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Michael F. Gross Michael A. Hardisky Paul L. Wolf Vytautas Klemas 《Estuaries and Coasts》1991,14(2):180-191
Aboveground and belowground biomass ofSpartina alterniflora were harvested during the period of peak aerial biomass from six sites along a latitudinal gradient ranging from Georgia to Nova Scotia. An equation relating live aboveground to live belowground biomass for short-form plants was formulated, using data collected in Delaware marshes. When data from the other sites were substituted into the equation, the mean live belowground biomass it predicted was within 15% of the value determined by harvesting at four of the five sites. At all sites, short-form plant live belowground biomass was concentrated in the upper 10 cm. Dead belowground biomass was located mostly in the top 15 cm in southern marshes, but was more evenly distributed with depth in northern marshes. Results were more ambiguous for tall-form plants, probably because of greater spatial variability in biomass distribution, and greater seasonal biomass dynamics. 相似文献
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LABORATORY MEASUREMENTS OF THE EFFECTS OF VISCOSITY ON SHORT WATER WAVE SPECTRA AND IMPLICATION FOR RADAR REMOTE SENSING OF THE OCEAN SURFACE 总被引：1，自引：0，他引：1
Using an X-band radar and a mechanical short wave generator, we measured the dependenceof radar return power on the viscosity of water which was adjusted by changing the watertemperature. From the measurements we drew two inferences: (1) the spectral density of short waterwaves, F, depends strongly on the viscosity of waterF(v)=F_0~mwhere is normalized viscosity, and m=-1.72; and (2) the normalized radar cross section, σ_0(dB), dependsstrongly on the water temperature△σ_0 (dB)=O.217△TAnalyses indicate that these dependencies can be observed in the field only at low wind conditionsat which the Bragg scattering is a dominant mechanism for producing the radar return signals. Theresults of this study can be used to interpret the sharp variability in radar cross section across a watertemperature front and SAR images of oeeanic phenomena. 相似文献
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Abstract Space shuttle photographs and satellite radar (SAR) images provide an excellent view of high‐contrast ocean features such as internal waves, fronts, eddies, oil slicks, and cloud patterns which contain the signatures of atmospheric processes. Since ocean internal waves generate local currents which modulate surface wavelets and slicks, we have been able to detect packets of internal waves in space shuttle photographs and radar imagery of the Atlantic, Pacific, and Indian Oceans. A global database on internal waves has been developed at our center with support from ONR and NASA, and is accessible on the Internet. The database includes visible and radar imagery. To test the database, digitally orthorectified images were used for dynamic and statistical analysis of internal waves. In the deep ocean we found the wavelength distribution to be Gaussian while in the coastal ocean it is Rayleigh. Results have also been applied to non‐linear evolution studies of ocean internal waves, atmospheric solitary waves and to estimate ocean currents. 相似文献
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Measurement of the surface emissivity of turbid waters 总被引：2，自引：0，他引：2
For interpreting thermal IR imagery of the ocean surface, the emissivity of the sea surface is usually assumed to be constant,
approximately 0.98. However, the emissivity varies with the roughness of the sea surface, and the concentration and type of
suspended particulates. The emissivity variations caused by the suspended sediments introduce significant errors in the satellite-derived
temperature maps of turbid coastal waters.
We measured in the laboratory the thermal IR emissivity of water as the suspended sediment concentration was varied from zero
to extremely high values. The results indicated that increasing the sediment concentration decreases the spectral emissivity
within the 8–14 μm waveband.
Editor’s note A conference on West Pacific Circulation Influence in China Seas (WEPACICS) was held during November 10–14, 1986 in Qingdao,
China, under the joint auspices of the Institute of Onceanology, Academic Sinica (IOAS) and the National Science Foundation,
United States, and under the convernorship of Ya Hsueh, Florida State University, and Hu, Dunxin, IOAS. The primary subject
of the conference is the influence of the West Pacific Circulation in the Yellow Sea and the East China Sea through the intermediary
of the Kuroshio. In the conference more than 20 papers were presented, summarizing the works on the interaction between the
Yellow and East China Sea, and the oceanic circulation, and the research experiences gained in the studies of the Gulf Stream
and its influences in the U.S. Coastal waters were shared. In order to facilitate scientific exchange we chose to published
successively the significant papers presented at the conference in the journal. 相似文献
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