Evaluating remotely sensed phenological metrics in a dynamic ecosystem model

© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Remote Sensing 6 (2014): 4660-4686, doi:10.3390/rs6064660.Vegetation phenology plays an important role in regulating processes of terrestrial ecosystems. Dynamic ecosystem models (DEMs) require representation of phenology to simulate the exchange of matter and energy between the land and atmosphere. Location-specific parameterization with phenological observations can potentially improve the performance of phenological models embedded in DEMs. As ground-based phenological observations are limited, phenology derived from remote sensing can be used as an alternative to parameterize phenological models. It is important to evaluate to what extent remotely sensed phenological metrics are capturing the phenology observed on the ground. We evaluated six methods based on two vegetation indices (VIs) (i.e., Normalized Difference Vegetation Index and Enhanced Vegetation Index) for retrieving the phenology of temperate forest in the Agro-IBIS model. First, we compared the remotely sensed phenological metrics with observations at Harvard Forest and found that most of the methods have large biases regardless of the VI used. Only two methods for the leaf onset and one method for the leaf offset showed a moderate performance. When remotely sensed phenological metrics were used to parameterize phenological models, the bias is maintained, and errors propagate to predictions of gross primary productivity and net ecosystem production. Our results show that Agro-IBIS has different sensitivities to leaf onset and offset in terms of carbon assimilation, suggesting it might be better to examine the respective impact of leaf onset and offset rather than the overall impact of the growing season length

Aqua­bis(benzoato-κO)(5,5′-dimethyl-2,2′-bipyridine-κ2 N,N′)copper(II)

In the crystal structure of the title compound, [Cu(C7H5O2)2(C12H12N2)(H2O)], the CuII ion is penta­coordinated in a distorted square-pyramidal geometry by two O atoms of two benzoate anions and two N atoms of a 5,5′-dimethyl-2,2′-bipyridine ligand occupying the basal plane, and a water O atom located at the apical site. In the crystal structure, O—H⋯O hydrogen bonds link the mol­ecules into a supra­molecular structure. The crystal studied was a racemic twin, as suggested by the Flack parameter of 0.584 (14)

A New 95 GHz Methanol Maser Catalog: I. Data

The Purple Mountain Observatory 13.7 m radio telescope has been used to search for 95 GHz (8$_0$--7$_1$A$^+$) class I methanol masers towards 1020 Bolocam Galactic Plane Survey (BGPS) sources, leading to 213 detections. We have compared the line width of the methanol and HCO$^+$ thermal emission in all of the methanol detections and on that basis we find 205 of the 213 detections are very likely to be masers. This corresponds to an overall detection rate of 95 GHz methanol masers towards our BGPS sample of 20%. Of the 205 detected masers 144 (70%) are new discoveries. Combining our results with those of previous 95 GHz methanol masers searches, a total of four hundred and eighty-one 95 GHz methanol masers are now known, we have compiled a catalog listing the locations and properties of all known 95 GHz methanol masers.Comment: 18 pages, 7 figures, 8 tables, accepted for publication in ApJ

Bis(μ-biphenyl-2,2′-dicarboxyl­ato)bis­[aqua­(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)copper(II)]

The mol­ecule of the title binuclear copper(II) complex, [Cu2(C14H8O4)2(C12H12N2)2(H2O)2], is bis­ected by a crystallographic twofold axis. Each CuII atom is coordinated in a distorted octa­hedral geometry by three O atoms from two biphen­yl-2,2′-dicarboxyl­ate anions, one aqua O atom and two N atoms of a 4,4′-dimethyl-2,2′-bipyridine ligand. Intramolecular O—H⋯O hydrogen bonds between the coordinated water molecules and the carboxylate O atoms are also present