Study of the Atmosphere-Ionosphere Coupling Using Observations of FORMOSAT-3/COSMIC

F3/C Workshop & TGA 2013

林建宏 Charles Lin 成功大學地球科學系

張起維 Loren C. Chang 中央大學太空科學研究所

林佳廷 Jia-Ting Lin 成功大學地球科學系

42 km

WVP/Specific humidity produced by

COSMIC obs. and ECMWF (courtesy of

Dr. Jens Wickert of the GFZ)

Forbes et al., JGR 2006

Meteorological Weather

@ 10 km

MLT Tn @110 km

Ionospheric Ne @ 350 km

Lin et al., JGR 2007

FORMOSAT-3/COSMIC explore the atmosphere – ionosphere vertical coupling processes

Do the ionospheric tidal components corresponde to the same MLT components?

FORMOSAT-3/COSMIC observed Ionospheric/Magnetic Migrating Tides Chang et al., JGR 2013

DW1 SW2 TW3

2007

2008

2009

2010

2011

Chang et al., JGR 2013 TIEGCM + GSWM simulations on relative importance of migrating tides

DW1 SW2 TW3

Goncharenko et al., 2010

Effect of the Stratospheric Sudden Warming (SSW) to Equatorial Ionosphere

Ne diff @ Japan Longitude for 2009 SSW

C. H. Lin et al., JGR 2012

Stratospheric temperature and ionospheric Ne observations during 2009

stratospheric sudden warming (SSW) event taken by FORMOSAT-3/COSMIC

Prior to SSW

During SSW, EI A appears earlier but weakens as early as 16 LT

Lin et al., JGR 2012

H-L. Liu et al. 2010

No QSPW With QSPW

Quasi Stationary Planetary Wave (QSPW) interacts with tides modulate the global neutral winds, leading to modulations of ionospheric electrodynamics and electron density

Chang et al. 2009 Possible Mechanism

SSW effects to the global zonal mean

SSW effects to the diurnal migrating tide

How about the harmonic analysis of the ionosphere data during 2009 SSW ?

FORMOSAT-3/COSMIC: NmF2 difference between DOY 032 (022-042) and DOY 009 (001-020), 2009

Modifications of the migrating tidal components of the ionospheric Ne during 2009 SSW

J. T. Lin et al., GRL 2012

Apparent phase shifts of SW2 and TW3 lead to semi-diurnal variation of the EIA peaks as reported by Goncharenko et al. (2010)

Resemblances of the ionospheric/magnetic tides during SSWs of 2008-2010

2008 2009 2010

Phase shifts of migrating tides during SSWs 2008-2010 are more clearly seen

Lin et al., JASTP 2013

2008 2009 2010

Resemblances of the ionospheric/magnetic tides during SSWs of 2008-2010 Modification of migrating tides could explain most of the observed SSW related ionospheric variations in EIA peaks

Lin et al., JASTP 2013

Summary: 1. The tidal analysis of ionosphere and MLT data help understand the

vertical coupling processes.

2. Based on multiple year observations of FORMOSAT-3/COSMIC, the migrating ionospheric/magnetic tides play the following roles.

a. DW1: represents the general ionospheric diurnal variation. b. SW2: represents the strength of EIA crests. c. TW3: represents the equatorial trough.

4. TIEGCM+GSWM simulations indicate that the MLT SW2 affect the

ionospheric SW2 (EIA crest strength) directly.

5. Modifications of the migrating tides (amplitudes and phases) during the SSWs 2008-2010 are responsible to the variations of observed EIA peaks.