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A generalized,structural,time series modeling framework was developed to analyze the monthly records of absolute surface temperature,one of the most important environmental parameters,using a deterministicstochastic combined(DSC) approach.Although the development of the framework was based on the characterization of the variation patterns of a global dataset,the methodology could be applied to any monthly absolute temperature record.Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal,involving polynomial functions and the Fourier method,respectively,while stochastic processes were employed to account for any remaining patterns in the temperature signal,involving seasonal autoregressive integrated moving average(SARIMA) models.A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years.The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors,suggesting that DSC models,when coupled with other ecoenvironmental models,can be used as a supplemental tool for short-term(~10-year) environmental planning and decision making. 相似文献
774.
Susan H. Cannon Eric M. Boldt Jayme L. Laber Jason W. Kean Dennis M. Staley 《Natural Hazards》2011,59(1):209-236
Following wildfires, emergency-response and public-safety agencies can be faced with evacuation and resource-deployment decisions
well in advance of coming winter storms and during storms themselves. Information critical to these decisions is provided
for recently burned areas in the San Gabriel Mountains of southern California. A compilation of information on the hydrologic
response to winter storms from recently burned areas in southern California steeplands is used to develop a system for classifying
magnitudes of hydrologic response. The four-class system describes combinations of reported volumes of individual debris flows,
consequences of debris flows and floods in an urban setting, and spatial extents of the hydrologic response. The range of
rainfall conditions associated with different magnitude classes is defined by integrating local rainfall data with the response
magnitude information. Magnitude I events can be expected when within-storm rainfall accumulations (A) of given durations (D) fall above the threshold A = 0.4D
0.5 and below A = 0.5D
0.6 for durations greater than 1 h. Magnitude II events will be generated in response to rainfall accumulations and durations
between A = 0.4D
0.5 and A = 0.9D
0.5 for durations less than 1 h, and between A = 0.5D
0.6 and A = 0.9D
0.5 or durations greater than 1 h. Magnitude III events can be expected in response to rainfall conditions above the threshold
A = 0.9D
0.5. Rainfall threshold-magnitude relations are linked with potential emergency-response actions as an emergency-response decision
chart, which leads a user through steps to determine potential event magnitudes and identify possible evacuation and resource-deployment
levels. Use of this information in planning and response decision-making process could result in increased safety for both
the public and emergency responders. 相似文献
775.
776.
Abstract: This article explores environmental imaginaries of colonization in lowland Canterbury. In 1844 Edward Shortland observed that his Māori companions had an exceptionally detailed geographical knowledge of the area and its resources, yet a few years later European settlers were viewing it as an empty stage on which to envision newly‐constructed landscapes. The terrain was contested, but colonial ‘improvement’, through the creation of spaces of modernity, took no cognizance of this. The legacies of that transformation are a simplified, orderly landscape, and fractured but persistent memories of indigenous ecosystems that are now being revived. 相似文献
777.
778.
Charles P. Gerba Sagar M. Goyal Eric M. Smith Joseph L. Melnick 《Marine pollution bulletin》1977,8(12):279-282
Significant concentrations of human enteric viruses and bacteria were found to be present in the water and sediment of a coastal canal community into which secondarily treated sewage was being discharged. 相似文献
779.
F. Zeb Page Lora S. Armstrong Eric J. Essene Samuel B. Mukasa 《Contributions to Mineralogy and Petrology》2007,153(5):533-555
Quantitative thermobarometry of inclusions in zoned garnet from a Franciscan eclogite block record a counter-clockwise P–T path from blueschist to eclogite and back. Garnet retains prograde zoning from inclusion-rich Alm52Grs30Pyp6Sps12 cores to inclusion-poor Alm62Grs25Pyp12Sps1 mantles, with overgrowths of highly variable composition. Barometry using the Waters–Martin version of the garnet–phengite–omphacite
thermobarometer yields conditions of 7–15 kbar, 400–500°C (garnet cores), 18–22 kbar, ∼550°C (mantles), and 10–14 kbar, 350–450°C
(overgrowths), in agreement with clinozoisite–sphene–rutile–garnet–quartz barometry. These pressures are ∼10–15 kbar less
than those obtained using more recent, fully thermodynamic calibrations of the phengite–omphacite–garnet thermobarometer.
Low early temperatures suggest that the block was subducted in a thermally mature subduction zone and not at the inception
of subduction when prograde temperature is expected to be higher. Franciscan high-grade blocks likely represent crust subducted
throughout the history of this convergent margin, rather than only at the inception of the subduction zone. 相似文献
780.
Low-level temperature inversions are a common feature of the wintertime troposphere in the Arctic and Antarctic. Inversion strength plays an important role in regulating atmospheric processes including air pollution, ozone destruction, cloud formation, and negative longwave feedback mechanisms that shape polar climate response to anthropogenic forcing. The Atmospheric Infrared Sounder (AIRS) instrument provides reliable measures of spatial patterns in mean wintertime inversion strength when compared with available radiosonde observations and reanalysis products. Here, we examine the influence of sea ice concentration on inversion strength in the Arctic and Antarctic. Correlation of inversion strength with mean annual sea ice concentration, likely a surrogate for the effective thermal conductivity of the wintertime ice pack, yields strong, linear relationships in the Arctic (r?=?0.88) and Antarctic (r?=?0.86). We find a substantially greater (stronger) linear relationship between sea ice concentration and surface air temperature than with temperature at 850?hPa, lending credence to the idea that sea ice controls inversion strength through modulation of surface heat fluxes. As such, declines in sea ice in either hemisphere may imply weaker mean inversions in the future. Comparison of mean inversion strength in AIRS and global climate models (GCMs) suggests that many GCMs poorly characterize mean inversion strength at high latitudes. 相似文献