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261.
262.
Chung-Lin SHIE Long S. CHIU Robert ADLER Eric NELKIN I-I LIN Pingping XIE Feng-Chin WANG R. CHOKNGAMWONG William OLSON D. Allen CHU 《大气科学进展》2009,26(6):1071-1080
Accurate sea surface flux measurements are crucial for
understanding the global water and energy cycles. The oceanic
evaporation, which is a major component of the global oceanic fresh
water flux, is useful for predicting oceanic circulation and
transport. The global Goddard Satellite-based Surface Turbulent
Fluxes Version-2 (GSSTF2; July 1987--December 2000) dateset that was
officially released in 2001 has been widely used by scientific
community for global energy and water cycle research, and regional
and short period data analyses. We have recently been funded by NASA
to resume processing the GSSTF dataset with an objective of
continually producing a uniform dataset of sea surface turbulent
fluxes, derived from remote sensing data. The dataset is to be
reprocessed and brought up-to-date (GSSTF2b) using improved input
datasets such as a recently upgraded NCEP/DOE sea surface
temperature reanalysis, and an upgraded surface wind and microwave
brightness temperature V6 dataset (Version 6) from the Special
Sensor Microwave Imager (SSM/I) produced by Remote Sensing Systems
(RSS). A second new product (GSSTF3) is further proposed with a
finer temporal (12-h) and spatial (0.25ox0.25o)
resolution. GSSTF2b (July 1987--December 2008) and GSSTF3 (July
1999--December 2009) will be released for the research community to
use by late 2009 and early 2011, respectively. 相似文献
263.
264.
Yu-Chen Song Hai-Dong Meng Michael J. O’Grady Gregory M. P. O’Hare 《Computational Geosciences》2010,14(2):263-271
A clustering algorithm that is based on density and is adaptive density-reachable is developed and presented for arbitrary data point distributions in some real-world applications, especially in geophysical data interpretation. Through comparisons of the new algorithm and other algorithms, it is shown that the new algorithm can reduce the dependency of domain knowledge and the sensitivity of abnormal data points, that it can improve the effectiveness of clustering results in which data are distributed in different shapes and different densities, and that it can get a better clustering efficiency. The application of the new clustering algorithm demonstrates that data mining techniques can be used in geophysical data interpretation and can get meaningful and useful results, and that the new clustering algorithm can be used in other real-world applications. 相似文献
265.
266.
Koen De Ridder 《Boundary-Layer Meteorology》2010,134(2):257-267
In the roughness sublayer (RSL), Monin–Obukhov surface layer similarity theory fails. This is problematic for atmospheric
modelling applications over domains that include rough terrain such as forests or cities, since in these situations numerical
models often have the lowest model level located within the RSL. Based on empirical RSL profile functions for momentum and
scalar quantities, and scaling the height with the RSL height z
*, we derive a simple bulk transfer relation that accounts for RSL effects. To verify the validity of our approach, these relations
are employed together with wind speed and temperature profiles measured over boreal forest during the BOREAS experimental
campaign to estimate momentum and heat fluxes. It is demonstrated that, when compared with observed flux values, the inclusion
of RSL effects in the transfer relations yields a considerable improvement in the estimated fluxes. 相似文献
267.
Errors and correction of precipitation measurements in China 总被引:2,自引:0,他引:2
In order to discover the range of various errors in Chinese precipitation measurements and seek a correction method, 30 precipitation evaluation stations were set up countrywide before 1993. All the stations are reference stations in China. To seek a correction method for wind-induced error, a precipitation correction instrument called the "horizontal precipitation gauge" was devised beforehand. Field intercomparison observations regarding 29,000 precipitation events have been conducted using one pit gauge, two elevated operational gauges and one horizontal gauge at the above 30 stations. The range of precipitation measurement errors in China is obtained by analysis of intercomparison measurement results. The distribution of random errors and systematic errors in precipitation measurements are studied in this paper. A correction method, especially for wind-induced errors, is developed. The results prove that a correlation of power function exists between the precipitation amount caught by the horizontal gauge and the absolute difference of observations implemented by the operational gauge and pit gauge. The correlation coefficient is 0.99. For operational observations, precipitation correction can be carried out only by parallel observation with a horizontal precipitation gauge. The precipitation accuracy after correction approaches that of the pit gauge. The correction method developed is simple and feasible. 相似文献
268.
A water quality investigation was carried out in the Deoria district, Ganga plain, to assess the suitability of surface and
groundwaters for domestic, agricultural, and industrial purposes. As much as 50 representative samples from river and groundwater
were collected from various stations to monitor the water chemistry of various ions, comprising Ca2+, Mg2+, Na+, K+, HCO3
−, SO4
2−, NO3
−, Cl−, F−, and trace metals, such as Fe, Cu, Mn, Zn, Cd, and Pb. The results showed that electrical conductance (EC), total dissolved
solids (TDS), HCO3
−, Mg2+, Na+, and total hardness (TH) are above the maximum desirable limit, and apart from Fe and Mn all other trace metals are within
the maximum permissible limit for drinking water. The calculated values for sodium absorption ratio (SAR), salinity, residual
sodium carbonate (RSC), and permeability index (PI) indicate well to permissible use of water for irrigation. High values
of Na%, RSC, and Mg-hazard (MH) at some stations restrict its use for agricultural purpose. Anthropogenic activities affect
the spatial variation of water quality. Economic and social developments of the study area is closely associated with the
characteristics of the hydrological network. 相似文献
269.
Dissolved proteins in seawater samples collected from a coastal area of Tokyo Bay, Sagami Bay and a location off the Kuroshio
Current were investigated by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and high
resolution two-dimensional electrophoresis (2-DE). Four to nine protein bands were detected in SDS-PAGE in the apparent molecular
weight (MW) range from 12 kilo Dalton (kDa) to 49 kDa. The 2-DE technique distinguished 10 to 46 protein spots exhibiting
isoelectric point (pI)/MW ranging 4.3–9.2/12–63 kDa. The elecrophoretic patterns were similar between the coastal and pelagic samples, as well
as previously reported patterns from various pelagic areas. The close similarity of electrophoretic mobility on both SDS-PAGE
and 2-DE gels indicates the compositional homogeneity of dissolved proteins in seawater throughout a broad range of marine
environments. Proteinaceous dissolved organic matter (DOM) that was unresolved and smeared staining characteristics on both
SDS-PAGE and 2-DE gels was first observed in Tokyo Bay waters in the present study and its possible sources are discussed.
Although the two protein species, 48 kDa and 39 kDa proteins, have been identified as homologues of Porin P and low molecular
weight-alkaline phosphatase of Pseudomonas aeruginosa PAO1, respectively, four strains of P. aeruginosa and two species of Pseudomonas spp. have been newly identified as the source organisms of these proteins using the N-terminal amino acid sequence data determined in previous studies. 相似文献
270.