1013号超强台风“鲇鱼”北折路径分析

应用日本JMA数值产品的格点资料和实况场分析资料,重点对1013号超强台风"鲇鱼"西行进入南海后发生近90°直角转向偏北移动,直至登陆福建的这一阶段路径进行分析。"鲇鱼"先是受位于华南的西环大陆副高引导,向西南西移动,之后转受加强北上的赤道高压引导,折向北到北偏东方向移动,最后受东环副高引导北偏西行至登陆福建。在这3个主要影响系统的先后转换过程中,分析500 hPa台风环流风场不对称分布可明显看到,"鲇鱼"受到不同天气系统的影响时,台风风场中最大风速区的位置也随之发生相应变化,因此"鲇鱼"出现了曲折多变的复杂路径。

Evaluation of Atmospheric Circulation in the Southern Hemisphere in 20CRv2

Evaluation of the mean climate and climate variability in the Southern Hemisphere （SH） in the Twentieth Century Reanalysis data version 2 （20CRv2） is conducted and the results are compared with the NCEP/NCAR version 2 Reanalysis data （NCEPv2） and the Hadley Center sea-level pressure data （HadSLPv2）.The results show that SH polar High,SH subtropical High,upper level split jet,cross-equatorial flow,Antarctic Oscillation （AAO）,and the pattem of Pacific-South-America （PSA） has been effectively captured by 20CRv2 during 1979-2010,with an apparent zonal asymmetry of AAO in the austral winter （June-July-August,JJA）.The notable upward linear trend of AAO in the entire period of 1871-2010 is represented in both 20CRv2 and HadS1Pv2.The most remarkable discrepancy of the SH climate variability between 20CRv2 and HadSLPv2 occurred in 1897-1920 and was partly caused by such factors as the paucity of meteorological and oceanographic data in the SH to be assimilated,the handling of the specified sea-ice concentration in South Pole,and imperfect climate models.The consistency of these reanalysis data is increased with the use of a large amount of satellite observation and radiosonde data,particularly after 1979.

An Alternative Mode of Elimination of Resin from Epithelial Cells of Resin Ducts in Pinus sylvestris

The fine structure of resin secreting cells of the conical resin ducts in stem of Pinus sylvestris Carr.was studied with the help of high pressure freezing and freeze-substitution techniques. An unprecedented modeof resin elimination was observed. It seems that the hydrolase-contained Golgi vesicles take part in the dissolution of plasmalemma, and a passage is formed, through which resin material may quickly pass outside of theprotoplast. Then, the ruptured plasmalemma was repaired by some vesicles, possibly derived from Golgi bodies.

Occurrences of Wintertime Tropical Cyclones in the Western North Pacific under the Background of Global Warming

Using tropical cyclone （TC） observations over a 58-yr period （1949-2006） from the China Meteorological Administration, the 40-year ECMWF Reanalysis （ERA-40）, NCEP-NCAR reanalysis, and the Hadley Centre sea ice and sea surface temperature （HadISST） datasets, the authors have examined the behaviors of tropical cyclones （TCs） in the western north Pacific （WNP） in boreal winter （November-December-January-February）. The results demonstrate that the occurrences of wintertime TCs, including super typhoons, have decreased over the 58 years. More TCs are found to move westward than northeastward, and the annual total number of parabolic-track-type TCs is found to be decreasing. It is shown that negative sea surface temperature anomalies （SSTAs） related to La Nifia events in the equatorial central Pacific facilitate more TC genesis in the WNP region. Large-scale anomalous cyclonic circulations in the tropical WNP in the lower troposphere are observed to be favorable for cyclogenesis in this area. On the contrary, the positive SSTAs and anomalous anticyclonic circulations that related to E1 Nifio events responsible for fewer TC genesis. Under the background of global warming, the western Pacific subtropical high tends to intensify and to expand more westward in the WNP, and the SSTAs display an increasing trend in the equatorial eastern-central Pacific. These climate trends of both atmospheric circulation and SSTAs affect wintertime TCs, inducing fewer TC occurrences and causing more TCs to move westward.

Definition of the South China Sea summer monsoon onset

We analyze statistically different definitions of the South China Sea summer monsoon(SCSSM) onset are to establish a SCSSM onset time series that is more recognizable by a majority of indicators.With the acknowledged index,we determine a key area(105°E-112.5°E,7.5°N-12.5°N) and define the zonal wind component in this key area as a new SCSSM onset index,using daily mean reanalysis data of the National Center for Environmental Prediction/National Center for Atmospheric Research.The atmospheric circulations before and after the onset of the SCSSM determined using the index defined in this paper are preliminarily studied.Results show that the Somalia cross-equatorial flow is enhanced,the strongest westerly wind in the tropical Indian Ocean shifts northward,the cyclone couple in the Bay of Bengal and the Southern Hemisphere weaken and move eastward,convection over the South China Sea increases,and the subtropical high retreats from the South China Sea after the outbreak of the SCSSM.By analyzing the atmospheric circulation,it is found that in 1984 and 1999,the SCSSM broke out in pentads 29 and 23,respectively,which is consistent with the onset times determined using our index.