scholarly journals Low‐latitude ionospheric height variation as observed by meridional ionosonde chain: Formation of ionospheric ceiling over the magnetic equator

2014 ◽  
Vol 119 (12) ◽  
Author(s):  
Takashi Maruyama ◽  
Jyunpei Uemoto ◽  
Mamoru Ishii ◽  
Takuya Tsugawa ◽  
Pornchai Supnithi ◽  
...  
Keyword(s):  
Magnetic Equator ◽  
Low Latitude ◽  
Height Variation ◽  
Chain Formation ◽  
Ionospheric Height

scholarly journals Low latitude ionosphere-thermosphere dynamics studies with inosonde chain in Southeast Asia

2007 ◽  
Vol 25 (7) ◽  
pp. 1569-1577 ◽  
Author(s):  
T. Maruyama ◽  
M. Kawamura ◽  
S. Saito ◽  
K. Nozaki ◽  
H. Kato ◽  
...  
Keyword(s):  
Magnetic Equator ◽  
Conjugate Points ◽  
Wind Model ◽  
Low Latitude ◽  
Model Calculations ◽  
Neutral Winds ◽  
West Sumatra ◽  
Ionospheric Height ◽  
Low Latitude Ionosphere ◽  
Magnetic Meridian

Abstract. An ionosonde network consisting of a meridional chain and an equatorial pair was established in the Southeast Asian area. Three of four ionosondes are along the magnetic meridian of 100° E; two are close to the magnetic conjugate points in Northern Thailand and West Sumatra, Indonesia, and the other is near the magnetic equator in the Malay Peninsula, Thailand. The fourth ionosonde is also near the magnetic equator in Vietnam but separated by about 6.3° towards east from the meridional chain. For a preliminary data analysis, nighttime ionospheric height variations at the three stations of the meridional chain were examined. The results demonstrate that the coordination of the network has a great potential for studying ionosphere/thermosphere dynamics. Through the assistance of model calculations, thermospheric neutral winds were inferred and compared with the HWM93 empirical thermospheric wind model. Higher-order wind variations that are not represented in the empirical model were found.

scholarly journals On the response of the equatorial and low latitude ionospheric regions in the Indian sector to the large magnetic disturbance of 29 October 2003

2009 ◽  
Vol 27 (6) ◽  
pp. 2539-2544 ◽  
Author(s):  
G. Manju ◽  
T. Kumar Pant ◽  
S. Ravindran ◽  
R. Sridharan
Keyword(s):  
Electron Content ◽  
Low Latitude ◽  
Total Electron ◽  
Equatorial Station ◽  
Neutral Winds ◽  
Storm Sudden Commencement ◽  
Magnetometer Data ◽  
Ionospheric Height ◽  
Electric Field Penetration ◽  
Low Latitude Ionosphere

Abstract. The present paper investigates the response of the equatorial and low latitude ionosphere over the Indian longitudes to the events on 29 October 2003 using ionosonde data at Trivandrum (8.5° N (0.5° N geomagnetic), 77° E) and SHAR (13.7° N (5.7° N geomagnetic), 80.2° E), ground-based magnetometer data from Trivandrum and Total Electron Content (TEC) derived from GPS data at the locations of Ahmedabad (23° N (15° N geomagnetic), 72° E), Jodhpur (26.3° N (18.3° N geomagnetic), 73° E) and Delhi (28° N (20° N geomagnetic), 77° E). Following the storm sudden commencement, the TEC at all the three stations showed an overall enhancement in association with episodes of inter-planetary electric field penetration. Interestingly, real ionospheric height profiles derived using the ionosonde data at both Trivandrum and SHAR showed significant short-term excursions and recoveries. In the post noon sector, these features are more pronounced over SHAR, an off equatorial station, than those over Trivandrum indicating the increased effects of neutral winds.

scholarly journals Decrease of total electron content during the 9 March 2016 total solar eclipse observed at low latitude stations, Indonesia

2019 ◽  
Author(s):  
Wahyu Srigutomo ◽  
Alamta Singarimbun ◽  
Winda Meutia ◽  
I Gede Putu Fadjar Soerya Djaja ◽  
Buldan Muslim ◽  
...  
Keyword(s):  
Solar Eclipse ◽  
Geographical Location ◽  
Total Solar Eclipse ◽  
Magnetic Equator ◽  
Initial Contact ◽  
Electron Content ◽  
Low Latitude ◽  
Total Electron ◽  
Photoionization Process ◽  
Time Required

Abstract. The total solar eclipse on 9 March 2016 was a rare phenomenon that could be observed in 12 provinces in Indonesia. The decline in solar radiation to the earth during a total solar eclipse affects the amount of electron content (TEC) in the ionosphere. The ionospheric dynamics during the eclipse above Indonesia have been studied using data from 40 GPS stations distributed throughout the archipelago. It was observed that TEC decrease occurred over Indonesia during the occurrence of the total eclipse. This TEC decrease did not instigate ionoshperic scintillation. Moreover, the relationship between eclipse magnitude and TEC decrease throughout three GPS stations was analysed using PRN 24 and PRN 12 codes. Data analysis from each station reveals that the time required by the TEC to achieve maximum reduction since the initial contact of the eclipse is faster than the recovery time. The maximum TEC reduction came about several minutes after the maximum obscuration indicating that the recombination process was still ongoing even though the peak of the eclipse had happened. The magnitude of this decline is positively correlated with the geographical location of the stations and the relative satellite trajectory with respect to the total solar eclipse trajectory. The amount of TEC reduction is proportional to the magnitude of the eclipse which is directly related to the photoionization process. Because Indonesia is located in a low latitude magnetic equator region, the dynamics of the ionosphere above it is more complex due to the fountain effect. During the solar eclipse, the fountain effect declines disturbing the plasma transport from the magnetic equator to low latitude regions.

Progress report on 21-cm observations at low latitude between longitudes (l 11) 0° and 66°

1967 ◽  
Vol 31 ◽  
pp. 177-179
Author(s):  
W. W. Shane
Keyword(s):  
Preliminary Report ◽  
Progress Report ◽  
Galactic Centre ◽  
Low Latitude ◽  
The Third ◽  
Introductory Lecture ◽  
Centre Region

In the course of several 21-cm observing programmes being carried out by the Leiden Observatory with the 25-meter telescope at Dwingeloo, a fairly complete, though inhomogeneous, survey of the regionl11= 0° to 66° at low galactic latitudes is becoming available. The essential data on this survey are presented in Table 1. Oort (1967) has given a preliminary report on the first and third investigations. The third is discussed briefly by Kerr in his introductory lecture on the galactic centre region (Paper 42). Burton (1966) has published provisional results of the fifth investigation, and I have discussed the sixth in Paper 19. All of the observations listed in the table have been completed, but we plan to extend investigation 3 to a much finer grid of positions.

Low‐Latitude Whistler‐Mode and Higher‐Latitude Z‐mode Emission at Jupiter Observed by Juno

2020 ◽  
Author(s):  
J. D. Menietti ◽  
T. F. Averkamp ◽  
M. Imai ◽  
W. S. Kurth ◽  
G. B. Clark ◽  
...  
Keyword(s):  
Low Latitude ◽  
Whistler Mode

Spatial Correlation and Diversity of Low-Latitude Multipath Multimode HF Skywave Radio Channels

2019 ◽  
Vol 9 (2) ◽  
pp. 110
Author(s):  
Indah Kurniawati ◽  
Gamantyo Hendrantoro ◽  
Wirawan Wirawan ◽  
Muhammad Taufik
Keyword(s):  
Spatial Correlation ◽  
Low Latitude ◽  
Radio Channels
Sign in / Sign up

Export Citation Format

Share Document