The TurbEFA Field Experiment—Measuring the Influence of a Forest Clearing on the Turbulent Wind Field     

Ronald Queck  Christian Bernhofer  Anne Bienert  Fabian Schlegel 《Boundary-Layer Meteorology》2016,160(3):397-423

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The Bremen ocean bottom tiltmeter (OBT) – a technical article on a new instrument to monitor deep sea floor deformation and seismicity level     

Marcus Fabian  Heinrich Villinger 《Marine Geophysical Researches》2007,28(1):13-26

The Bremen ocean bottom tiltmeter is a new 6000 m-depth deep sea instrument for autonomous observation of sea floor tilt with signal periods longer than 7.5 s. The instrument also records vertical acceleration in the frequency range from DC to 1 Hz. The tiltmeter has an Applied Geomechanics Inc. 756 wide angle biaxial bubble tilt sensor with a resolution of 1.0μ rad (0.2 arc second). A Kistler Corp. MEMS accelerometer of type Servo K-Beam 8330A2.5 with about 10⁻⁵m/s² resolution is used for the acceleration measurements. An Oceanographic Embedded Systems AD24 24 bit Sigma-Delta converter, which is controlled by a low-power Persistor Inc. embedded computer system of type CF 2, samples the data. The duration of tiltmeter operation is more than one year, which is controlled by the battery life. In our design the tiltmeter does not need active leveling devices, i.e., servo motors or other moving components to adjust sensors or frame. We designed the instrument for deployments by means of a remote operated vehicle. Since May 2005 the Bremen ocean bottom tiltmeter has recorded sea floor deformation and seismicity level in the Logatchev hydrothermal vent field, Mid-Atlantic Ridge. The tiltmeter is a part of the monitoring system of project ‘Logatchev Long-Term Environmental Monitoring,’ called LOLEM, of the German research program with the name ‘Schwerpunktprogramm 1144: Vom Mantel zum Ozean.’  相似文献   

The impact of climate change on the fish community structure of the eastern continental shelf of the Bay of Biscay   总被引：2，自引：1，他引：2  

Poulard  Jean-Charles; Blanchard  Fabian 《ICES Journal of Marine Science》2005,62(7):1436-1443

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Molecular and cellular biomarker responses to pesticide exposure in juvenile chinook salmon (Oncorhynchus tshawytscha)     

Eder KJ  Leutenegger CM  Wilson BW  Werner I 《Marine environmental research》2004,58(2-5):809-813

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Cooling flows in clusters of galaxies     

A. C. Fabian  P. E. J. Nulsen  C. R. Canizares 《Astronomy and Astrophysics Review》1991,2(3-4):191-226

Summary X-ray images and spectra of clusters of galaxies show strong evidence for cooling flows. In many clusters, the hot gas in the core is cooling at rates of 100Myr^–1 and greater. Few traces of the cooled gas have been observed, but it probably forms into low-mass stars (perhaps brown dwarf or even Jupiter-mass objects). X-ray surface-brightness profiles show that the cooling gas is highly inhomogeneous. Overdense gas cools rapidly to form cooled clumps distributed throughout the flow, with little of the gas ever reaching the cluster centre. Cooled and cooling clumps are disrupted because of their motion relative to the remainder of the gas, tending to produce small cooled fragments and, ultimately, low-mass stars. Large molecular clouds, which are the sites of massive star formation in our galaxy, do not occur in the outer parts of cooling flows. There is evidence of larger gas clumps and the formation of more massive stars in the central few kpc of some cooling flows. It is argued that cooling flows efficiently form dark matter. This has wider implications for the formation of dark matter in massive galaxies.  相似文献   

X-ray reflection in accreting stellar-mass black hole systems     

R. R. Ross  A. C. Fabian 《Monthly notices of the Royal Astronomical Society》2007,381(4):1697-1701

The X-ray spectra of accreting stellar-mass black hole systems exhibit spectral features due to reflection, especially broad iron Kα emission lines. We investigate the reflection by the accretion disc that can be expected in the high/soft state of such a system. First, we perform a self-consistent calculation of the reflection that results from illumination of a hot, inner portion of the disc with its atmosphere in hydrostatic equilibrium. Then, we present reflection spectra for a range of illumination strengths and disc temperatures under the assumption of a constant-density atmosphere. Reflection by a hot accretion disc differs in important ways from that of a much cooler disc, such as that expected in an active galactic nucleus.  相似文献   

British–Irish Ice Sheet and polar front history of the Goban Spur,offshore southwest Ireland over the last 250 000 years     

Stanislaus G. Fabian  Stephen J. Gallagher  David De Vleeschouwer 《Boreas: An International Journal of Quaternary Research》2023,52(4):476-497

Deep Sea Drilling Program (DSDP) Site 548 was cored in 1984 at a water depth of 1256 m on the Goban Spur, offshore southwest Ireland. Coring retrieved a ~100-m-thick Pleistocene contourite sequence. This study uses planktonic foraminiferal assemblage and benthic foraminiferal oxygen isotope analyses to establish an age model for the upper 40 m of this core. This site's multidisciplinary analyses of planktonic foraminiferal assemblages, lithic grains, facies and calcium carbonate concentration reveal a 250 000-year record of the North Atlantic polar front variability and British–Irish Ice Sheet (BIIS) history. The sequence is characterized by alternations of ice rafted debris (IRD) laden pelagic mud facies with calcium carbonate-rich silty sand contourite facies that track glacial/interglacial cycles. The polar front migrated southward across the area several times during glacial maxima and stadial periods, while warmer Mediterranean Outflow Water (MOW) flowed northward across the region during interglacial and interstadial periods depositing contourites. Lithic analyses reveal a complex history of IRD deposition associated with iceberg calving from the Laurentide Ice Sheet and northwest European ice sheets, mainly the BIIS. Comparison between the Goban Spur (DSDP Site 548) and the Celtic Margin (MD03-2692) and central North Atlantic Integrated Ocean Drilling Program (IODP) Site U1308 suggests differences between the ‘non-Laurentide Ice Sheet’ Heinrich Events (HE) 6 and 3 at the Goban Spur, with IRD from the BIIS being prominent during HE 6 and IRD from other European ice sheets north of the BIIS likely being more dominant during HE 3. The nature of lithics in IRD-rich horizons during Terminations 3, 3A, 2 and 1 suggests significant iceberg calving episodes preceding BIIS retreat during the onset of interstadial intervals.  相似文献   

Meridional tropospheric ozone distribution north of 50° from airplane measurements     

Bischof  W.  Fabian  P. 《Pure and Applied Geophysics》1973,106(1):1041-1043

Ozone measurements aboard commercial airliners over Scandinavia and on transpolar flights were analyzed for tropospheric ozone concentration. The results confirm a region of enhanced stratospheric-tropospheric exchange around 60° latitude which was expected from Sr-90 fallout measurements.  相似文献   

Celestial Mechanics and Dynamical Astronomy     

Fabian Josef Winterberg  Efi Meletlidou 《Celestial Mechanics and Dynamical Astronomy》2004,88(4):415-420

Volume Contents

Celestial Mechanics and Dynamical Astronomy  相似文献   

Measuring the power spectrum of density fluctuations at intermediate redshift with X-ray background observations     

Barcons  Fabian  & Carrera 《Monthly notices of the Royal Astronomical Society》1998,293(1):60-70

The precision of intensity measurements of the extragalactic X-ray background (XRB) on an angular scale of about a degree is dominated by spatial fluctuations caused by source confusion noise. X-ray source counts at the flux level responsible for these fluctuations, ∼10⁻¹² erg cm⁻² s⁻¹, will soon be accurately measured by new missions, and it will then be possible to detect the weaker fluctuations caused by the clustering of the fainter, more distant sources which produce the bulk of the XRB. We show here that measurements of these excess fluctuations at the level of (Δ I/I )∼2×10⁻³ are within reach, improving by an order of magnitude on present upper limits. Since it is likely that most (if not all) of the XRB will be resolved into sources by AXAF , subsequent optical identification of these sources will reveal the X-ray volume emissivity in the Universe as a function of redshift. With these ingredients, all-sky observations of the XRB can be used to measure the power spectrum (PS) of the density fluctuations in the Universe at comoving wavevectors k _c∼0.01–0.1 Mpc⁻¹ at redshifts where most of the XRB is likely to originate ( z ∼1–2) with a sensitivity similar to, or better than, the predictions from large-scale structure theories. A relatively simple X-ray experiment, carried out by a large-area proportional counter with a 0.5–2 deg² collimated field of view scanning the whole sky a few times, would be able to determine the PS of the density fluctuations near its expected peak in wavevector with an accuracy better than 10 per cent.  相似文献