CELIAS - Charge, Element and Isotope Analysis System for SOHO   总被引：1，自引：0，他引：1  

D. Hovestadt  M. Hilchenbach  A. Bürgi  B. Klecker  P. Laeverenz  M. Scholer  H. Grünwaldt  W. I. Axford  S. Livi  E. Marsch  B. Wilken  H. P. Winterhoff  F. M. Ipavich  P. Bedini  M. A. Coplan  A. B. Galvin  G. Gloeckler  P. Bochsler  H. Balsiger  J. Fischer  J. Geiss  R. Kallenbach  P. Wurz  K. -U. Reiche  F. Gliem  D. L. Judge  H. S. Ogawa  K. C. Hsieh  E. Möbius  M. A. Lee  G. G. Managadze  M. I. Verigin  M. Neugebauer 《Solar physics》1995,162(1-2):441-481

The CELIAS experiment on SOHO is designed to measure the mass, ionic charge and energy of the low and high speed solar wind, of suprathermal ions, and of low energy flare particles. Through analysis of the elemental and isotopic abundances, the ionic charge state, and the velocity distributions of ions originating in the solar atmosphere, the investigation focuses on the plasma processes on various temporal and spatial scales in the solar chromosphere, transition zone, and corona. CELIAS includes 3 mass- and charge-discriminating sensors based on the time-of-flight technique: CTOF for the elemental, charge and velocity distribution of the solar wind, MTOF for the elemental and isotopic composition of the solar wind, and STOF for the mass, charge and energy distribution of suprathermal ions. The instrument will provide detailed in situ diagnostics of the solar wind and of accelerated particles, which will complement the optical and spectroscopic investigations of the solar atmosphere on SOHO. CELIAS also contains a Solar Extreme Ultraviolet Monitor, SEM, which continously measures the EUV flux in a wide band of 17 – 70 nm, and a narrow band around the 30.4 nm He II line.Principal-InvestigatorPrincipal-Investigator for data phase  相似文献   

Liquid water on Mars: An energy balance climate model for CO₂/H₂O atmospheres     

M.I. Hoffert  A.J. Callegari  C.T. Hsieh  W. Ziegler 《Icarus》1981,47(1):112-129

Geologic evidence of the prior existence of liquid water on Mars suggests surface temperatures T_s were once considerably warmer than at present; and that such a condition may have arisen from a larger atmospheric greenhouse. Here we develop a simple climate model for a CO₂/H₂O Mars atmosphere including water vapor-longwave opacity feedback in the atmosphere and temperature-albedo feedback at surface icecaps, under the assumption that once the Martian surface pressure was p_s ≥ 1 atm CO₂. Longwave flux to space is computed as a function of T_s and p_s using band-absorption models for the effect of the 15-μm fundamental, and the 10- and 15-μm hot bands, of the CO₂ molecule; as well as the pure rotation bands and e continuum of H₂O. The derived global radiative balance predicts a global mean surface temperature of 283°K at 1 atm CO₂. When the emission model is coupled to a latitudinally resolved energy balance climate model, including the effect of poleward heat transfer by atmospheric baroclinic eddies, the solutions vary, depending on p_s. We considered two cases: (1) the present Mars (p_s ? 0.007 atm) with pressure-buffering by solid CO₂ icecaps, and limited poleward heat flux by the atmosphere; and (2) a hypothetical “hot Mars” (p_s ? 1.0 atm), whose much higher CO₂ amount augmented by H₂O evaporative feedback yields a theoretical T_s distribution with latitude admitting liquid water over 95% of the surface, water icecaps at the poles, and a diminished equator-to-pole temperature gradient relative to the present.  相似文献   

Spectral analysis of the AVHRR sea surface temperature variability off the west coast of Vancouver Island     

Ralf Bürgert  William W. Hsieh 《大气与海洋》2013,51(3):577-587

Abstract

From 16 AVHRR infrared satellite images of the west coast of Vancouver Island, British Columbia, collected during the five summers of 1984–1988, 4 alongshore temperature transects were sampled. Upon Fourier transforming the transect data, we found that the energy spectra of the temperature variance in alongshore wavenumber space in general followed a –2.1 power law, which agreed with previous observations from other parts of the world.

Summer images may be divided into 2 types: upwelling dominated and non‐upwelling dominated. When a strong upwelling‐induced alongshore cold front was observed, the regimes shoreward and seaward of the front had distinctly different spectra. Cross‐spectral analysis of transect data between images taken a day apart in the presence of strong upwelling events revealed significant coherence at the low wavenumber regime (wavelength 300 km and above, corresponding to the large eddies) and often at the high wavenumber regime (wavelength 30 km or below, corresponding to the fine structures of the eddies). The coherence dropped for images taken 2 or more days apart, suggesting a decorrelation time‐scale of about 2 days. In the absence of strong upwelling and associated eddies, summer transect temperature data from different years often showed a similar alongshore linear trend in addition to possible large differences in the mean temperature.  相似文献   

Determining anisotropic transmissivity using a simplified Papadopulos method   总被引：1，自引：0，他引：1  

Heilweil VM  Hsieh PA 《Ground water》2006,44(5):749-753

The straight-line method presented by Papadopulos requires a minimum of three observation wells for determining the transmissivity tensor of a homogeneous and anisotropic aquifer. A simplification of this method was developed for fractured aquifers where the principal directions of the transmissivity tensor are known prior to implementation, such as when fracture patterns on outcropping portions of the aquifer may be used to infer the principal directions. This new method assumes that observation wells are drilled along the two principal directions from the pumped well, thus reducing the required number of observation wells to two. This method was applied for an aquifer test in the fractured Navajo Sandstone of southwestern Utah and yielded minimum and maximum principal transmissivity values of 70 and 1800 m(2)/d, respectively, indicating an anisotropy ratio of approximately 24 to 1.  相似文献   

Bioremediation in Fractured Rock: 1. Modeling to Inform Design,Monitoring, and Expectations          下载免费PDF全文

Claire R. Tiedeman  Allen M. Shapiro  Paul A. Hsieh  Thomas E. Imbrigiotta  Daniel J. Goode  Pierre J. Lacombe  Mary F. DeFlaun  Scott R. Drew  Carole D. Johnson  John H. Williams  Gary P. Curtis 《Ground water》2018,56(2):300-316

Field characterization of a trichloroethene (TCE) source area in fractured mudstones produced a detailed understanding of the geology, contaminant distribution in fractures and the rock matrix, and hydraulic and transport properties. Groundwater flow and chemical transport modeling that synthesized the field characterization information proved critical for designing bioremediation of the source area. The planned bioremediation involved injecting emulsified vegetable oil and bacteria to enhance the naturally occurring biodegradation of TCE. The flow and transport modeling showed that injection will spread amendments widely over a zone of lower‐permeability fractures, with long residence times expected because of small velocities after injection and sorption of emulsified vegetable oil onto solids. Amendments transported out of this zone will be diluted by groundwater flux from other areas, limiting bioremediation effectiveness downgradient. At nearby pumping wells, further dilution is expected to make bioremediation effects undetectable in the pumped water. The results emphasize that in fracture‐dominated flow regimes, the extent of injected amendments cannot be conceptualized using simple homogeneous models of groundwater flow commonly adopted to design injections in unconsolidated porous media (e.g., radial diverging or dipole flow regimes). Instead, it is important to synthesize site characterization information using a groundwater flow model that includes discrete features representing high‐ and low‐permeability fractures. This type of model accounts for the highly heterogeneous hydraulic conductivity and groundwater fluxes in fractured‐rock aquifers, and facilitates designing injection strategies that target specific volumes of the aquifer and maximize the distribution of amendments over these volumes.  相似文献   

Bioremediation in Fractured Rock: 2. Mobilization of Chloroethene Compounds from the Rock Matrix          下载免费PDF全文

Allen M. Shapiro  Claire R. Tiedeman  Thomas E. Imbrigiotta  Daniel J. Goode  Paul A. Hsieh  Pierre J. Lacombe  Mary F. DeFlaun  Scott R. Drew  Gary P. Curtis 《Ground water》2018,56(2):317-336

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