Evaluation of Remotely Sensed Precipitation Estimates from the NASA POWER Project for Drought Detection Over Jordan

Droughts can cause devastating impacts on water and land resources and therefore monitoring these events forms an integral part of planning. The most common approach for detecting drought events and assessing their intensity is use of the Standardized Precipitation Index (SPI), which requires abundant precipitation records at good spatial distribution. This may restrict SPI usage in many regions around the world, particularly in areas with limited numbers of ground meteorological stations. Therefore, the use of remotely sensed derived data of precipitation can contribute to drought monitoring. In this study, remotely sensed precipitation estimates from the POWER/Agroclimatology archive of NASA and their derived SPI for different time intervals were evaluated against gauged observations of precipitation from 13 different stations in arid and semiarid locations in Jordan. Results showed significant correlations between remotely sensed and ground data with relatively high R values (0.67–0.91), particularly where seasonal precipitation exceeded 50 mm/year. For evaluation of remotely sensed data in SPI calculation, several objective functions were used; the results showed that SPI based on satellite estimates (SAT-SPI) showed good performance in detecting extreme droughts and indicating wet/dry conditions. However, SAT-SPI showed high tendency to overestimate drought intensity. Based on these findings, remotely sensed precipitation from the POWER/Agroclimatology archive showed good potential for use in detecting extreme meteorological drought with the provision of careful interpretation of the data. These types of studies are essential for evaluating the applicability of new drought monitoring information and tools to support decision-making at relevant scales

Development of a Low Flow Early Warning System for the National Weather Service

The National Weather Service\u27s Advanced Hydrologic Prediction Service (AHPS) currently provides river flow/stage and forecast information at more than 3,600 forecast points across the United States. Along with this information, AHPS describes potential flood impacts that may occur within the upstream and downstream influence of the forecasts points. However, similar information is not available for low flow events. In order to incorporate low flow information into the current AHPS river forecast database, the National Weather Service has undertaken pilot studies to obtain relevant low flow impact information near 83 forecast points in the Upper Mississippi, Upper Missouri, and North Platte river basins

A population-based study of reduced sleep duration and hypertension : the strongest association may be in premenopausal women

Objectives: Recent evidence indicates that reduced sleep duration may be associated with an increased risk of hypertension with possibly stronger effects among women than men. We therefore examined cross-sectional sex-specific associations of sleep duration with hypertension in a large population-based sample from the Western New York Health Study (1996<2001). Methods: Participants were 3027 white men (43.5%) and women (56.5%) without prevalent cardiovascular disease (median age 56 years). Hypertension was defined as blood pressure at least 140 or at least 90&mmHg or regular use of antihypertensive medication. Multivariate logistic regression analyses were performed to estimate odds ratios (ORs) of hypertension comparing less than 6&h of sleep per night versus the reference category (&6&h) while accounting for a number of potential confounders. Results: In multivariate analyses, less than 6&h of sleep was associated with a significant increased risk of hypertension compared to sleeping at least 6&h per night, only among women [OR&=&1.66 (1.09 to 2.53)]. No significant association was found among men [OR&=&0.93 (0.62 to 1.41)]. In subgroup analyses by menopausal status, the effect was stronger among premenopausal women [OR&=&3.25 (1.37 to 7.76)] than among postmenopausal women [OR&=&1.49 (0.92 to 2.41)]. Conclusion: Reduced sleep duration, by increasing the risk of hypertension, may produce detrimental cardiovascular effects among women. The association is independent of socioeconomic status, traditional cardiovascular risk factors, and psychiatric comorbidities, and is stronger among premenopausal women. Prospective and mechanistic evidence is necessary to support causality

Bis(2,6-diamino-3,5-dibromo­pyridinium) hexa­bromidostannate(IV)

The asymmetric unit of the title compound, (C5H6Br2N3)2[SnBr6], contains one cation and one half-anion in which the Sn atom is located on a crystallographic centre of inversion and is in a quasi-octa­hedral geometry. The crystal structure is assembled via hydrogen-bonding inter­actions of two kinds, N(pyridine/amine)—H⋯Br—Sn, along with C—Br⋯Br—Sn interactions [3.4925 (19) Å]. The cations are involved in π–π stacking, which adds an extra supra­molecularity as it presents a strong case of offset-face-to-face motifs [centroid–centroid distance = 3.577 (3) Å]. The inter­molecular hydrogen bonds, short Br⋯Br inter­actions and π–π stacking result in the formation of a three-dimensional supra­molecular architecture

Bis(2-bromo­pyridinium) hexa­bromido­stannate(IV)

The asymmetric unit of the title compound, (C5H5BrN)2[SnBr6], contains one cation and one half-anion. The [SnBr6]2− anion is located on an inversion center and forms a quasi-regular octa­hedral arrangement. The crystal structure consists of two-dimensional supra­molecular layers assembled via hydrogen-bonding inter­actions of N—H⋯Br—Sn [D⋯A = 3.375 (13)–3.562 (13) Å and D—H⋯A = 127–142°, along with C—Br⋯Br synthons [3.667 (2) and 3.778 (3) Å]. These layers are parallel to the bc plane and built up from anions inter­acting extensively with the six surrounding cations

The solution of the quantum A1A_1 T-system for arbitrary boundary

We solve the quantum version of the $A_1$ $T$-system by use of quantum networks. The system is interpreted as a particular set of mutations of a suitable (infinite-rank) quantum cluster algebra, and Laurent positivity follows from our solution. As an application we re-derive the corresponding quantum network solution to the quantum $A_1$ $Q$-system and generalize it to the fully non-commutative case. We give the relation between the quantum $T$-system and the quantum lattice Liouville equation, which is the quantized $Y$-system.Comment: 24 pages, 18 figure

Bis(2-bromo­pyridinium) hexa­chlorido­stannate(IV)

The asymmetric unit of the title compound, (C5H5BrN)2[SnCl6], contains one cation and one half-anion. The [SnCl6]2− anion is located on an inversion center and forms a quasi-regular octa­hedral arrangement. Hydrogen-bonding inter­actions of two kinds, viz. N—H⋯Cl—Sn and C—H⋯Cl—Sn, along with Cl⋯Br inter­actions [3.4393 (15) Å], connect the ions in the crystal structure into two-dimensional supra­molecular arrays. These supra­molecular arrays are arranged in layers approximately parallel to (110) built up from anions inter­acting with six symmetry-related surrounding cations

The Complete transmission spectrum of WASP-39b with a precise water constraint

This is the author accepted manuscript. The final version is available from American Astronomical Society via the DOI in this record.WASP-39b is a hot Saturn-mass exoplanet with a predicted clear atmosphere based on observations in the optical and infrared. Here we complete the transmission spectrum of the atmosphere with observations in the near-infrared (NIR) over three water absorption features with the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) G102 (0.8-1.1 microns) and G141 (1.1-1.7 microns) spectroscopic grisms. We measure the predicted high amplitude H2O feature centered at 1.4 microns, and the smaller amplitude features at 0.95 and 1.2 microns, with a maximum water absorption amplitude of 2.4 planetary scale heights. We incorporate these new NIR measurements into previously published observational measurements to complete the transmission spectrum from 0.3-5 microns. From these observed water features, combined with features in the optical and IR, we retrieve a well constrained temperature Teq = 1030(+30,-20) K, and atmospheric metallicity 151 (+48,-46)x solar which is relatively high with respect to the currently established mass-metallicity trends. This new measurement in the Saturn-mass range hints at further diversity in the planet formation process relative to our solar system giants.This work is based on observations made with the NASA/ESA Hubble Space Telescope that were obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. These observations are associated with programs GO-14169 (PI. HR Wakeford) and GO-14260 (PI. D Deming). D.K.S., H.R.W., T.E., B.D., and N.N., acknowledge funding from the European Research Council (ERC) under the European Unions Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 336792. J.G. acknowledges support from Leverhulme Trust. A.L.C. acknowledges support from the STFC. H.R.W. also acknowledges support from the Giacconi Fellowship at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc

A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion

PublishedLetterThousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1 to 1.7 μm). Recent studies show that some hot- Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet’s formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3–5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures.European Research Council European Union’s Seventh Framework Programme (FP7/2007-2013)NASACNES and the French Agence Nationale de la Recherche (ANR)UK Science and Technology Facilities Council (STFC)NSFTennessee State UniversityState of Tennesse