Impact of land-atmospheric coupling in CFSv2 on drought prediction     

Joshua K. Roundy  Craig R. Ferguson  Eric F. Wood 《Climate Dynamics》2014,43(1-2):421-434

Recent summers in the United States have been plagued by intense droughts that have caused significant damage to crops and have had a large impact on society. The ability to forecasts such events would allow for preparations that could help reduce the impact on society. Coupled land–atmosphere–ocean models were created to provide such forecasts but there are large uncertainties associated with their predictions. The predictive skill of these models is particularly low during the convective season due to the weaker connections with the oceans and an increase in the land–atmosphere interactions. To better understand the degradation of forecasts skill during the summer months and its connection to the land–atmosphere interactions we analyze National Centers for Environmental Prediction’s Climate Forecast System Version 2 (CFSv2) in terms of its climatological land–atmosphere interactions. To do this we use a recently developed classification of land–atmosphere interactions and other diagnostic variables to compare the reanalysis from the Climate Forecast System (CFSR) with CFSv2 re-forecasts (CFSRR) over the period 1982–2009. Coupling in the CFSRR tends toward the wet coupling regime for most areas east of the Rocky Mountains. Although the specific mechanism driving CFSRR to wet coupling state varies by region, the overall cause is enhanced vegetation rooting depth, originally implemented to address a near-surface warm bias in CFSR. The long-term tendency to wet coupling precludes the forecast model from consistently predicting and maintaining drought over the continental US.  相似文献   

Improved time-delay estimates of underwater acoustic signals usingbeamforming and prefiltering techniques     

Ferguson  B.G. 《Oceanic Engineering, IEEE Journal of》1989,14(3):238-244

Passive sonar systems that localize broadband sources of acoustic energy estimate the difference in arrival times (or time delays) of an acoustic wavefront at spatially separated hydrophones, The output amplitudes from a given pair of hydrophones are cross-correlated, and an estimate of the time delay is given by the time lag that maximizes the cross correlation function. Often the time-delay estimates are corrupted by the presence of noise. By replacing each of the omnidirectional hydrophones with an array of hydrophones, and then cross-correlating the beamformed outputs of the arrays, the author shows that the effect of noise on the time-delay estimation process is reduced greatly. Both conventional and adaptive beamforming methods are implemented in the frequency domain and the advantages of array beamforming (prior to cross-correlation) are highlighted using both simulated and real noise-field data. Further improvement in the performance of the broadband cross-correlation processor occurs when various prefiltering algorithms are invoked  相似文献   

Geomagnetic induction in the Tasman Sea and electrical conductivity structure beneath the Tasman Seafloor     

I. J. Ferguson  F. E. M. Lilley  J. H. Filloux 《Geophysical Journal International》1990,102(2):299-312

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Laboratory investigation of the ionospheric O₂⁺(X²π_g, v ≠ 0) reaction with NO     

W. Lindinger  E.E. Ferguson 《Planetary and Space Science》1983,31(10):1181-1182

Laboratory measurements of the reaction of O₂⁺ with NO from thermal energy to 0.6 eV in an Ar buffered flow drift tube agree with similar measurements made earlier in the same drift tube with He buffer. Since the O₂⁺ ions are substantially vibrationally excited in Ar and not in He it follows that the reaction is not enhanced by vibrational excitation of the O₂⁺.  相似文献   

Near-IR Integral Field Spectroscopy of High-z Galaxies     

Andrew Bunker  Annette Ferguson  Rachel Johnson  Richard McMahon  Ian Parry  Max Pettini  Alfonso Aragón-Salamanca  Rachel Somerville  Nicole Vogt 《Astrophysics and Space Science》2002,281(1-2):529-529

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Colin C. Ferguson 《Mathematical Geology》1977,9(6):605-617

Dome-shaped concentrations of mica adjacent to garnet porphyroblasts in a hornfelsed metagreywacke are seen in thin-section as cleavage arcs. This paper examines some of the stereological relationships between dome shape and are shape by modelling the domes as spherical segments of one base. The relationship between the true thickness of mica flakes within the domes and their apparent thickness as measured in thin section is also derived.  相似文献   

THE CHEMISTRY AND MINERALOGY OF THE HOMEWOOD,MANITOBA, METEORITE     

W.K. Mysyk  R.B. Ferguson  F.C. Hawthorne  K. Ramlal 《Meteoritics & planetary science》1979,14(2):207-214

The Homewood meteorite is a slightly weathered find of 325 grams discovered in 1970 about 64 km southwest of Winnipeg, Manitoba. It consists of olivine (Fa_25.4; 43.8 normative wt. percent), orthopyroxene (Fs_23.3; 28.5 percent), kamacite and taenite (7.5 percent), troilite (5.6 percent), maskelynite (8.3 percent), chromite (1.0 percent), whitlockite (0.7 percent) and minor patchy Ca pyroxene. Bulk chemical analysis yielded Fe_total 21.60 wt. percent, Fe/SiO₂0.55, SiO₂/MgO 1.53 and Fe^O/Fe_total 0.29. Barred olivine, radiating pyroxene and porphyritic chondrules, all with ill-defined outlines, occur in the meteorite. Most chemical and mineralogical features characterize the Homewood meteorite as an L6 (hypersthene) chondrite. The presence of maskelynite, the undulatory extinction, extensive fracturing and pervasive mosaicism of olivine, and the poor definition of chondrule outlines suggest that the Homewood meteorite has been shocked in the range of 300–350 kbar.  相似文献   

Significance of the pyroxene chemistry from leucite-bearing and related assemblages     

A. Cundari  A. K. Ferguson 《Mineralogy and Petrology》1983,31(3-4):290-290

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Preface: Hydrogeology of shallow thermal systems     

Diana M. Allen  Peter Bayer  Grant Ferguson  Philipp Blum 《Hydrogeology Journal》2014,22(1):1-6

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Delamerian Glenelg tectonic zone,western Victoria: Geology and metamorphism of stratiform rocks     

C. M. Gray  A. I. S. Kemp  J. A. C. Anderson  D. J. Bushell  D. J. Ferguson  J. Fitzherbert 《Australian Journal of Earth Sciences》2013,60(2):187-200

The Cambro‐Ordovician Glenelg tectonic zone of western Victoria is a distinctive metamorphic‐igneous segment of the Delamerian Orogenic Belt comprising two northwest‐striking regional metamorphic segments of andalusite‐sillimanite type prograding towards an axial granitic batholith. The second of five deformations (D₂) was most significant, producing isoclinal folds, transposition and a pervasive regional foliation (S₂). Southwest of the central batholith, biotite to migmatite zones contain mainly quartzo‐feldspathic rock (turbiditic metagreywacke, quartzo‐feldspathic schist and migmatite), plus less common metaquartzite and calc‐silicate rocks and minor metapelite. Metagabbro, metadolerite and amphibolite typically have the chemistry of mid‐ocean ridge basalts. Serpentinite pods and sheets were tectonically introduced to low‐grade areas. Northeast of the central batholith, quartzo‐feldspathic rock occupies the sillimanite and migmatite zones exclusively, with a regional concentration of pegmatites adjacent to the zone boundary. Gross interleaving of quartzo‐feldspathic schist, migmatite, pegmatite and muscovite‐bearing granitic rock is characteristic. Peak metamorphic conditions of 550 MPa at 640°C leading to migmatite formation were established by D₂ time and accompanied by tonalite‐granodiorite and pegmatite emplacement. Subsequently, the thermal high contracted to the northeast culminating in the more extensive syn‐, post‐D4 to pre‐D5 granitic magmatism.  相似文献