bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Hurricane Intensity Issue
Authors: Krishnamurti T. N. , Pattnaik S. , Stefanova L. , Kumar T. S. V. Vijaya , Mackey B. P. , O’Shay A. J. , Pasch Richard J. 
Published: July 2005

Abstract
The intensity issue of hurricanes is addressed in this paper using the angular momentum budget of a hurricane in storm-relative cylindrical coordinates and a scale-interaction approach. In the angular momentum budget in storm-relative coordinates, a large outer angular momentum of the hurricane is depleted continually along inflowing trajectories. This depletion occurs via surface and planetary boundary layer friction, model diffusion, and “cloud torques”; the latter is a principal contributor to the diminution of outer angular momentum. The eventual angular momentum of the parcel near the storm center determines the storm’s final intensity. The scale-interaction approach is the familiar energetics in the wavenumber domain where the eddy and zonal kinetic energy on the hurricane scale offer some insights on its intensity. Here, however, these are cast in storm-centered local cylindrical coordinates as a point of reference. The wavenumbers include azimuthally averaged wavenumber 0, principal hurricane-scale asymmetries (wavenumbers 1 and 2, determined from datasets) and other scales. The main questions asked here relate to the role of the individual cloud scales in supplying energy to the scales of the hurricane, thus contributing to its intensity. A principal finding is that cloud scales carry most of their variance, via organized convection, directly on the scales of the hurricane. The generation of available potential energy and the transformation of eddy kinetic energy from the cloud scale are in fact directly passed on to the hurricane scale by the vertical overturning processes on the hurricane scale. Less of the kinetic energy is generated on the scales of individual clouds that are of the order of a few kilometers. The other major components of the energetics are the kinetic-to-kinetic energy exchange and available potential-to-available potential energy exchange among different scales. These occur via triad interaction and were noted to be essentially downscale transfer, that is, a cascading process. It is the balance among these processes that seems to dictate the final intensity.
A Cyclogenesis Evolving into Two Distinct Scenarios and Its Implications for Short-Term Ensemble Forecasting
Authors: Plu Matthieu , Arbogast Philippe 
Published: July 2005

Abstract
In a nonlinear quasigeostrophic model with uniform potential vorticity, an idealized initial state sharing some features with atmospheric low-predictability situations is built. Inspired by previous work on idealized cyclogenesis, two different cyclogenesis scenarios are obtained as a result of a small change of the initial location of one structure. This behavior is interpreted by analyzing the baroclinic interaction between upper- and lower-level anomalies. The error growth mechanism is nonlinear; it does not depend on the linear stability properties of the jet, which are the same in both evolutions.
The ability of ensemble forecasts to capture these two possible evolutions is then assessed given some realistic error bounds in the knowledge of the initial conditions. First, a reference statistical distribution of each of the evolutions is obtained by means of a large Monte Carlo ensemble. Smaller ensembles with size representative of what is available in current operational implementations are then built and compared to the Monte Carlo reference: several singular-vector-based ensembles, a small Monte Carlo ensemble, and a “coherent structure”-based ensemble. This new technique relies on a sampling of the errors on the precursors of the cyclogenesis: amplitude and position errors. In this context, the precursors are handled as coherent structures that may be amplified or moved within realistic error bounds. It is shown that the singular vector ensemble fails to reproduce the bimodal distribution of the variability if the ensemble is not initially constrained, whereas it is accessible at a relatively low cost to the new coherent structures initialization.
Improving Convective Precipitation Forecasting through Assimilation of Regional Lightning Measurements in a Mesoscale Model
Authors: Papadopoulos Anastasios , Chronis Themis G. , Anagnostou Emmanouil N. 
Published: July 2005

Abstract
A technique developed for assimilating regional lightning measurements into a meteorological model is presented in this paper. The goal is to assess the effectiveness of cloud-to-ground (CG) lightning information for improving the convective precipitation forecasting. The main concept of the technique is that utilizing real-time location, timing, and flash-rate data retrieved from a long-range lightning detection network, a regional/mesoscale meteorological model is informed about the deep moist convection spatiotemporal development and intensity. This information is then used to nudge the model-generated humidity profiles to empirical profiles as a function of the observed lightning intensity. The empirical humidity profiles are assumed to be representative of convective regimes since they have been produced on the basis of atmospheric soundings obtained during thunderstorm days. Case studies from three thunderstorm developments in a warm-season environment over the Mediterranean are used to investigate the relationship between lightning density and different empirical humidity profiles, and consequently demonstrate the impact of the technique on model precipitation forecasts. Results show that assimilation of lightning data can significantly improve the model’s prediction accuracy of convective precipitation in the assimilation period, while maintaining the improvement in short-range (up to 12 h) forecasts compared to the control case. The approach is general enough to be applied to any mesoscale model, but with an expectable varying degree of success. Its advantage when applied in an operational setting is that real-time lightning data responding promptly to the occurrence of convection would continuously get assimilated to update the moist state of the atmosphere in the model.
Boundary Layer and Shallow Cumulus Clouds in a Medium-Range Forecast of a Large-Scale Weather System
Authors: Bélair Stéphane , Mailhot Jocelyn , Girard Claude , Vaillancourt Paul 
Published: July 2005

Abstract
The role and impact that boundary layer and shallow cumulus clouds have on the medium-range forecast of a large-scale weather system is discussed in this study. A mesoscale version of the Global Environmental Multiscale (GEM) atmospheric model is used to produce a 5-day numerical forecast of a midlatitude large-scale weather system that occurred over the Pacific Ocean during February 2003. In this version of GEM, four different schemes are used to represent (i) boundary layer clouds (including stratus, stratocumulus, and small cumulus clouds), (ii) shallow cumulus clouds (overshooting cumulus), (iii) deep convection, and (iv) nonconvective clouds. Two of these schemes, that is, the so-called MoisTKE and Kuo Transient schemes for boundary layer and overshooting cumulus clouds, respectively, have been recently introduced in GEM and are described in more detail.
The results show that GEM, with this new cloud package, is able to represent the wide variety of clouds observed in association with the large-scale weather system. In particular, it is found that the Kuo Transient scheme is mostly responsible for the shallow/intermediate cumulus clouds in the rear portion of the large-scale system, whereas MoisTKE produces the low-level stratocumulus clouds ahead of the system. Several diagnostics for the rear portion of the system reveal that the role of MoisTKE is mainly to increase the vertical transport (diffusion) associated with the boundary layer clouds, while Kuo Transient is acting in a manner more consistent with convective stabilization. As a consequence, MoisTKE is not able to remove the low-level shallow cloud layer that is incorrectly produced by the GEM nonconvective condensation scheme. Kuo Transient, in contrast, led to a significant reduction of these nonconvective clouds, in better agreement with satellite observations. This improved representation of stratocumulus and cumulus clouds does not have a large impact on the overall sea level pressure patterns of the large-scale weather system. Precipitation in the rear portion of the system, however, is found to be smoother when MoisTKE is used, and significantly less when the Kuo Transient scheme is switched on.
Limited-Area Fourier Spectral Models and Data Analysis Schemes: Windows, Fourier Extension, Davies Relaxation, and All That
Authors: Boyd John P. 
Published: July 2005

Abstract
Regional spectral models have previously periodized and blended limited-area data through ad hoc low-order schemes justified by intuition and empiricism. By using infinitely differentiable “window functions” or “bells” borrowed from wavelet theory, one can periodize with preservation of spectral accuracy. Similarly, it is shown through a mixture of theory and numerical examples that Davies relaxation for blending limited-area and global data in one-way nested forecasting can be performed using the same C∞ bells as employed for the Fourier blending.“The relative success of empirical methods . . . may be used as partial justification to allow us to make the daring approximation that the data on a limited area domain may be decomposed into a trend and a periodic perturbation, and to proceed with Fourier transformation of the latter.” Laprise (2003, p. 775)
Evaluation of an Urban Canopy Parameterization in a Mesoscale Model Using VTMX and URBAN 2000 Data
Authors: Chin Hung-Neng S. , Leach Martin J. , Sugiyama Gayle A. , Leone John M. , Walker Hoyt , Nasstrom J. S. , Brown Michael J. 
Published: July 2005

Abstract
A modified urban canopy parameterization (UCP) is developed and evaluated in a three-dimensional mesoscale model to assess the urban impact on surface and lower-atmospheric properties. This parameterization accounts for the effects of building drag, turbulent production, radiation balance, anthropogenic heating, and building rooftop heating/cooling. U.S. Geological Survey (USGS) land-use data are also utilized to derive urban infrastructure and urban surface properties needed for driving the UCP. An intensive observational period with clear sky, strong ambient wind, and drainage flow, and the absence of a land–lake breeze over the Salt Lake Valley, occurring on 25–26 October 2000, is selected for this study.
A series of sensitivity experiments are performed to gain understanding of the urban impact in the mesoscale model. Results indicate that within the selected urban environment, urban surface characteristics and anthropogenic heating play little role in the formation of the modeled nocturnal urban boundary layer. The rooftop effect appears to be the main contributor to this urban boundary layer. Sensitivity experiments also show that for this weak urban heat island case, the model horizontal grid resolution is important in simulating the elevated inversion layer.
The root-mean-square errors of the predicted wind and temperature with respect to surface station measurements exhibit substantially larger discrepancies at the urban locations than their rural counterparts. However, the close agreement of modeled tracer concentration with observations fairly justifies the modeled urban impact on the wind-direction shift and wind-drag effects.
An Observational and Modeling Analysis of the Landfall of Hurricane Marty (2003) in Baja California, Mexico
Authors: Farfán Luis M. , Cortez Miguel 
Published: July 2005

Abstract
This paper documents the life cycle of Tropical Cyclone Marty, which developed in late September 2003 over the eastern Pacific Ocean and made landfall on the Baja California peninsula. Observations and best-track data indicate that the center of circulation moved across the southern peninsula and proceeded northward in the Gulf of California. A network of surface meteorological stations in the vicinity of the storm track detected strong winds. Satellite and radar imagery are used to analyze the structure of convective patterns, and rain gauges recorded total precipitation. A comparison of Marty’s features at landfall, with respect to Juliette (2001), indicates similar wind intensity but differences in forward motion and accumulated precipitation.
Official, real-time forecasts issued by the U.S. National Hurricane Center prior to landfall are compared with the best track. This resulted in a westward bias of positions with decreasing errors during subsequent forecast cycles. Numerical simulations from the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model were used to examine the evolution of the cyclonic circulation over the southern peninsula. The model was applied to a nested grid configuration with horizontal resolution as detailed as 3.3 km, with two (72- and 48-h) simulations. The output of the model provides a reasonable prediction of Marty’s motion during landfall and the circulation characteristics are consistent with the information derived from observations. Additionally, the model was used to estimate the role of the peninsular mountain ranges in a realistic simulation of the storm track over the Gulf of California.
An Observational Study of Intraseasonal Variations over Southeast Asia during the 1998 Rainy Season
Authors: Yokoi Satoru , Satomura Takehiko 
Published: July 2005

Abstract
In the present study, intraseasonal variations of precipitation over Thailand [Thailand daily rainfall (TDR)] during 1998 and the accompanying variations of the tropospheric circulation are analyzed, mainly with the use of rain gauge data and the Global Energy and Water Cycle Experiment (GEWEX) Asian Monsoon Experiment (GAME) reanalysis version 1.5.
Wavelet analysis reveals that the amplitudes of the intraseasonal variations of the 1998 TDR exhibit two peaks. One peak is categorized as a 30–60-day variation that appeared in the early half of the rainy season, while the other peak is categorized as a 10–20-day variation that appears in the later half of the rainy season.
The variation of atmospheric circulation associated with the latter peak of the TDR is analyzed. When the 10–20-day variation of the TDR is in the most active phase, a negative streamfunction anomaly at the 850-hPa level exists over the Bay of Bengal, and a positive anomaly is found in the Southern Hemisphere to the south of the negative anomaly. Both anomalies are associated with cyclonic vortices and are accompanied by negative height anomalies at the same level. Such horizontal structures resemble the horizontal structure of an equatorial Rossby wave of the gravest meridional mode (n1ERW). The cyclonic disturbances move westward with speeds of 6–6.4 m s−1.
In the vertical, the disturbances have a first-baroclinic structure in the troposphere, with a node at the 300–400-hPa levels. In addition, the amplitude of the streamfunction anomaly in the lower troposphere is smaller than that in the upper troposphere over the western Pacific but larger than that in the upper troposphere over the Bay of Bengal.
The mechanism for the longitudinal difference in the vertical structure and comparison of the analyzed disturbance with n1ERW-type disturbances over the Pacific are also discussed.
Water in the Earth's mantle
Authors: Bolfan-Casanova N. 
Published: July 2005

AbstractWater plays an important role in most processes within the Earth's mantle, e.g. transport phenomena, differentiation and seismic properties. This paper reviews the various aspects of water in the mantle, with a special emphasis on the water content in nominally anhydrous minerals, especially lower-mantle minerals. The saturation of the upper mantle with respect to water is calculated as a function of pressure, based on available water-solubility data obtained for upper-mantle minerals. The result indicates that the upper mantle is saturated at pressures between 2 and 4 GPa for bulk water contents of 250 to 700 ppm wt., as retrieved from measurements on mid-ocean ridge basalts (MORBs) and ocean island basalts (OIBs). Whereas up to 4000 ppm wt. of H2O could be dissolved in the upper mantle at pressures corresponding to 410 km depth, such a value is less than the 1.5–2.5 wt.% solubility stored in the hydrous phases of the transition zone. Water solubility in mantle perovskite is still controversial, because of the difficulty of synthesizing samples free of impurities. Reported data indicate that water solubility in perovskite decreases with increasing temperature and Al content. Water partitions preferentially into ferropericlase rather than into perovskite, and its water solubility increases with the incorporation of trivalent cations.
Combined neutron powder and X-ray single-crystal diffraction refinement of the atomic structure and hydrogen bonding of goslarite (ZnSO4·7H2O)
Authors: Anderson J. L. , Peterson R. C. , Swainson I. P. 
Published: July 2005

AbstractThe atomic structure of synthetic, deuterated goslarite (ZnSO4·7D2O),a= 11.8176(6) Å,b= 12.0755(7) Å,c= 6.8270(4)Å, space groupP212121,Z= 4, has been refined in a combined neutron powder diffraction and X-ray single-crystal data refinement towRp1.92%,Rp1.45% andR(F2)12.66% for the neutron powder data contribution andR(F2) 8.72% for the X-ray single-crystal data contribution. Both data sets were necessary to achieve the best overall fit agreement in the Rietveld refinement and reasonable geometry within structural units. The results of this study confirm that the H-bonding scheme for goslarite is the same as that of the other epsomite group minerals. Small but significant variations of the Zn–O bond lengths can be attributed to details of the H bonds to the O atoms of the Zn octahedra. This investigation of the atomic structure and hydrogen bonding of goslarite is groundwork for future studies into phase relationships and the mechanisms of hydration and dehydration in the ZnSO4–H2O system.
Equations of state of dense hydrous magnesium silicates: results from single-crystal X-ray diffraction
Authors: Crichton W. A. , Ross N. L. 
Published: July 2005

AbstractThe equations of state of dense hydrous magnesium silicates (DHMS), determined from high-pressure single-crystal X-ray diffraction are reviewed, including hydroxylchondrodite, hydroxylclinohumite, phase A, phase B (anhydrous and hydrous), superhydrous phase B and phase E. The phases along the forsterite–brucite join, Mg2SiO4–Mg(OH)2, display near (increasing) linearity in compressibility with respect to water content and increasing bulk moduli (KT) with density. Such trends allow prediction of the as yet unknown bulk moduli of phases such as OH-Mg norbergite. The addition of water also reduces the bulk modulus of the B-phases and the anisotropy observed in axial compression. The alternating layers of octahedra and octahedra + tetrahedra completely control compression of the B phases, with the stacking direction becoming more compressible with addition of water. The enigmatic Phase E has the highestKT'yet measured for a hydrous silicate and one of the lowestKT. In contrast with other DHMS, Phase E is only slightly anisotropic in axial compression and we attribute this to the role of the intralayer cations in the structure. The degree of hydration and the vacancy concentration appear to be coupled in Phase E.
Molecular dynamics modelling of hydrated mineral interlayers and surfaces: structure and dynamics
Authors: R. J. Kirkpatrick  , A. G. Kalinichev  , Wang J. 
Published: July 2005

AbstractThis paper reviews the results of recent molecular dynamics (MD) modelling studies of the interaction of water and solute species with mineral surfaces and their behaviour in mineral interlayers. Emphasis is on results for single and double hydroxide phases. Computational results are presented for water and anions in the interlayers of the Ca2Al, Mg2Al, and LiAl2 layered double hydroxides and on the surfaces of the Ca2Al phase. Detailed results for water on the (001) surface of brucite (Mg(OH)2) are presented and compared to published results for other phases. In all these cases, hydrogen bonding and the development of a hydrogen-bond network involving the H2O molecules and the solid substrate play very significant roles. The MD methods are especially effective for investigating the structure and dynamics of mineral-fluid interfaces and mineral interlayers, because they can be applied to systems containing hundreds to thousands of atoms and for extended durations of the order of nanoseconds.
Equation of state of hydrous Fo90 ringwoodite to 45 GPa by synchrotron powder diffraction
Authors: Manghnani M. H. , Amulele G. , Smyth J. R. , Holl C. M. , Chen G. , Prakapenka V. , Frost D. J. 
Published: July 2005

AbstractThe equation of state of Fo90 hydrous ringwoodite has been measured using X-ray powder diffraction to 45 GPa at the GSECARS beam line at the Advanced Photon Source synchrotron at Argonne National Laboratory. The sample was synthesized at 1400°C and 20 GPa in the 5000 ton multi anvil press at Bayerisches Geoinstitut in Bayreuth. The sample has the formula Mg1.70Fe0.192+ Fe0.023+H0.13- Si1.00O4 as determined by electron microprobe, Fourier transform infrared and Mössbauer spectroscopies, and contains ~0.79% H2O by weight. Compression of the sample had been been measured previously to 11 GPa by single crystal X-ray diffraction. A third-order Birch-Murnaghan equation of state fit to all of the data gives V0 = 530.49±0.07 Å3, K0 = 174.6±2.7 GPa and K' = 6.2±0.6. The effect of 1% H incorporation in the structure on the bulk modulus is large and roughly equivalent to an increase in the temperature of ∼600°C at low pressure. The large value of K' indicates significant stiffening of the sample with pressure so that the effect of hydration decreases with pressure.
Ikaite (CaCO3.6H2O) compressibility at high water pressure: a synchrotron X-ray diffraction study
Authors: Lennie A. R. 
Published: July 2005

AbstractIkaite (CaCO3.6H2O), which forms in cold carbonate-rich marine environments, also crystallizes from calcite under aqueous conditions above ∼0.5 GPa at room temperature. Using synchrotron X-ray powder diffraction, measurements have been made of pressure-induced changes in unit-cell dimensions of ikaite contained in a diamond anvil cell. Ikaite shows anisotropic compressibility along the crystallographic axes in the order a > c > b up to 4 GPa. Comparison with other phases shows the relative volume compressibility of ikaite to be greater than that of gypsum (CaSO4.2H2O), calcite and aragonite. The volume of ikaite is less than that occupied by equivalent volumes of CaCO3 (calcite/aragonite) + 6H2O at all pressures below the freezing point (H2O(l) to ice VI). The bulk modulus of ikaite has been obtained from a fit to the Vinet equation of state, giving V0 = 760.3±0.1 Å3, K0 = 21.3±1.4 GPa, and K0' = 11.7±1.7. Dissolution of CaCO3 in H2O (l) at high pressure resulting in crystallization of CaCO3.6H2O suggests equilibrium behaviour between a carbonate-rich fluid species and the condensed hydrated calcium carbonate. The potential for ikaite as a candidate phase for water transport in cold subduction zones is considered.