Effects of summer precipitation on urban transportation     

Stanley A. Changnon 《Climatic change》1996,32(4):481-494

Potential shifts in summer precipitation due to an enhanced greenhouse effect indicate the possibility of more rain days and heavier rains in the Midwest, and this study assessed the effects of such changes on transportation in Chicago using a 3-year period of data. Traffic accidents in the metropolitan area doubled on rainy days, with 30% more accidents in more densely populated urban areas than in suburban-rural areas. During rain events accident severity (number of injuries) was 55% higher in suburban and rural areas where less dense but higher speed traffic flows exist than in the city, however. Rain days during dry months produced more accidents and injuries than during normal or wet months. Three times as many accidents occurred during heavy rain periods (> 12.8 mm) as during nonrain conditions. Rain had a negligible influence on weekday traffic volume on busy highways but there was a 9% decrease in traffic volume on rainy weekends. A 3–5% decrease in ridership of public transportation occurred on rainy days, with most decreases during midday. Nationally, 27% of all fatality-producing aircraft accidents occurred during rainy weather conditions, as did 57% of the 30-min flight delays at Chicago's O'Hare Airport. Results suggest that given continued transportation use patterns extend into the future, a future climate with more summer rain days, somewhat higher rain rates, and more storms would mean more total vehicular accidents, more total injuries in vehicular accidents, decreased ridership on public transportation systems, and more aircraft accidents and delays. A drier climate would likely experience fewer moderate to heavy rain events but results show that rain events during drier conditions produced a greater frequency of accidents and injuries per event than during wetter conditions.  相似文献   

The Great Lakes diversion at Chicago and its implications for climate change   总被引：1，自引：0，他引：1  

Stanley A. Changnon  Michael H. Glantz 《Climatic change》1996,32(2):199-214

In 1900 the city of Chicago began diverting sizable amounts of water from Lake Michigan to move its sewage down the Illinois River. This diversion launched a series of continuing legal controversies involving Illinois as a defendant against claims by the federal government, various lake states, and Canada who wanted the diversion stopped or drastically reduced. During the past 96 years extended dry periods have lowered the lake levels. Using these dry periods as surrogates for future conditions, their effects on the past controversies were examined as analogs for what might occur as a result of climate change from an enhanced Greenhouse effect. The results reveal that changing socioeconomic factors including population growth will likely cause increased water use, and Chicago will seek additional water from the Great Lakes. New priorities for water use will emerge as in the past. Drier future conditions will likely lead to enhanced diversions from the Great Lakes to serve interests in and outside the basin. Future lower lake levels (reflecting a drier climate) will lead to conflicts related to existing and proposed diversions, and these conflicts would be exacerbated by the consequences of global warming. In any event, a warmer, drier climatic regime will challenge existing laws and institutions for dealing with Great Lakes water issues.  相似文献   

Storm catastrophes in the United States     

Stanley A. Changnon  Joyce M. Changnon 《Natural Hazards》1992,6(2):93-107

A unique historical data set describing the 142 storms each producing losses in excess of $100 million in the United States during the 1950–89 period were analyzed to describe their temporal characteristics. The storms caused $66.2 billion in losses (in 1991 values), 76% of the nation's insured storm losses in this period. These extreme storm catastrophes (SCs) were most prevalent in the south, southeast, northeast, and central U.S., with few in and west of the Rocky Mountains. Storm incidences were high in the 1950s, low in the 1960s-early 1970s, and increased in the 1980s. Losses due to SCs peaked in the 1950s, again in the late 1960s, with a lesser peak after 1985. The areal extent of storm losses peaked after 1975 and was least in the 1960s. The temporal variations of the three storm measures (incidence, losses, and extent) did not agree except when they all peaked in the 1950s. Regionally-derived time distributions of SCs showed a marked north-south differences in the United States with a U-shaped 40-year distribution in the northern half of the nation, and a relatively flat trend until a peak in the 1980s in the southern regions. The temporal distributions of hurricane-caused catastrophes differed regionally with occurrences in the prime areas, the southern, southeastern, and northeastern U.S., each quite different. Temporal distributions of thunderstorm and winter storm catastrophes were regionally more uniform.  相似文献   

Stratification and bottom-water hypoxia in the Pamlico River estuary   总被引：1，自引：0，他引：1  

Donald W. Stanley  Scott W. Nixon 《Estuaries and Coasts》1992,15(3):270-281

Relationships among bottom-water dissolved oxygen (DO), vertical stratification, and the factors responsible for stratification-destratification in this shallow, low tidal-energy estuary were studied using a 15-yr set of biweekly measurements, along with some recent continuous-monitoring data. Hypoxia develops only when there is both vertical water-column stratification and warm water temperature (>15°C). In July, 75% of the DO readings were <5 mg 1^?1, and one-third were <1 mg 1^?1. Severe hypoxia occurs more frequently in the upper half of the estuary than near the mouth. Both the time series data and correlation analysis results indicate that stratification events and DO levels are tightly coupled with variations in freshwater discharge and wind stress. Stratification can form or disappear in a matter of hours, and episodes lasting from one to several days seem to be common. Estimated summertime respiration rates in the water and sediments are sufficient to produce hypoxia if the water is mixed only every 6–12 d. There has been no trend toward lower bottom water DO in the Pamlico River Estuary over the past 15 yr. *** DIRECT SUPPORT *** A01BY059 00002  相似文献   

New dimensions in world shipbuildingNeue größenordnungen im welt-schiffbauNouvelles dimensions dans le monde des constructions navales     

W.R Stanley  J.M Goicoechea 《Geoforum》1973,4(4):47-66

New classes of bulk carriers and general cargo vessels are becoming more specialized and larger. The trend towards containerizing cargo has spurred construction of the large cellular containership, the roll-on/roll-off vessel, and the barge carrying ship (LASH). Bulk vessels, especially tankers, have undergone tremendous increases in size until few of the newer ones can pass through the Suez Canal. Crews have not increased primarily because of greater use of shipboard automation devices. Few ports have sufficient water depths to accommodate supertankers, necessitating more off-loading at sea and construction of new deep water terminals. Japanese yards dominate world supership construction, with Scandinavian shipyards most important in Europe. Substantial supership construction is taking place in southern Europe and is an indication of the recent economic growth of Italy, Spain and Yugoslavia. Supership construction in Great Britain has declined relative to Scandinavian and Japanese production and that in the United States is of little significance worldwide.  相似文献   

Carbon monoxide on the primitive earth     

James E. Van Trump  Stanley L. Miller 《Earth and Planetary Science Letters》1973,20(1):145-150

The reaction of CO + OH^? in aqueous solution to give formate was studied as a carbon monoxide sink on the primitive earth and in the present ocean. The reaction is first order in OH^? and first order in the molar CO concentration. The second order rate constant is given by log k(M^?1hr^?1) = 15.83?4886/T between 25°C and 60°C. Using the solubility of CO in sea water, and assuming a pH of 8 for a primitive ocean of the present size, the halflife of CO in the atmosphere is calculated to be 12 × 10⁶ yr at 0°C and 5.5 × 10⁴ yr at 25°C.Three other CO sinks would have been important in the primitive atmosphere: CO + H₂ → H₂CO driven by various energy sources, CO + OH → CO₂ + H, and the Fischer-Tropsch reaction of CO + H₂ → hydrocarbons, etc. It is concluded that the lifetime of a CO atmosphere would have been very short on the geological time scale although the relative importance of these four CO sinks is difficult to estimate.The CO + OH^? reaction to give formate is a very minor CO sink on the earth at the present time.  相似文献   

Characteristics of electron and high-energy proton flares     

Emmanuel T. Sarris  Stanley D. Shawhan 《Solar physics》1973,28(2):519-532

High-energy proton (E _p > 55 MeV) and electron (E _e > 50 keV) events were observed by University of Iowa experiments on the satellites Explorer 33 and 35. The solar X-ray (2–12 Å) flares associated with the energetic proton events were found to have in general higher peak fluxes, considerably longer decay times (t) and smaller rise to decay time ratios (r) than the X-ray flares associated with the electron events. The most common decay times and rise to decay time ratios are: 80 t 100 min, 0.1 r 0.2 for the proton X-ray flares and t 20 min, 0.3 r 0.7 for the electron ones.  相似文献   

Autobiographical note: Stanley N. Davis     

Davis SN 《Ground water》2003,41(6):872-874

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The distribution of meteoric <Superscript>36</Superscript>Cl/Cl in the United States: a comparison of models     

Stephen?MoyseyEmail author  Stanley?N.?Davis  Marek?Zreda  L.?DeWayne?Cecil 《Hydrogeology Journal》2003,11(6):615-627

The natural distribution of ³⁶Cl/Cl in groundwater across the continental United States has recently been reported by Davis et al. (2003). In this paper, the large-scale processes and atmospheric sources of ³⁶Cl and chloride responsible for controlling the observed ³⁶Cl/Cl distribution are discussed.The dominant process that affects ³⁶Cl/Cl in meteoric groundwater at the continental scale is the fallout of stable chloride from the atmosphere, which is mainly derived from oceanic sources. Atmospheric circulation transports marine chloride to the continental interior, where distance from the coast, topography, and wind patterns define the chloride distribution. The only major deviation from this pattern is observed in northern Utah and southern Idaho where it is inferred that a continental source of chloride exists in the Bonneville Salt Flats, Utah.In contrast to previous studies, the atmospheric flux of ³⁶Cl to the land surface was found to be approximately constant over the United States, without a strong correlation between local ³⁶Cl fallout and annual precipitation. However, the correlation between these variables was significantly improved (R ²=0.15 to R ²=0.55) when data from the southeastern USA, which presumably have lower than average atmospheric ³⁶Cl concentrations, were excluded. The total mean flux of ³⁶Cl over the continental United States and total global mean flux of ³⁶Cl are calculated to be 30.5±7.0 and 19.6±4.5 atoms m^–2 s^–1, respectively.The ³⁶Cl/Cl distribution calculated by Bentley et al. (1986) underestimates the magnitude and variability observed for the measured ³⁶Cl/Cl distribution across the continental United States. The model proposed by Hainsworth (1994) provides the best overall fit to the observed ³⁶Cl/Cl distribution in this study. A process-oriented model by Phillips (2000) generally overestimates ³⁶Cl/Cl in most parts of the country and has several significant local departures from the empirical data.

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Resumen Davis et al. (2003) han informado de la distribución natural de la proporción ³⁶Cl/Cl en las aguas subterráneas de la parte continental de los Estados Unidos de América [EUA]. En este artículo, se discute cuáles son los procesos a gran escala y las fuentes atmosféricas del ³⁶Cl y del cloruro que dan lugar a la distribución observada de ³⁶Cl/Cl.El proceso dominante que afecta a la relación ³⁶Cl/Cl en las aguas subterráneas de origen meteórico a escala continental es el aporte de cloruro estable desde la atmósfera, que procede principalmente de los océanos. La circulación atmosférica transporta el cloruro marino hacia el interior, donde la distancia a la costa, topografía y corrientes del viento definen la distribución del cloruro. La única desviación principal de este esquema tiene lugar al norte de Utah y en el sur de Idaho, donde se deduce que existe una fuente continental de cloruro en los Rellanos Salados de Bonneville (Salt Flats).En contraste con estudios previos (Knies et al. 1994; Phillips 2000), se ha descubierto que el flujo atmosférico de ³⁶Cl hacia la superficie terrestre es aproximadamente constante en todos los estados, sin deducirse una correlación fuerte entre el aporte de ³⁶Cl y la precipitación anual. Sin embargo, la correlación entre estas variables se ve mejorada de forma significativa, con coeficientes de regresión comprendidos entre 0,15 y 0,55, cuando se excluyen los datos recogidos en el sudeste de los EUA, que tienen concentraciones de ³⁶Cl atmosférico presuntamente inferiores a la media. El flujo medio total de ³⁶Cl calculado en la zona continental de los Estados Unidos vale 30,5±7,0 átomos por metro cuadrado y segundo, mientras que el flujo total global de ³⁶Cl es de 19,6±4,5 átomos por metro cuadrado y segundo.La distribución de ³⁶Cl/Cl calculada por Bentley et al. (1986) infravalora la magnitud y variabilidad observada en los valores medidos a lo largo de los Estados Unidos. El modelo propuesto por Hainsworth (1994) proporciona el mejor ajuste conjunto a la distribución observada de ³⁶Cl/Cl en este estudio. El modelo orientado a procesos de Phillips (2000) sobreestima por lo general la distribución de ³⁶Cl/Cl en la mayoría del país y difiere significativamente de algunos valores locales empíricos.

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Résumé La distribution naturelle du rapport ³⁶Cl/Cl dans les eaux souterraines des États-Unis a été récemment présentée par Davis et al. (2003). Dans ce travail, les processus à grande échelle et les sources atmosphériques de ³⁶Cl et de chlorure responsables du contrôle de la distribution observée du rapport ³⁶Cl/Cl sont discutés. Le processus dominant qui affecte le rapport ³⁶Cl/Cl dans les eaux souterraines dorigine météorique à léchelle continentale est lapport atmosphérique de chlorure stable, qui provient pour lessentiel de sources océaniques. La circulation atmosphérique transporte des chlorures marins vers lintérieur des continents, où la distribution de chlorure est définie par la distance à la côte, la topographie et les régimes des vents. La seule exception majeure à ce schéma est observée dans le nord de lUtah et le sud de lIdaho où lon suppose quil existe une source continentale de chlorure dans les bas-fonds salés de Bonneville. Au contraire de précédentes études (Knies et al. 1994; Phillips 2000), on trouve que le flux atmosphérique de ³⁶Cl vers le sol est approximativement constant sur lensemble des États-Unis, sans forte corrélation entre la retombée locale de ³⁶Cl et les précipitations annuelles. Cependant, la corrélation entre ces variables devient significative (R ²=0.15 à 0.55) lorsquon supprime les données du sud-est des États-Unis, dont on pense quelles présentent des concentrations en ³⁶Cl atmosphérique inférieures à la moyenne. Le flux total moyen de ³⁶Cl sur les États-Unis continentaux et le flux moyen global de ³⁶Cl sont respectivement évalués à 30.5 ± 7.0 et 19.6 ± 4.5 atomes.m^–2.s^–1. La distribution du rapport ³⁶Cl/Cl calculée par Bentley et al. (1986) sous-estime lordre de grandeur et la variabilité observés pour la distribution mesurée du rapport ³⁶Cl/Cl sur les États-Unis continentaux. Le modèle proposé par Hainsworth (1994) fournit le meilleur ajustement densemble à la distribution du rapport ³⁶Cl/Cl observée dans cette étude. Un modèle orienté vers les processus proposé par Phillips (2000) surestime dans lensemble le rapport ³⁶Cl/Cl dans la plupart des régions du pays et présente plusieurs désaccords locaux avec les données empiriques.

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Stable Isotope Ratios: Hurricane Olivia   总被引：1，自引：0，他引：1  

James R. Lawrence  Stanley David Gedzelman  John Gamache  Michael Black 《Journal of Atmospheric Chemistry》2002,41(1):67-82

The oxygen and hydrogen isotopic compositions of rains from HurricaneOlivia (1994) in the eastern Pacific were measured. The rains werecollected on 24 and 25 September during airplane flights conducted at anelevation of 3 km. Hurricane Olivia peaked in intensity to a category-4storm between the two dates. Isotope ratios of rains from HurricaneOlivia were markedly lower ( ¹⁸O = –13.9to –28.8) than that of rain collected from a thunderstormat an elevation of 2.3 km outside the influence of Olivia (¹⁸O = –3.8). A distinct decrease in isotoperatios from the first day to the next ( ¹⁸O =–18.4 to –21.9) in Hurricane Olivia wasattributed to decreased updraft velocities and outflow aloft. Thisshifted the isotopic water mass balance so that fewer hydrometeors werelifted and more ice descended to flight level. A decrease in the averagedeuterium excess from the first day to the next (d = 15.5 to 7.1)was attributed to an increase in the relative humidity of the watervapor `source' area. We hypothesize that the `source' region for therain was in the boundary layer near the storm center and that becausethe hurricane was at peak intensity prior to the second day the relative humidity was higher.  相似文献