ALBERT

Description: Three new 2D/3D supramolecular architectures derived from Cu-organic subunits and Keggin anions, [Cu II 2 (biz) 8 (HPMo VI 10 Mo V 2 O 40 )(H 2 O) 2 ] · 2H 2 O ( 1 ), [Cu I 4 (biz) 8 (SiW 12 O 40 )] · 2H 2 O ( 2 ) and [Cu I 2 (dmbiz) 4 (Hdmbiz) 2 (SiW 12 O 40 )] ( 3 ) (biz = benzimidazole, dmbiz = 5, 6-dimethyl benzimidazole), were obtained under hydrothermal conditions. Single crystal X-ray diffraction analysis reveals that compound 1 has two kinds of [Cu II (biz) 2 ] 2+ cations, which are further extended by Keggin anions into a 2D (4, 8)-connected supramolecular network by hydrogen bonding interactions. In compound 2 , four types of [Cu I (biz) 2 ] + subunits link the [SiW 12 O 40 ] 4– anions to form a 3D (2, 6)-connected supramolecular structure. Compound 3 shows a 3D supramolecular network with a NaCl-type topology constructed by [Cu I (dmbiz) 2 ] + subunits, anions, and discrete [Hdmbiz] + cations. Moreover, the electrochemical and photocatalytic properties of compounds 1 and 2 were investigated.

Description: The real-time availability of satellite-derived precipitation estimates provides hydrologists an opportunity to improve current hydrologic prediction capability for medium to large river basins. Due to the availability of new satellite data and upgrades to the precipitation algorithms, the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis real-time estimates (TMPA-RT) have been undergoing several important revisions over the past ten years. In this study, the changes of the relative accuracy and hydrologic potential of TMPA-RT estimates over its three major evolving periods were evaluated and inter-compared at daily, monthly and seasonal scales in the high-latitude Laohahe basin in China. Assessment results show that the performance of TMPA-RT in terms of precipitation estimation and streamflow simulation was significantly improved after 3 February 2005. Overestimation during winter months was noteworthy and consistent, which is suggested to be a consequence from interference of snow cover to the passive microwave retrievals. Rainfall estimated by the new version 6 of TMPA-RT starting from 1 October 2008 to present has higher correlations with independent gauge observations and tends to perform better in detecting rain compared to the prior periods, although it suffers larger mean error and relative bias. After a simple bias correction, this latest data set of TMPA-RT exhibited the best capability in capturing hydrologic response among the three tested periods. In summary, this study demonstrated that there is an increasing potential in the use of TMPA-RT in hydrologic streamflow simulations over its three algorithm upgrade periods, but still with significant challenges during the winter snowing events.

Description: This paper studies one of the most important problems of dry countries that are confronted with water deficit and the competition of rivals to allocate water. Some common methods have been investigated for computing the minimum water requirement to save a river's biological activity. After a discussion of the currently used method in Iran (the Tenant Method), the application of some other methods, which are known as Hydraulic and Hydrological Methods, are illustrated. The case study is a river in the northern part of Iran and this research addresses the critical situation of this river in near future regarding the planned anthropogenic alteration and its consequences . It has been shown that the application of environmental water allocation methods that have no background in a region could be misleading. The first proposed method is the Texas Method, in which flexibility in water allocation helps to develop an integrated river management paradigm in the study area. The second preferred method is a Hydraulic Method, by which the implementation of morphological parameters or flow geometrical properties could sustain physical habitat within an acceptable range in terms of depth, width, velocity, and bed shear stress. In the case study, the Maximum Curvature Method was superior to the Slope Method. The investigation revealed that using a widely recommended slope of 1 for the discharge-wetted perimeter function can lead to an overestimated and unacceptable discharge. The Tenant Method in respect to minimum environmental flow requirement yielded the weakest result, and it has been illustrated that its application might impose irrecoverable shock to the ecosystem. The Flow Duration Curve Method (the Q 95 Method), in spite of its subjectivity, showed more compatibility with the river's condition in comparison with the Tenant Method. Copyright © 2011 John Wiley & Sons, Ltd.

Description: [1]  The spatial error structure of surface precipitation derived from successive versions of the TRMM Multisatellite Precipitation Analysis (TMPA) algorithms are systematically studied through comparison with the Climate Prediction Center Unified Gauge daily precipitation Analysis (CPCUGA) over the Continental United States (CONUS) for 3 years from June 2008 to May 2011. The TMPA products include the version-6(V6) and version-7(V7) real-time products 3B42RT (3B42RTV6 and 3B42RTV7) and research products 3B42 (3B42V6 and 3B42V7). The evaluation shows that 3B42V7 improves upon 3B42V6 over the CONUS regarding 3 year mean daily precipitation: the correlation coefficient (CC) increases from 0.85 in 3B42V6 to 0.92 in 3B42V7; the relative bias (RB) decreases from −22.95% in 3B42V6 to −2.37% in 3B42V7; and the root mean square error (RMSE) decreases from 0.80 in 3B42V6 to 0.48 mm in 3B42V7. Distinct improvement is notable in the mountainous West especially along the coastal northwest mountainous areas, whereas 3B42V6 (also 3B42RTV6 and 3B42RTV7) largely underestimates: the CC increases from 0.86 in 3B42V6 to 0.89 in 3B42V7, and the RB decreases from −44.17% in 3B42V6 to −25.88% in 3B42V7. Over the CONUS, 3B42RTV7 gained a little improvement over 3B42RTV6 as RB varies from −4.06% in 3B42RTV6 to 0.22% in 3B42RTV7. But there is more overestimation with the RB increasing from 8.18% to 14.92% (0.16–3.22%) over the central US (eastern).

Description: Flood monitoring was conducted using multi-sensor data from space-borne optical, and microwave sensors; with cross-validation by ground-based rain gauges and streamflow stations along the Indus River; Pakistan. First; the optical imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) was processed to delineate the extent of the 2010 flood along Indus River; Pakistan. Moreover; the all-weather all-time capability of higher resolution imagery from the Advanced Synthetic Aperture Radar (ASAR) is used to monitor flooding in the lower Indus river basin. Then a proxy for river discharge from the Advanced Microwave Scanning Radiometer (AMSR-E) aboard NASA’s Aqua satellite and rainfall estimates from the Tropical Rainfall Measuring Mission (TRMM) are used to study streamflow time series and precipitation patterns. The AMSR-E detected water surface signal was cross-validated with ground-based river discharge observations at multiple streamflow stations along the main Indus River. A high correlation was found; as indicated by a Pearson correlation coefficient of above 0.8 for the discharge gauge stations located in the southwest of Indus River basin. It is concluded that remote-sensing data integrated from multispectral and microwave sensors could be used to supplement stream gauges in sparsely gauged large basins to monitor and detect floods.

Description: Flood monitoring was conducted using multi-sensor data from space-borne optical, and microwave sensors; with cross-validation by ground-based rain gauges and streamflow stations along the Indus River; Pakistan. First; the optical imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) was processed to delineate the extent of the 2010 flood along Indus River; Pakistan. Moreover; the all-weather all-time capability of higher resolution imagery from the Advanced Synthetic Aperture Radar (ASAR) is used to monitor flooding in the lower Indus river basin. Then a proxy for river discharge from the Advanced Microwave Scanning Radiometer (AMSR-E) aboard NASA’s Aqua satellite and rainfall estimates from the Tropical Rainfall Measuring Mission (TRMM) are used to study streamflow time series and precipitation patterns. The AMSR-E detected water surface signal was cross-validated with ground-based river discharge observations at multiple streamflow stations along the main Indus River. A high correlation was found; as indicated by a Pearson correlation coefficient of above 0.8 for the discharge gauge stations located in the southwest of Indus River basin. It is concluded that remote-sensing data integrated from multispectral and microwave sensors could be used to supplement stream gauges in sparsely gauged large basins to monitor and detect floods.

Description: Accurate estimation of the satellite-based global terrestrial latent heat flux ( LE ) at high spatial and temporal scales remains a major challenge. In this study, we introduce a Bayesian model averaging ( BMA ) method to improve satellite-based global terrestrial LE estimation by merging five process-based algorithms. These are the moderate resolution imaging spectroradiometer ( MODIS ) LE product algorithm, the revised remote-sensing-based Penman-Monteith LE algorithm, the Priestley-Taylor-based LE algorithm, the modified satellite-based Priestley-Taylor LE algorithm, and the semi-empirical Penman LE algorithm. We validated the BMA method using data for 2000-2009 and by comparison with a simple model averaging ( SA ) method and five process-based algorithms. Validation data were collected for 240 globally distributed eddy covariance ( EC ) tower sites provided by FLUXNET projects. The validation results demonstrate that the five process-based algorithms used have variable uncertainty and the BMA method enhances the daily LE estimates, with smaller root mean square errors ( RMSEs ) than the SA method and the individual algorithms driven by tower-specific meteorology and Modern Era Retrospective Analysis for Research and Applications ( MERRA ) meteorological data provided by the NASA Global Modeling and Assimilation Office ( GMAO ), respectively. The average RMSE for the BMA method driven by daily tower-specific meteorology decreased by more than 5 W/m 2 for crop and grass sites, and by more than 6 W/m 2 for forest, shrub and savanna sites. The average coefficients of determination ( R 2 ) increased by approximately 0.05 for most sites. To test the BMA method for regional mapping, we applied it for MODIS data and GMAO-MERRA meteorology to map annual global terrestrial LE averaged over 2001–2004 for spatial resolution of 0.05°. The BMA method provides a basis for generating a long-term global terrestrial LE product for characterizing global energy, hydrological and carbon cycles.

Description: Two coordination polymers, namely Zn(HL)(4,4′-bpy) 1.5 ( 1 ), [Zn 3 (L) 2 (BIMB) 2 ] · 5H 2 O ( 2 ) [H 3 L = 5-(4-carboxybenzyloxy)isophthalic acid, 4,4′-bpy = 4,4′-bipyridine, BIMB = 1,4-bis(1H-imidazol-1-yl)benzene] were synthesized under hydrothermal conditions. Their structures are determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectroscopy, and thermogravimetric (TG) analyses. Complex 1 features a 2D 4-connected network. Complex 2 is a 3D twofold interpenetrating (3,4,6)-connected net. In addition, the luminescent properties for 1 and 2 were studied in the solid state at room temperature.

Description: A comprehensive analysis of long-term and multi-spectral auroral observations made in the Arctic and Antarctica demonstrates that the dayside auroral ovals in two hemispheres are both presented a two-peak structure, namely the prenoon 09:00 MLT and postnoon 15:00 MLT peaks. The two-peak structures of dayside ovals, however, are asymmetric in two hemispheres, i.e., the postnoon average auroral intensity is more than the prenoon one in the northern hemisphere, but less in the southern hemisphere. The hemispheric asymmetry cannot be accounted for by the effect of the IMF By component and the seasonal difference of ionospheric conductivities in two hemispheres, which were used to interpret satellite-observed real-time auroral intensity asymmetries in the two hemispheres in previous studies. We suggest that the hemispheric asymmetry is the combined effect of the prenoon-postnoon variations of the magnetosheath density and local ionospheric conductivity.

Description: Three new phthalides, gnaphalides A–C ( 1 – 3 , resp.), together with three known phthalides, were isolated from the aerial part of Gnaphalium adnatum. The structures of the new compounds were elucidated as 6-(1,1-dimethylprop-2-en-1-yl)-5,7-dihydroxy-2-benzofuran-1(3 H )-one ( 1 ), 5-hydroxy-7-[(2-hydroxy-3-methylbut-3-en-1-yl)oxy]-2-benzofuran-1(3 H )-one ( 2 ), and 1,3-dihydro-7-[(3-methylbut-2-en-1-yl)oxy]-1-oxo-2-benzofuran-5-yl β - D -glucopyranoside ( 3 ) on the basis of spectral analyses. The structure of 1 was also confirmed by X-ray crystallographic analysis. The three known phthalides, identified as 5,7-dihydroxyisobenzofuran-1(3 H )-one ( 4 ), anaphatol ( 5 ), and 7- O -( β -glucopyranosyl)-5-hydroxyisobenzofuran-1(3 H )-one ( 6 ), were isolated from the genus Gnaphalium for the first time.