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801.
Deliang CHEN Tinghai OU Lebing GONG Chong-Yu XU LI Weijing Chang-Hoi Ho QIAN Weihong 《大气科学进展》2010,27(6):1221-1232
Climate research relies heavily on good quality
instrumental data; for modeling efforts gridded data are needed. So
far, relatively little effort has been made to create gridded
climate data for China. This is especially true for high-resolution
daily data. This work, focuses on identifying an accurate method to
produce gridded daily precipitation in China based on the observed
data at 753 stations for the period 1951--2005. Five interpolation
methods, including ordinary nearest neighbor, local polynomial,
radial basis function, inverse distance weighting, and ordinary
kriging, have been used and compared. Cross-validation shows that
the ordinary kriging based on seasonal semi-variograms gives the
best performance, closely followed by the inverse distance weighting
with a power of 2. Finally the ordinary kriging is chosen to
interpolate the station data to a 18 km×18 km grid system
covering the whole country. Precipitation for each 0.5o×0.5o latitude-longitude block is then obtained by averaging
the values at the grid nodes within the block. Owing to the higher
station density in the eastern part of the country, the
interpolation errors are much smaller than those in the west (west
of 100oE). Excluding 145 stations in the western region, the
daily, monthly, and annual relative mean absolute errors of the
interpolation for the remaining 608 stations are 74%, 29%, and
16%, respectively. The interpolated daily precipitation has been
made available on the internet for the scientific community. 相似文献
802.
The Role of Land–sea Distribution and Orography in the Asian Monsoon. Part I: Land–sea Distribution 总被引:3,自引:3,他引:0
A number of AGCM simulations were performed by including various land--sea
distributions (LSDs), such as meridional LSDs, zonal LSDs, tropical
large-scale LSDs, and subcontinental-scale LSDs, to identify their effects
on the Asian monsoon. In seven meridional LSD experiments with the
continent/ocean located to the north/south of a certain latitude, the LSDs
remain identical except the southern coastline is varied from 40o to
4oN in intervals of 5.6o. In the experiments with the coastline
located to the north of 21oN, no monsoon can be found in the subtropical
zone. In contrast, a summer monsoon is simulated when the continent extends
to the south of 21oN. Meanwhile, the earlier onset and stronger
intensity of the tropical summer monsoon are simulated with the southward
extension of the tropical continent. The effects of zonal LSDs were
investigated by including the Pacific and Atlantic Ocean into the model
based on the meridional LSD run with the coastline located at 21oN. The
results indicate that the presence of a mid-latitude zonal LSD induces a
strong zonal pressure gradient between the continent and ocean, which in
turn results in the formation of an East Asian subtropical monsoon. The
comparison of simulations with and without the Indian Peninsula and
Indo-China Peninsula reveals that the presence of two peninsulas remarkably
strengthens the southwesterly winds over South Asia due to the tropical
asymmetric heating between the tropical land and sea. The tropical zonal LSD
plays a crucial role in the formation of cumulus convection. 相似文献
803.
冈底斯造山带两套不同成矿体系的含矿斑岩对比研究 总被引:4,自引:1,他引:3
Cu(Mo、Au)矿化和Pb-Zn-Ag矿化分别是冈底斯成矿带南缘和北缘最重要的成矿作用,目前在冈底斯南缘发现了长达350km、宽40km的斑岩铜矿带,对该成矿带铜矿化及相关斑岩已有深入研究,而北缘的Pb-Zn-Ag矿化及相关斑岩还刚为人们所认识。纳如松多银铅锌矿是冈底斯北缘Pb-Zn-Ag矿化带的典型矿床之一,并出露未风化的斑岩。与冈底斯南部铜矿带斑岩相比较,纳如松多斑岩具有高Si,低Ti、Ca、Mg和极度贫Na的特点;总体上富集Th、U等大离子亲石元素,而Ba、Sr、P等元素则明显亏损;稀土元素配分模式为略微右倾的燕型模式,轻、重稀土元素分异不明显,具有明显的Eu负异常。纳如松多斑岩与林子宗群典中组火山岩在空间上和时间上具有非常紧密的联系,整体上也具有较为相似的地球化学特征,应与典中组火山岩具有相同的岩浆起源,即主碰撞期后仍然残留的新特提斯洋板片及卷入的陆源沉积物的部分熔融形成的原始岩浆;原始岩浆经过约75%的斜长石分离结晶后,在主碰撞期典中组火山岩喷发后上侵形成纳如松多斑岩。 相似文献
804.
辽上金矿床位于胶东新发现的胶莱盆地东北缘成矿区之内,为胶东东部首例特大型金矿。矿区金成矿以充填作用为特征,载金矿物主要为自形—半自形结构黄铁矿和白云石,以网脉状、细脉状、微细脉状黄铁矿白云石细脉形式出现于岩石碎裂隙中,或以黄铁矿白云石大脉状充填于断裂构造中。矿石包括含金黄铁矿白云石脉型和含黄铁矿白云石脉蚀变岩型2大类。通过对比认为,该矿床为一新类型,即黄铁矿白云石脉型金矿床。这一新类型特大型金矿的发现,预示着胶莱盆地边缘地区具有较好的找矿前景,尤其在金牛山地区应有可能在短期内取得更大的找矿突破。 相似文献
805.
论证了柴里矿区现代地应力场为大地静力场型,指出地应力研究的工程意义,通过层位,实践,经济效益几方面的对比,指出三灰是二水平主干岩层位选择的最佳层位。 相似文献
806.
807.
详细地研究了亳县陨石中的主要标型特征。亳县陨石是一块不平衡的普通球粒陨石 ,球粒结构齐全 ,保持原始信息多。对球粒中出现的 2 6种结构类型进行了合理的解释 ,为讨论球粒成因提供了科学依据。对亳县陨石中的几种特殊的标型矿物——指示强还原环境生成的标型矿物张衡矿、指示高压的标型矿物 Wadsleyite和指示高温凝聚产物的标型矿物亚铁尖晶石及 CAI包体的发现均作了详细的研究与讨论。 相似文献
808.
SEASONAL VARIATIONS OF CONVECTIVE ACTIVITIES OVER THE SOUTH CHINA SEA AND ITS NEIGHBORHOOD AND THEIR COMPARATIVE ANALYSES IN THE STRONG AND WEAK CONVECTION YEARS* 下载免费PDF全文
The seasonal variations of convective activities over the South China Sea(SCS) and its neighborhood.as well as the similarities and differences of convection in the different key regions during the strong and weak convection years are analyzed by using the pentad data of TBB from 1980 to 1993.The results show that in winter and summer the seasonal variations of the convective activities are synchronous over the SCS and its neighborhood,the anomalous convection amplitudes are obviously different in different regions.The significant extents of convective activities have somewhat seasonal differences in the strong and weak convection years.In the strong convection years,it is in winter,spring and autumn that the convection anomaly is more evident than that in the normal years,however,after the summer monsoon onset the convection is sustained.stable and similar to that in the normal years.In the weak convection years.the convection weakens greatly in each season.but the primary weakening occurs in spring.summer and autumn.No matter in the strong or the weak convection years.the convective activities are somewhat of difference in the Bay of Bengal.the Indochina Peninsula.the SCS and the Philippines.In addition.the convective activities are also different over the south and the north parts of the SCS.the convection variation in the strong year is similar to that in the weak year over the north part of the SCS.but over the south part there are great differences. 相似文献
809.
I. INTRODUCTIONThe Yellow River is a heavily sediment--laden river. The sediment load of the Yellow River ranks the first in the world while its annual runoff is only of medium size. Toharness the river, it is necessary to build reservoirs for regulating runoff to meet the demands of economic development. Since the founding of PRC in 1949, I S4 large and medium--sized reservoirs have been constructed on the main stem and the tributaries with atotal storage capacity of 84.5 billion m3.… 相似文献
810.