Role of snow depth in spring of Tibetan Plateau in onset of South China Sea summer monsoon

The role of snow depth of Tibetan Plateau in the onset of South China Sea summer monsoon and the influence of ENSO on snow depth of Tibetan Plateau are investigated with use of data from ECMWF reanalysis and NCEP/NCAR reanalysis. The results are as follows: (1) The snow depth data from ECMWF reanalysis are tested and reliable, and can be used to study the influence of snow depth of Tibetan Plateau on the onset of South China Sea summer monsoon; (2) Anomaly of snow depth of Tibetan Plateau causes anomaly in air temperature and its contrast between the Indian Ocean and the continent resulting in easterly wind anomaly over 500 hPa and hence as well as in the atmospheric circulation in the lower layer. For the year of negative anomaly of snow depth a westerly wind anomaly with a cyclone pair takes place, while for positive anomaly of snow depth an easterly anomaly occurs with an anticyclone pair; (3) While positive anomaly of SST occurs in the eastern Pacific Ocean, positive anomaly of air pressure also takes place over the eastern Indian Ocean and the South China Sea, causing stronger meridional pressure gradient between the ocean and continent and then westerly wind anomaly. At the same time, the atmospheric pressure increases in the northern Tibetan Plateau, northerly wind gets stronger, and subtropical front strengthens. All of these are favorable for snowfall over Tibetan Plateau.

基于GIS的黄河三角洲地面沉降研究及相关分析

黄河三角洲存在着不可忽视的地面沉降现象，并在一定程度上阻碍着三角洲的快速发展。对黄河三角洲地面沉降的研究在黄河三角洲防灾减灾、土地利用、河口河道治理等方面具有理论与实践指导意义。 本文收集了黄河三角洲地区1956年、1967年、1980年和1995年四个时期的1：5万地形图，提取高程信息，应用地理信息系统（GIS）软件生成数字高程模型并展开了相应的空间分析，得到各个时间段内黄河三角洲的地面沉降速率图，通过对各沉降速率图的统计分析得出了三角洲地区地面沉降的时空变化规律。文章继而分析了引发黄河三角洲地面沉降的三个主要诱导因子、它们在影响范围、作用时间、作用强度等方面的特点，以及在不同时间段内各诱导因子在引发地面沉降方面所发挥作用的主次。随后，在列举地面沉降对黄河三角洲产生的影响之后，归纳总结了防治地面沉降及其引发灾害的对策。最后，基于采用常规水准测量方法进行地面沉降监测费时费力，提出利用InSAR技术对黄河三角洲地面沉降进行监测的设想，并简要分析了其可行性。

Feeding and egg production of the planktonic copepod Calanus sinicus in spring and autumn in the Yellow Sea, China

Shipboard incubations were conducted in spring (April) and autumn (October/November) 2006 to measure the feeding and egg production rates (EPR) of Calanus sinicus in the Yellow Sea, China. The ingestion rate (2.08-11.46 and 0.26-3.70 mu g C female(-1) day(-1) in spring and autumn, respectively) was positively correlated with microplankton carbon concentrations. In the northern part of the Yellow Sea, feeding on microplankton easily covers the respiratory and production requirements, whereas in the southern part in spring and in the frontal zone in autumn, C. sinicus must ingest alternative food sources. Low ingestion rates, no egg production and the dominance of the fifth copepodite (CV) stage indicated that C. sinicus was in quiescence inside the Yellow Sea Cold Bottom Water (YSCBW) area in autumn. Calanus sinicus ingested ciliates preferentially over other components of the microplankton. The EPR (0.16-12.6 eggs female(-1) day(-1) in spring and 11.4 eggs female(-1) day(-1) at only one station in autumn) increased with ciliate standing stock. Gross growth efficiency (GGE) was 13.4% (3-39%) in spring, which was correlated with the proportion of ciliates in the diet. These results indicate that ciliates have higher nutrient quality than other food items, but the low GGE indicates that the diet of C. sinicus is nutritionally incomplete.