地球对太阳风暴的响应

太陽風的帶電粒子進入地球磁層的動態示意圖太陽風的帶電粒子如何進入地球磁層SolarwindparticlesarenotabletopenetratetotheEarth'ssurfacebutareforcedbythemagneticfieldtomovearoundtheEarth.ParticlesgainentrythroughthecuspsthatareshapedlikefunnelsoverthepolarregionsortheygainentryfardownstreamfromtheEarth.TheparticlesthatenterdownstreamtraveltowardtheEarthandareacceleratedintothehigh-latitudeionosphereandproducetheauroralovallightshows.OtherhigherenergyparticleradiationthatcouldposeadangertolifehereonEarth,isforcedtodriftaroundtheEarthwithintwolargedonut-shapedregionscalledtheradiationbelts.Invisiblemagneticfieldsarethereasonthatparticleradiationmovesinthisway.

上圖為用於表示磁暴強度的DST指數，此圖為2003年11月的磁暴紀錄，其中曲線大幅陡降處為磁暴的發生。其地磁變化幅度達500nT(nano-Tesla)，是少見的強磁暴事件。極光與磁副暴磁副暴發生時才會出現的明曜區域右圖為POLAR衛星以可見光拍攝的極光橢圓圈(圖上的亮環)，地球左上半球的明亮範圍是太陽光照射所致。POLAR以可見光拍攝之極光橢圓圈在磁副暴發生時的發展過程人造衛星POLAR以極紫外波段(Ultraviolet)拍攝的極光於磁副暴發生時發展的過程，依序由左上向右，再由左下向右。人造衛星POLAR以極紫外波段(Ultraviolet)拍攝的極光活動性之動態過程磁副暴發生時POLAR衛星以X射線波段拍攝的南極上空極光之活動性2005/11/20地磁暴期間，磁副暴發生時極區磁場變化情形，圖中的極光橢圓圈區磁擾動指數分別有AU,AL,AE=AU-AL,AO=(AU+AL)/2等四種指數。電離層對地磁暴的反應Theatmosphere'sionizationlayersmakepossiblelongdistanceradiocommunicationbyreflectingtheradiowavesbacktoEarth.Theyalsoarehometotheauroraandthemega-amperecurrentsthatheattheatmosphereathighlatitudesduringgeomagneticallyactivetimes.Duringstormsdepletionsandenhancementsofionizationoccurdependingonthelocaltimeandgeographicallocation.Depletionsareparticularlyeffectiveatcausingproblemswiththenormaloperationofradiocommunications.精品课件！精品课件！Themovieisa24-hourlongsimulationofthetotalelectroncontentinacolumnabovetheEarth'ssurface(between100and400kmaltitude)duringtheApril10-11,1997ionosphericstormevent.Thisstormoccurredinassociationwithamagneticstormthatbeganinnear-Earthspaceat~21UTonApril10duetothearrivalofacoronalmassejectionfromt