scholarly journals Magnetic signatures and conjugate features of low-latitude plasma blobs as observed by the CHAMP satellite

2008 ◽  
Vol 113 (A9) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jaeheung Park ◽  
Claudia Stolle ◽  
Hermann Lühr ◽  
Martin Rother ◽  
Shin-Yi Su ◽  
...  
Keyword(s):  
Low Latitude ◽  
Champ Satellite ◽  
Magnetic Signatures ◽  
Plasma Blobs

scholarly journals Field-aligned current associated with low-latitude plasma blobs as observed by the CHAMP satellite

2010 ◽  
Vol 28 (3) ◽  
pp. 697-703 ◽  
Author(s):  
J. Park ◽  
H. Lühr ◽  
C. Stolle ◽  
M. Rother ◽  
K. W. Min ◽  
...  
Keyword(s):  
Low Latitude ◽  
Champ Satellite ◽  
Plasma Bubbles ◽  
Equatorial Plasma Bubbles ◽  
Magnetic Signature ◽  
Linearly Polarized ◽  
Field Aligned Current ◽  
Magnetic Deflection ◽  
Magnetic Meridian ◽  
Plasma Blobs

Abstract. Here we give two examples of low-latitude plasma blobs accompanied by linearly polarized perpendicular magnetic deflections which imply that associated field-aligned currents (FACs) have a 2-D sheet structure located at the blob walls. The estimated FAC density is of the order of 0.1 μA/m2. The direction of magnetic deflections points westward of the magnetic meridian and there is a linear correlation between perpendicular and parallel variations. All these properties are similar to those of equatorial plasma bubbles (EPBs). According to CHAMP observations from August 2000 to July 2004, blobs show except for these two good examples no clear signatures of 2-D FAC sheets at the walls. Generally, perpendicular magnetic deflections inside blobs are weaker than inside EPBs on average. Our results are consistent with existing theories: if a blob exists, (1) a significant part of EPB FAC will be closed through it, exhibiting similar perpendicular magnetic deflection inside EPBs and blobs, (2) the FAC closure through blobs leads to smaller perpendicular magnetic deflection at its poleward/downward side, and (3) superposition of different FAC elements might result in a complex magnetic signature around blobs.

scholarly journals Improving and testing the empirical equatorial electrojet model with CHAMP satellite data

2004 ◽  
Vol 22 (9) ◽  
pp. 3323-3333 ◽  
Author(s):  
V. Doumouya ◽  
Y. Cohen
Keyword(s):  
Equatorial Electrojet ◽  
Ground Level ◽  
Longitudinal Variation ◽  
Equatorial Station ◽  
Champ Satellite ◽  
Magnetic Effects ◽  
Level Data ◽  
The Pacific ◽  
Magnetic Signatures ◽  
Data Points

Abstract. The longitudinal variation of the Equatorial Electrojet (EEJ) intensity has been revised including data from the equatorial station of Baclieu (Vietnam), where an unexpected enhancement of the EEJ magnetic effects is observed. The features of this longitudinal variation were also obtained with the CHAMP satellite, except in the Pacific and Atlantic Oceans, where no ground level data points were available.The EEJ magnetic signatures recorded on board the CHAMP satellite have been isolated for 325 passes in different longitude sectors around local noon. The results have been compared with the EEJ magnetic effects computed using the Empirical Equatorial Electrojet Model (3EM) proposed by Doumouya et al. (2003). The modeled EEJ magnetic effects are generally in good agreement with CHAMP observed EEJ magnetic signatures.

scholarly journals Discovering the Low-Latitude Ionospheric Trough Associated With the Inner Radiation Belt

2021 ◽  
Author(s):  
Alexander Karpachev
Keyword(s):  
Geomagnetic Storm ◽  
Radiation Belt ◽  
Ring Current ◽  
Recovery Phase ◽  
Low Latitude ◽  
Champ Satellite ◽  
Main Ionospheric Trough ◽  
Long Time ◽  
Late Recovery ◽  
First Time

Abstract The dynamics of ionospheric troughs during great geomagnetic storm on April 11–13, 2001 is considered. An analysis is based on measurements of electron density at altitudes of the CHAMP satellite 410–465 km. The subauroral, mid-latitude and low-latitude troughs were observed at nighttime, sometimes simultaneously. The subauroral trough is usually defined as the main ionospheric trough. The mid-latitude trough is associated with the magnetospheric ring current. It appears at the beginning of the storm recovery phase at latitudes of 40–45° GMLat (L=1.7–2.0) and exists for a long time at the late recovery phase at latitudes of the residual ring current 50–55° GMLat (L~2.4–3.0). The low-latitude trough was revealed for the first time. It is developed at the latitudes of the inner radiation belt 34–45° GMLat (L=1.45–2.00). This trough is associated with the precipitation of energetic particles from the inner radiation belt.

Observations of Low‐Latitude Traveling Ionospheric Disturbances by a 630.0‐nm Airglow Imager and the CHAMP Satellite Over Indonesia

2019 ◽  
Vol 124 (3) ◽  
pp. 2198-2212
Author(s):  
Aysegul Ceren Moral ◽  
Kazuo Shiokawa ◽  
Shin Suzuki ◽  
Huixin Liu ◽  
Yuichi Otsuka ◽  
...  
Keyword(s):  
Ionospheric Disturbances ◽  
Low Latitude ◽  
Champ Satellite ◽  
Traveling Ionospheric Disturbances

scholarly journals Sub-Auroral, Mid-Latitude, and Low-Latitude Troughs during Severe Geomagnetic Storms

2021 ◽  
Vol 13 (3) ◽  
pp. 534
Author(s):  
Alexander Karpachev
Keyword(s):  
Radiation Belt ◽  
Ring Current ◽  
Geomagnetic Storms ◽  
Recovery Phase ◽  
Internal Radiation ◽  
Low Latitude ◽  
Champ Satellite ◽  
Main Ionospheric Trough ◽  
Long Time ◽  
First Time

The dynamics of ionospheric troughs during intense geomagnetic storms is considered in this paper. The study is based on electron density measurements at CHAMP satellite altitudes of 405–465 km in the period from 2000 to 2002. A detailed analysis of four storms with Kp from 5+ to 9− is presented. Three troughs were identified: sub-auroral, mid-latitude, and low-latitude. The sub-auroral trough is usually defined as the main ionospheric trough (MIT). The mid-latitude trough is observed equatorward of the MIT and is associated with the magnetospheric ring current; therefore, it is named the ring ionospheric trough (RIT). The RIT appears at the beginning of the storm recovery phase at geomagnetic latitudes of 40–45° GMLat (L = 1.75–2.0) and exists, for a long time, at the late stage of the recovery phase at latitudes of the residual ring current 50–55° GMLat (L ~ 2.5–3.0). The low-latitude trough (LLT) is discovered for the first time. It forms only during great storms at the latitudes of the internal radiation belt (IRB), 34–45° GMLat (L = 1.45–2.0). The LLT’s lowest latitude of 34° GMLat was recorded in the night sector (2–3 LT). The occurrence probability and position of the RIT and LLT depend on the hemisphere and longitude.

Statistical description of low-latitude plasma blobs as observed by DMSP F15 and KOMPSAT-1

2008 ◽  
Vol 41 (4) ◽  
pp. 650-654 ◽  
Author(s):  
J. Park ◽  
K.W. Min ◽  
V.P. Kim ◽  
H. Kil ◽  
H.J. Kim ◽  
...  
Keyword(s):  
Low Latitude ◽  
Plasma Blobs

scholarly journals Low Latitude Plasma Blobs: A Review

2016 ◽  
Vol 33 (1) ◽  
pp. 13-19
Author(s):  
Vitaly P. Kim ◽  
Valery V. Hegai
Keyword(s):  
Low Latitude ◽  
Plasma Blobs

scholarly journals Substorm-related thermospheric density and wind disturbances derived from CHAMP observations

2010 ◽  
Vol 28 (6) ◽  
pp. 1207-1220 ◽  
Author(s):  
P. Ritter ◽  
H. Lühr ◽  
E. Doornbos
Keyword(s):  
Atmospheric Models ◽  
Low Latitude ◽  
Magnetospheric Substorm ◽  
Champ Satellite ◽  
Zonal Winds ◽  
Night Side ◽  
High Latitude Ionosphere ◽  
Wind Velocities ◽  
Substorm Onsets ◽  
Energy And Momentum

Abstract. The input of energy and momentum from the magnetosphere is most efficiently coupled into the high latitude ionosphere-thermosphere. The phenomenon we are focusing on here is the magnetospheric substorm. This paper presents substorm related observations of the thermosphere derived from the CHAMP satellite. With its sensitive accelerometer the satellite can measure the air density and zonal winds. Based on a large number of substorm events the average high and low latitude thermospheric response to substorm onsets was deduced. During magnetic substorms the thermospheric density is enhanced first at high latitudes. Then the disturbance travels at an average speed of 650 m/s to lower latitudes, and 3–4 h later the bulge reaches the equator on the night side. Under the influence of the Coriolis force the travelling atmospheric disturbance (TAD) is deflected westward. In accordance with present-day atmospheric models the disturbance zonal wind velocities during substorms are close to zero near the equator before midnight and attain moderate westward velocities after midnight. In general, the wind system is only weakly perturbed (Δvy<20 m/s) by substorms.

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