Weakening of Winter North Atlantic Oscillation Signal in Spring Precipitation over Southern China

In this study,the relationship between the North Atlantic Oscillation （NAO） in winter （DecemberFebruary） and the precipitation over southem China （SCP） in the following spring （March-May） was investigated.Results showed an interdecadal change,from strong to weak connection,in their connection.Before the early 1980s,they were highly correlated,with a strong （weak） winter NAO followed by an increased （decreased） spring SCP.However,after the early 1980s,their relationship was weakened significantly.This unstable relationship may be linked to the climatological change of East Asian jet.Before the early 1980s,the wave train along the Asian jet propagated the NAO signal eastward to East Asia and affected local upper-tropospheric atmospheric circulation.A strong NAO in winter led to an anomalous anticyclonic circulation at the south side of 30°N in East Asia in spring,resulting in an increase of SCP.In contrast,after the early 1980s,the wave train pattern along the Asian jet extended eastward due to strengthening of the climatological East Asian jet.Correspondingly,the NAO-related East Asian atmospheric circulations in the upper troposphere shifted eastward,thereby weakening the linkage between the spring SCP and the winter NAO.

Correlation,Regression and Path Analysis between Yield Traits and Yield of Yongyou No.9

[Objective] The research aimed to understand the high and efficiency technique in intersubspecific hybrid rice Yongyou No.9.[Method] We conducted the correlation analysis,regression analysis and path analysis of intersubspecific hybrid rice Yongyou No.9 based on the data of its ear,grain and weight at different yield levels.[Result]The performance of ear,grain and weight in Yongyou No.9 showed significant difference among different yield levels.The enhancement of effective ears would restrain the number of per ear total grains.It was found that the direct contributions of main economic traits to yield were determined to be per ear total grainseffective earseed setting rate1 000-grain weight.[Conclusion]The high-yield and effective cultivation techniques were suggested as follows：on the basis of certain effective ear number,grain number per ear should be mainly focused with a consideration to 1 000-grain weight.

Approach to the Ways for High-yielding Technique of Zhongzheyou No.8

[Objective] The paper was focused on the way how to increase the yield of hybrid rice Zhongzheyou No.8. [Method] The relationship among yield-related traits and their contribution to yield were investigated through correlation analysis, regression analysis and path analysis. [Result] The performance of ear, grain and weight in Zhongzheyou No.8 showed significant difference among yield levels. The enhancement of effective ears would restrain the number of total grains per ear. It was found that the direct contributions of main economic traits to yield were： number of fil ed grains per ear 〉 number of effective ears 〉1 000-grain weight 〉number of total grains per ear. [Conclusion] The promotion of high-yielding techniques was suggested as fol ows： on the basis of certain number of effective ears, number of fil ed grains per ear should be mainly focused with a consideration to grain weight.

Recent Changes of Northern Indian Ocean Summer Rainfall Based on CMIP5 Multi-Model

This study evaluates the simulation of summer rainfall changes in the Northern Indian Ocean (NIO) based on the fifth phase of Coupled Model Intercomparison Project (CMIP5). The historical runs of 20 CMIP5 coupled General Circulation Models (GCMs) are analyzed. The Multi-Model ensemble (MME) of the CMIP5 models well reproduces the general feature of NIO summer rainfall. For a short period 1979?2005, 14 out of 20 models show an increased trend in the mean rainfall and a similar spatial distri-bution to the Global Precipitation Climatology Project (GPCP) observations in MME. The increasing of the convergence in the equatorial IO results in the increase of rainfall significantly. The equatorial rainfall trend patterns seem modulated by the SST warm-ing in the tropical Indian Ocean, which confirm the mechanism of 'warmer-get-wetter' theory. For a long period 1950?2005, the trend of monsoon rainfall over India shows a decrease over the most parts of the India except an increase over the south corn er of the Indian Peninsula, due to a weakened summer monsoon circulation. The pattern is well simulated in half of the CMIP5 models. The rainfall over the north India is different for a short period, in which rainfall increases in 1979?2005, implying possible decadal varia-tion in the NIO summer climate.

从许杰的两封来信说开去

《上海鲁迅研究》2005年夏,季号所刊的《蒋径三先生年谱》和仇志琴同志撰的《蒋径三年谱简介》,阅后颇受启迪,并想起了20世纪80年代,许杰先生曾给我几封来信,现还珍藏着两封。许杰先生是华东师范大学的教授,鲁迅先生的好友。那时,因工作关系,笔者曾多次拜访许杰先生,或致信向他请教有关事宜.

Analysis of seasonal signals and long-term trends in the height time series of IGS sites in China

The seasonal signal and long-term trend in the height time series of 10 IGS sites in China are investigated in this paper. The offset detection and outlier removal as well as the removal of common mode error are performed on the raw GPS time-series data developed by the Scripps Orbit and Permanent Array Center(SOPAC). The seasonal-trend decomposition procedure based on LOESS(STL) is utilized to extract precise seasonal signals, followed by an estimation of the long-term trend with the application of maximum likelihood estimation(MLE) to the seasonally adjusted time series. The Up-compo- nents of all sites are featured by obvious seasonal variations, with significant phase and amplitude modulation on some sites. After Kendall's tau test, a significant trend(99% confidence interval) for all sites is achieved. Furthermore, the trends at sites TCMS and TNML have significant changes at epochs 2009.5384 and 2009.1493(95% confidence interval), respectively, using the Breaks For Additive Seasonal and Trend test. Finally, the velocities and their uncertainties for all sites are estimated using MLE with the white noise plus flicker noise model. And the results are analyzed and compared with those announced by SOPAC. The results obtained in this paper have a higher precision than the SOPAC results.

Calling underwater is a costly signal： size-related differences in the call rates of Antarctic leopard seals

It is proposed that where sexually selected vocal communication is an honest signal, the call production rate is predicted to change throughout the breeding season. Male leopard seals call underwater for many hours each day over their three- to four-month breeding season, and it is hypothesized that a decrease in calling rate would be associated with the declining body condition of smaller males. The calling rates of leopard seals were measured （N= 49 recordings） and com- pared between seals of different size classes throughout the breeding season. Male leopard seals produce their calls at more stable rates as they become larger. In this study, larger male leopard seals adopted a strategy of consistent underwater calling throughout the breeding season, whereas there was a breakdown in the calling stereotypy of the smaller males at its height. Toward the end of the breeding season, the smaller seals produced fewer calls in shortened calling bouts, and they took more rest periods. Therefore, underwater calling may represent an honest signal in the leopard seal. For marine mammals that call underwater, the production of repetitive sequences advertises the breath-holding ability of the caller to the listeners, and this ability may be related to male stamina and endurance, thus representing an honest signal that could be widespread in other species.