Ground-based lightning detection systems geolocated 877 terrestrial gamma ray flashes (TGFs) from a sample of 2,279 TGFs detected with the Fermi Gamma Ray Burst Monitor (GBM). From these accurate geolocations, 24 TGFs are found within the Next Generation Weather Radar (NEXRAD) operational range in the Gulf of Mexico, the Caribbean, and the Pacific near Guam. NEXRAD-enhanced echo-top (EET) data show that these 24 TGFs are consistently adjacent to high-altitude regions of the storms. The high EET values suggest that there is likely a detection–selection effect, in which the gamma rays from lower-altitude TGFs are attenuated by the atmosphere so that such TGFs fall below the detection threshold of current space-based detectors. The vertical integrated liquid density (VILD) values and the volume scan reflectivities Z show that these 24 TGFs originate from storms of a wide range of convective strengths. Convective available potential energy (CAPE) values from reanalysis also vary widely, providing additional evidence of the range of convection in these TGF-producing storms.

The signal enhancement of an easy to fabricate, nanoporous alumina assisted surface plasmon resonance ͑SPR͒ sensor is investigated. It is theoretically shown that the presence of a thin ͑under 200 nm͒ porous alumina layer on top of an aluminum film supporting the surface plasmons, may significantly increase ͑over one order of magnitude͒ the sensitivity of the SPR method in the case where the adsorption of relatively small molecules is probed. The comparative experimental investigation of self-assembled monolayer formation on planar metal films and porous alumina layers verifies the theoretical predictions. Based on these results, we discuss the extended applicability of this setup in biosensor and other related applications.

Convective cold pools over oceans contribute to the air‐sea exchange of heat and moisture. Beyond cold pools' physical properties, cold pools and their intersections are important mechanisms controlling the life cycle of tropical convective systems. However, few observational techniques are available to routinely observe the properties of cold pools and their association with convection. The primary goal of this study is to demonstrate a new technique using gradients in remotely sensed ocean vector winds as a proxy for the structure and characteristics of tropical oceanic cold pools. Using Advanced Scatterometer (ASCAT) vector wind retrievals with field of view of 12.5 km, regions of enhanced gradients in surface winds are identified as gradient features. A 3‐km Weather Research and Forecasting (WRF) model simulation was carried out to illustrate the technique over the Indian Ocean during the 2011 DYNAmics of Madden‐Julian Oscillation (DYNAMO) field campaign. A forward operator was applied to the model wind fields, allowing direct comparisons of wind gradients and virtual temperature‐defined cold pool thermodynamic and kinematic properties. In situ buoy measurements of air temperature were also used to validate ASCAT‐identified cold pools. Quantitative skill metrics demonstrate that the technique has a low false alarm rate (<10%), high critical success index (>85%), and a low bias (~1). The gradient feature technique was then applied to ASCAT‐retrieved ocean vector winds, revealing global variations in cold pool properties. These properties are shown to be related to the properties of global convective systems observed by the Tropical Rainfall Measurement Mission (TRMM).

The formation process of n-alkane phosphonic acid CH 3 (CH 2 ) n−1 PO(OH) 2 (n = 10,12,14,18) self-assembled monolayers (SAMs), deposited from ethanol solutions on aluminum oxide, has been monitored in situ using surface plasmon resonance (SPR) spectroscopy. In addition, the two-solvent approach is used to obtain both film thickness and refractive index of the fully formed adsorbed layers. A densely packed adsorbed layer is formed only for the longest molecules with n = 18. The chain length and solution concentration dependence of formation kinetics are studied, and the existence of two distinct kinetic steps is revealed. Fittings of the experimental results with various kinetic models are performed. Our analysis suggests that during the first kinetic step, a transition from a lying-down to a standing-up phase takes place, and the growth of this standing-up phase is governed by second-order kinetics. The second slow kinetic step is described by a modified first-order Langmuir law.

In this work, the adsorption behavior at the silver/toluene and alumina/toluene interface of polystyrene–polyethylene oxide (PS‐PEO) diblock copolymers of various molecular weights was investigated by implementation of the surface plasmon resonance (SPR) technique. This was accomplished under a careful choice of experimental setup and the use of a suitable physical model for the interpretation of the experimental data. Comparison between polystyrene homopolymer and PS‐PEO diblock copolymer adsorption measurements indicate that PS‐PEO is anchored on the alumina surface via the PEO block, while on silver the copolymer is attached by various chain segments. The measured final adsorption amounts on alumina are typical of end‐attached polymeric brush formation while the dynamics of the adsorption process present two clearly different evolution regimes. This work provides insight into the many advantages of the use of the SPR technique as a valuable tool for similar surface studies. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1580–1591, 2006