Observation of Equatorial Electrodynamics in Africa using AMBER Magnetometer Network

Observation of Equatorial Electrodynamics in Africa using AMBER Magnetometer NetworkEndawoke Yizengaw

Institute for Scientific Research, Boston College, USAMark Moldwin (Michigan University, USA),Alem Mebrahtu (Mekelle University, Ethiopia), Baylie Damtie (Bahir Dar University, Ethiopia), Fatma Anad (CRAAG, Algeria), and Cesar Mbane Biouele (University of Yaound I, Cameroon)2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09

2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09

Future direction Objectives of AMBER Project Initial results from AMBER magnetometer network OutlineWhy focus on Africa? 2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09


Equatorial plasma bubble occurrence rates measured by DMSP satellites (1989 2002)Why Africa?Burke et al., JGR, 2004

PAAMAFINFallFallFallBubbles occurrence at different longitudinal sectors using data from the AE-E satellite (Hei et al., 2005) Not confirmed from the ground yet!Why Africa?2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09


IHY-Africa 2009 meeting, Livingstone, Zambia, 06/09/09Electron Density, 1 Jun 08 @ 22:20 UTcourtesy of Odile de La BeaujardireRecent C/NOFS observation over Africa

Global Magnetometer network2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09


Objectives of AMBER Magnetometer ArrayTo address two fundamental areas of space physics: the processes governing electrodynamics of the equatorial ionosphere as a function of local time, longitude, magnetic activity, and season, and ULF pulsation strength and its connection with equatorial electrojet strength at low/mid-latitude regions.AMBER (African Meridian B-field Education and Research)2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09


JULIA 150-km vertical drift and magnetometer estimated drift velocity comparisonAugust December 20082009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09Drift Velocity Validation


2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09South AmericaAfricaDrift velocity comparison


Density response to the counter electrojet(08/09/08)(08/04/08)(08/10/08)2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09


2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09GPS TEC response to the counter electrojetTEC depleted at the middle of the day!


Toroidal and poloidal (compressional) mode of ULF wavesToroidal and compressional mode have north-south and east-west electric field perturbation in the ionosphere when it mapped along the field line, respectively.Toroidal mode can only have pointing vector along the magnetic field; while compressional mode have pointing vector both in the parallel and perpendicular directions of the magnetic field. The compressional ULF wave can propagate all the way down to the equatorial ionosphere right across the magnetic field.2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09Geomagnetic pulsation caused by ultra-low-frequency (ULF) wave


IHY-Africa 2009 meeting, Livingstone, Zambia, 06/09/09ULF wave observation at the Equator

IHY-Africa 2009 meeting, Livingstone, Zambia, 06/09/09ULF wave and density irregularity correlationcourtesy of Odile de La Beaujardire

2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09ULF wave and density irregularity correlation(Reddy et al., AG, 1994)Time series of Doppler frequency variation at three different altitudes, observed by 54.95 MHz coherent backscatter radar!


Future Direction during ISWI!2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09


2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09Future Direction!Current GPS coverageProposed to fill the gapAugmented with1hr LEO coverage2hr LEO coverage3hr LEO coverage


In conclusion, such multi-instrument observations in the African longitudinal sector, a region that has been devoid from ground-based instruments, will provide excellent opportunity to the scientific community to understand clearly the physics behind the unique ionospheric irregularities that has been often observed by flyby LEO satellites. The preliminary results presented here clearly shows that the ideal locations of AMBER magnetometers will play a key role in estimating the electrodynamics that control the equatorial ionospheric irregularities. Summary and Conclusion 2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09


Thank You! 2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09


2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09MALI GPS station on August 09, 2008

No major scintillation activity


2009 UN BSS & IHY Workshop, Daejeon, Korea, 09/22/09PUER GPS station on August 09, 2008

No major scintillation activity


IHY-Africa 2009 meeting, Livingstone, Zambia, 06/09/09ULF wave observation at the Equator

****************

Observation of Equatorial Electrodynamics in Africa using AMBER Magnetometer Network

Documents

Transcript of Observation of Equatorial Electrodynamics in Africa using AMBER Magnetometer Network