns to become locked
  • Continents can impose long-term thermal structures mimicking a thermal plume
  • An Earth with >50% continents would not possess plate tectonics

Free Access

Implications of high core thermal conductivity on Earth's coupled mantle and core evolution

Takashi Nakagawa,  Paul J. Tackley, 
  • Pages: 2652-2656
  • First Published: 20 May 2013
Key Points

  • We assess the thermal and magnetic evolution of Earth's core
  • T-C structures in the mantle are identical with various core properties
  • Extremely high thermal conductivity causes a 100s km of sub-adiabatic region

Free Access

A new way to detect volcanic plumes

Kristine M. Larson, 
  • Pages: 2657-2660
  • First Published: 14 May 2013
Key Points

  • Detection of plumes is of interest for both geophysics and aircraft safety
  • Plumes are detectable in real-time with GPS
  • This method isn't influenced by position changes

Free Access

Low-frequency earthquakes in the Mexican Sweet Spot

William B. Frank,  Nikolaï M. Shapiro,  Vladimir Kostoglodov,  Allen L. Husker,  Michel Campillo,  Juan S. Payero,  Germán A. Prieto, 
  • Pages: 2661-2666
  • First Published: 16 May 2013
Key Points

  • Detected and characterized 15 low-frequency earthquake families in Mexico
  • Sources locate to a region known for constant non-volcanic tremor activity
  • Focal mechanisms reflect shearing on the subducting plate interface

Hydrology and Land Surface Studies

Open Access

Paleofire reconstruction based on an ensemble-member strategy applied to sedimentary charcoal

Olivier Blarquez,  Martin P. Girardin,  Bérangère Leys,  Adam A. Ali,  Julie C. Aleman,  Yves Bergeron,  Christopher Carcaillet, 
  • Pages: 2667-2672
  • First Published: 25 April 2013
Key Points

  • Our innovative approach enables to determine robust fire event dates
  • We assessed paleofire frequency using ensemble member's reconstructions

Free Access

Quantifying the modern recharge of the “fossil” Sahara aquifers

J. Gonçalvès,  J. Petersen,  P. Deschamps,  B. Hamelin,  O. Baba-Sy, 
  • Pages: 2673-2678
  • First Published: 17 April 2013
Key Points

  • Sahara aquifers are recharged at present-day with a renewal rate of 40%
  • Infiltration towards the water table takes at least 9 to 12 month
  • Groundwater budget involving GRACE is a relevant approach in semiarid regions

Cryosphere

Open Access

Energy budget of first-year Arctic sea ice in advanced stages of melt

Stephen R. Hudson,  Mats A. Granskog,  Arild Sundfjord,  Achim Randelhoff,  Angelika H. H. Renner,  Dmitry V. Divine, 
  • Pages: 2679-2683
  • First Published: 02 May 2013
Key Points

  • First-year sea ice reflects less and transmits more sunlight than multiyear ice
  • The increased transmittance allows for greater ocean heat fluxes
  • Some transmitted energy is stored, released later in the year or during storms

Free Access

Recent snowfall anomalies in Dronning Maud Land, East Antarctica, in a historical and future climate perspective

Jan T. M. Lenaerts,  Erik van Meijgaard,  Michiel R. van den Broeke,  Stefan R. M. Ligtenberg,  Martin Horwath,  Elisabeth Isaksson, 
  • Pages: 2684-2688
  • First Published: 15 May 2013
Key Points

  • Recent East Antarctic snowfall anomalies are unparalleled since 1979
  • Firn core data suggest that there have been similar anomalies before the 1950's
  • Such anomalies are projected to occur more frequently in future

Free Access

High biolability of ancient permafrost carbon upon thaw

Jorien E. Vonk,  Paul J. Mann,  Sergey Davydov,  Anna Davydova,  Robert G. M. Spencer,  John Schade,  William V. Sobczak,  Nikita Zimov,  Sergei Zimov,  Ekaterina Bulygina,  Timothy I. Eglinton,  Robert M. Holmes, 
  • Pages: 2689-2693
  • First Published: 15 March 2013
Key Points

  • Ancient dissolved OC (>21ky) is mobilized in thaw streams draining Yedoma cliffs
  • The dissolved OC is highly biolabile: 34+/-1% was lost during 14-d incubations
  • Yedoma OC reactivity should be incorporated in regional and global C budgets

Free Access

Modeling the influence of photochemistry on hydrogen peroxide concentrations in an Arctic snowpack

Ted Hullar,  Cort Anastasio, 
  • Pages: 2694-2698
  • First Published: 27 May 2013
Key Points

  • We modeled one year of hydrogen peroxide photochemistry in a polar snowpack
  • Photolysis can destroy up to 40% of HOOH deposited in summer
  • Photochemistry complements physical mechanisms to control HOOH concentrations

Correction

Cryosphere

Free Access

Correction to “Changes in Arctic sea ice result in increasing light transmittance and absorption”

M. Nicolaus,  S. Arndt,  C. Katlein,  J. Maslanik,  S. Hendricks, 
  • Pages: 2699-2700
  • First Published: 02 May 2013

Regular Articles

Oceans

Free Access

Climate-driven sea level anomalies modulate coastal groundwater dynamics and discharge

Meagan Eagle Gonneea,  Ann E. Mulligan,  Matthew A. Charette, 
  • Pages: 2701-2706
  • First Published: 26 January 2013
Key Points

  • Salinity of the coastal aquifer mixing zone is dynamic across a 4 year time series
  • Mean sea level oscillations drive the coastal hydraulic gradient
  • Coastal aquifer geochemistry is sensitive to climate-influenced sea level anomalies

Free Access

Tidal dissipation in the early Eocene and implications for ocean mixing

J. A. M. Green,  M. Huber, 
  • Pages: 2707-2713
  • First Published: 26 April 2013
Key Points

  • The tidal dissipation during the Eocene was weaker than at present
  • The abyssal Pacific was the main location of tidal dissipation
  • The vertical mixing in the Eocene Pacific was stronger than at present

Free Access

Interaction network based early warning indicators for the Atlantic MOC collapse

Mirjam van der Mheen,  Henk A. Dijkstra,  Avi Gozolchiani,  Matthijs den Toom,  Qingyi Feng,  Jürgen Kurths,  Emilio Hernandez‒Garcia, 
  • Pages: 2714-2719
  • First Published: 01 May 2013
Key Points

  • New indicators for MOC collapse
  • Indicators based on spatial correlations
  • Network analysis useful to monitor critical transitions

Free Access

Aragonite saturation state dynamics in a coastal upwelling zone

Katherine E. Harris,  Michael D. DeGrandpre,  Burke Hales, 
  • Pages: 2720-2725
  • First Published: 11 April 2013
Key Points

  • Aragonite saturation states are calculated from time series pH and pCO2 data
  • Seasonal processes controlling aragonite saturation state are determined
  • Current coastal upwelling zone variability compared to preindustrial range

Free Access

A mechanism for sandbar straightening by oblique wave incidence

R. Garnier,  A. Falqués,  D. Calvete,  J. Thiébot,  F. Ribas, 
  • Pages: 2726-2730
  • First Published: 12 April 2013
Key Points

  • We show why oblique waves induce morphological reset of surf-zone rhythmic bars
  • Rip currents are weakened and shifted alongshore for increasing wave obliquity
  • Crescentic bar straightening is highly sensitive to the offshore wave angle

Open Access

Shipping contributes to ocean acidification

Ida-Maja Hassellöv,  David R. Turner,  Axel Lauer,  James J. Corbett, 
  • Pages: 2731-2736
  • First Published: 01 May 2013
Key Points

  • Ocean acidification attributable to shipping emissions deposition is modeled
  • Ship-derived acidification in heavily trafficked areas can equal that from CO2
  • Future ship sulfur reductions create a natural geophysical experiment

Open Access

Intraseasonal variations in the surface layer heat balance of the central equatorial Indian Ocean: The importance of zonal advection and vertical mixing

M. J. McPhaden,  G. R. Foltz, 
  • Pages: 2737-2741
  • First Published: 06 May 2013
Key Points

  • Two MJO events forced an SST decrease that was in part due to reduced heat flux
  • For one MJO zonal advection contributed substantial cooling
  • For other event lack of barrier layer enabled pronounced entrainment

Free Access

Eddy-induced variability of the meridional overturning circulation in a model of the North Atlantic

M. D. Thomas,  X. Zhai, 
  • Pages: 2742-2747
  • First Published: 06 May 2013
Key Points

  • Unpredictable eddy-induced overturning variability is isolated in 1/10deg model
  • Eddies make up 2/3 of overturning variability in the subtropics and 1/3 outside
  • An important component of eddy driven overturning is at interannual time scales

Free Access

Large-amplitude internal tides, solitary waves, and turbulence in the central Bay of Biscay

X. H. Xie,  Y. Cuypers,  P. Bouruet-Aubertot,  B. Ferron,  A. Pichon,  A. Lourenço,  N. Cortes, 
  • Pages: 2748-2754
  • First Published: 06 May 2013
Key Points

  • Internal tides and solitary waves are characterized in the central Bay of Biscay
  • Microstructure measurements are firstly presented in the central Bay of Biscay
  • Observed dissipation rates are reproduced by the Mackinnon-Gregg scaling

Free Access

Remotely induced warming of Antarctic Bottom Water in the eastern Weddell gyre

Matthew P. Couldrey,  Loïc Jullion,  Alberto C. Naveira Garabato,  Craig Rye,  Laura Herráiz-Borreguero,  Peter J. Brown,  Michael P. Meredith,  Kevin L. Speer, 
  • Pages: 2755-2760
  • First Published: 02 May 2013
Key Points

  • Bottom Water from Cape Darnley, Antarctica has warmed and lightened 1993-2008
  • Warming linked to changes in mixing with the Circumpolar Current
  • This new mechanism may affect other regions of the Southern Ocean

Free Access

The response of the large-scale ocean circulation to 20th century Asian and non-Asian aerosols

T. Cowan,  W. Cai, 
  • Pages: 2761-2767
  • First Published: 28 May 2013
Key Points

  • Anthropogenic aerosols force circulation changes to the global ocean
  • Non-Asian aerosols account for most of the aerosol-induced circulation trends
  • As non-Asian sulfate aerosols peaked in the 1980s, the trends may be reversing

Climate

Free Access
Highlight

Uncertainty in future regional sea level rise due to internal climate variability

Aixue Hu,  Clara Deser, 
  • Pages: 2768-2772
  • First Published: 03 May 2013
Key Points

  • Internal climate variability can affect the regional sea level
  • Regional sea level rise can significantly differ from the global mean changes
  • Ocean dynamics plays important role on regional sea level rise

Free Access

Decadal prediction of observed and simulated sea surface temperatures

Timothy DelSole,  Liwei Jia,  Michael K. Tippett, 
  • Pages: 2773-2778
  • First Published: 25 January 2013
Key Points

  • This paper shows that SSTs can be predicted with skill on decadal time scales
  • Patterns of SST that can be predicted are identified explicitly
  • Initial condition information improves climate predictions

Free Access

Spatiotemporal distribution patterns of dissolved methane in lakes: How accurate are the current estimations of the diffusive flux path?

Hilmar Hofmann, 
  • Pages: 2779-2784
  • First Published: 12 April 2013
Key Points

  • In lakes, bays and extended littoral zones are
  • Dissolved methane and diffusive efflux are heterogeneously distributed
  • Heterogeneous distributions of methane affect the accuracy flux estimations

Free Access

The climate impact of aviation aerosols

A. Gettelman,  C. Chen, 
  • Pages: 2785-2789
  • First Published: 01 May 2013
Key Points

  • Aviation Aerosol Impacts affect liquid clouds below flight levels
  • Effect is mostly a cooling due to SO4 emissions
  • Cooling is larger than expected warming from contrails

Free Access

Variability of central United States April–May tornado day likelihood by phase of the Madden-Julian Oscillation

Bradford S. Barrett,  Victor A. Gensini, 
  • Pages: 2790-2795
  • First Published: 02 May 2013
Key Points

  • Relationship between MJO and central U.S. tornado days examined
  • Environmental parameters explain tornado day anomalies
  • Implications for extended range forecasting of central U.S. tornado days

Free Access

Climate impact of stratospheric ozone recovery

S. Bekki,  A. Rap,  V. Poulain,  S. Dhomse,  M. Marchand,  F. Lefevre,  P.M. Forster,  S. Szopa,  M.P. Chipperfield, 
  • Pages: 2796-2800
  • First Published: 14 March 2013
Key Points

  • climate impact of stratospheric ozone recovery

Free Access

Revisiting the controversial issue of tropical tropospheric temperature trends

D. M. Mitchell,  P. W. Thorne,  P. A. Stott,  L. J. Gray, 
  • Pages: 2801-2806
  • First Published: 15 April 2013
Key Points

  • High horizontal resolution models improve temperature trends
  • There is no discrepancy in tropical temperature trends
  • Observational uncertainty needs to be considered

Open Access

Decadal predictability of tropical basin average and global average sea surface temperatures in CMIP5 experiments with the HadCM3, GFDL-CM2.1, NCAR-CCSM4, and MIROC5 global Earth System Models

Vikram M. Mehta,  Hui Wang,  Katherin Mendoza, 
  • Pages: 2807-2812
  • First Published: 12 February 2013
Key Points

  • Estimate of decadal hindcast skill of sea surface temperature anomalies
  • Hindcast experiments with four Global Earth System Models from 1960 to 2010
  • Significant skill in some ocean basin-decade combinations

Atmospheric Science

Free Access
Highlight

Recent observations of high mass density polar mesospheric clouds: A link to space traffic?

David E. Siskind,  Michael H. Stevens,  Mark E. Hervig,  Cora E. Randall, 
  • Pages: 2813-2817
  • First Published: 08 May 2013
Key Points

  • No solar cycle variation in polar mesospheric clouds
  • Meteorological variation and rocket exhaust dominate cloud occurrence
  • Enhanced mesospheric water vapor in 2011 and 2012

Free Access
Highlight

GNSS observations of deep convective time scales in the Amazon

D. K. Adams,  Seth I. Gutman,  Kirk L. Holub,  Dulcineide S. Pereira, 
  • Pages: 2818-2823
  • First Published: 20 May 2013
Key Points

  • A new timescale is developed for the shallow-to-deep convective transition
  • First ever, long-term study of deep convection in the tropics using GNSS/GPS
  • Convergence timescale is robust, independent of forcing/nature of the convection

Free Access

On the parameterization of surface momentum transport via drag coefficient in low-wind conditions

Ping Zhu,  Jonathan Furst, 
  • Pages: 2824-2828
  • First Published: 01 May 2013
Key Points

  • Surface layer momentum transport is investigated using 20Hz tower data
  • Drag coefficient increases with a decrease in wind speed for low wind speeds
  • A new parameterization framework for drag coefficient is developed

Free Access

Interpreting seasonal changes in the carbon balance of southern Amazonia using measurements of XCO2 and chlorophyll fluorescence from GOSAT

Nicholas C. Parazoo,  Kevin Bowman,  Christian Frankenberg,  Jung-Eun Lee,  Joshua B. Fisher,  John Worden,  Dylan B. A. Jones,  Joseph Berry,  G. James Collatz,  Ian T. Baker,  Martin Jung,  Junjie Liu,  Gregory Osterman,  Chris O'Dell,  Athena Sparks,  Andre Butz,  Sandrine Guerlet,  Yukio Yoshida,  Huilin Chen,  Christoph Gerbig, 
  • Pages: 2829-2833
  • First Published: 08 April 2013
Key Points

  • XCO2 exhibits strong seasonal variability (~ 4 ppm) in southern Amazonia
  • This is possible because vertical mixing and local seasonal NEE are coupled
  • XCO2 is inversely correlated with fluorescence, indicating GPP drives NEE

Free Access

Adsorption of organic molecules may explain growth of newly nucleated clusters and new particle formation

Jian Wang,  Anthony S. Wexler, 
  • Pages: 2834-2838
  • First Published: 12 April 2013
Key Points

  • Organic molecules may adsorb on the surface of nascent clusters
  • Adsorption may facilitate the condensation of organics on nascent clusters
  • Adsorption of organics may explain enhanced initial particle growth rate

Free Access

Surface ozone variability and the jet position: Implications for projecting future air quality

Elizabeth A. Barnes,  Arlene M. Fiore, 
  • Pages: 2839-2844
  • First Published: 27 March 2013
Key Points

  • Ozone variability is a function of the jet position
  • Surface ozone variability follows the jet in future climate simulations
  • Regional ozone-temperature relationships may change in the future

Free Access

Anthropogenic sulfate aerosol and the southward shift of tropical precipitation in the late 20th century

Yen-Ting Hwang,  Dargan M. W. Frierson,  Sarah M. Kang, 
  • Pages: 2845-2850
  • First Published: 24 April 2013
Key Points

  • A southward shift of tropical rain in the 1980s is detected in observations
  • Most CMIP3/5 GCMs simulate the shift, although less than observed
  • Anthropogenic sulfate emissions cause most of the southward shift in the GCMs

Open Access

Response of extratropical cyclone activity to the Kuroshio large meander in northern winter

Masamitsu Hayasaki,  Ryuichi Kawamura,  Masato Mori,  Masahiro Watanabe, 
  • Pages: 2851-2855
  • First Published: 10 May 2013
Key Points

  • High-resolution air-sea coupled model reproduces a large meander of the Kuroshio
  • Its meander leads to decreased latent heat flux and weakened baroclinicity
  • Primary path of cyclones is very sensitive to the large meander of Kuroshio

Open Access

A robust mode of climate variability in the Arctic: The Barents Oscillation

Hans W. Chen,  Qiong Zhang,  Heiner Körnich,  Deliang Chen, 
  • Pages: 2856-2861
  • First Published: 16 May 2013
Key Points

  • The Barents Oscillation (BO) is a robust mode of atmospheric variability
  • The BO is well related to westerly wind anomalies into the Barents Sea
  • Temperature anomalies in the Barents Sea can largely be explained by the BO

Free Access

Interannual variability of tropical tropopause layer clouds

Sean M. Davis,  Calvin K. Liang,  Karen H. Rosenlof, 
  • Pages: 2862-2866
  • First Published: 29 April 2013
Key Points

  • Extreme interannual variability in TTL cloudiness identified with A-train data
  • QBO, ENSO, and the Brewer-Dobson circulation impact zonal mean TTL cloudiness
  • ENSO causes zonally-asymmetric TTL cloud anomalies

Free Access

Contrail ice particles in aircraft wakes and their climatic importance

Ulrich Schumann,  Philipp Jeßberger,  Christiane Voigt, 
  • Pages: 2867-2872
  • First Published: 08 May 2013
Key Points

  • Gaseous and ice particle concentrations were measured within aircraft wakes
  • Contrails contain more ice particles than expected for previous BC estimates
  • Ice particle concentration in contrails is important for aviation climate impact

Free Access

Toward resolution-independent dust emissions in global models: Impacts on the seasonal and spatial distribution of dust

D. A. Ridley,  C. L. Heald,  J. R. Pierce,  M. J. Evans, 
  • Pages: 2873-2877
  • First Published: 25 March 2013
Key Points

  • Better representation of sub-grid winds reduces resolution dependence of dust
  • Improved dust seasonality and spatial distribution for coarse resolution models
  • Sea-salt emissions are found to be relatively independent of model resolution