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  • Journal article
    Volwerk M, Richter I, Tsurutani B, Gotz C, Altwegg K, Broiles T, Burch J, Carr CM, Cupido E, Delva M, Dosa M, Edberg NJT, Eriksson A, Henri P, Koenders C, Lebreton JP, Mandt KE, Nilsson H, Opitz A, Rubin M, Schwingenschuh K, Stenberg Wieser G, Szego K, Vallat C, Vallieres X, Glassmeier KHet al., 2016,

    Mass-loading, pile-up, and mirror-mode waves at comet 67P/Churyumov-Gerasimenko

    , Annales Geophysicae, Vol: 34, Pages: 1-15, ISSN: 1432-0576

    . The data from all Rosetta Plasma Consortium instruments and from the ROSINA COPSinstrument are used to study the interaction of the solar wind with the outgassing cometary nucleusof 67P/Churyumov-Gerasimenko. During 6 and 7 June 2015, the interaction was first dominatedby an increase in the solar wind dynamic pressure, caused by a higher solar wind ion density. Thispressure compressed the draped magnetic field around the comet, and the increase in solar windelectrons enhanced the ionization of the outflow gas through collisional ionization. The new ionsare picked up by the solar wind magnetic field, and create a ring/ring-beam distribution, which, in ahigh-β plasma, is unstable for mirror mode wave generation. Two different kinds of mirror modesare observed: one of small size generated by locally ionized water and one of large size generatedby ionization and pick-up farther away from the comet.
  • Journal article
    Edberg NJT, Eriksson AI, Odelstad E, Vigren E, Andrews DJ, Johansson F, Burch JL, Carr CM, Cupido E, Glassmeier KH, Goldstein R, Halekas JS, Henri P, Koenders C, Mandt K, Mokashi P, Nemeth Z, Nilsson H, Ramstad R, Richter I, Stenberg Wieser Get al., 2016,

    Solar wind interaction with comet 67P: impacts of corotating interaction regions

    , Journal of Geophysical Research: Space Physics, Vol: 121, Pages: 949-965, ISSN: 2169-9402

    We present observations from the Rosetta Plasma Consortium of the effects of stormy solar wind on comet 67P/Churyumov-Gerasimenko. Four corotating interaction regions (CIRs), where the first event has possibly merged with a CME, are traced from Earth via Mars (using Mars Express and MAVEN) and to comet 67P from October to December 2014. When the comet is 3.1-2.7 AU from the Sun and the neutral outgassing rate ∼1025−1026 s−1 the CIRs significantly influence the cometary plasma environment at altitudes down to 10-30 km. The ionospheric low-energy (∼5 eV) plasma density increases significantly in all events, by a factor >2 in events 1-2 but less in events 3-4. The spacecraft potential drops below -20V upon impact when the flux of electrons increases. The increased density is likely caused by compression of the plasma environment, increased particle impact ionisation, and possibly charge exchange processes and acceleration of mass loaded plasma back to the comet ionosphere. During all events, the fluxes of suprathermal (∼10-100 eV) electrons increase significantly, suggesting that the heating mechanism of these electrons is coupled to the solar wind energy input. At impact the magnetic field strength in the coma increases by a factor of 2-5 as more interplanetary magnetic field piles up around of the comet. During two CIR impact events, we observe possible plasma boundaries forming, or moving past Rosetta, as the strong solar wind compresses the cometary plasma environment. We also discuss the possibility of seeing some signatures of the ionospheric response to tail disconnection events.
  • Journal article
    Sigsbee K, Kletzing CA, Smith CW, MacDowall R, Spence H, Reeves G, Blake JB, Baker DN, Green JC, Singer HJ, Carr CM, Santolik Oet al., 2016,

    Van Allen Probes, THEMIS, GOES, and Cluster Observations of EMIC waves, ULF pulsations, and an electron flux dropout

    , Journal of Geophysical Research: Space Physics, Vol: 121, Pages: 1990-2008, ISSN: 2169-9402

    We examined an electron flux dropout during the 12–14 November 2012 geomagnetic storm using observations from seven spacecraft: the two Van Allen Probes, THEMIS-A (P5), Cluster 2, and Geostationary Operational Environmental Satellite (GOES) 13, 14, and 15. The electron fluxes for energies greater than 2.0 MeV observed by GOES 13, 14, and 15 at geosynchronous orbit and by the Van Allen Probes remained at or near instrumental background levels for more than 24 hours from 12–14 November. For energies of 0.8 MeV, the GOES satellites observed two shorter intervals of reduced electron fluxes. The first interval of reduced 0.8 MeV electron fluxes on 12–13 November was associated with an interplanetary shock and a sudden impulse. Cluster, THEMIS, and GOES observed intense He+ EMIC waves from just inside geosynchronous orbit out to the magnetopause across the dayside to the dusk flank. The second interval of reduced 0.8 MeV electron fluxes on 13–14 November was associated with a solar sector boundary crossing and development of a geomagnetic storm with Dst < −100 nT. At the start of the recovery phase, both the 0.8 and 2.0 MeV electron fluxes finally returned to near pre-storm values, possibly in response to strong ultra-low frequency (ULF) waves observed by the Van Allen Probes near dawn. A combination of adiabatic effects, losses to the magnetopause, scattering by EMIC waves, and acceleration by ULF waves can explain the observed electron behavior.
  • Journal article
    Felici M, Arridge CS, Coates AJ, Badman SV, Dougherty MK, Jackman CM, Kurth WS, Melin H, Mitchell DG, Reisenfeld DB, Sergis Net al., 2016,

    Cassini observations of ionospheric plasma in Saturn's magnetotail lobes

    , Journal of Geophysical Research: Space Physics, Vol: 121, Pages: 338-357, ISSN: 2169-9402

    Studies of Saturn's magnetosphere with the Cassini mission have established the importance of Enceladus as the dominant mass source for Saturn's magnetosphere. It is well known that the ionosphere is an important mass source at Earth during periods of intense geomagnetic activity, but lesser attention has been dedicated to study the ionospheric mass source at Saturn. In this paper we describe a case study of data from Saturn's magnetotail, when Cassini was located at ≃ 2200 h Saturn local time at 36 RS from Saturn. During several entries into the magnetotail lobe, tailward flowing cold electrons and a cold ion beam were observed directly adjacent to the plasma sheet and extending deeper into the lobe. The electrons and ions appear to be dispersed, dropping to lower energies with time. The composition of both the plasma sheet and lobe ions show very low fluxes (sometimes zero within measurement error) of water group ions. The magnetic field has a swept-forward configuration which is atypical for this region, and the total magnetic field strength is larger than expected at this distance from the planet. Ultraviolet auroral observations show a dawn brightening, and upstream heliospheric models suggest that the magnetosphere is being compressed by a region of high solar wind ram pressure. We interpret this event as the observation of ionospheric outflow in Saturn's magnetotail. We estimate a number flux between (2.95 ± 0.43) × 109 and (1.43 ± 0.21) × 1010 cm−2 s−1, 1 or about 2 orders of magnitude larger than suggested by steady state MHD models, with a mass source between 1.4 ×102 and 1.1 ×103 kg/s. After considering several configurations for the active atmospheric regions, we consider as most probable the main auroral oval, with associated mass source between 49.7 ±13.4 and 239.8 ±64.8 kg/s for an average auroral oval, and 10 ±4 and 49 ±23 kg/s for the specific auroral oval morphology found
  • Journal article
    Kasoar M, Voulgarakis A, Lamarque JF, Shindell DT, Bellouin N, Collins WJ, Faluvegi G, Tsigaridis Ket al., 2016,

    Regional and global climate response to anthropogenic SO<inf>2</inf> emissions from China in three climate models

    , Atmospheric Chemistry and Physics Discussions, Vol: 2016, ISSN: 1680-7367

    We use the HadGEM3-GA4, CESM1, and GISS ModelE2 climate models to investigate the global and regional aerosol burden, radiative flux, and surface temperature responses to removing anthropogenic sulfur dioxide (SO2) emissions from China. We find that the models differ by up to a factor of six in the simulated change in aerosol optical depth (AOD) and shortwave radiative flux over China that results from reduced sulfate aerosol, leading to a large range of magnitudes in the regional and global temperature responses. Two of the three models simulate a near-ubiquitous hemispheric warming due to the regional SO2 removal, with similarities in the local and remote pattern of response, but overall with a substantially different magnitude. The third model simulates almost no significant temperature response. We attribute the discrepancies in the response to a combination of substantial differences in the chemical conversion of SO2 to sulfate, translation of sulfate mass into AOD, and differences in the radiative forcing efficiency of sulfate aerosol in the models. The model with the strongest response (HadGEM3-GA4) compares best with observations of AOD regionally, however the other two models compare similarly (albeit poorly) and still disagree substantially in their simulated climate response, indicating that total AOD observations are far from sufficient to determine which model response is more plausible. Our results highlight that there remains a large uncertainty in the representation of both aerosol chemistry as well as direct and indirect aerosol radiative effects in current climate models, and reinforces that caution must be applied when interpreting the results of single-model studies of aerosol influences on climate. Model studies that implicate aerosols in climate responses should ideally explore a range of radiative forcing strengths representative of this uncertainty, in addition to thoroughly evaluating the models used against observations.
  • Journal article
    Kasoar M, Voulgarakis A, Lamarque J-F, Shindell DT, Bellouin N, Collins WJ, Faluvegi G, Tsigaridis Ket al., 2016,

    Supplementary material to &amp;quot;Regional and global climate response to anthropogenic SO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; emissions from China in three climate models&amp;quot;
  • Journal article
    Hood AW, Cargill PJ, Browning PK, Tam KVet al., 2016,

    An MHD avalanche in a multi-threaded coronal loop

    , Astrophysical Journal, Vol: 817, ISSN: 1538-4357
  • Book chapter
    Haigh JD, 2016,

    Blue Sky; Mirages, haloes and sundogs; Rainbows; Space Weather; Sunshine; Sunspots and Climate

    , 30-Second Meteorology: The 50 Most Significant Events and Phenomena, Each Explained in Half a Minute, Editors: Scaife, ISBN: 978-1-7824-0310-4
  • Journal article
    Good SW, Forsyth RJ, 2016,

    Interplanetary coronal mass ejections observed by MESSENGER and Venus Express

    , Solar Physics, Vol: 291, Pages: 239-263, ISSN: 1573-093X

    Interplanetary coronal mass ejections (ICMEs) observed by the MESSENGER and Venus Express spacecraft have been catalogued and analysed. The ICMEs were identified by a relatively smooth rotation of the magnetic field direction consistent with a flux rope structure, coinciding with a relatively enhanced magnetic field strength. A total of 35 ICMEs were found in the surveyed MESSENGER data (primarily from March 2007 to April 2012), and 84 ICMEs in the surveyed Venus Express data (from May 2006 to December 2013). The ICME flux rope configurations have been determined. Ropes with northward leading edges were about four times more common than ropes with southward leading edges, in agreement with a previously established solar cycle dependence. Ropes with low inclinations to the solar equatorial plane were about four times more common than ropes with high inclinations, possibly an observational effect. Left- and right-handed ropes were observed in almost equal numbers. In addition, data from MESSENGER, Venus Express, STEREO-A, STEREO-B and ACE were examined for multipoint signatures of the catalogued ICMEs. For spacecraft separations below 15° in heliocentric longitude, the second spacecraft observed the ICME flux rope in 82 % of cases; this percentage dropped to 49 % for separations between 15 and 30°, to 18 % for separations between 30 and 45°, and to 12 % for separations between 45 and 60°. As the spacecraft separation increased, it became increasingly likely that only the sheath and not the flux rope of the ICME was observed, in agreement with the notion that ICME flux ropes are smaller in longitudinal extent than the shocks or discontinuities that they often drive. Furthermore, this study has identified 23 ICMEs observed by pairs of spacecraft close to radial alignment. A detailed analysis of these events could lead to a better understanding of how ICMEs evolve during propagation.
  • Journal article
    Kurth WS, Hospodarsky GB, Gurnett DA, Lamy L, Dougherty MK, Nichols J, Bunce EJ, Pryor W, Baines K, Stallard T, Melin H, Crary FJet al., 2016,

    Saturn kilometric radiation intensities during the Saturn auroral campaign of 2013

    , Icarus, Vol: 263, Pages: 2-9, ISSN: 1090-2643

    The Saturn auroral campaign carried out in the spring of 2013 used multiple Earth-based observations, remote-sensing observations from Cassini, and in situ-observations from Cassini to further our understanding of auroras at Saturn. Most of the remote sensing and Earth-based measurements are, by nature, not continuous. And, even the in situ measurements, while continuously obtained, are not always obtained in regions relevant to the study of the aurora. Saturn kilometric radiation, however, is remotely monitored nearly continuously by the Radio and Plasma Wave Science instrument on Cassini. This radio emission, produced by the cyclotron maser instability, is tightly tied to auroral processes at Saturn as are auroral radio emissions at other planets, most notably Jupiter and Earth. This paper provides the time history of the intensity of the radio emissions through the auroral campaign as a means of understanding the temporal relationships between the sometimes widely spaced observations of the auroral activity. While beaming characteristics of the radio emissions are known to prevent single spacecraft observations of this emission from being a perfect auroral activity indicator, we demonstrate a good correlation between the radio emission intensity and the level of UV auroral activity, when both measurements are available.
  • Journal article
    Badman SV, Provan G, Bunce EJ, Mitchell DG, Melin H, Cowley SWH, Radioti A, Kurth WS, Pryor WR, Nichols JD, Jinks SL, Stallard TS, Brown RH, Baines KH, Dougherty MKet al., 2016,

    Saturn's auroral morphology and field-aligned currents during a solar wind compression

    , Icarus, Vol: 263, Pages: 83-93, ISSN: 1090-2643

    On 21–22 April 2013, during a coordinated auroral observing campaign, instruments onboard Cassini and the Hubble Space Telescope observed Saturn’s aurora while Cassini traversed Saturn’s high latitude auroral field lines. Signatures of upward and downward field-aligned currents were detected in the nightside magnetosphere in the magnetic field and plasma measurements. The location of the upward current corresponded to the bright ultraviolet auroral arc seen in the auroral images, and the downward current region was located poleward of the upward current in an aurorally dark region. Within the polar cap magnetic field and plasma fluctuations were identified with periods of ∼20 and ∼60 min. The northern and southern auroral ovals were observed to rock in latitude in phase with the respective northern and southern planetary period oscillations. A solar wind compression impacted Saturn’s magnetosphere at the start of 22 April 2013, identified by an intensification and extension to lower frequencies of the Saturn kilometric radiation, with the following sequence of effects: (1) intensification of the auroral field-aligned currents; (2) appearance of a localised, intense bulge in the dawnside (04–06 LT) aurora while the midnight sector aurora remained fainter and narrow; and (3) latitudinal broadening and poleward contraction of the nightside aurora, where the poleward motion in this sector is opposite to that expected from a model of the auroral oval’s usual oscillation. These observations are interpreted as the response to tail reconnection events, initially involving Vasyliunas-type reconnection of closed mass-loaded magnetotail field lines, and then proceeding onto open lobe field lines, causing the contraction of the polar cap region on the night side.
  • Journal article
    Roussos E, Krupp N, Mitchell DG, Paranicas C, Krimigis SM, Andriopoulou M, Palmaerts B, Kurth WS, Badman SV, Masters A, Dougherty MKet al., 2016,

    Quasi-periodic injections of relativistic electrons in Saturn’s outer magnetosphere

    , Icarus, Vol: 263, Pages: 101-116, ISSN: 1090-2643

    Quasi-periodic, short-period injections of relativistic electrons have been observed in both Jupiter’s and Saturn’s magnetospheres, but understanding their origin or significance has been challenging, primarily due to the limited number of in-situ observations of such events by past flyby missions. Here we present the first survey of such injections in an outer planetary magnetosphere using almost nine years of energetic charged particle and magnetic field measurements at Saturn. We focus on events with a characteristic period of about 60–70 min (QP60, where QP stands for quasi-periodic). We find that the majority of QP60, which are very common in the outer magnetosphere, map outside Titan’s orbit. QP60 are also observed over a very wide range of local times and latitudes. A local time asymmetry in their distribution is the most striking feature, with QP60 at dusk being between 5 and 25 times more frequent than at dawn. Field-line tracing and pitch angle distributions suggest that most events at dusk reside on closed field lines. They are distributed either near the magnetopause, or, in the case of the post-dusk (or pre-midnight) sector, up to about 30 RS inside it, along an area extending parallel to the dawn–dusk direction. QP60 at dawn map either on open field lines and/or near the magnetopause. Both the asymmetries and varying mapping characteristics as a function of local time indicate that generation of QP60 cannot be assigned to a single process. The locations of QP60 seem to trace sites that reconnection is expected to take place. In that respect, the subset of events observed post-dusk and deep inside the magnetopause may be directly or indirectly linked to the Vasyliunas reconnection cycle, while magnetopause reconnection/Kelvin–Helmholtz (KH) instability could be invoked to explain all other events at the duskside. Using similar arguments, injections at the dawnside magnetosphere may result from solar-wind induced storm
  • Journal article
    Ceppi P, Hartmann DL, Webb MJ, 2016,

    Mechanisms of the negative shortwave cloud feedback in middle to high latitudes

    , Journal of Climate, Vol: 29, Pages: 139-157, ISSN: 0894-8755

    Increases in cloud optical depth and liquid water path (LWP) are robust features of global warming model simulations in high latitudes, yielding a negative shortwave cloud feedback, but the mechanisms are still uncertain. Here the importance of microphysical processes for the negative optical depth feedback is assessed by perturbing temperature in the microphysics schemes of two aquaplanet models, both of which have separate prognostic equations for liquid water and ice. It is found that most of the LWP increase with warming is caused by a suppression of ice microphysical processes in mixed-phase clouds, resulting in reduced conversion efficiencies of liquid water to ice and precipitation. Perturbing the temperature-dependent phase partitioning of convective condensate also yields a small LWP increase. Together, the perturbations in large-scale microphysics and convective condensate partitioning explain more than two-thirds of the LWP response relative to a reference case with increased SSTs, and capture all of the vertical structure of the liquid water response. In support of these findings, a very robust positive relationship between monthly mean LWP and temperature in CMIP5 models and observations is shown to exist in mixed-phase cloud regions only. In models, the historical LWP sensitivity to temperature is a good predictor of the forced global warming response poleward of about 45°, although models appear to overestimate the LWP response to warming compared to observations. The results indicate that in climate models, the suppression of ice-phase microphysical processes that deplete cloud liquid water is a key driver of the LWP increase with warming and of the associated negative shortwave cloud feedback.
  • Conference paper
    Palchetti L, Olivieri M, Pompei C, Labate D, Brindley H, Natale GD, Bianchini Get al., 2016,

    The Far Infrared FTS for the FORUM Mission

    A wide-band FTS has been designed to perform the spectral observation of the entire infrared Earth's outgoing emission, including the far infrared portion, for the FORUM space mission.
  • Conference paper
    Brindley H, Murray J, Bellisario C, Harlow C, Woolley A, Fox S, Last A, Pickering Jet al., 2016,

    Estimating far infrared surface emissivity over greenland from the tropospheric airborne fourier transform spectrometer (TAFTS)

    We report on efforts to obtain observationally based estimates of far-infrared surface emissivity over snow and ice. We highlight one flight from the CIRCCREX-COSMICS airborne campaign over Greenland during March 2015.
  • Conference paper
    Murray J, Fox S, O'Shea S, Thornton J, Trembath J, Fugal J, Pickering J, Fox C, Brooke J, Harlow C, Bower K, Ulanowski J, Baran A, Brindley H, Ritter G, Last Aet al., 2016,

    The cirrus coupled cloud-radiation experiment-II

    A cirrus study has been undertaken during the second Cirrus Cloud-Radiation Experiment field campaign based in Prestwick, Scotland. We report on a case study describing the radiation and microphysics measurements and cloud modelling work.
  • Journal article
    Vanniere B, Czaja A, Dacre H, Woollings T, Parfitt Ret al., 2016,

    A Potential Vorticity Signature for the Cold Sector of Winter Extratropical Cyclones

    , Quarterly Journal of the Royal Meteorological Society, Vol: 142, Pages: 432-442, ISSN: 1477-870X

    The cold sector of mid-latitude storms is characterised by distinctive features such as strong surface heat fluxes, shallow convection, convective precipitation and synoptic subsidence. In order to evaluate the contribution of processes occurring in the cold sector to the mean climate, an appropriate indicator is needed. This study describes the systematic presence of negative PV behind the cold front of extratropical storms in winter. The origin of this negative PV is analysed using ERA-Interim data, potential vorticity tendencies averaged over the depth of the boundary layer are evaluated. It is found that negative PV is generated by diabatic processes in the cold sector and by Ekman pumping at the low centre, whereas positive PV is generated by Ekman advection of potential temperature in the warm sector. We suggest here that the negative PV at low-levels can be used to identify the cold sector. A PV-based indicator is applied to estimate the respective contributions of the cold sector and the remainder of the storm to upward motion, and large scale and convective precipitation. We compare the PV-based indicator with other distinctive features that could be used as markers of the cold sector, and find that potential vorticity is the best criterion when taken alone, and the best when combined with any other.
  • Journal article
    Martinovic MM, Zaslavsky A, Maksimovic M, Meyer-Vernet N, Segan S, Zouganelis I, Salem C, Pulupa M, Bale SDet al., 2016,

    Quasi-thermal noise measurements on STEREO: Kinetic temperature deduction using electron shot noise model

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 121, Pages: 129-139, ISSN: 2169-9380
  • Journal article
    Ceppi P, Hartmann DL, 2016,

    Clouds and the Atmospheric Circulation Response to Warming

    , JOURNAL OF CLIMATE, Vol: 29, Pages: 783-799, ISSN: 0894-8755
  • Journal article
    Southwood DJ, 2016,

    Space in 150 years: From fantasy through fiction to fact and function

    , Aeronautical Journal, Vol: 120, Pages: 201-208, ISSN: 0001-9240

    In the last century and half, space has moved from the realm of fantasy to everyday reality.In parallel the way space has been regarded by the person in the street and the ideas of whataccess to space might be used for have evolved extraordinarily.
  • Journal article
    Goswami BN, Rao S, Sengupta D, Chowdary Set al., 2016,

    Monsoons to Mixing in the Bay of Bengal: Multiscale Air-Sea Interactions and Monsoon Predictability

    , Oceanography, Vol: 29, Pages: 18-27, ISSN: 1042-8275
  • Book chapter
    Badman SV, Branduardi-Raymont G, Galand M, Hess SLG, Krupp N, Lamy L, Melin H, Tao Cet al., 2016,

    Auroral Processes at the Giant Planets: Energy Deposition, Emission Mechanisms, Morphology and Spectra

    , MAGNETODISCS AND AURORAE OF GIANT PLANETS, Editors: Szego, Achilleos, Arridge, Badman, Delamere, Grodent, Kivelson, Louarn, Publisher: SPRINGER, Pages: 99-179, ISBN: 978-1-4939-3394-5
  • Journal article
    group ISOSISOS, Holt P, Rhodes A, Wilson M, Ferguson M, Macmahon M, Gillespie D, Phillips K, Reynolds J, Kerridge R, Bennett M, Stewart M, Hartmann A, Jacobs T, Ortega D, Dias F, Machado M, Garcia J, Lopes M, Carr A, Yu HC, Rowe B, Sampson S, George R, Jones P, Tran D, Dobson G, Hall R, Lee E, Tsui A, Choi S, Dwyer H, McCartney C, Carroll J, Huang Y, Cao Y, Gao H, Hu T, Yang J, Yang Y, Zhong Y, Zhou J, He M, Li X, Wang H, Chen L, Wang L, Cai Y, Li Y, Sun H, Wang S, Wang Z, Wang K, Zhu Y, Du X, Fu Y, Huang L, Huang Y, Wang Z, Wang G, Wang S, Zhang Y, Zhang X, Chen C, Wang W, Liu Z, Fan L, Tang J, Chen Y, Chen Y, Huang C, Shen J, Wang J, Yang Q, Zhou H, Chen J, Chen Z, Li X, Zhang X, Bi Y, Cao J, Lin H, Liu Y, Sun C, Sun Y, Wang Y, Wang S, Zhang M, Shen Z, Zhang Y, Zhao B, Zhou X-J, Chen Q, Guo H, Guo Y, Qi Y, Zhang W, Zheng L, Chen Y, Chen Y, Hu X, Li X, Shen C, Sun Y, Wang Y, Wang D, Wu C, Xu L, Yuan J, Zhang L, Zhang H, Zhang Y, Zhao J, Zhao C, Zhou H, Zhou C, Chen H, Chen S, He J, Li C, Li H, Pan Y, Shi Y, Wu S, Zhang K, Zhao B, Chen F, Lin X, Liu G, Tao J, Yang L, Zhou J, Chen F, Cheng Z, Feng Y, Hou B, Hu CH, Huang H, Huang J, Jiang Z, Li M, Lin J, Liu M, Liu W, Liu Z, Ma L, Min J, Song Z, Xiong Y, Xu L, Yang S, Zhang Q, Zhang H, Zhang H, Zhang X, Zhao W, Zhao W, Zhu X, Chen L, Chen S, Dai Q, Han K, He X, Huang L, Jia D, Jin S, Li Q, Luo S, Pan Y, Qian M, Qin J, Shi Y, Wang J, Wang J, Wang L, Yan Y, Yao Y, Zhang M, Zhao J, He L, Huang L, Li Z, Li H, Li Y, Li L, Yuan Y, Zhang E, Zhang J, Zhao S, Chen C, Li J, Wen Z, Yu Y, Yuan F, Hu X, Zhang Y, Xiao W, Zhu Z, Dai Q, Fu K, Hu R, Hu X, Huang S, Li Y, Liang Y, Yu S, Guo Z, Wu J, Zhang R, Zhao X, Li Y, Liu C-X, Liu F-F, Ren W, Wang X-L, Xu G-J, Li B, Ou Y, Tang Y, Yao S, Zhang S, Kong C-C, Liu B, Wang T, Xiao W, Lu B, Xia Y, Zhou J, Hu S, Wang H, Hu L, Li B, Liu Q, Liu Y, Qiu X, Ren Q, Tong Y, Wang J, Xia J, Xiong X, Xu S, Yang T, Yuan J, Zhang B, Chen S, Fan Y, Fu S, Ge X, Guo B, Huang W, Jiang L, Jiang X, Liu Y, Paet al., 2016,

    Global patient outcomes after elective surgery: Prospective cohort study in 27 low-, middle- and high-income countries

    , British Journal of Anaesthesia, ISSN: 0007-0912
  • Book chapter
    Turnbull JC, Graven H, Krakauer NY, 2016,

    Radiocarbon in the Atmosphere

    , RADIOCARBON AND CLIMATE CHANGE: MECHANISMS, APPLICATIONS AND LABORATORY TECHNIQUES, Editors: Schuur, Druffel, Trumbore, Publisher: SPRINGER INTERNATIONAL PUBLISHING AG, Pages: 83-137, ISBN: 978-3-319-25641-2
  • Conference paper
    Tao J, Wang L, Zong Q, Li G, Salem CS, Wimmer-Schweingruber RF, He J, Tu C, Bale SDet al., 2016,

    Solar Wind ∼0.1-1.5 keV Electrons at Quiet Times

    , 14th International Solar Wind Conference (Solar Wind), Publisher: AMER INST PHYSICS, ISSN: 0094-243X
  • Conference paper
    Franci L, Hellinger P, Matteini L, Verdini A, Landi Set al., 2016,

    Two-dimensional Hybrid Simulations of Kinetic Plasma Turbulence: Current and Vorticity vs Proton Temperature

    , 14th International Solar Wind Conference (Solar Wind), Publisher: AMER INST PHYSICS, ISSN: 0094-243X
  • Conference paper
    Yang L, Wang L, Li G, He J, Salem CS, Tu C, Wimmer-Schweingruber RF, Bale SDet al., 2016,

    The Angular Distribution of Solar Wind ∼20-200 keV Superhalo Electrons at Quiet Times

    , 14th International Solar Wind Conference (Solar Wind), Publisher: AMER INST PHYSICS, ISSN: 0094-243X
  • Journal article
    Mistry R, Eastwood JP, Hietala H, 2015,

    Development of bifurcated current sheets in solar wind reconnection exhausts

    , Geophysical Research Letters, Vol: 42, Pages: 10513-10520, ISSN: 1944-8007

    Petschek-type reconnection is expected to result in bifurcations of reconnection current sheets. In contrast, Hall reconnection simulations show smooth changes in the reconnecting magnetic field. Here we study three solar wind reconnection events where different spacecraft sample oppositely directed reconnection exhausts from a common reconnection site. The spacecraft's relative separations and measurements of the exhaust width are used to geometrically calculate each spacecraft's distance from the X line. We find that in all cases spacecraft farthest from the X line observe clearly bifurcated reconnection current sheets, while spacecraft nearer to the X line do not. These observations suggest that clear bifurcations of reconnection current sheets occur at large distances from the X line (~1000 ion skin depths) and that Petschek-type signatures are less developed close to the reconnection site. This may imply that fully developed bifurcations of reconnection current sheets are unlikely to be observed in the near-Earth magnetotail.
  • Journal article
    Odelstad E, Eriksson AI, Edberg NJT, Johansson F, Vigren E, Andre M, Tzou CY, Carr CM, Cupido Eet al., 2015,

    Evolution of the plasma environment of comet 67P from spacecraft potential measurements by the Rosetta Langmuir probe instrument

    , Geophysical Research Letters, Vol: 42, Pages: 10126-10134, ISSN: 1944-8007

    We study the evolution of the plasma environment of comet 67P using measurements of the spacecraft potential from early September 2014 (heliocentric distance 3.5 AU) to late March 2015 (2.1 AU) obtained by the Langmuir probe (RPC-LAP) instrument. The low collision rate keeps the electron temperature high (~ 5 eV), resulting in a negative spacecraft potential whose magnitude depends on the electron density. This potential is more negative in the northern (summer) hemisphere, particularly over sunlit parts of the neck region on the nucleus, consistent with neutral gas measurements by ROSINA-COPS. Assuming constant electron temperature, the spacecraft potential traces the electron density. This increases as the comet approaches the Sun, most clearly in the southern hemisphere by a factor possibly as high as 20 - 44 between September 2014 and January 2015. The northern hemisphere plasma density increase stays around a factor of around or below 8 - 12, consistent with seasonal insolation change.
  • Journal article
    Archer MO, Hartinger MD, Walsh BM, Plaschke F, Angelopoulos Vet al., 2015,

    Frequency variability of standing Alfven waves excited by fast mode resonances in the outer magnetosphere

    , Geophysical Research Letters, Vol: 42, Pages: 10150-10159, ISSN: 0094-8276

    Coupled fast mode resonances (cFMRs) in the outer magnetosphere, between the magnetopause and a turning point, are often invoked to explain observed discrete frequency field line resonances. We quantify their frequency variability, applying cFMR theory to a realistic magnetic field model and magnetospheric density profiles observed over almost half a solar cycle. Our calculations show that cFMRs are most likely around dawn, since the plasmaspheric plumes and extended plasmaspheres often found at noon and dusk can preclude their occurrence. The relative spread (median absolute deviation divided by the median) in eigenfrequencies is estimated to be 28%, 72%, and 55% at dawn, noon, and dusk, respectively, with the latter two chiefly due to density. Finally, at dawn we show that the observed bimodal density distribution results in bimodal cFMR frequencies, whereby the secondary peaks are consistent with the so-called “CMS” frequencies that have previously been attributed to cFMRs.

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