A look at some details of the growth of initial uncertainties     

EDWARD N. LORENZ 《地球，A辑:动力气象学与海洋学》2005,57(1):1-11

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The general circulation of the atmosphere: an evolving problem     

EDWARD N. LORENZ 《地球，A辑:动力气象学与海洋学》1991,43(4):8-15

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Thoroughly anomalous chromium in Orgueil     

F. A. PODOSEK  U. OTT  J. C. BRANNON  C. R. NEAL  T. J. BERNATOWICZ  P. SWAN  S. E. MAHAN 《Meteoritics & planetary science》1997,32(5):617-627

Abstract— Stepwise dissolution of bulk Orgueil reveals that all of the Cr in the whole rock is isotopically anomalous, with an anomaly pattern that is thus far unique. Most of the Cr (along with other major and minor cations) is dissolved by acetic and nitric acids; it is deficient in ⁵⁴Cr by ～5 ?. Subsequent treatment with hydrochloric acid dissolves a small fraction of the Cr with positive ⁵⁴Cr anomalies, up to ～210 ?. Mass balance indicates that whole rock Cr is isotopically normal within analytical uncertainties. The least extravagant interpretation of these results is that some mineral phase is enriched in a heavy-Cr nucleosynthetic component, while most of the Cr is a homogenized mixture of diverse nucleosynthetic components that would be normal except for lack of the postulated heavy Cr carrier. The carrier is likely, but not necessarily, presolar interstellar grains. Its identity is unknown and constrained only circumstantially: it must be relatively rich in Cr, it is substantially soluble in hydrochloric acid, and it is not magnetite or spinel/chromite. Scanning electron microscope (SEM) examination of Orgueil reveals candidate Cr-rich oxides, silicates, sulfides and phosphides, but none of these can be identified yet as the heavy Cr carrier. Whether presolar or not, the carrier is not chemically resistant and likely not thermally refractory, thereby differing from most other phases known to host isotopic anomalies. Its survival (or production) thus establishes constraints on a different regime of nebular history.  相似文献   

Presolar silicon carbide from the Indarch (EH4) meteorite: Comparison with silicon carbide populations from other meteorite classes     

SARA S. RUSSELL  ULRICH OTT  CONEL M. O'D. ALEXANDER  ERNST K. ZINNER  JOHN W. ARDEN  C. T. PILLINGER 《Meteoritics & planetary science》1997,32(5):719-732

Abstract— Presolar SiC from the Indarch (EH4) meteorite was studied by scanning electron microscopy (SEM), by ion probe analysis for C and Si isotopic compositions, and by static source mass spectrometry for noble gas and C isotopic compositions. The data obtained are compared to SiC data from other meteorites, especially from Murchison (CM2), for which there is the most information available. The isotopic compositions of the major elements in SiC from Indarch and Murchison are similar. Stepped combustion data suggest a mean δ¹³C for SiC from both meteorites of ～+1430%o. Silicon isotopes in Indarch and Murchison SiC also compare well. In some other important respects, however, SiC in the two meteorites are different. Morphologically, SiC from Indarch appears finer grained than SiC from Murchison and is entirely composed of submicron grains. The finer-grained nature of Indarch SiC is confirmed by its noble gas characteristics. The mean Ne-E/Xe-S ratio for bulk Indarch SiC is significantly lower than the same ratio in Murchison (625 ± 47 vs. ～3500) but is similar to that of the finest grain-size fractions (<1 μm) in Murchison. A comparison of noble gas data from SiC from several different meteorites suggests that it might be Murchison SiC, rather than Indarch SiC, that is unusual. The grain-size disparities in SiC between meteorites are difficult to explain by residue processing differences or differing parent body processing. Instead, we speculate that a grain-size sorting mechanism for SiC may have operated in the solar nebula.  相似文献   

The general circulation of the atmosphere: an evolving problem     

EDWARD N. LORENZ 《Tellus. Series B, Chemical and physical meteorology》1991,43(4):8-15

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HYDROLOGICAL RESPONSE OF SMALL WATERSHEDS FOLLOWING THE SOUTHERN CALIFORNIA PAINTED CAVE FIRE OF JUNE 1990     

EDWARD A. KELLER  DAVID W. VALENTINE  DENNIS R. GIBBS 《水文研究》1997,11(4):401-414

Following the Painted Cave Fire of 25 June 1990 in Santa Barbara, California which burned 1214 ha, an emergency watershed protection plan was implemented consisting of stream clearing, grade stabilizers and construction of debris basins. Research was initiated focusing on hydrological response and channel morphology changes on two branches of Maria Ygnacio Creek, the main drainage of the burned area. Research results support the hypothesis that the response of small drainage basins in chaparral ecosystems to wildfire is complex and flushing of sediment by fluvial processes is more likely than by high magnitude debris flows. During the winter of 1990–1991, 35–66 cm of rainfall and intensities up to 10 cm per hour for a five-minute period were recorded with a seasonal total of 100% of average (normal) rainfall (average=63 cm/year). During the winter of 1991–1992, 48–74 cm of rainfall and intensities up to 8 cm per hour were recorded with a seasonal total of 115% of normal. Even though there was moderate rainfall on barren, saturated soils, no major debris flows occurred in burned areas. The winter of 1992–1993 recorded total precipitation of about 170% of normal, annual average intensities were relatively low and again no debris flows were observed. The response to winter storms in the first three years following the fire was a moderate but spectacular flushing of sediment, most of which was derived from the hillslopes upstream of the debris basins. The first significant storm and stream flow of the 1990–1991 winter was transport-limited resulting in large volumes of sediment being deposited in the channel of Maria Ygnacio Creek; the second storm and stream flow was sediment-limited and the channel scoured. Debris basins trapped about 23 000 m³, the majority coming from the storm of 17–20 March 1991. Sediment transported downstream during the three winters following the fire and not trapped in the debris basins was eventually flushed to the estuarine reaches of the creeks below the burn area, where approximately 108 000 m³ accumulated. Changes in stream morphology following the fire were dramatic as pools filled with sediment which greatly smoothed longitudinal and cross-sectional profiles. Major changes in channel morphology occur following a fire as sediment derived from the hillslope is temporarily stored in channels within the burned area. However, this sediment may quickly move downstream of the burned region, where it may accumulate reducing channel capacity and increasing the flood hazard. Ecological consequences of wildfire to the riparian zone of streams in the chaparral environment are virtually unknown, but must be significant as the majority of sediment (particularly gravel necessary for fish and other aquatic organisms) entering the system does so in response to fires. © 1997 John Wiley & Sons, Ltd.  相似文献