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A diagnostic analysis is performed of the quasi-biennial oscillations during the ENSO cycle and
the results are based to study the interactions between ENSO and the Asian monsoons. It shows that the Asian
monsoons have significant influence on the ENSO cycle on the quasi-biennial scale. Materialized through the
onset and southward progression of the winter monsoon, the influence appears in the tropical western Pacific to
excite severe convection and to further affect the ENSO cycle. The phenomenon is not only reflected in the
quasi-biennial mode but the annual variation of the Asian winter monsoon in reality. 相似文献
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基于岩性光谱特征的雄安新区地面古河道识别研究 总被引:1,自引:0,他引:1
雄安新区地面古河道与河漫滩岩性分别以砂土和黏性土为主,两种岩性所含矿物成分对电磁波的反射率不同。将地表岩性调查与光谱采集分析相结合,捕捉了这两种岩性在遥感影像中反射光谱的差异,在此基础上识别了古河道,并利用钻孔数据加以验证分析。结果表明:雄安新区表层砂土和黏性土在TM影像B5波段的DN值差值最大,该波段可作为识别河道砂体的必选波段;综合考虑波段信息量、波段之间信息重复程度,R(4)G(5)B(1)组合下河道砂体的形迹清晰可辨;钻孔数据与遥感解译结果吻合,岩心揭露的古河道发育深度在3.2~8.7 m之间;研究区古河道总体较发育,河道宽度多在0.5~2.0 km之间,多处分叉和汇聚后呈辫状河形态,河网密度约0.26 km/km~2;钻孔剖面显示河道地势高于河漫滩,属条状高地型古河道,河道有"游荡"痕迹;古河道的发育位置控制着区内居民地的分布。 相似文献