550～600 km高度上热层大气密度的中长期变化

选用了2005年8月20日至2006年7月28日高度550～600 km附近的热层大气密度探测数据,对表征太阳活动的F10.7值和表征地磁活动强度的Ap指数进行了相关特性的统计.分析结果表明,在无明显地磁扰动时热层大气密度日平均值的涨落呈现27日和准半年的周期性变化,但在地磁扰动期间这种变化的周期性会被削弱,且大气密度的周日变化幅度与F10.7值呈正相关关系.     

2005年8月24日强磁暴事件对高层大气密度的扰动

对2005年8月24日发生的突发型强磁暴(Kp峰值达到9)事件,利用星载大气密度探测器在轨实时的连续探测数据进行了处理和分析.结果表明,此次强磁暴事件期间,引起560 km高度附近大气密度剧烈扰动,并存在着两种响应过程.一种是跟随地磁扰动程度变化的全球性大气密度涨落变化,响应时间滞后6h左右, 最大涨落变化比为2.5;另一种为磁暴峰期出现在高纬地区的大气密度突发性跃增,增变比高达5.5.后者存在着区域上的不对称性及时间上的突发性和增幅的差异.此次强磁暴峰期还同时出现了南北半球高纬地区的大气密度跃增双峰.同时还表明这种增变峰可能存在着由高纬向低纬地区迅速推移的现象,在中纬地区推移速度可达15°/h(纬度)左右.      

在强地磁活动期间热层大气成份和密度的变化

选用了１９７４－０７－０６,１９８２－０３－０２和１９８２－０９－０６三次强地磁活动时的Ａｐ值,由ＡＥ－Ｃ和ＤＥ－Ｂ卫星所测得的热层成份数据,进行统计分析,结果表明;在强地磁活动期间,热层大气密度涨落变化十分清晰、涨幅随高度增高而增大,高度６００ｋｍ附近涨幅可直达４倍,热层大气成份中Ｎ２的数密度涨幅最大,而原子氧的丰度在强地磁活动期间明显地下降。     

The thermospheric composition different responses to geomagnetic storm in the winter and summer hemisphere measured by “SZ” Atmospheric Composition Detectors

Three “SZ” Atmospheric Composition Detectors (ACDs) on board spacecraft “SZ-2”, “SZ-3” and “SZ-4” were launched on 10th January 2001, 26th March 2002 and 31st December 2002 separately. A large quantity of thermospheric composition data at the orbital altitude ranging from 330 to 362 km were collected from the in-situ measurement of ACDs. The spacecrafts’ lifetime was just in the second peak period of the 23rd solar cycle which includes two peaks and the solar activity value F_10.7 was from 89 to 228. During this period, several intense geomagnetic disturbances happened.     

神舟二号大气密度探测器的探测结果Ⅱ.在太阳和地磁扰动期间高层大气密度的变化

选用了Sz—2大气密度探测器在2001年2—4月间的探测数据,进行日照和阴影区域热层大气密度对太阳和地磁活动程度的响应变化的探讨．结果表明,日照区大气密度峰值主要随F10.7值而变,在地磁扰动期间,阴影区大气密度对扰动的响应更明显,通常响应变化开始于高纬度地区,然后向低纬度地区推移．     

神舟4号大气成分探测的新结果

神舟4号（SZ-4）大气成分探测器搭载在SZ-4留轨舱上于2002年12月30日发射入轨,在在轨运行的前3个多月中,正值地球南半球处于夏半球季节,并发生了多次中低强度的地磁扰动事件,SZ-4大气成分探测器测得了轨道舱运行高度上（330-362 km附近）大气成分的响应变化和异常现象新结果.探测数据表明,中低强度的地磁扰动事件也能引起热层大气中主要成分O和N₂的数密度值增高的响应变化.同样在进入地磁扰动峰期后较高纬度处出现了N₂的异常增变和O的异常降变以及大气密度异常扰动的现象,但此期间所出现异常现象的地域与SZ-3和SZ-2大气成分探测器探测结果相反,它仅位于南半球较高纬度地区.     

SOME RESULTS OF UPPER ATMOSPHERIC COMPOSITION MEASUREMENTS BY A MASS-SPECTROMETER ON BOARD "SZ-2":CHANGE OF COMPOSITIONS DURING SOLAR AND GEOMAGNETIC DISTURBANCES

Upper atmosphere composition data were obtained for the last half year with a quadruple mass spectrometer on board spacecraft "SZ-2" launched on 10 Jan uary 2001. Based on the analysis of these data, the variations of atmospheric compositions in solar and geomagnetic quiet conditions are reported first, then a detailed discussion on the atmospheric composition variations under the so lar and geomagnetic disturbed conditions is given. The results show that near the altitude of 400 km the variations of main atmospheric compositions corre sponding to solar disturbances are more remarkable in the sunlit area than in the shade area. On the contrary, in geomagnetic disturbance events the corre sponding variations are more obvious in the shade area, an evident increase of N2 density at relatively higher latitudes was observed.     

神舟2号大气密度探测器的探测结果(Ⅰ)日照和阴影区域热层大气密度变化

选用了神舟2号(SZ-2)大气密度探测器在2001年2—4月间的探测数据,进行日照和阴影区域热层大气密度变化的探讨.结果表明:在高度410km附近,日照和阴影区域大气密度变幅为2—3倍,变幅的大小与地磁活动程度呈负相关关系.日照面大气密度峰区位于星下点地方时1400—1500LT的纬度处,峰值大小与太阳活动程度呈正相关关系.阴影面大气密度谷区位于星下点地方时0400-0500的纬度处,同时在±10°纬度区域中还出现了阴影面峰区.     

1989年3月太阳活动引起的强烈磁暴群

本文分析了1989年3月上旬一个太阳超级活动区中多次特大耀斑引起的强磁暴群.联系源耀斑的等级、位置等讨论了磁暴形态特征.随着耀斑活动区位置由东向西旋转,磁暴的形态呈现有规律的变化,充分显示了磁暴形态特征有依赖于耀斑位置的中心子午线效应和东西不对称性.     

神舟3号运行高度上大气密度的变化

神舟3号(SZ-3)大气密度探测器搭载在SZ-3留轨舱上于2002年3月发射入轨,在轨运行期间获得了轨道舱运行高度范围(330-410km)内的大气密度数据.数据分析表明,无明显太阳和地磁扰动时,热层大气密度的主要变化之一是日照和阴影区域之间的涨落变化,最大涨落变化比约为3.0,变化比与太阳和地磁活动程度有关.在2002-04-17和2002-04-19的强地磁扰动时,全球热层大气密度上涨,同时在磁扰峰期探测获得30°N-40°N区域出现密度扰动异常现象.对强地磁扰动在运行轨道高度上大气密度最大涨幅约为60%左右,响应过程在时间上要比地磁扰动过程滞后6-7h,日照和阴影区域中大气密度的响应变化程度明显不同.在太阳活动程度发生变化时,热层大气密度会呈现出明显的正相关变化关系.     

"神舟三号"大气成分探测器探测结果--2002年4月磁暴期间大气成分的异常变化

"神州三号"(SZ-3)大气成分探测器搭载在SZ-3留轨舱上于2002年3月26日发射入轨,正遇2002年4月发生的连续两次地磁扰动事件,SZ-3大气成分探测器测得了轨道舱运行高度上(330-350 km附近)大气成分的响应变化和异常现象.探测数据表明,在地磁扰动期间,不仅发生了大气中主要成分O和N2的数密度值增变的响应变化,而且在进入地磁扰动峰期开始后6h左右在较高纬度处出现了N2的异常增变和O的异常降变.4-5h后,这种异常增变峰和降变谷由纬度42°N左右逐渐推移向纬度较低地区,直至消失.     

强磁暴、能量粒子暴与热层大气密度涨落之间的相关关系

利用1997-2007年由GOES8, GOES11和GOES12星载高能粒子探测器在地球同步轨道高度上所探测到的高能质子和高能电子通量探测数据以及高度560km左右星载大气密度探测器所得的热层大气密度探测数据, 统计分析了强地磁扰动、高能粒子通量跃变和热层大气密度涨落之间的相关关系, 初步获得强地磁扰动期间, 地球同步轨道(外辐射带外环)均出现了增幅大于三个数量级的高能质子通量(尤其是E>1MeV)强增强现象, 随后热 层大气密度强烈上涨, 表明三者之间是正相关关系. 在时间上地球同步轨道高能质子通量强增强现象先于日均Ap值(地磁活动程度)上涨约一天左右, 而热层大气密度强涨落现象又明显滞后于强地磁扰动事件.     

2007-2009谷年期间高热层大气密度的变化

在第23至第24太阳活动周的峰年之间,太阳活动谷年具有持续时间长,极低F_10.7太阳辐射通量（低至65）和超长期的零太阳黑子数记录等特点,因此是观测和研究在这种特殊背景下热层大气变化的极好机会.尤其是能充分理解和掌握在宁静环境下热层大气密度对弱太阳活动和小地磁扰动的响应特性.本文利用高度650 km以上星载大气密度探测器2007—2009年的连续探测数据进行分析,结果表明,在太阳辐射通量F_10.7极低值期间,较高热层大气密度对F_10.7的起伏具有更显著的响应变化.当F_10.7由70降至65时,日均大气密度会有4～5倍的显著降变,远大于通常大气模式中的降变值.同样在F_10.7极低值期间,较高热层大气密度对小地磁扰动也具有显著的响应增变,当日K_p指数之和由23增至30时,较高热层大气密度则会有80%～160%的强增变.     

Long-term changes in indices of geomagnetic activity at the auroral station Sodankylä

Here we compare the traditional analog measure of geomagnetic activity, Ak, with the more recent digital indices of IHV and Ah based on hourly mean data, and their derivatives at the auroral station Sodankylä. By this selection of indices we study the effects of (i) analog vs. digital technique, and (ii) full local-time vs. local night-time coverage on quantifying local geomagnetic activity. We find that all other indices are stronger than Ak during the low-activity cycles 15–16 suggesting an excess of very low scalings in Ak at this time. The full-day indices consistently depict stronger correlation with the interplanetary magnetic field strength, while the night-time indices have higher correlation with solar wind speed. The Ak index correlates better with the digital indices of full-day coverage than with any night-time index. However, Ak depicts somewhat higher activity levels than the digital full-day indices in the declining phase of the solar cycle, indicating that, due to their different sampling rates, the latter indices are less sensitive to high-frequency variations driven by the Alfvén waves in high-speed streams. On the other hand, the night-time indices have an even stronger response to solar wind speed than Ak. The results strongly indicate that at auroral latitudes, geomagnetic indices with different local time coverage reflect different current systems, which, by an appropriate choice of indices, allows studying the century-scale dynamics of these currents separately.     

1991年6月地磁扰动—地面和同步高度特征

给出了1991年6月地磁扰动的地面和同步高度特征及引起这些扰动的可能的源.在长达近对天的扰动过程中，出现四次主相强度不同的磁暴和多次强急始，有的磁暴由多次扰动迭加而形成形态复杂的复合型磁暴·同步高度Hq分量多次出现反相.这些特征很可能主要是对广大的行星际空间多个高速度高密度结构的响应，这些结构有时伴随大尺度强南向磁场分量.     

Temporal variation of the arterial pressure in healthy young people and its relation to geomagnetic activity in Mexico

We present a study of the temporal behavior of the systolic (SBP) and diastolic (DBP) blood pressure for a sample of 51 normotensive, healthy volunteers, 18 men and 33 women with an average age of 19 years old in Mexico City, Mexico, during April and May, 2008. We divided the data by sex along the circadian rhythm. Three geomagnetic storms occurred during the studied time-span. The strongest one, a moderate storm, is attributed to a coronal hole border that reached the Earth. The ANOVA test applied to the strongest storm showed that even though we are dealing with a moderate geomagnetic storm, there are statistically significant responses of the blood pressure. The superposed epoch analysis during a three-day window around the strongest storm shows that on average the largest changes occurred for the SBP. Moreover, the SBP largest increases occurred two days before and one day after this storm, and women are the most sensitive group as they present larger SBP and DBP average changes than men. Finally, given the small size of the sample, we cannot generalize our results.     

A study on possible solar and geomagnetic effects on the precipitation over northwestern Argentina

The precipitation over Tucuman (26.8°S; 65.2°W), which is representative of the Northwestern region of Argentina, is analyzed in search of an association with solar and geomagnetic activity, with the purpose of contributing to the controversial issue on the connection between climate variation and anthropogenic vs. natural forcing. Monthly time series of precipitation, sunspot number (Rz), and aa index were used for the period 1884–2010. A wavelet analysis was performed first which, due to the time series length, shows significant results only for periodicities lower than 32 years. Due to the transient character and non-constant phase of the results, any sustained wavelet coherence between precipitation and either sunspots or aa could be noticed. Moving averages and correlations were also assessed. The 11 and 22-year running mean of precipitation is positively correlated to Rz and aa when the whole period of analysis is considered. However, a shift in the long-term behavior of precipitation is noticed around 1940, which implies different correlation values with Rz and aa when the period before or after this year are considered. The solar cycle length is also considered for this statistical study and partly confirms the results obtained with Rz and aa. We propose plausible physical explanations based on geomagnetic activity and total solar irradiance effects over atmospheric circulation that could support the statistical result. A deeper analysis and broader geographical coverage is needed in order to detect a connection between precipitation and solar variability discernible from greenhouse gases effects. We emphasize the idea of the importance of recognizing and quantifying the different forcing acting on precipitation (or any other climate parameter), which sometimes can be barely evident from a solely statistical analysis.