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Dr. Marguerite Wuthrich Prof. Dr Willy Matthey 《Aquatic Sciences - Research Across Boundaries》1980,42(2):269-284
By means of 18 traps, 124 species (including 4 fossil ones) with a total of 3.5×105 cells/m2 have been identified an determined as transported by wind. 119 species have been detected on the feet and bills of waterbirds (Gallinago gallinago). Large migratory insects are capable of transporting diatoms over long distances, whereas small insects partake in the microdistribution. An average of 13.5 diatoms per insect (43 diatom species) were found on 44 insects. 相似文献
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Frequency of Boundary-Layer-Top Fluctuations in Convective and Stable Conditions Using Laser Remote Sensing 总被引：1，自引：0，他引：1
Giovanni Martucci Renaud Matthey Valentin Mitev Hans Richner 《Boundary-Layer Meteorology》2010,135(2):313-331
The planetary boundary-layer (PBL) height is determined with high temporal and altitude resolution from lidar backscatter
profiles. Then, the frequencies of daytime thermal updrafts and downdrafts and of nighttime gravity waves are obtained applying
a fast Fourier transform on the temporal fluctuation of the PBL height. The principal frequency components of each spectrum
are related to the dominant processes occurring at the daytime and nighttime PBL top. Two groups of cases are selected for
the study: one group combines daytime cases, measured in weak horizontal wind conditions and dominated by convection. The
cases show higher updraft and downdraft frequencies for the shallow, convective boundary layer and lower frequencies for a
deep PBL. For cases characterized by strong horizontal winds, the frequencies directly depend on the wind speed. The temporal
variation of the PBL height is determined also in the likely presence of lee waves. For nighttime cases, the main frequency
components in the spectra do not show a real correlation with the nocturnal PBL height. Altitude fluctuations of the top of
the nocturnal boundary layer are observed even though the boundary layer is statically stable. These oscillations are associated
with the wind shear effect and with buoyancy waves at the PBL top. 相似文献
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V. Rizi G. Redaelli G. Visconti F. Masci C. Wedekind B. Stein F. Immler B. Mielke P. Rairoux L. Woste M. Del Guasta M. Morandi F. Castagnoli S. Balestri L. Stefanutti R. Matthey V. Mitev M. Douard J.P. Wolf E. Kyro M. Rummukainen R. Kivi 《Journal of Atmospheric Chemistry》1999,32(1):165-181
Polar stratospheric clouds (PSC) were observed with the multi-wavelength lidar of the MOANA project (Modelling and Observations of Aerosols in the Northern Atmosphere) during SESAME (Second European Stratospheric Arctic and Mid-latitude Experiment). The physical state, liquid or solid, of the cloud particles can be inferred from the lidar data. Using isentropic back-trajectories to obtain the thermal history of the sampled air masses, it is possible to reconcile most of the observations with current ideas on PSC formation and evolution. When the cloud particles were identified as liquid, changes in the size distribution of the droplets along the trajectory were calculated using a micro-physical box model. Backscatter ratios calculated from the size distributions are in broad agreement with the lidar data, giving confidence in current understanding of the evolution of ternary solution (H2SO4, HNO3 and H2O) droplets.Results from two soundings are shown which bear on the problem of the formation of solid particles. In the first, solid particles were detected. The air mass had cooled to the frost point 12 hours earlier. In the second no solid particles were detected although the air temperature was below the nitric acid trihydrate existence point, and had decreased by 12K in the previous 14 hours. 相似文献
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Par Bernard Büttiker Gilbert Matthey 《Aquatic Sciences - Research Across Boundaries》1986,48(2):153-160
A total of 2588 adult migratory brown trout (Salmo trutta lacustris) have been tagged from 1964 to 1974 on their spawning sites, in tributaries of the western part of Lake Geneva (Switzerland).
Most of the fish (96.2%) recaptured during spawning seasons in the following years have been found in the same river where
they had previously been caught.
Most tagged fish recaptured by fishermen were found in the western part of the Lake, near their home rivers. This tendency
is very strong in autumn and winter. It still remains highly significant in spring and summer.
Dédié à Wolfgang Geiger 相似文献
Dédié à Wolfgang Geiger 相似文献
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Par Bernard Büttiker Gilbert Matthey Julius Bel Patrick Durand 《Aquatic Sciences - Research Across Boundaries》1987,49(3):316-328
The age and growth of adult Lake Geneva trout (Salmo trutta lacustris L.) caught from 1964 to 1974 for mark-and-recapture experiments was studied by scale analysis. The median lengths of 3 years
and older fish were fitted to Von Bertalanffy growth curves. Their growth rates are higher than those of the fish younger
than 3 years. It is conculded that this increase of growth rate concides with beginning of life in the lake, after the downstream
migration of the juvenile trout which probably takes place in the second and third summer. No general increase of growth rates
between cohorts could be detected from the beginning to the end of the period studied, in spite of a serious increase of eutrophication
of Lake Geneva during the same time.
相似文献
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Pascal Sailhac Maksim Bano Mickael Behaegel Jean-François Girard Ester Falgàs Para Juanjo Ledo Guy Marquis Pierre-Daniel Matthey José Ortega-Ramírez 《Comptes Rendus Geoscience》2009,341(10-11):818-830
We consider a series of hydrogeophysical techniques that provide a multiscale investigation of the water content in the vadose zone and of the perched aquifer at the experimental site of “La Soutte” in the Vosges Mountains (France). It is located in a catchment area where several springs and streams occur along fractured volcanic and weathered plutonic rocks. The site is the object of a long-term study that uses both continuous and repeated measurements to monitor hydrogeological processes. The main results from AMT and DC resistivity techniques allow the determination of a high-resolution 3D resistivity model over a large range of depths (from 100 to 103 m). We discuss their use and propose a hydrogeological model (porosity, water conductivity and water content). We also use MRS and GPR for a detailed investigation of the shallow part of the catchment that consists of soil and weathered rocks of highly varying thickness (0 to 15 m). MRS is used to map the thickness and total water volume content by unit surface of the saturated weathered zone. It also yields estimates of the vadose zone thickness through the depth to the top of the saturated zone. Moreover, we show results from GPR CMP measurements that yield estimates of the water content and porosity in the shallowest layer (0–30 cm) by simple interpretation of the ground direct wave. 相似文献
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