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Sea surface temperature (SST) variability has been shown to have predictive value for land precipitation, although SSTs are unable to fully predict intraseasonal to interannual hydrologic extremes. The possible remote effects of large‐scale land surface temperature (LST) and subsurface temperature (SUBT) anomalies in geographical areas upstream and closer to the areas of drought/flood have largely been ignored. Here evidence from climate observations and model simulations addresses these effects. Evaluation of observational data using Maximum Covariance Analysis identifies significant correlations between springtime 2‐m air temperature (T2 m) cold (warm) anomalies in both the western U.S. and the Tibetan Plateau and downstream drought (flood) events in late spring/summer. To support these observational findings, climate models are used in sensitivity studies, in which initial LST/SUBT anomaly is imposed to produce observed T2 m anomaly, to demonstrate a causal relationship for two important cases: between spring warm T2 m/LST/SUBT anomalies in western U.S. and the extraordinary 2015 flood in Southern Great Plains and adjacent regions and between spring cold T2 m/LST/SUBT anomalies in the Tibetan Plateau and the severe 2003 drought south of the Yangtze River region. The LST/SUBT downstream effects in North America are associated with a large‐scale atmospheric stationary wave extending eastward from the LST/SUBT anomaly region. The effects of SST in these cases are also tested and compared with the LST/SUBT effects. These results suggest that consideration of LST/SUBT anomalies has the potential to add value to intraseasonal prediction of dry and wet conditions, especially extreme drought/flood events. The results suggest the importance of developing land data and models capable of preserving observed soil memory.

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NMR studies of the structure and dynamics of a system composed of the acidic polymer poly(acrylic acid) (PAA) and the basic polymer poly(4-vinyl pyridine) (P4VP) are presented. This system aims at the application of anhydrous proton-conducting membranes that can be used at elevated temperatures at which the proton conduction of hydrated membranes breaks down. The 1 H NMR measurements have been preformed under fast magic angle spinning (MAS) conditions to achieve sufficient resolution and the applied 1 H NMR methods vary from simple 1 H MAS to double-quantum filtered methods and two-dimensional 1 H double-quantum spectroscopy. The dynamic behavior of the systems has been investigated via variable temperature V C 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 138-155, 2009

We present a statistical mechanical approach for predicting the self-assembled morphologies of amphiphilic copolymers-sulfonated poly (ether ether ketone) (sPEEK) and Nafion-which combine, in one macromolecule, both hydrophobic and hydrophilic segments, giving rise to a constrained hydrophobic/hydrophilic nano-separation. We have developed a coarse-grained model of sPEEK that constitutes an important class of the promising membrane materials for fuel cell applications. Using a mesoscale dynamic density functional theory (DDFT) framework, we explore the phase behavior of sPEEK and Nafion in the presence of physisorbed water. To determine the impact of polymer chemistry on the morphology of sPEEK membranes, multiblock copolymers with a variation in both molecular architecture (block size) and chemical composition (degree of sulfonation) are studied in a large window of water contents. At sufficiently high hydration levels, the simulations predict a tricontinuous morphology, where all the microphase-separated subphases-hydrophilic and hydrophobic blocks and water-percolate, resulting in the formation of three co-continuous phases. Above the percolation threshold, the distribution of water in the sPEEK membrane can be represented as a topologically complex sponge-like network consisting of narrow channels, while the main structural motif of Nafion is characterized by the presence of long but randomly packed water-filled tubes, in agreement with the fibrillar model recently proposed by Schmidt-Rohr and Chen. Although the polymer matrix of sPEEK tends to confine water to narrower channels compared to those in Nafion, the average cross-sectional area of the channels is comparable for the two systems with the same hydration level.

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Segments of conjugated polymers display the propensity to aggregate in solutions with common organic solvents. Here we revealed that the segmental aggregation of a conjugated polymer, poly(9,9-bis(2-ethylhexyl)fluorene-2,7-diyl), (PF2/6), in toluene was stabilized by the polymer-solvent complex formation through pi-pi stacking induction of solvent molecules and polymer segments. In this case, a portion of the solvent was trapped inside the aggregate domains upon bringing the system to the subambient temperatures. The residence time of these associated solvent molecules became long enough to yield a separate upfield-shifted NMR resonance. The line-shape of this resonance revealed alignment of the polymer segments in the aggregates. A portion of the solvent was frozen in the compact structure due to the formation of strong polymer-solvent complex.