Miracle-dz/UniFAR-FTUs huggingface dataset:
Aerosol characterization of Morocco with AERONET and intercomparison with satellite data: TOMS, MODIS, and MISR

The aim of this paper is to characterize the aerosol loadings, their optical and microphysical properties over Morocco, by use of the AERONET network and satellite data. Three AERONET stations in Morocco; Saada, Ras_El_Ain and Dakhla are considered in this work. The aerosol parameters studied are the aerosol optical thickness, the Angstrom parameter, the size distribution, the single scattering albedo and the refraction index. An inter-comparison with satellite data has been achieved. The most popular satellite products, TOMS (Earth Probe and OMI), MODIS and MISR have been considered. It comes out from this study that the mean aerosol optical thickness (550 nm) vary from 0.22 to 0.3, with a peak in summer time of 0.56 for Dakhla, 0.42 for Ras_El_Ain and 0.35 for Saada. The Angstrom parameter mean is 0.6 for Dakhla and 0.75 for Saada and Ras_El_Ain with a summer minimum of 0.32 for Dakhla and 0.55 for Saada and Ras_El_Ain. The size distribution is bimodal with a predominance of the coarse mode except for Saada in winter and autumn. This region depicts desert dust predominant environment with a single scattering albedo varying from 0.72 to 0.96. Saada and Ras_El_Ain being at 52 km apart, their coincident daily AOT correlate with a correlation coefficient; R=0.93. Concerning the correlation between satellite data and AERONET AOT, TOMS EP has a correlation coefficient of 0.53 for Saada (all data), 0.68 for Dakhla (all data). TOMS OMI correlation coefficient is 0.68 for Saada (all data) and 0.71 for Ras_El_Ain (year 2006). MISR (level 3 data) correlation coefficient is 0.77 for Saada (all data) and 0.85 for Dakhla (all data). MODIS (level 3) correlation coefficient is 0.86 for Saada (all data) and 0.92 for Dakhla (all data). Level 2 MODIS correlation coefficient is 0.69 for Saada (year 2006), 0.86 for Ras_El_Ain (year 2006) and 0.97 for Dakhla (year 2003).
Diurnal Cycle of Precipitation in the Tropics Simulated in a Global Cloud-Resolving Model

Abstract This study analyzes the diurnal cycle of precipitation simulated in a global cloud-resolving model (GCRM) named the Nonhydrostatic Icosahedral Atmospheric Model (NICAM). A 30-day integration of NICAM successfully simulates the precipitation diurnal cycle associated with the land–sea breeze and the thermally induced topographic circulations as well as the horizontal propagation of diurnal cycle signals. The first harmonic of the diurnal cycle of precipitation in the 7-km run agrees well with that from satellite observations in its geographical distributions although its amplitude is slightly overestimated. The NICAM simulation revealed that the precipitation diurnal cycle over the Maritime Continent is strongly coupled with the land–sea breeze that controls the convergence/divergence pattern in the lower troposphere around the islands. The analysis also suggests that the cold pool often forms over the open ocean where the precipitation intensity is high, and the propagation of the cold pool events.
Mantle stratigraphy and evolution of the Slave province

A data set of 1033 three-component, P wave seismograms from five broadband stations at the Yellowknife Array is assembled to investigate mantle structure below the southern Slave province in Canada's Northwest Territories. Following wave field decomposition, seismograms are source-normalized through simultaneous deconvolution to estimate the near-receiver impulse response as a function of epicentral distance and back azimuth. Images of impulse response reveal a well-developed mantle stratigraphy, anisotropic in part, extending from the Mohorovicic discontinuity to the transition zone, A layer of depth-localized anisotropy (±5%), termed H, is situated between ∼70 and 80 km depth with an average shear velocity comparable to that of the ambient mantle and a sharp upper boundary less than 100 m in transition width. The absence of free surface crustal reverberations on the transverse component affords a window into the upper mantle between 100 and 200 km depth. A sequence of at least two layers between 120–150 km depth, collectively termed X, is most clearly evident to the north and is underlain by a second structure L which dips from 170 km in the west to 230 km into the center of the Slave province. The deepest interface above the transition zone W marks a shear velocity inversion near 350 km depth whose signature is restricted to the SV component signalling a dominantly isotropic response. Consideration of these observations in light of data acquired in a recent LITHOPROBE seismic reflection traverse and in petrological studies of kimberlite xenoliths prompts speculation into the role of subduction in craton stabilization. It is suggested that the proto-Slave craton was assembled through processes of shallow subduction resulting in a near-horizontal mantle stratigraphy (i.e., H, X) both compositional and rheological in nature. Interpretation of L as the continuation of dipping reflectors on the seismic reflection profile argues for a final phase of craton assembly involving oblique underplating of subducted lithosphere in the Proterozoic. Subsequent modification of the lithosphere, as manifest by Phanerozoic kimberlite volcanism, may be related to W if an interpretation as the top of a layer containing a dense silicate melt fraction is invoked.
Estimating Methane Emissions from Dairy Cattle Housed in a Barn and Feedlot Using an Atmospheric Tracer

Methane emissions from a barn and feedlot/paddock housing dairy cattle were estimated using a tracer gas (SF6) to simulate the dispersion of CH4. The tracer gas was released from 16 point sources distributed within the barn or feedlot to simulate the CH4 sources (cows). Using a two-dimensional (y, z) sampling grid, the observed downwind SF6/CH4 crosswind concentration field was integrated to give the portion of the SF6/CH4 plume that was captured by the sampling grid. Assuming that both SF6 and CH4 underwent similar turbulent atmospheric transport, the ratio of the respective captured plumes was then used to estimate the emission strength of methane from the known release rate of SF6. The predicted source strength of CH4 from the barn was within 6% of the estimate made using a different technique whereby the entire barn was used as an enclosed chamber. The methane emissions predicted in the barn and feedlot experiments were 542 (± 30%) L CH4 d-1 cow-1 and 631 (± 30%) L CH4 d-1 cow-1, respectively. Using c.
Land subsidence characteristics of the Bandung Basin, Indonesia, as estimated from GPS and InSAR

Abstract The Bandung Basin is a large intra-montane basin surrounded by volcanic highlands, in western Java, Indonesia, inhabited by more than five million people. Based on the results of five GPS surveys conducted in February 2000, November 2001, July 2002, June 2003, and June 2005, it can be concluded that for the period of 2000 to 2005 several locations in the Bandung Basin have experienced land subsidence. Over this 5-year period land subsidence in a few locations reached a magnitude of about 70 cm, with a subsidence speed of about 1–2 cm/month. A similar rate of subsidence was also detected by the InSAR (Interferometric Synthetic Aperture Radar) technique during the period between June 2006 and March 2007. The statistical testing showed no strong correlation between GPS-derived land subsidence and registered groundwater extraction during the period of February 2000 to July 2002. The InSAR technique, however, detected significant subsidence in the textile industry area, which very large volumes of groundwater are usually extracted.
Estimating Bolus Velocities from Data—How Large Must They Be?

Abstract This paper examines the representation of eddy fluxes by bolus velocities. In particular, it asks the following: 1) Can an arbitrary eddy flux divergence of density be represented accurately by a nondivergent bolus flux that satisfies the condition of no normal flow at boundaries? 2) If not, how close can such a representation come? 3) If such a representation can exist in some circumstances, what is the size of the smallest bolus velocity that fits the data? The author finds, in agreement with earlier authors, that the answer to the first question is no, although under certain conditions, which include a modification to the eddy flux divergence, a bolus representation becomes possible. One such condition is when the eddy flux divergence is required to balance the time-mean flux divergence. The smallest bolus flow is easily found by solving a thickness-weighted Poisson equation on each density level. This problem is solved for the North Pacific using time-mean data from an eddy-permitting model.
Skeletal Muscle Dysfunction in Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a debilitating disease characterized by infl ammation-induced airfl ow limitation and parenchymal destruction. In addition to pul- monary manifestations, patients with COPD develop systemic problems, including skeletal muscle and other organ-specifi c dysfunctions, nutritional abnormalities, weight loss, and adverse psychological responses. Patients with COPD often complain of dyspnea on exertion, reduced exercise capacity, and develop a progressive decline in lung function with increasing age. These symptoms have been attributed to increases in the work of breathing and in impair- ments in gas exchange that result from airfl ow limitation and dynamic hyperinfl ation. However, there is mounting evidence to suggest that skeletal muscle dysfunction, independent of lung function, contributes signifi cantly to reduced exercise capacity and poor quality of life in these patients. Limb and ventilatory skeletal muscle dysfunction in COPD patients has been attributed to a myriad of factors, including the presence of low grade systemic infl ammatory processes, nutritional depletion, corticosteroid medications, chronic inactivity, age, hypoxemia, smoking, oxidative and nitrosative stresses, protein degradation and changes in vascular density. This review briefl y summarizes the contribution of these factors to overall skeletal muscle dysfunction in patients with COPD, with particular attention paid to the latest advances in the fi eld.
Influence of water on plastic deformation of olivine aggregates 2. Dislocation creep regime

Triaxial compressive creep experiments have been conducted over a range of hydrous conditions to investigate the effect of water fugacity on the creep behavior of olivine aggregates in the dislocation creep regime. Samples synthesized from powders of San Carlos olivine were deformed at confining pressures of 100 to 450 MPa and temperatures between 1473 and 1573 K. Water was supplied by the dehydration of talc. Water fugacities of ∼80 to ∼520 MPa were obtained by varying the confining pressure under water-saturated conditions with the oxygen fugacity buffered at Ni/NiO. Sancles were deformed at differential stresses of ∼20 to 230 MPa. The transition from diffusion creep to dislocation creep occurs near 100 MPa for both the hydrous case and the anhydrous case. Under hydrous conditions creep experiments yield a stress exponent of n ≈ 3 and an activation energy of Q ≈ 470 kJ/mol. The creep rate of olivine is enhanced significantly with the presence of water. At a water fugacity of ∼300 MPa, samples crept ∼5–6 times faster than those deformed under anhydrous conditions at similar differential stresses and temperatures. Within the range of water fugacity investigated, the strain rate is proportional to water fugacity to the 0.69 to 1.25 power, assuming values for the activation volume of 0 to 38×10−6 m3/mol, respectively. We argue that water influences creep rate primarily through its effect on the concentrations of intrinsic point defects and hence on ionic diffusion and dislocation climb. With increasing water fugacity the charge neutrality condition changes from [FeMe•] = 2[VMe″] to [FeMe•] = [HMe′]. For the latter charge neutrality condition the concentration of silicon interstitials is proportional to fH2O1, suggesting that under hydrous conditions dislocation climb is rate limited by diffusion of Si occurring by an interstitial mechanism. Our experimentally determined constitutive equation permits extrapolation from laboratory to mantle conditions in order to assess the rheological behavior of regions of the upper mantle with different water contents, such as beneath a mid-ocean ridge and in the mantle wedge above a subducting slab.
Low cost 3D-modelling of a complex archaeological site using aerial photography in the hinterland of Petra, Jordan

Individual archaeological sites can sometimes show a complex morphology. One such site is the Roman quarries located one kilometre northwest of the Roman fortress at Udhruh, in the hinterland of Petra. In archaeology there are various platforms such as balloons, kites and unmanned aerial vehicles (uav's) from which low altitude aerial photographs can be taken that have been proven to work. All with their specific advantages above others in different circumstances. By designing a very distinct setup for the kite and optimizing the workflow accordingly, an effective and steady platform for the camera was created. The Quarries were photographed from the air and the images then provided enough material to accurately create a 3D model of the site.
Iron supply and demand in the upper ocean: Is extraterrestrial dust a significant source of bioavailable iron?

Interplanetary dust particles accrete on the Earth at a rate of ∼40 ktons yr−1. Some 90% of this material evaporates in the atmosphere, producing a bioavailable iron flux of 3×10−7 mol Fe m−2 yr−1. This extraterrestrial Fe flux is 30–300% of the eolian flux of bioavailable iron transported from terrestrial sources in remote marine regions and ∼20% of the upwelled Fe flux in the Southern Ocean. Extraterrestrial Fe may play an important role in regulating the marine carbon cycle in these regions.
Viscoelastic properties of polycrystalline solid methane and carbon dioxide

The viscoelastic properties of polycrystalline solid methane and carbon dioxide were measured in a low‐temperature deformation apparatus. It was found that solid methane flowed easily under a shear stress of 5 MPa even at a temperature of 77 K. Its stress was relaxed with exponent 1.9±0.2 in non‐Newtonian power‐law. The effective viscosity of solid methane estimated at 0.1 MPa was 1011 Pa sec. Solid carbon dioxide was deformed brittly at 77 K.
Natural radioactivity levels and the radiological health implications of tailing enriched soil and sediment samples around two mining sites in Southwest Nigeria

The activity concentrations of natural radionuclides in tailing enriched soil and sediment samples collected from two mining sites in southwest Nigeria are reported. The samples were analyzed by gamma spectrometry with low background NaI (Tl) detector. The activity concentrations of 40 K, 226 Ra and 232 Th in all the measured samples varied from 249.66 to 1459.25 Bq/kg, 7.62 to 50.31 Bq/kg and 12.68 to 234.18 Bq/kg, respectively in soil samples. For sediment samples, the values varied from 241.86 to 1590.40 Bq/kg, 9.86 to 74.8 Bq/kg and 15.47 to 145.46 Bq/kg for 40 K, 226 Ra and 232 Th, respectively. The results show that the mean activity concentrations of the radionuclides in soil and sediment of the study area are higher than their world-wide average crustal values. The mean concentration of 232 Th is >6 times higher than that of 226 Ra in soil samples from Ijero mining site. This shows that 232 Th is slightly enhanced in the soil from this location than 226 Ra. In order to evaluate the radiological hazards of the natural radioactivity, the radium equivalent activity, external hazard index, absorbed gamma dose rates and the annual effective dose rates were determined. All these hazard indices have mean values, which are within their acceptable limits but higher than their world average values.
Electrostatic discharge in Martian dust storms

Although the Martian atmosphere does not satisfy general requirements for lightning generation, there is a possibility of electrical discharge in the case of strong surface winds and a resulting extremely large dust mass loading in the course of large dust storms occurring on this planet. On Earth, negative potential gradients of many thousands of volts per meter have been measured during dust storms when winds are sufficiently strong. However, owing to a lower pressure in the Martian atmosphere, the required voltage for electrical breakdown is lower than on Earth. After a brief review of the observations concerning Earth's atmosphere and the laboratory experiments performed to understand these phenomena, the results of numerical simulation of the electrification in Martian dust storms are presented. Known characteristics of Martian dust grains and the Martian atmosphere are considered, and the different forces applied to the dust particles are taken into account. The electrostatic potential and the evolution of the charge density are calculated using Poisson's equation and the continuity equation. Two different wind configurations in the Martian atmosphere are studied: a wind vortex and a wind parallel to the ground encountering an obstacle (a small hill). It is shown that electric discharge occurs under specific conditions.
The outer limits of the lunar sodium exosphere

A new wide‐angle coronagraphic‐type imaging system used for the lunar eclipse of 16 July 2000 resulted in detections of the lunar sodium exosphere out to ∼20 lunar radii, approximately twice the size recorded with narrower fields of view during previous eclipses. These measurements and subsequent modeling provide a unique constraint on the fastest atoms ejected from the lunar surface that form the lunar exosphere, indicative of the most energetic space weathering processes acting on the lunar surface. At most, only a small fraction of the atoms are ejected from the surface with speeds faster than escape speed of 2.4 km s−1, meaning solar photon radiation pressure largely contributes to the escape of sodium atoms which form the comet‐like tail. The total rate of sodium ejection from the surface for speeds >2.0 km s−1 is comparable to estimates from previous lunar eclipse observations and earlier images of the lunar sodium tail.
Late Pleistocene Variability of the Carbon Isotopic Composition of Organic Matter in the Eastern Mediterranean: Monitor of Changes in Carbon Sources and Atmospheric CO2 Concentrations

The organic carbon isotopic record of the sapropels (S1 and S3–S10) and intercalated marl oozes has been determined in a 12-m piston core from the eastern Mediterranean. The δ13Corganic values are systematically lighter (mean=−21.0±0.82 ‰) in all sapropels and heavier (mean=−18.8±1.07‰) in the marl oozes. These differences are not due to variable marine and terrestrial organic matter mixtures because all values are heavier than modern plankton in the Mediterranean, there is no relationship between the Corganic/N ratios and the isotopic values, and published information on the abundance and distribution of organic biomarkers shows that terrestrial material constitutes a minor fraction of the total organic matter. Temperature effects on isotope fractionation are also discounted because the change in δ13Corganic values between glacial and interglacial horizons is in the opposite sense. Diagenesis, which can produce relatively small changes in the carbon isotopic composition of sedimentary organic matter under certain circumstances, is unlikely to have caused the observed differences because this mechanism would cause an enrichment in 12C, implying that all values were even heavier originally, and there is no secular trend in the δ13Corganic record. The observed differences in δ13Corganic between the two lithologies are probably produced by changes in the isotopic composition and the concentration of dissolved CO2. First, freshwater flooding during the formation of the sapropels caused the isotopic composition of the dissolved inorganic carbon in the surface waters of the Mediterranean to become lighter because of the 13C deficiency in fresh waters. Hence photosynthesis would have produced isotopically lighter organic material. Second, changes in atmospheric pCO2 between glacial and interglacial periods, as shown by the Vostok ice core, caused marked changes in the concentration of free dissolved CO2 in the mixed layer; lower values during glacial maxima caused a smaller fractionation of the carbon isotopes by phytoplankton, whereas levels were less limiting during the interglacials. Concentrations of dissolved CO2 could also have been much higher during the deposition of the sapropels because of the supply of regenerated CO2 to the mixed layer by upwelling, and this could have further lightened the δ13Corganic values in the sapropels themselves. Carbon isotope records may provide an alternative method for estimating atmospheric pCO2 levels over longer time periods than can be obtained from ice cores.
Silencing and Un-silencing of Tetracycline-Controlled Genes in Neurons

To identify the underlying reason for the controversial performance of tetracycline (Tet)-controlled regulated gene expression in mammalian neurons, we investigated each of the three components that comprise the Tet inducible systems, namely tetracyclines as inducers, tetracycline-transactivator (tTA) and reverse tTA (rtTA), and tTA-responsive promoters (Ptets). We have discovered that stably integrated Ptet becomes functionally silenced in the majority of neurons when it is inactive during development. Ptet silencing can be avoided when it is either not integrated in the genome or stably-integrated with basal activity. Moreover, long-term, high transactivator levels in neurons can often overcome integration-induced Ptet gene silencing, possibly by inducing promoter accessibility.
Tropical Cyclone Climatology in a High-resolution AGCM -Impacts of SST Warming and CO2 Increase-

Using a high-horizontal-resolution atmospheric general circulation model (AGCM), impacts of SST warming and CO2 increase on the tropical cyclone (TC) climatology are investigated. The SST effect is examined from numerical experiments in which SST is uniformly higher/lower by 2 K, without changing the atmospheric CO2 concentration. The CO2 effect is shown from doubled and quadrupled CO2 experiments with a fixed SST condition. The results demonstrate that the increases in CO2 have large impacts to reduce TC frequency globally, while the SST changes have relatively small influences on the TC frequency. The SST warming causes significant increase in climatological precipitation, and this indicates intensification of convective heating and should have some influences to activate the atmospheric circulation in terms of vertical mass flux in the tropics. In the high-SST experiment, however, larger warming in the upper troposphere causes higher dry static stability, which should have some impacts to weaken the atmospheric circulation. It seems that these two conflicting factors, in terms of TC frequency, may cancel out to a large extent. As the effect of CO2 enhancement, precipitation decreases significantly in the tropics, which may lead to the reduction in TC frequency.