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221.
Stamps convey important visible messages about a state’s heritage and worldview. They are images or official visible products seen by those living within the state’s borders and those beyond. They also can be considered as “imagined communities,” as like festivals, holidays, or WWW pages, they represent attachments to and images of place. We investigate stamps as elements of visual culture by examining salient music themes and topics from several countries and then focus on the music stamps of Brazil, Hungary, and Senegal. In each case, we examine the number and variety of issues, the importance they place on musical instruments, composers and performers, and musical events. 相似文献
222.
Catastrophic winter storms: An escalating problem 总被引:2,自引:0,他引:2
Stanley A. Changnon 《Climatic change》2007,84(2):131-139
Winter storms are a major weather problem in the USA and their losses have been rapidly increasing. A total of 202 catastrophic
winter storms, each causing more than $1 million in damages, occurred during 1949–2003, and their losses totaled $35.2 billion
(2003 dollars). Catastrophic winter storms occurred in most parts of the contiguous USA, but were concentrated in the eastern
half of the nation where 88% of all storm losses occurred. They were most frequent in the Northeast climate district (95 storms),
and were least frequent in the West district (14 catastrophic storms). The annual average number of storms is 3.7 with a 1-year
high of 9 storms, and 1 year had no storms. Temporal distributions of storms and their losses exhibited considerable spatial
variability across the nation. For example, when storms were very frequent in the Northeast, they were infrequent elsewhere,
a result of spatial differences in storm-producing synoptic weather conditions over time. The time distribution of the nation’s
202 storms during 1949–2003 had a sizable downward trend, whereas the nation’s storm losses had a major upward trend for the
55-year period. This increase over time in losses, given the decrease in storm incidences, was a result of significant temporal
increases in storm sizes and storm intensities. Increases in storm intensities were small in the northern sections of the
nation, but doubled across the southern two-thirds of the nation, reflecting a climatic shift in conditions producing intense
winter storms. 相似文献
223.
Kefeng ZHU Ming XUE Yujie PAN Ming HU Stanley G. BENJAMIN Stephen S. WEYGANDT Haidao LIN 《大气科学进展》2019,36(12):1308-1326
A regional ensemble Kalman filter (EnKF) data assimilation (DA) and forecast system was recently established based on the Gridpoint Statistical Interpolation (GSI) analysis system. The EnKF DA system was tested with continuous threehourly updated cycles followed by 18-h deterministic forecasts from every three-hourly ensemble mean analysis. Initial tests showed negative to neutral impacts of assimilating satellite radiance data due to the improper bias correction procedure. In this study, two bias correction schemes within the established EnKF DA system are investigated and the impact of assimilating additional polar-orbiting satellite radiance is also investigated. Two group experiments are conducted. The purpose of the first group is to evaluate the bias correction procedure. Two online bias correction methods based on GSI 3DVar and EnKF algorithms are used to assimilate AMSU-A radiance data. Results show that both variational and EnKF-based bias correction procedures effectively reduce the observation and background radiance differences, achieving positive impacts on forecasts. With proper bias correction, we assimilate full radiance observations including AMSU-A, AMSU-B, AIRS, HIRS3/4, and MHS in the second group. The relative percentage improvements(RPIs) for all forecast variables compared to those without radiance data assimilation are mostly positive, with the RPI of upper-air relative humidity being the largest. Additionally, precipitation forecasts on a downscaled 13-km grid from 40-km EnKF analyses are also improved by radiance assimilation for almost all forecast hours. 相似文献
224.
The presence of outer stably stratified layers in planetary cores has been suggested for Earth, Saturn and Mercury. In this study, we use a 3-D numerical dynamo model to investigate the effects of a thin stable layer surrounding a convecting interior on the produced magnetic field. We find that a stable layer can destabilize the field morphology through a thermal wind that produces unfavorable zonal flows throughout the core. The direction of these zonal flows is prograde in equatorial regions, unlike a model with no stable layer that has retrograde equatorial flows. Our models therefore suggest that the Earth does not have a stable layer since we observe a westward drift as opposed to an eastward drift. For Saturn, we find that due to coupling of the flows in the stable and unstable layers, the layer does not act to shear out the non-axisymmetry in the observed magnetic field, and therefore cannot explain Saturn’s axisymmetric magnetic field. For Mercury, we find that if the stable layer is thin, it can actively produce strong or weak surface fields and not necessarily attenuate smaller scale features through the skin effect. 相似文献
225.
Hctor Lpez Loera Jos Jorge Aranda-Gmez Jorge A. Arzate Roberto Stanley Molina-Garza 《Journal of Volcanology and Geothermal Research》2008,170(3-4):135-152
Joya Honda (JH) is a Quaternary maar excavated in Mesozoic limestone. It is located in central Mexico and belongs to the Ventura volcanic field (VVF), which is composed by cinder cones and maars made of intraplate-type mafic alkalic rocks. Volcanoes in the region form N20W lineaments, roughly parallel to a regional set of normal faults, but there is no obvious relation between these faults and vent distribution in the exposed geology around the maar. The volcanic rock volume is small in the VVF, and most volcanoes and their products are scattered in a region where outcrops are dominated by limestone.The near-vent tephra associated to the JH maar lies north of the crater. This relation suggests that the crater was formed by directed hydromagmatic explosions and may indicate an inclined volcanic conduit near the surface. The tephra stratigraphy suggests that the initial explosions were relatively dry and the amount of water increased during the maar forming eruption. Therefore, the existing model of the maar–diatreme formation may not be applicable to Joya Honda as it requires the formation of a cone of depression in the aquifer and deepening of the focii of the explosions as the crater and underlying diatreme grew. Thus, it is unlikely that there is a diatreme below Joya Honda.Aeromagnetic data shows a boundary between two regional magnetic domains near the elongated volcanic cluster of the VVF. The boundary is straight, with a distinct kink, from NE- to NW-trend, near JH. The limit between the domains is interpreted as fault contacts between mid-Tertiary volcanic rocks and marine Mesozoic sedimentary rocks. Hence, magma ascent in the area may have been facilitated by fractures near the surface.Magnetic and gravimetric ground surveys show that the anomalies associated with the maar are not centered in the crater, which could be consistent with an inclined volcanic conduit. A magnetic profile measured on exposed limestone across the volcanic lineament failed to show an anomaly such as that caused by a connecting dike between the volcanoes. Therefore, either the dike does not exist or it is so deep or so thin that it is beyond the limit of detection of the method and/or equipment used. Thus, the volcanic conduit immediately below Joya Honda can be reasonably modeled in the shape of a plug. A 2-D model of the crater anomaly is consistent with a roughly tabular deposit formed by fall-back pyroclasts and slump deposits near the surface. Based on this result we propose an alternative model for the formation of maar-type volcanoes excavated in hard rock, where there is no evidence of a gradual decrease of the water/magma ratio as the eruption advanced. 相似文献
226.
The hydraulic integrity of aquitards is generally assumed and relies on a few core-scale permeability measurements, drill-stem tests, or textbook values. This approach is because hydraulic data across the full aquitard thickness is generally lacking. Proper assessment of aquitard integrity should be studied at the formation (spanning its entire thickness at a single point) or regional (formation properties at multiple locations throughout the basin) scale. One formation-scale approach uses environmental tracers and advection-dispersion modeling to constrain fluid flow rates. This study demonstrates the use of helium concentrations in quartz as a method of constraining the rate of fluid flow in a 520-m thick aquitard in the Gunnedah Basin, NSW, Australia. Quartz was separated from existing core samples in the Watermark and Porcupine Formations at depths from 750 to 1200 m. The helium was released from these samples by heating and select samples were impregnated with helium to determine the rate of helium diffusion through the quartz. One-dimensional advection-dispersion modeling of the helium profile accounting for diffusive helium exchange between quartz and pore water revealed, that (1) vertical fluid velocity has been on the order of 0.02 mm/year or less for tens to thousands of years, (2) helium is in equilibrium between quartz and pore water, and (3) the helium profile is transient indicating that helium concentrations in the underlying Maules Creek Formation has varied over geological time. Further modeling identified aquitard conditions (thickness and temperature) for which equilibrium exists, a precondition for deriving formation-scale permeability. 相似文献
227.
228.
Humboldt, Arago, and the temperature of groundwater 总被引:1,自引:0,他引:1
Stanley N. Davis 《Hydrogeology Journal》1999,7(5):501-503
229.
Stanley D. Brunn 《GeoJournal》2000,52(2):315-323
Stamps are products or `windows' of the state that illustrate how it wishes to be seen by its own citizens and those beyond its boundaries. The topics of the first issues reveal what messages the state considers most important. The first issues from nineteen new East European and Central Asian states illustrate the importance of maps, flags, coats of arms and prominent religious and political symbols; overt propaganda and ideology were lacking. 相似文献
230.