Prediction of satellite track of tropical cyclone from spiral bands

ABSTRACT. The sector of the eye wall where a spiraling convective barxi a~ars to fasten with it changes and oscillates over the eye wall and such a sector is easily discernible in EnhancOO fufra Red (EIR) imagery received from satellite for a cyclone whose intensity is more than T5.0. It has been argued that a vector having initial point at the centre of the cyclone arxi passing through this particular sector of the eye wall, indicates the future satellite track of a tropical cyclone. The data of the two cyclones. which were showing above mentioned identifiable feawre during a part of their lives. withstood the logic within observational errors.

Microspheres and Nanorods Produced in the Dissolution of Mildly Carboxylated Cellulose Fibers in Alkaline Solutions

A mild etherification of spruce kraft pulp was performed to introduce 1.3 and 2.5 mmol/g carboxyl groups on cellulose chains. 1.3 mmol/g carboxymethyl fibers (CMF) were dissolved partially in alkaline water to form balloons and collars on the tracheid and their ultra-structure was investigated. Primary wall, expanded S1, swollen S2, wrinkled S3, spiral bands of S1, parallel microfibrils of S2 and their transverse splitting were observed on swollen fibers. It is indicated that balloons, collars and wrinkled S3 were formed due to different cellulose microfibril features in different layers of tracheid cell wall. Microspheres with a size up to about 0.6 µm were observed by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). It is shown that they originated from transverse splitting of S2 microfibrils and contain bundles of well-known cellulose nanocrystals (CNC). After homogenization and sonication of an aqueous dispersion of 2.5 mmol/g CMF, electroacoustic spectroscopy showed the presence of nanorods with a size distribution of 18-208 nm. Similar sizes were observed by TEM.

Shell colour and banding polymorphism in Cepaea nemoralis(Gastropoda, Pulmonata, Helicidae) from the Moscow region

The shell colour and banding were analyzed in more than 2000 specimens of Cepaea nemoralis collected in 11 localities in Moscow and the Moscow region. In the colonies studied, snails with pink shells usually predominate, most often represented by the phenotype 00000 (complete absence of the spiral bands). In most cases, yellow unbanded shells were absent or represented by single specimens. Brown shells, almost exclusively unbanded, were found only in 5 sites. On the example of colonies from Zagoryanski and Buch (Berlin), as well as Sheremetievski and Dolgoprudnyi, the phenotypic composition of newly formed colonies and colonies that could have been their origins was compared. A decrease in phenotypic diversity of newly formed colonies was noted.

A transplantation experiment yields no evidence for phenotypic plasticity in shell band width in Cepaea nemoralis

The common European grove snail, Cepaea nemoralis (Helicidae), has been a model species in genetics and evolutionary biology for over a century thanks largely to its genetic shell colour polymorphism. Although most aspects of its shell colour variation are known to be purely genetic, with little or no phenotypic plasticity involved, the width of the spiral bands has been suspected to display a certain amount of plasticity. To test this, we conducted a transplantation experiment, in which 548 growing banded snails were marked and transplanted, either within the same habitat (open or closed vegetation, displaying 19% and 61% band fusion, respectively) or between habitat types. The numbers recaptured were low: 8%, 5% after removal of individuals that had not grown. Based on these samples, we did not find any substantial influence of transplantation on band width.

The Boundary Layer Dynamics of Tropical Cyclone Rainbands

Spiral bands are ubiquitous features in tropical cyclones and significantly affect boundary layer thermodynamics, yet knowledge of their boundary layer dynamics is lacking. Prompted by recent work that has shown that relatively weak axisymmetric vorticity perturbations outside of the radius of maximum winds in tropical cyclones can produce remarkably strong frictional convergence, and by the observation that most secondary eyewalls appear to form by the “wrapping up” of a spiral rainband, the effect of asymmetric vorticity features that mimic spiral bands is studied. The mass field corresponding to an axisymmetric vortex with added spiral vorticity band is constructed using the nonlinear balance equation, and supplied to a three-dimensional boundary layer model. The resulting flow has strong low-level convergence and a marked updraft extending along the vorticity band and some distance downwind. There is a marked along-band wind maximum in the upper boundary layer, similar to observations, which is up to about 20% stronger than the balanced flow. A marked gradient in the inflow-layer depth exists across the band and there is an increase in the surface wind factor (the ratio of surface wind speed to nonlinear-balanced wind speed) near the band. The boundary layer dynamics near a rainband therefore form a continuum with the flow near a secondary eyewall. None of these features are due to convective momentum transports, which are absent from the model. The sensitivities of the flow to band length, width, location, crossing angle, and amplitude are examined, and the possible contribution of boundary layer dynamics to the formation of the tropical cyclone rainbands discussed.

Cephaloziella konstantinovae (Cephaloziellaceae, Marchantiophyta), A New Leafy Liverwort Species from Russia and Mongolia Identified by Integrative Taxonomy

In the course of a taxonomic study of the genus Cephaloziella (Spruce) Schiffn. (Cephaloziellaceae, Marchantiophyta) in Asia, the new species Cephaloziella konstantinovae Mamontov & Vilnet, sp. nov., from the eastern regions of Russia and from the Republic of Mongolia was discovered. The new species is formally described and illustrated here. Morphologically it is similar to C. divaricata var. asperifolia (Taylor) Damsh., but differs in its leaf shape and thin-walled, inflated stem and leaf cells. The new species can be distinguished from other Cephaloziella taxa by the following characters: (i) female bracts entirely free from each other and from bracteole, (ii) perianth campanulate, (iii) cells of perianth mouth subquadrate, (iv) capsule spherical, (v) seta with 8–10 + 4–6-seriate morphology, and (vi) elaters with 1–2 spiral bands. Molecular phylogenetic analyses of nrITS1-5.8S-ITS2 and chloroplast trnL-F sequences from 63 samples (34 species, 23 genera) confirm the taxonomical status of the new species. Five specimens of C. konstantinovae form a clade placed sister to a clade of C. elachista (J. B. Jack) Schiffn. and C. rubella (Nees) Warnst.

Convection and Rapid Filamentation in Typhoon Sinlaku during TCS-08/T-PARC

This study examines the convection and rapid filamentation in Typhoon Sinlaku (2008) using the Naval Research Laboratory (NRL) P-3 aircraft data collected during the Tropical Cyclone Structure 2008 (TCS-08) and The Observing System Research and Predictability Experiment (THORPEX) Pacific Asian Regional Campaign (T-PARC) field experiments. The high-resolution aircraft radar and wind data are used to directly compute the filamentation time, to allow an investigation into the effect of filamentation on convection. During the reintensification stage, some regions of deep convection near the eyewall are found in the vorticity-dominated area where there is little filamentation. In some other parts of the eyewall and the outer spiral rainband region, including areas of upward motion, the filamentation process appears to suppress deep convection. However, the magnitude of the suppression differs greatly in the two regions. In the outer spiral band region, which is about 200 km from the center, the suppression is much more effective, such that the ratio of the deep convective regime occurrence over the stratiform regime varies from around 50% (200%) for filamentation time shorter (longer) than 24 min. In the eyewall cloud region where the conditions are conducive to deep convection, the filamentation effect may be quite limited. While effect of filamentation suppression is only about 10%, it is still systematic and conspicuous for filamentation times shorter than 19 min. The results suggest the possible importance of vortex-scale filamentation dynamics in suppressing deep convection and organizing spiral bands, which may affect the development and evolution of tropical cyclones.