A diagnosis of twentieth century temperature records at West Lafayette,Indiana   总被引：1，自引：0，他引：1  

Ernest M. Agee 《Climatic change》1982,4(4):399-418

A diagnostic study of 80 yrs(1901–80) of surface temperatures collected at West Lafayette, Indiana, has been found to be in tune with the global trend and that for the eastern two-thirds of the United States, namely, cold at the turn of the century, warming up to about 1940, and then cooling to present. The study was divided into two cold periods (1901–18, 1947–80) and a warm period (1919–46), based on the distribution of annual mean temperature. Decadal mean annual temperatures ranged from 10 °C in period I to 12.2 °C in period II, to 9.4 °C during the present cold period. Themean annual temperature for the 80 yr ranged from the coldest of 8.7 °C in 1979 to the warmest of 13.6 °C in 1939. Thedaily mean temperature for the entire 80-yr ranged from -4.7 °C on 31 January to 25.1 °C on 27 July. Thecoldest daily mean was -26.7 °C on 17 January, 1977, and thewarmest daily mean was 35 °C on 14 July, 1936. The range of values for thedaily mean maximum temperatures was -.2 °C on 31 January to 31.4 °C on 27 July. Corresponding values for thedaily mean minimum are -9.2 °C on 31 January and 18.7 °C on 27 July. The all-time extreme temperatures are -30.6 °C on 26 February, 1963 and 43.9 °C on 14 July, 1936. Climatic variability has been considered by computing the standard deviations of a) the daily mean maximum and minimum temperature per year, and b) the daily mean maximum and minimum temperatures for each day of the year for the 80-yr period. These results have shown that there is more variability in the daily mean maximum per year than in the daily mean minimum, for each year of the 80-yr period. Also the variability for both extremes has been greater in each of the two cold periods than in the warm period. Particularly noticeable has been theincrease in the variability of the daily mean minima per year during the current cooling trend. Further, it has been determined that the variability in the daily mean maxima and minima for each day of the year (based on the entire 80 yrs is a) two times greater in the winter than in the summer for both extremes, and b) about the same for each in the summer, greater for daily maximum in the spring and fall, but greater for the daily minimum during the winter. The latter result is undoubtedly related to the effect of snow cover on daily minimum temperatures. An examination of daily record maximum and minimum temperatures has been made to help establish climatic trends this century. For the warm period, 175 record maxima and 68 record minima were set, compared to 213 record minima and 105 record maxima during the recent cold period. For West Lafayette, the present climatic trend is definitely one of extreme record-breaking cold. Evidence has also been presented to show the substantial increases in snowfall amounts in the lee regions of the Great Lakes during the present cold period, due to the lake-induced snow squalls associated with cold air mass intrusions. The possible impact of the cooling trend on agricultural activities has also been noted, due to a reduced growing season.  相似文献   

Instrumental Thermal Neutron Activation Determination of 20 Elements in Nineteen Silicate Reference Materials     

Ernest S. GLADNEY  Daniel R. PERRIN 《Geostandards and Geoanalytical Research》1981,5(2):113-124

Elemental concentrations of Al, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, Mn, Na, Rb, Sb, Sc, Ta, Th, Ti and V have been measured in 11 USGS, 6 CCRMP and 2 NBS reference materials by instrumental thermal neutron activation analysis. The results are compared with recent consensus and agency values.  相似文献   

Glacial geomorphology: Clifford Embleton and C. A. M. King. Halsted Press,New York, 573 pp     

Ernest H. Muller 《Quaternary Research》1976,6(3):459-460

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Nodular celestite in the Chihsia Formation (Middle Permian) of south China   总被引：7，自引：0，他引：7  

Jiaxin Yan  Ernest H. Carlson† 《Sedimentology》2003,50(2):265-278

The middle Permian Chihsia Formation of south China accumulated on a shallow shelf, and consists mainly of black to dark grey micritic limestone rich in chert nodules and organic matter. A unique type of nodular crystal cluster is distributed widely in the carbonate succession. Most crystal clusters consist of calcite. Some, however, are composed of celestite, and geochemical, microscopic and crystal morphological data suggest that celestite was the precursor of the calcite. The celestite developed displacively within the sediments during early diagenesis, before compaction and before local dolomitization of the host rock. Similar strontium isotopic values were obtained from the celestite clusters, replacement calcite, vein calcite and host rock. The values are within the range of middle Permian sea water. The strontium in the celestite was furnished chiefly by either diagenetic alteration of strontium‐rich marine aragonite to strontium‐poor calcite, or aragonite dissolution induced by aerobic oxidation of organic matter, or both. The sulphur isotopic values of the celestite are about 6–11‰ heavier than the sulphur isotopic value of sulphate in coeval sea water. Based on geological context, this difference is attributed to microbial reduction of porewater sulphate in the Chihsia sediments.  相似文献   

Review and assessment of biotic variables and analytical methods used in estuarine inflow studies     

Ernest D. Estevez 《Estuaries and Coasts》2002,25(6):1291-1303

Published and gray literature, and works in progress, were reviewed to identify biotic variables and analytical methods used in studying freshwater inflow needs of estuaries. Landings, CPUE, and other measures of single-species abundance are most often used, especially for shellfish and finfish. These efforts work best when biomass is used and lag times are allowed for recruitment, but neither method is always used, and most efforts have assumed that physical habitat availability is constant. Efforts employing habitat and community-level variables are used less often but more recent attempts are using dynamic as well as stationary definitions of habitat. Even stationary habitat methods have given less attention to tidal freshwater and brackish estuarine reaches, than to other reaches. Natural long-period climate cycles (El Ninõ Southern Oscillation; North Atlantic Multi-Decadal Oscillation) are not factored into most inflow studies. Three promising approaches are encouraged; a mixture of variables representing different levels of ecological organization should be used, the natural non-linear geometry of estuaries (especially tidal rivers) should be exploited to identify critical thresholds of inflow, and the validity of using instream flow methods to calculate estuarine requirements by proxy should be determined.  相似文献   

Seasonal　Variations　in　the　Vertical　Structure　of　Water　Vapor　Optical　Depth　in　the　Lower　Troposphere　over　a　Tropical　Station     

P. Ernest Raj  P.C.S. Devara 《大气科学进展》1997,14(1):103-110

Spatio-temporal variations of water vapor optical depth in the lower troposphere (450-3850 m) over Pune (18o32’N, 73o51’E, 559 m Above Mean Sea Level), India have been studied over a period of five years. The mean ver-tical structure showed that the moisture content is greatest at the lowest level and decreases with increasing altitude, except in the south-west monsoon season (June to September) when an increase upto 950 m has been found. Optical depths are maximum in the monsoon season. The increase from pre-monsoon (March-May) to monsoon season in moisture content on an average is by about 58% in the above altitude range. The temporal variations in surface Rela-tive Humidity and optical depth at 450 m show positive correlation. The amplitude of seasonal oscillation is the larg-est at 1465 m altitude. The time-height cross-sections of water vapor optical depths in the lower troposphere showed a contrast between years of good and bad monsoon.  相似文献   

Forest Fragmentation in the Humid Tropics: A Cross–National Analysis     

Tom Rudel  & Jill Roper 《Singapore journal of tropical geography》1997,18(1):99-109

While habitat destruction always causes species extinctions, the rate of extinction may be highest in those habitats which become the most fragmented as they decline in size. For this reason, knowledge about the patterns and origins of rain forest fragmentation in the tropics may prove useful in efforts to preserve biodiversity. This paper calculates the degree of fragmentation in the tropical rain forests of 51 nations containing 83 per cent of the world's tropical forests. By these measures, West Africa and Central America have the most fragmented tropical rain forests in the world. Not surprisingly, rain forests in the Amazon basin are the world's least fragmented. Some patterns of tropical deforestation appear to produce more fragmentation than others. A two-stage least squares analysis of these data suggest that deforestation driven by smallholders is most likely to produce highly fragmented forest habitats. The implications of these findings for policy and for further research are briefly discussed.  相似文献   

Lidar Measurements of Aerosols in the Tropical Atmosphere   总被引：3，自引：0，他引：3  

P.C.S. Devar  P. Ernest Raj 《大气科学进展》1993,10(3):365-378

Measurements of atmospheric aerosols and trace gases using the Laser radar (lidar) techniques, have been in pro-gress since 1985 at the Indian Institute of Tropical Meteorology, Pune (18o32’N, 73o51’E, 559 m AMSL), India. These observations carried out during nighttime in the lower atmosphere (up to 5.5 km AGL), employing an Argon ion / Helium-Neon lidar provided information on the nature, size, concentration and other characteristics of the constituents present in the tropical atmosphere. The time-height variations in aerosol concentration and associated layer structure exhibit marked differences between the post-sunset and pre-sunrise periods besides their seasonal va-riation with maximum concentration during pre-monsoon / winter and minimum concentration during monsoon months. These observations also revealed the influence of the terrain of the experimental site and some selected me-teorological parameters on the aerosol vertical distributions. The special observations of aerosol vertical profiles ob-tained in the nighttime atmospheric boundary layer during October 1986 through September 1989 showed that the most probable occurrence of mixing depth lies between 450 and 550 m, and the multiple stably stratified aerosol lay-ers present above the mixing depth with maximum frequency of occurrence at around 750 m. This information on nighttime mixing depth / stable layer derived from lidar aerosol observations showed good agreement with the height of the ground-based shear layer / elevated layer observed by the simultaneously operated sodar at the lidar site.  相似文献   

1988 Compilation of Elemental Concentration Data for CCRMP Reference Rock Samples SY-2, SY-3 and MRG-1     

Ernest S. GLADNEY  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1990,14(3):373-458

Concentration data on 80 individual constituents in Canadian Certified Reference Materials Project rock reference materials SY-2, SY-3, and MRG-I have been collected from 382 journal articles and technical reports. These data are summarized as consensus (mean) values with uncertainties expressed as one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables. Recommended values are proposed based upon data criteria used by NIST (National Institute of Standards and Technology, formerly the National Bureau of Standards or NBS).  相似文献   

1988 Compilation of Elemental Concentration Data for CCRMP Soils SO-1 to SO-4     

Ernest S. GLADNEY  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1989,13(2):217-268

Concentration data on 74 individual constituents in CCRMP (Canadian Certified Reference Materials Project) soils SO-1, SO-2, SO-3, and SO-4 have been collected from 83 journal articles and technical reports. These data are summarized in consensus (mean) values with uncertainties expressed as one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables. Recommended values are proposed based upon data criteria used by NIST (National Institute of Standards and Technology, formerly the National Bureau of Standards or NBS).  相似文献