好朋友,你的手干净吗?——美国秘密调查沙特王室与恐怖资金渠道

有人曾为“9·11”劫机分子支付房租,而租金却是来自沙特王子帐户的神秘支票。人们不禁要问:沙特王室在其中扮演了什么角色?可以肯定的是,布什政府不希望外界知晓调查的内幕。 2000年新年伊始,两名“基地”组织成员抵达洛杉矶国际机场,并受到了热情接待。这两个人名叫纳尔夫‘阿尔哈兹米和卡利德·阿尔米德哈尔。当时,他们只是两名来美国寻找栖身之地的沙特青年。而一年半之后,他们却参与了劫持美国航空公司77号航班的行动,并驾驶该机撞向五角大楼。

Response of magnetic fields at geosynchronous orbit and on the ground to the sudden changes of IMF B_Z

The rapid change in the Earth’s magnetosphere caused by solar wind disturbances has been an important part of the solar wind-magnetosphere interaction.However most of the previous studies focused on the perturbation of the Earth’s magnetic field caused by solar wind dynamic pressure changes.In this paper,we studied the response of geosynchronous magnetic field and the magnetic field to the rapid southward turning of interplanetary magnetic field during the interval 1350 1420 UT on 7May 2007.During this event,BZ component of the interplanetary magnetic field decreased from 15 nT to 10 nT within 3 min(1403 1406 UT).The geosynchronous magnetic field measured by three geosynchronous satellites(GOES 10 12)first increased and then decreased.The variations of magnetic field strength in the morning sector(9 10 LT)were much larger than those in the dawn sector(5 LT).Meanwhile,the H components of geomagnetic field on the ground have similar response features but exhibit latitude and LT dependent variations.Compared with H components,the D components do not have regular variations.Although the solar wind dynamical pressure encounters small variations,the magnetic field both in space and on the ground does not display similar variations.Therefore,the increase of geomagnetic field in the dawn sector is caused by the southward turning of IMF(interplanetary magnetic field)BZ.These results will help to better understand the coupling process of geomagnetic filed and interplanetary magnetic field.

SuperDARN CUTLASS Finland radar observations of high-latitude magnetic reconnections under northward interplanetary magnetic field (IMF) conditions

A number of backscatter power enhancement events with ＂equatorward-moving radar auroral forms＂ in the high-latitude ionosphere were observed by SuperDARN CUTLASS Finland radar when the IMF was northward during 09：00 -10：00 UT on 26 March 2004. These events were also associated with sunward flow enhancements at each location in the Northern Hemisphere which were shown in ionospheric convections measured by the SuperDARN radars. These are typical features of high-latitude （lobe） magnetic reconnections. The durations of the velocity enhancements imply that the evolution time of the lobe reconnec- tions is about 8-16 rain from their origin at the reconnection site to their addition to the magnetotall lobe again. In additional, the Double Star TC-1 spacecraft was moving from magnetosheath into magnetosphere, and crossing the magnetopause near the subsolar region during this interval, and observed typical low-latitude magnetic reconnection signatures. This infers that the dayside high- and low-latitude reconnections may occur simultaneously.

Some properties of field-aligned electron events in high-altitude polar regions

Using data from the Cluster spacecraft from January 2003 to December 2004, we perform a statistical study on some properties of the field-aligned electron(FAE) events and interplanetary magnetic field(IMF) By dependence of FAE events with different durations in high-altitude polar regions. A total of 1335 FAE events were observed by the C3 spacecraft. More down-flowing events were observed in the Southern Hemisphere, and more up-flowing events were observed in the Northern Hemisphere. It proves that down-flowing events mainly originate from magnetosphere or solar wind and up-flowing events are mainly derived from ionosphere. Short-lifetime events showed a morning concentration in the magnetic local time distribution, and long-lifetime events were concentrated both before and after noon. For the IMF By dependence of the FAE events, short-lifetime events were much affected by IMF By and resulted in a morning concentration, while the long-lifetime events were almost unaffected by IMF By. With further analysis, we determined that the short-lifetime and long-lifetime events had different sources.