skip to main content


Title: A new source of the midlatitude ionospheric peak density structure revealed by a new Ionosphere-Plasmasphere model: NEW MIDLATITUDE IONOSPHERIC DENSITY PEAK
NSF-PAR ID:
10015792
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Geophysical Research Letters
Volume:
43
Issue:
6
ISSN:
0094-8276
Page Range / eLocation ID:
2429 to 2435
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    Global Navigation Satellite System (GNSS) Radio Occultation (RO) missions, such as the Formosa Satellite‐3/Constellation Observing System for Meteorology, Ionosphere, and Climate (FORMOSAT‐3/COSMIC) and the upcoming FORMOSAT‐7/COSMIC‐2, provide valuable profiling of the ionized atmosphere for the monitoring of space weather. This study shows that the FORMOSAT‐3/COSMIC and FORMOSAT‐7/COSMIC‐2 missions' ability to monitor highly variable ionospheric weather can be considerably extended with the help of data assimilation. The Gridpoint Statistical Interpolation (GSI) Ionosphere is a new data assimilation system designed specifically for the low‐latitude and midlatitude ionosphere. The capability of the GSI Ionosphere is first demonstrated with actual FORMOSAT‐3/COSMIC RO total electron content (TEC) data for January 2013. Features of the ionospheric equatorial ionization anomaly in a coupled plasmasphere ionosphere thermosphere model become more consistent with the TEC maps created with independent ground‐based GPS data. The consistency has improved by assimilation of FORMOSAT‐3/COSMIC RO data up to about 50% in comparison to the control simulation case without data assimilation. To evaluate the impact of future RO missions on ionospheric weather specification, comparative Observing System Simulation Experiments (OSSEs) are carried out with synthetic RO TEC data. An OSSE of FORMOSAT‐7/COSMIC‐2 shows that the GSI Ionosphere can improve the ionospheric specification within ±30° geomagnetic latitude by 67% over the control case, which is comparable to the improvement yielded by FORMOSAT‐3/COSMIC for 2009 (61%). These results indicate a great potential for improving the monitoring of realistic ionospheric weather with the help of FORMOSAT‐7/COSMIC‐2 RO TEC data.

     
    more » « less
  2. Abstract

    Postsunset midlatitude traveling ionospheric disturbances (TIDs) and equatorial plasma bubbles (EPBs) were simultaneously observed over American sector during the geomagnetic storm on 8 September 2017. The characteristics of TIDs are analyzed by using a combination of the Millstone Hill incoherent scatter radar data and 2‐D detrended total electron content (TEC) from ground‐based Global Navigation Satellite System receivers. The main results associated with EPBs are as follows: (1) stream‐like structures of TEC depletion occurred simultaneously at geomagnetically conjugate points, (2) poleward extension of the TEC irregularities/depletions along the magnetic field lines, (3) severe equatorial and midlatitude electron density (Ne) bite outs observed by Defense Meteorological Satellite Program and Swarm satellites, and (4) enhancements of ionosphereFlayer virtual height and vertical drifts observed by equatorial ionosondes near the EPBs initiation region. The stream‐like TEC depletions reached 46° magnetic latitudes that map to an apex altitude of 6,800 km over the magnetic equator using International Geomagnetic Reference Field. The formation of this extended density depletion structure is suggested to be due to the merging between the altitudinal/latitudinal extension of EPBs driven by strong prompt penetration electric field and midlatitude TIDs. Moreover, the poleward portion of the depletion/irregularity drifted westward and reached the equatorward boundary of the ionospheric main trough. This westward drift occurred at the same time as the sudden expansion of the convection pattern and could be attributed to the strong returning westward flow near the subauroral polarization stream region. Other possible mechanisms for the westward tilt are also discussed.

     
    more » « less