Vertical Coverage Research Articles

Measurement and comparison of wi-fi and super wi-fi indoor propagation characteristics in a multi-floored building

Super Wi-Fi is a Wi-Fi-like service exploiting TV white space (WS) which is expected to achieve larger coverage than today's Wi-Fi thanks to its superior propagation characteristics. Super Wi-Fi has been materialized as an international standard, IEEE 802.11af, targeting indoor and outdoor applications, and is undergoing worldwide field tests. This paper demonstrates the true potential of indoor Super Wi-Fi, by experimentally comparing the signal propagation characteristics of SuperWi-Fi andWi-Fi in the same indoor environment. Specifically, we measured the wall and floor attenuation factors and the path-loss distribution at 770MHz, 2.401 GHz, and 5.540 GHz, and predicted the downlink capacity of Wi-Fi and Super Wi-Fi. The experimental results have revealed that TVWS signals can penetrate up to two floors above and below, whereasWi-Fi signals experience significant path loss even through a single floor. It has been also shown that Super Wi-Fi mitigates shaded regions of Wi-Fi by providing almost-homogeneous data rates within its coverage, performs comparable to Wi-Fi utilizing less bandwidth, and always achieves better spectral efficiency than Wi-Fi. The observed phenomena imply that SuperWi-Fi is suitable for indoor applications and has the potential of extending horizontal and vertical coverage of today's Wi-Fi.

Seasonal shifts in the vertical distribution of fish in a shallow coastal area

Abstract Depth structures aquatic habitats, creating substantial differences in the species composition of underwater communities even at small intervals. Those communities also undergo considerable cyclic variation annually. In this study, we surveyed variation in the vertical distribution of fish in a shallow (20 m) coastal basin in the northern Baltic Sea during the ice-free period from May to October. The waters were strongly mixed throughout the season and only transient signs of stratification were observed. As production shifted towards higher trophic levels over summer, with sequential biomass peaks in zooplankton and juvenile fish, the vertical distribution of the entire fish assemblage became increasingly even. The results suggest that spatial resource partitioning can be strongly correlated with seasonal productivity cycles even in physically uniform environments with high connectivity. Further, the results stress the importance of sampling design (seasonal and vertical coverage) of fish studies in shallow coastal areas.

Application of high-precision 3D seismic technology to shale gas exploration: A case study of the large Jiaoshiba shale gas field in the Sichuan Basin

The accumulation pattern of the marine shale gas in South China is different from that in North America. The former has generally thin reservoirs and complex preservation conditions, so it is difficult to make a fine description of the structural features of shale formations and to reflect accurately the distribution pattern of high-quality shale by using the conventional 2D and 3D seismic exploration technology, which has an adverse effect on the successful deployment of horizontal wells. In view of this, high-precision 3D seismic prospecting focusing on lithological survey was implemented to make an accurate description of the distribution of shale gas sweet spots so that commercial shale gas production can be obtained. Therefore, due to the complex seismic geological condition of Jiaoshiba area in Fuling, SE Sichuan Basin, the observation system of high-precision 3D seismic acquisition should have such features as wide-azimuth angles, small trace intervals, high folds, uniform vertical and horizontal coverage and long spread to meet the needs of the shale gas exploration in terms of structural interpretation, lithological interpretation and fracture prediction. Based on this idea, the first implemented high-precision 3D seismic exploration project in Jiaoshiba area played an important role in the discovery of the large Jiaoshiba shale gas field. Considering that the high-quality marine shale in the Sichuan Basin shows the characteristics of multi-layer development from the Silurian system to the Cambrian system, the strategy of shale gas stereoscopic exploration should be implemented to fully obtain the oil and gas information of the shallow, medium and deep strata from the high-precision 3D seismic data, and ultimately to expand the prospecting achievements in an all-round way to balance the high upstream exploration cost, and to continue to push the efficient shale gas exploration and development process in China.

Assessing the impacts of assimilating IASI and MOPITT CO retrievals using CESM‐CAM‐chem and DART

AbstractWe show the results and evaluation with independent measurements from assimilating both MOPITT (Measurements Of Pollution In The Troposphere) and IASI (Infrared Atmospheric Sounding Interferometer) retrieved profiles into the Community Earth System Model (CESM). We used the Data Assimilation Research Testbed ensemble Kalman filter technique, with the full atmospheric chemistry CESM component Community Atmospheric Model with Chemistry. We first discuss the methodology and evaluation of the current data assimilation system with coupled meteorology and chemistry data assimilation. The different capabilities of MOPITT and IASI retrievals are highlighted, with particular attention to instrument vertical sensitivity and coverage and how these impact the analyses. MOPITT and IASI CO retrievals mostly constrain the CO fields close to the main anthropogenic, biogenic, and biomass burning CO sources. In the case of IASI CO assimilation, we also observe constraints on CO far from the sources. During the simulation time period (June and July 2008), CO assimilation of both instruments strongly improves the atmospheric CO state as compared to independent observations, with the higher spatial coverage of IASI providing better results on the global scale. However, the enhanced sensitivity of multispectral MOPITT observations to near surface CO over the main source regions provides synergistic effects at regional scales.

A simple position estimator that improves advanced RAIM performance

We describe a simple method to determine a Global Navigation Satellite System (GNSS) position estimator for advanced receiver autonomous integrity monitoring (RAIM) that improves availability upon the commonly used least squares estimator. The idea consists in searching the estimator among all affine combinations of the all-in-view least squares estimator and a fault-tolerant estimator - the one corresponding to the most difficult fault to mitigate. Availability simulations show a significant improvement in vertical guidance coverage levels for a dual constellation scenario.

Effects of Gold-Nanoparticle Surface and Vertical Coverage by Conducting Polymer between Indium Tin Oxide and the Hole Transport Layer on Organic Light-Emitting Diodes.

PSS), which was used as a capping layer between indium tin oxide (ITO) and a hole transport layer (HTL) on small-molecule fluorescent organic light-emitting diodes (OLEDs), was systemically investigated. With respect to the Au-NP loading amount and size, the resultant current densities influenced the charge balance and, therefore, the OLED device performance. When the capping layer consisted of ITO/Au-NPs/ PSS+Au-NPs, superior device performance was obtained with 10-nm Au-NPs through increased surface coverage in comparison to other Au-NP PEDOT:PSS coverage conditions. Furthermore, the Au-NP size determined the vertical coverage of the capping layer. The current densities of OLEDs containing small Au-NPs (less than 30 nm, small vertical coverage) covered by PSS decreased because of the suppression of the hole carriers by the Au-NP trapping sites. However, the current densities of the devices with large Au-NPs (over 30 nm, large vertical coverage) increased. The increased electromagnetic fields observed around relatively large Au-NPs under electrical bias were attributed to increased current densities in the OLEDs, as confirmed by the finite-difference time-domain simulation. These results show that the coverage conditions of the Au-NPs by the PSS clearly influenced the OLED current density and efficiency.

Extreme detached dust layers near Martian volcanoes: Evidence for dust transport by mesoscale circulations forced by high topography

AbstractModeling suggests that thermal circulations over Mars's highest volcanoes transport water vapor and dust from the surface into the middle atmosphere, forming detached layers in these constituents. Intense vertical mixing also takes place in regional and global dust storms, which can generate detached layers that are extreme in both altitude and magnitude. Here we employ observations by the Mars Climate Sounder (MCS) on board Mars Reconnaissance Orbiter, taking advantage of improved vertical coverage in MCS's aerosol retrievals, to discover a new class of extreme detached dust layers (EDDLs). Observed during minimal dust storm activity and furthermore distinguished by their potentially large and measurable horizontal extent (>1000 km), these EDDLs cluster near Olympus Mons and the Tharsis Montes, from which they likely originate. The existence of these EDDLs suggests that vertical mixing by topographic circulations can be much stronger than previously modeled and more frequent than previously observed.

When Is Induced Fracture Complexity Necessary for Unconventionals Stimulation?

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 168976, “Induced Fracture Complexity—When Is It Really Required in Unconventional Reservoir Stimulation?” by Leopoldo Sierra, SPE, and Mike Mayerhofer, SPE, Pinnacle—A Halliburton Service, prepared for the 2014 SPE Unconventional Resources Conference—USA, The Woodlands, Texas, USA, 1–3 April. The paper has not been peer reviewed. Induced-fracture-complexity maximization in addition to the primary hydraulic fractures has been accepted and fully implemented to improve recovery efficiency or productivity in unconventional reservoirs. This paper aims to develop criteria for identifying situations in which induced fracture complexity and sustained conductivity are or are not required. The results show that the fracture complexity and sustained conductivity are generally important for reservoir permeabilities lower than 100 nd for gas production and 500 nd for liquid production. Introduction The industry-implemented completion strategy for unconventional gas- or liquid- producing reservoirs considers increased reservoir contact to maximize productivity and hydrocarbon recovery through the following methods: Drilling long horizontal wellbores Optimizing the horizontal-wellbore placement to maximize the vertical coverage of the prospective formation Placing multiple transverse fractures by perforating the most-brittle and -prospective areas to generate complex fractures Alternating fractures in parent horizontal wellbores to induce stress interference that could result in more-complex fractures Engineering stimulation fluids to help induce complex fractures Although the existing completion strategy for each shale play has been optimized or is in the optimization process, a correlation between production and the perceived fracture surface area was not observed in some cases. Assuming the stimulation process is adequate and properly implemented in the field, the observed production behavior might be related to the combination of unknown reservoir permeability and induced fracture complexity. This paper investigates the benefits of induced fracture complexity in the stimulation of unconventional gas-or liquid-producing reservoirs for a wide range of reservoir permeabilities (10 nd to 0.001 md) and with a variable stimulation efficiency. Ultimately, this paper aims to answer the question of when induced fracture complexity is really necessary.

English

Introduction: Orthodontic treatment in-deep bite subjects has generally been focused on the correction of excessive vertical coverage (overbite); however, the impact on functional problems following treatment has not been well evaluated. This study aimed to investigate the differences in mandibular movements between deep bite and normal occlusion, and to compare the functional changes of mandible in the subjects with deep bite before and after treatment. Methods: This study included students from School of Dentistry, China Medical University (CMU), and employees from CMU Hospital. The participants were categorized into normal bite (n = 11) and deep bite (n = 16) groups. Considering the clinical practicability, convenience and affordability, Digi Gnatho software (Japan), was used to analyze mandibular movements recorded by digital video camera. Results: No significant difference was observed in the left side masticatory movements between two groups. Significant difference was only detected in the horizontal direction of right side mastication. All of the velocities and masticatory cycle duration of both sides showed no difference. In the mandibular border movements, protrusive movements in deep-bite group were distinct from normal occlusion group. Normal occlusion group had a larger range of mandibular movements compared to deep bite group. Conclusions: Different degrees of vertical coverage of the incisors not only presented differences in the ranges of masticatory movements and border movements, but also had an impact on the final occlusal phase of mastication.

Gravity wave momentum fluxes from MF and meteor radar measurements in the polar MLT region

AbstractAnnual cycles of horizontal winds and gravity wave (GW) momentum fluxes in the mesosphere/lower thermosphere (MLT) are presented for the medium frequency Doppler radar at Saura (SMF radar, located at 69°N, 16°E) for the first time. Four year mean wind and momentum flux fields for 2008 through 2011 clearly show the coupling and interactions between GWs and the mean flow especially in the summer months. GW breaking at mesopause heights results in momentum flux divergence and affects the wind field by forcing a reversal of the wind profile in summer. Height‐time cross sections for the individual years (2008 to 2011) illustrate the year‐to‐year variation of horizontal winds and the vertical fluxes of zonal and meridional momentum. They show similar annual patterns from year to year which are more consistent in the summer months than during winter and have maximum absolute values in 2009. Furthermore, the precise SMF radar measurements give an excellent possibility to evaluate momentum flux estimates from the colocated meteor radar at Andenes. Both radars have different capabilities, and different techniques are applied to derive momentum fluxes. They show comparable results for the 4 year mean annual cycles of horizontal winds and momentum fluxes especially in summer. This holds for both structure and magnitudes in the overlapping heights, where the SMF radar data provide a wider vertical coverage. The best agreement is found for the zonal components of both radars, whereas there are some larger discrepancies in the meridional components, especially in the vertical flux of meridional momentum.

Comparison of Vertical Coverage Diagram for Multi Beams Radar for Different Frequencies and RCS

Comparison of Vertical Coverage Diagram for Multi Beams Radar for Different Frequencies and RCS

Towards IASI-New Generation (IASI-NG): impact of improved spectral resolution and radiometric noise on the retrieval of thermodynamic, chemistry and climate variables

Abstract. Besides their strong contribution to weather forecast improvement through data assimilation, thermal infrared sounders onboard polar-orbiting platforms are now playing a key role for monitoring atmospheric composition changes. The Infrared Atmospheric Sounding Interferometer (IASI) instrument developed by the French space agency (CNES) and launched by EUMETSAT onboard the Metop satellite series is providing essential inputs for weather forecasting and pollution/climate monitoring owing to its smart combination of large horizontal swath, good spectral resolution and high radiometric performance. EUMETSAT is currently preparing the next polar-orbiting program (EPS-SG) with the Metop-SG satellite series that should be launched around 2020. In this framework, CNES is studying the concept of a new instrument, the IASI-New Generation (IASI-NG), characterized by an improvement of both spectral and radiometric characteristics as compared to IASI, with three objectives: (i) continuity of the IASI/Metop series; (ii) improvement of vertical resolution; and (iii) improvement of the accuracy and detection threshold for atmospheric and surface components. In this paper, we show that an improvement of spectral resolution and radiometric noise fulfil these objectives by leading to (i) a better vertical coverage in the lower part of the troposphere, thanks to the increase in spectral resolution; and (ii) an increase in the accuracy of the retrieval of several thermodynamic, climate and chemistry variables, thanks to the improved signal-to-noise ratio as well as less interference between the signatures of the absorbing species in the measured radiances. The detection limit of several atmospheric species is also improved. We conclude that IASI-NG has the potential to strongly benefit the numerical weather prediction, chemistry and climate communities now connected through the European GMES/Copernicus initiative.

Characterization Method of Radar for Air Surveillance Coverage

Aiming at the radar vertical detection coverage limitation given by manufacturing factories, this paper put forwards a new characterization method of radar’s air surveillance coverage: it is the projection distance of furthest detection point for different RCS targets at different altitudes, which can directly show radar’s quick response to the attack action launched by fighter. Then this paper gives the calculating method of coverage characterization method, and calculates radar detection coverage of typical medium-low altitude search. The result shows that the detection ability to penetration fighter is weak for high altitude and below 300m altitude, especially for the high altitude penetration stealth fighter.

Quasi-optics design of the dual-array ECE imaging system on the EAST Tokamak

A novel large aperture quasi-optical imaging system is designed for the new dual-array electron cyclotron emission (ECE) imaging (ECEI) instrument on the EAST tokamak. The zoom doublet scheme is used in the microwave imaging system on a super-conducting tokamak for the first time, and the focal plane can reach the high magnetic field side region even in the narrowest zoom configuration. The best spatial resolution in the vertical direction is 1.1 cm and the maximum vertical coverage can reach 80 cm. The field curvature is largely reduced in the narrow zoom configuration by the parabolic correction of a single lens surface. The imaging performance is fully characterized in the laboratory, and the characterized beam patterns show good agreements with the Gaussian beam specifications in the simulation results of the design.

Overview and sample applications of SMILES and Odin-SMR retrievals of upper tropospheric humidity and cloud ice mass

Abstract. Retrievals of cloud ice mass and humidity from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) and the Odin-SMR (Sub-Millimetre Radiometer) limb sounder are presented and example applications of the data are given. SMILES data give an unprecedented view of the diurnal variation of cloud ice mass. Mean regional diurnal cycles are reported and compared to some global climate models. Some improvements in the models regarding diurnal timing and relative amplitude were noted, but the models' mean ice mass around 250 hPa is still low compared to the observations. The influence of the ENSO (El Niño–Southern Oscillation) state on the upper troposphere is demonstrated using 12 years of Odin-SMR data. The same retrieval scheme is applied for both sensors, and gives low systematic differences between the two data sets. A special feature of this Bayesian retrieval scheme, of Monte Carlo integration type, is that values are produced for all measurements but for some atmospheric states retrieved values only reflect a priori assumptions. However, this "all-weather" capability allows a direct statistical comparison to model data, in contrast to many other satellite data sets. Another strength of the retrievals is the detailed treatment of "beam filling" that otherwise would cause large systematic biases for these passive cloud ice mass retrievals. The main retrieval inputs are spectra around 635/525 GHz from tangent altitudes below 8/9 km for SMILES/Odin-SMR, respectively. For both sensors, the data cover the upper troposphere between 30° S and 30° N. Humidity is reported as both relative humidity and volume mixing ratio. The vertical coverage of SMILES is restricted to a single layer, while Odin-SMR gives some profiling capability between 300 and 150 hPa. Ice mass is given as the partial ice water path above 260 hPa, but for Odin-SMR ice water content, estimates are also provided. Besides a smaller contrast between most dry and wet cases, the agreement with Aura MLS (Microwave Limb Sounder) humidity data is good. In terms of tropical mean humidity, all three data sets agree within 3.5 %RHi. Mean ice mass is about a factor of 2 lower compared to CloudSat. This deviation is caused by the fact that different particle size distributions are assumed, combined with saturation and a priori influences in the SMILES and Odin-SMR data.

Effects of residual hydrocarbons on the reed community after 10 years of oil extraction and the effectiveness of different biological indicators for the long-term risk assessments

The selection of certain indicators is critical to undertake ecological risk assessments of long-term oil pollution and other environmental changes. The indicators should be easily and routinely monitored, be sensitive to pollution, respond to pollution in a predictable manner, and match the spatial and temporal scales of investigations. To compare the effectiveness of indicators for the long-term risk assessments, this study investigated the multiple ecological effects of chronic oil pollution on the plant community dominated by reed (Phragmites australis). The physiology, growth and reproduction of reed, together with the composition and productivity of the reed community, were measured around oil wells that have operated for approximately 10 years in the Yellow River Delta, eastern China. The predictive power of each indicator was evaluated using the coefficients of determination (R2) of linear regression models established for each indicator and soil Total Petroleum Hydrocarbons (TPH) concentration. The sensitivities of indicators were evaluated by comparing slopes of new established regression lines using standardized data. The top three indicators in terms of predictive power were leaf length, width and number, followed by the Shannon–Wiener index, Pielou evenness index and Simpson's diversity index. Community aboveground biomass, foliar projective coverage and species richness showed predictive power lower than those of the three diversity indexes, but higher than those of leaf net photosynthetic rate, reed height, aboveground biomass and vertical projective coverage of reed plants. Leaf transpiration, chlorophyll concentration and reed stem density showed no significant linear response to elevated soil TPH concentration. In terms of sensitivity, the top three biological indicators were Pielou evenness index, Simpson's diversity index and Shannon–Wiener index, followed by community vertical projective coverage, community aboveground biomass, and species richness. Leaf number, length and width were moderately sensitive, followed by reed coverage, aboveground biomass and height. The sensitivity of net photosynthetic rate was the lowest. The predictive power and sensitivities of indicators were compared in terms of their spatial and temporal scales. In conclusion, scale can be used to facilitate the selection of indicators, and the combination of different indicators may yield improved understanding of the various effects of elevated soil TPH concentration at the different biological levels.

Provider-initiated HIV testing and counselling for children.

While prevention of mother-to-child transmission (PMTCT) interventions have made significant impacts on the reduction of vertical HIV transmission coverage is uneven and substantial gaps remain. The success of these programs indicates that most ongoing transmission probably remains to be postnatal from mothers and not diagnosed antenatally. There is evidence that half of HIV-infected infants die before their second birthday. Since early antiretroviral treatment (ART) significantly reduces morbidity and mortality this has led to an appropriate focus on early infant diagnoses (EID) with less emphasis on later testing. However some vertically-infected children may be “slow progressors” and may present late already with health immune system suppression and organ damage. In 2007 WHO therefore recommended routine testing among older children though while this is feasible and acceptable its implementation and uptake are not necessarily universal. Several barriers to testing beyond infancy exist and they are multifactorial and operate on various levels of the health system. Common misconceptions include the belief that HIV testing is only for symptomatic children and disclosure and stigma are frequently reported reasons for children not being tested. At the facility level lack of child-friendly services negative health care worker attitudes cost and transportation issues and insufficient staff and equipment are frequently noted. A new study of barriers to HIV testing in older children in presented in this series the results of which urge for strengthening later provider-initatived HIV testing and counseling (PITC) and to focus on identifying “best practices” for PITC.

A sensitivity analysis of the SimSphere SVAT model in the context of EO-based operational products development

Use of simulation process models often combined with Earth Observation (EO) data, has played a key role in extending our abilities to study land surface interaction processes and enhancing our understanding of how different components of the Earth system interplay. Use of these synergistic techniques aims to improve the estimates of key parameters characterising land surface interactions by combining the horizontal coverage and spectral resolution of remote sensing data with the vertical coverage and fine temporal continuity of simulation process models.This study performs a Global Sensitivity Analysis (GSA) on the SimSphere land surface model aiming to further extend our understanding of the model structure and establish its coherence. It builds on previous works conducted on the model to which a sophisticated and cutting edge GSA meta-modelling method adopting Bayesian theory is implemented. Our first objective is to examine the effect of assuming uniform probability distribution function (PDFs) for the model inputs/outputs on the sensitivity of key quantities simulated by SimSphere. A further objective is to explore the sensitivity of new, previously unexplored variables simulated by the model, namely of the Daily Evaporative, Non-Evaporative Fractions and Radiometric Temperature.The GSA conducted assuming uniform PDFs showed comparable results to previous studies in terms of identifying the most sensitive model inputs to each of the outputs considered. Yet, in absolute terms, the statistical parameters measuring the sensitivity of the model inputs were notably different. SA on the newly examined model outputs showed largely explainable results and allowed identification of the most responsive model inputs and interactions. In general, our results provided further evidence supporting the model coherence and correspondence to the behaviour of a natural system. The implications of the main findings are discussed in the framework of the model use either as a stand-alone tool or synergistically with EO data, particularly so towards the operational development of such products.

Absorbing aerosol radiative effects in the limb-scatter viewing geometry

Abstract. The limb-scatter satellite viewing geometry is well suited to detecting low-concentration aerosols in the upper troposphere due to its long observation path length (~200 km), high vertical resolution (~1–2 km) and good geographic coverage. We use the fully three-dimensional radiative transfer code SASKTRAN to simulate the sensitivity of limb-scatter viewing Odin/OSIRIS satellite measurements to absorbing mineral dust and carbonaceous aerosols (smoke and pure soot), as well as to non-absorbing sulfate aerosols and ice in the upper troposphere. At long wavelengths (813 nm) the addition of all aerosols (except soot) to an air only atmosphere produced a radiance increase as compared to air only, on account of the low Rayleigh scattering in air only at 813 nm. The radiance reduction due to soot aerosol was negligible (<0.1%) at all heights (0–100 km). At short wavelengths (337, 377, 452 nm), we found that the addition of any aerosol species to an air only atmosphere caused a decrease in single-scattered radiation due to an extinction of Rayleigh scattering in the direction of OSIRIS. The reduction was clearly related to particle size first, with absorption responsible for second-order effects only. Multiple-scattered radiation could either increase or decrease in the presence of an aerosol species, depending both on particle size and absorption. Large scatterers (ice, mineral dust) all increased multiple-scattered radiation within, below and above the aerosol layer. Small, highly absorbing pure soot particles produced a negligible multiple-scattering response (<0.1%) at all heights, primarily confined to within and below the soot layer. Medium-sized scatterers produced a multiple-scattering response that depended on their absorbing properties. Increased radiances were simulated as compared to air only at all short wavelengths (337, 377 and 452 nm) for sulfate aerosol particles (non-absorbing) while decreased radiances were simulated for smoke particles (absorbing) at 337 and 377 nm, where multiple scattering involving the medium-sized carbonaceous particles amplified their absorbing properties. At 452 nm, however, this effect was attenuated and albedo-dependent. At short wavelengths, the combined effect of single scattering decreases and multiple scattering increases led to complex total radiance signatures that generally could not unambiguously distinguish absorbing versus non-absorbing aerosols. Smoke aerosols led to a total radiance decrease (as compared to air only) at all altitudes above the aerosol layer (15–100 km). This unique signature was a result of the aerosols' strong absorbing properties, non-negligible scattering efficiency, and number concentrations high enough to make multiple scattering effects due to the aerosol itself significant. Thus, in the limb-scatter viewing geometry scene darkening above the aerosol layer is unambiguously due to absorption whereas scene darkening within and below the aerosol layer can simply be the result of a reduction in single-scattered radiance. Our simulations show a greater scene darkening for decreasing wavelengths, increasing surface albedo, decreasing solar zenith angle, and increasing particle number concentration, however, at 337 nm this effect did not exceed 0.5% of the total radiance due to air only, making the unique identification of medium-sized carbonaceous aerosols, i.e., smoke, difficult. Scene darkening (or brightening) varies linearly with particle number concentration over three orders of magnitude. A fortuitous, unexpected implication of our analysis is that limb-scatter retrievals of aerosol extinction are not sensitive to external information about aerosol absorption.

Scientific Drilling

Abstract. Integrated Ocean Drilling Program (IODP) Expedition 340T returned to the 1.4-km-deep Hole U1309D at Atlantis Massif to carry out borehole logging including vertical seismic profiling (VSP). Seismic, resistivity, and temperature logs were obtained throughout the geologic section in the footwall of this oceanic core complex. Reliable downhole temperature measurements throughout and the first seismic coverage of the 800–1400 meters below seafloor (mbsf) portion of the section were obtained. Distinct changes in velocity, resistivity, and magnetic susceptibility characterize the boundaries of altered, olivine-rich troctolite intervals within the otherwise dominantly gabbroic se-quence. Some narrow fault zones also are associated with downhole resistivity or velocity excursions. Small deviations in temperature were measured in borehole fluid adjacent to known faults at 750 mbsf and 1100 mbsf. This suggests that flow of seawater remains active along these zones of faulting and rock alteration. Vertical seismic profile station coverage at zero offset now extends the full length of the hole, including the uppermost 150 mbsf, where detachment processes are expected to have left their strongest imprint. Analysis of wallrock properties, together with alteration and structural characteristics of the cores from Site U1309, highlights the likely interplay between lithology, structure, lithospheric hydration, and core complex evolution. doi: 10.2204/iodp.sd.15.04.2013