ROCSAT-1 Satellite Research Articles

Response of ion velocities of daytime ionospheric wavenumber-4 to solar activity observed by ROCSAT-1 and DEMETER

The electron/ion density/temperature and ion velocities observed by the ROCSAT-1 and DEMETER satellites are used to examine the daytime wavenumber-4 (WN4) feature in the equatorial/low latitude ionosphere during various months and solar activity levels of 1999–2010. A moving median process has been employed to isolate WN4 features and calculate their amplitudes, while the upward ion drift is used to estimate electric fields. The ROCSAT-1 and DEMETER ion density, ion temperature, and ion velocity generally yield prominent WN4 features over the center of Pacific Ocean, the west side of South America, the center of the Atlantic Ocean, and Southern India. The correlation coefficient between the deviation of ion density and upward ion drift is significant during high solar activity of 1999–2004, while it approaches to zero during low solar activity of 2004–2010. This confirms that the longitudinal variation of the upward ion drift is essential during high solar activity, and the associated amplitude of dynamo eastward electric field is in the range of 0.10–0.14 mV/m, which is 15–19% of daily dynamo electric field. By contrast, the deviation of the ion density and the northward field-aligned ion flow show a clear anti-correlation which yields a maximum coefficient in August during low solar activity but no correlation during high solar activity. These indicate that the longitudinal variation of the meridional field-aligned ion flow could play an important role during low solar activity, and its amplitude is in the range of 10.44–13.91 m/s, which is 10–13% of the ambient ion flows.

Multi-Instrumental Observations of Midlatitude Plasma Irregularities over Eastern Asia during a Moderate Magnetic Storm on 16 July 2003

This study presents the observations of midlatitude plasma irregularities over Eastern Asia during a moderate magnetic storm on 16 July 2003. Multi-instrumental observations, including the ground-based ionosondes, the GNSS networks, and the CHAMP and ROCSAT-1 satellites, were utilized to investigate the occurrence and characteristics of midlatitude plasma irregularities. The midlatitude strong spread F (SSF) mainly occurred in the midnight–morning sector as observed by ionosondes over Japan during this storm. SSF was related to plasma depletions, which is also recorded by GNSS network in the form of the enhancement of the rate of total electron content (TEC) change index (ROTI). The possible mechanism for the generation of SSF is that the enhanced eastward electric fields, associated with the prompt penetration electric fields and disturbance dynamo electric fields, cause the uplift and latitudinal extension of equatorial plasma bubbles (EPBs) to generate the observed midlatitude SSF further. Meanwhile, plasma density increased significantly under the influence of this storm. In addition, other common type of spread F, frequency spread F (FSF), was observed over Japan on the non-storm day and/or at high latitude station WK545, which seems to be closely related to the coupling of medium-scale traveling ionospheric disturbances (MSTIDs) and sporadic E (Es) layer. The above results indicate that various types of midlatitude spread F can be produced by different physical mechanisms. It is found that SSF can significantly affect the performance of radio wave propagation compared with FSF. Our results show that space weather events have a significant influence on the day-to-day variability of the occurrence and characteristics of ionospheric F-region irregularities at midlatitudes.

A Study of the Topside Plasma Blob and Adjacent Bubble Near Sunrise in Low-Latitude Ionosphere During the Main Phase of August 2003 Storm

In this paper, a plasma blob and an adjacent plasma bubble in low-latitude region at 245°E region near sunrise recorded by the Defense Meteorological Satellite Program (DMSP) F13 satellite around 840 km on 18 August 2003 were presented. On the previous local night, the blob and adjacent bubble at 265°E region were also detected by the first satellite of the Republic of China (ROCSAT-1) at about 600 km. Total Electron Content (TEC) derived from ground-global positioning system (GPS) measurements also showed both the evident enhancements and the decreases adjacent to the enhancements, at one low-latitude station near 265°E region. Based on the characteristics of the blob, we conclude that the blob and adjacent bubble near sunrise recorded by DMSP were the remnant of the blob and bubble formed on the previous night, which were detected by ROCSAT-1 satellite and ground-based TEC variations. The long duration of the blob and bubble during storm main phase may be related to the prompt penetration electric field.

Equatorial Plasma Bubbles: Occurrence Probability versus Local Time

The character of the variability of the LT distributions of the equatorial plasma bubble occurrence probability with an increase of the recording altitude is under consideration. The conditions of the high and maximal solar activity, when the generation of the plasma bubbles is the most active, are examined. For this purpose the detailed comparative analysis of the LT distributions of the equatorial plasma bubble occurrence probability derived from the ISS-b (~972–1220 km), Hinotori (~650 km), ROCSAT-1 (~600 km), AE-E (~300–475 km), and CHAMP (~380–450 km) satellite data was done. The pronounced trend of the local time shift of the bubble occurrence probability maximum with an increase of the altitude is revealed. Thus, if the maximum occurs after sunset (~2030–2200 LT) at the bottom-side of the F-layer, it shifts toward the premidnight (~2100–2400 LT, ~600 km), then to the postmidnight (~0100–0300 LT, ~650 km), and, finally, to the predawn hours (~0300–0400 LT, ~972–1220 km) as the observation altitude increases. The most typical velocities of the equatorial plasma bubble rise are found to be ~150–300 m/s, which correspond to the numerous observational data.

Equatorial Plasma Bubbles: Variation of the Longitudinal Distribution with Altitude

The equatorial plasma “bubbles” that form at the bottom-side of the F-layer are affected by zonal plasma drift when they rise to greater altitudes. Under the influence of the drift, the bubbles move eastward. Conversely, a plasma bubble that is “stretched” along a magnetic flux tube repeats its spatial course. For example, a change in the magnetic declination of a flux tube will result in a change in the longitudinal orientation of the bubble. Bubbles undergo an eastward shift in regions with an eastern magnetic declination and a westward shift in regions with a western magnetic declination. The character of the influence of these factors has been studied on the examples of the longitudinal distributions of the equatorial plasma bubbles calculated for the winter and spring periods. For this purpose, the data from the ISS-b, AE-E, OGO-6, ROCSAT-1, and Hinotori satellites obtained in the years of high solar activity at the different orbital altitudes were used. It was found that the bubbles detected at the altitudes of ~972–1220 km in the 0°–50° DIPLAT band follow the course of the magnetic declination of the flux tube, experiencing almost no influence of the zonal plasma drift. The bubbles detected at the altitudes of ~300–700 km within ±20° DIPLAT were found to be strongly influenced by the eastward zonal drift. The magnetic declination only controls the magnitude of their shift in the east direction.

Variations of ion density and temperature as measured by ROCSAT-1satellite and comparison with IRI-2016 model over low latitude region

Topside ionospheric parameters-total ion density (Ni) and ion temperature (Ti) have been analysed at low latitude region with changing solar activity (years 1999 to 2003). The Ni and Ti data collected from ROCSAT-1 satellite has been compared with the estimated values of IRI-2016 model. The annual diurnal features observed for Ni (measured by ROCSAT-1) are: a minimum value just before local sunrise (~04:00/05:00 LT), a day-time peak (~13:00/14:00 LT) and then a gradual decrement throughout the evening and nighttime. The annual diurnal variation of Ti (measured by ROCSAT-1) shows that Ti exhibits a morning peak (morning overshoot, ~07:00 LT), a day-time trough, a secondary peak (evening enhancement) followed by nighttime minima and a minimum value before the sunrise. The distinct annual diurnal feature observed by the IRI model is the presence of a secondary evening peak in Ni which is absent in Ti, which is ex- actly opposite to the trend measured by ROCSAT-1. Some other discrepancies observed in the model are:overestimation of Ni during all the years, specifically in the morning and evening time; overestimation of Ti, during the entire day except in the morning peak hours of the year 1999, 2000 and 2003.For each year, the hourly averaged ROCSAT-1 measured value of Ni and Ti has been correlated with the estimated value of IRI-2016 model. The correlation coefficient factor R2 is ~ 0.8 for Ni and ~ 0.9 for Ti respectively. The variations of Ni and Ti with changing solar flux have also been studied. The ionospheric parameters are found positively and linearly correlated with solar- flux (F10.7). The correlation coefficient factor R2 for Ni and Ti with F10.7 is ~ 0.8 and ~ 0.9 respectively.

Typical comparisons between plasma bubble and blob distributions at different altitudes over the Indian sector using a unique combination of satellite-based observations – a case study

We report in this article, for the first time, on the altitudinal variations of ionospheric irregularities during post-sunset hours between 14 and 17 October 2001 at Indian longitudes by using a unique combination of Challenging Mini Satellite Payload (CHAMP), Republic of China Satellite (ROCSAT-1), and Defense Meteorological Satellite Programme (DMSP) satellites located at about 400, 650, and 850 km, respectively. It became possible for us to study the width of plasma bubbles and plasma blobs in the longitudinal (zonal) direction at different altitudes along with temporal variations of ion velocity components in horizontal (Vy) and vertical (Vz) directions as probed by ROCSAT-1 and DMSP satellites. The dominant features noticed in Vy and Vz components are their anti-correlation relationship at the ROCSAT-1 satellite’s altitude (mirroring effect). The most important observation from this study is that plasma bubbles are found to have occurred immediately after post-sunset hours, whereas plasma blobs were observed after three hours following the bubbles’ appearance time and continued until pre-sunrise hours at higher altitudes between around ±5° and ±20° from the magnetic equator, which indicate that the plasma blobs emanate from plasma bubbles that generated at the bottomside of the ionospheric F-layer shortly after sunset on similar lines to a few recent research studies. It is therefore believed that the polarized electric fields generated inside plasma bubbles might have played a role in the generation of higher-altitude plasma blobs. Importantly, the calculated power spectra of bubbles and blobs show a nearly equal trend, indicating that they are intricately connected with each other.

Regional morphology features of electron concentration disturbances at the midlatitude F2-layer maximum during magnetic superstorm of July 15, 2000

Using data from ground-based ionospheric sounding stations, we studied the morphologic features of the disturbance pattern of the electron concentration at the midlatitude F2-layer maximum (NmF2) in the period of a magnetic superstorm, which began on July 15, 2000. In the Southern (winter) Hemisphere in the latitudinal sector, where the main storm phase began after sunrise, negative NmF disturbances were observed at quite high midlatitudes both day and night; whereas large positive NmF disturbances took place at lower midlatitudes in nighttime hours. In the Northern (summer) Hemisphere at latitudes where the main storm phase occurred in the local evening, only long-term negative disturbances were observed in daytime and nighttime hours; whereas at latitudes where the main storm phase began in the afternoon, NmF2 experienced both negative and positive disturbances. Based on analysis of data of KOMPSAT-l, ROCSAT-1, DMSP F13, F14, and F15 satellites, we present clear arguments for the viewpoint of many authors that it is just the enhancement of the eastward electric field in the evening sector that led to formation of the large-scale trough in the nighttime low-latitude upper ionosphere. This field enhancement was due to penetration of the magnetospheric electric field to low latitudes, not to the dynamo action of the disturbed neutral wind. It is also shown that, due to equatorward expansion of the magnetospheric convection system during the main storm phase, the plasmapause and the main ionospheric trough were shifted to a magnetic latitude of 40° (L ∼ 1.7).

The role of the vertical <I><B>E</B></I>×<I><B>B</B></I> drift for the formation of the longitudinal plasma density structure in the low-latitude F region

Abstract. The formation of a longitudinally periodic plasma density structure in the low-latitude F region by the effect of vertical E×B drift was investigated by analyzing the ROCSAT-1 satellite data and conducting SAMI2 model simulations. The daytime equatorial ionosphere observed during the equinox in 1999–2002 from ROCSAT-1 showed the formation of wave number-4 structures in the plasma density and vertical plasma drift. The coincidence of the longitudes of the peak density with the longitudes of the peak upward drift velocity during the daytime supported the association of the longitudinal density structure with the vertical E×B drift. The reproduction capability of the observed wave-4 structure by the effect of vertical E×B drift was tested by conducting SAMI2 model simulations during the equinox under solar maximum condition. When the ROCSAT-1 vertical drift data were used, the SAMI2 model could reproduce the observed wave-4 density structure in the low-latitude F region. On the other hand, the SAMI2 model could not reproduce the observed wave-4 structure using the Scherliess and Fejer vertical E×B drift model. The observation and model simulation results demonstrated that the formation of the longitudinally periodic plasma density structure can be explained by the longitudinal variation of the daytime vertical E×B drift.

The correlation of longitudinal/seasonal variations of evening equatorial pre-reversal drift and of plasma bubbles

Abstract. The evening pre-reversal vertical drift velocity enhancement (PRE) constitutes an important seeding mechanism for the generation of F region irregularities. Ion density and drift measurements from ROCSAT-1 and DMSP satellites are used to examine the correlation of longitudinal/seasonal (l/s) variations in the evening pre-reversal vertical drift velocity at the magnetic equator in the topside ionosphere and the plasma bubble (PB) occurrence probability. The analysis performed for three years 2000–2002 (solar maximum), provides consistent evidence as the ground observations that the equatorial PB occurrence is dependent on and increases approximately linearly with PRE, and the l/s variations of PRE play an important role in the global l/s distribution of PB occurrence. The solstitial evening PRE and equatorial PB occurrence show similar longitudinal variations: During June solstice, two peaks appear in the African and Pacific longitude sectors, and two minimums are observed in the Indian and American regions; During December solstice, the situation is approximately opposite. The equinoctial longitudinal effects are comparably small. It is concluded that the large-scale l/s variations of equatorial PB occurrence can be closely related to the l/s variations of PRE.

On a possible relationship between density depletions in the SAA region and storm-enhanced densities in the conjugate hemisphere

During the great magnetic storm of July 15, 2000, the ROCSAT-1 satellite with an orbital altitude of 640 km detected a large density depletion region at low latitudes (<35°) in the southern hemisphere while storm-enhanced density (SED) was observed in the northern hemisphere. Convective electric fields deduced from measurements of the ROCSAT-1 drift meters and retarding potential analyzer (RPA) indicate negligible electric fields in the eastern portion of the SED region where density enhancement was evident, suggesting a lack of ion upward motion at the equator of the SED longitudes. However, a localized electric field enhancement was observed in association with South Atlantic magnetic anomaly density structures (MADS) during the event. The zonal electric field component was eastward corresponding to radial convection, and the radial electric field component on the magnetic meridional plane was outward corresponding to westward convection. In general, both components of the observed convective electric fields were enhanced inside the density depletion region and reduced inside the density enhancement. The electric field patterns are consistent with those arising from a circular region of flux tubes with enhanced conductance in the presence of a background electric field. The mapping of the MADS region and convective electric fields from the southern hemisphere to the northern hemisphere suggests that these localized electric fields could drive ionospheric plasma from the conjugate MADS region to the SED at higher latitudes. We thus propose a new idea that the conjugate MADS region could be the plasma source for producing the SED.

Concurrent study of bottomside spread F and plasma bubble events in the equatorial ionosphere during solar maximum using digisonde and ROCSAT-1

Abstract. Data from the Jicamarca digisonde and the ROCSAT-1 satellite are employed to study the equatorial ionosphere on the west side of South America during April 1999-March 2000 for the concurrent bottomside spread F (BSSF) and plasma bubble events. This study, using digisonde and ROCSAT-1 concurrently, is the first attempt to investigate the equatorial spread F. Results show that BSSF and plasma bubble observations appear frequently respectively in the summer (January, February, November, and December) and in the equinoctial (March, April, September, and October) months, respectively, but are both rarely observed in the winter (May-August) months. The upward drift velocity during the concurrent BSSF and bubble observations has been determined to study the driving mechanism. This analysis shows that large vertical drift velocities favor BSSF and bubble formations in the equinoctial and summer months. Conversely, the smaller upward velocities during the winter months cause fewer BSSF and bubble occurrences. For the geomagnetic effect, the BSSF/bubble occurrence decreases with an increasing Kp value in the equinoctial months, but no such correlation is found for the summer and winter months. Moreover, the anti-correlations between Kp and dh'F/dt are apparent in the equinoctial months, but not in the summer and winter months. These results indicate that in the equinoctial months the BSSF/bubble generations and the pre-reversal drift velocity can be suppressed by geomagnetic activity, because the disturbance dynamo effects could have decreased the eastward electric field near sunset. However, BSSF and bubble occurrences may not be suppressed by the geomagnetic activity in the summer and winter months.

Ion temperature variation observed by ROCSAT-1 satellite in the afternoon sector and its comparison with IRI-2001 model

The ion temperature has been measured with the ionospheric plasma and electrodynamics instrument (IPEI) onboard the first satellite of Republic of China, ROCSAT-1, orbiting at 600 km altitude with a 35° inclination. Global ion temperature distributions in the afternoon sector for different seasons are investigated during the solar maximum year of 2000. The temperature troughs at the dip equator are found to incline and become shallower until the evening temperature enhancement has reached to its peak. The temperature troughs follow with the electron temperature variation through the heat exchange between electrons and ions. The temperature crests in the winter hemisphere are also noticed in the afternoon sector but have a smaller magnitude than those in the morning sector. The magnitudes of the temperature crests are reduced first and then enhanced later as local time increases. The locations of the temperature maxima within the temperature crests shift from longitudes of positive magnetic declination to longitudes of negative magnetic declination during the June solstice and from longitudes of negative magnetic declination to longitudes of positive magnetic declination during the December solstice. Both magnitudes and movements of the temperature crests can be understood with the field-aligned ion flow pattern observed by ROCSAT and are attributed to the change of the neutral wind pattern in zonal direction from westward to eastward. These features from the ROCSAT observations are not available in the IRI-2001 model yet.

Grid effects on the derived ion temperature and ram velocity from the simulated results of the retarding potential analyzer data

The ROCSAT-1 satellite circulating at 600 km altitude in the low- and mid-latitude topside ionosphere carries a retarding potential analyzer to measure the ion composition, temperature, and the plasma flow velocity in the ram direction. Based on an existing three-dimensional model, the particle's motion inside the instrument is simulated with the exact wire and mesh sizes but with a smaller aperture of the real sensor configuration. The simulation results indicate that the retarding grids could not provide a uniform retarding potential barrier to completely repel low energy particles. Some of low energy particles could pass through those grids and arrive at the collector. The leakage will cause the ram velocity to be over-estimated for by about 180 m/sec. Furthermore, the simulated O + temperature derived from the I-V curve is lower than the input temperature due to ion losses from colliding with the grids from the non-uniform potential field generated by the high retarding voltage.

Monitoring of Sandstorms with ROCSAT-1 OCI Data

The Ocean Color Imager(OCI)onboard the ROCSAT-1 Satellite was employed to demonstrate its capability in monitoring sandstorm events around Mongolia and northwestern China where they have been occurring in great frequency over these past few years. The OCI measures the radiance from the visible to near infrared regions in six spectral channels. The radiance can be used to calculate the aerosol optical depth(AOD)of the atmosphere through an atmospheric correction algorithm. The variation in the AOD during January and February of 2001 is investigated in this study. A set of OCI images covering the Yellow Sea was selected for analysis. The results showed that the AOD values increased significantly after the sandstorms erupted, where its value was almost four times higher than before.

Determination of plume impingement disturbance characteristics for the ROCSAT-1 satellite

The impingement disturbance characteristics of the hydrazine thruster plumes have been examined comprehensively for the ROCSAT-1 satellite. In this study, the velocity and temperature distributions at the nozzle exit are obtained from the nozzle flowfield analysis. The axial velocity, transverse velocity and temperature profiles are further correlated with the curve-fitting procedure for resolving inflow properties of molecules ejected into a vacuum. The free-molecular direct simulation Monte Carlo technique is used to describe the particle nature of the distant plume flow behaviour near the impingement surface. The inflow molecular motions as well as the collision interactions between the molecules and the solid surface are treated on a probabilistic basis. On the other hand, the inter-collisions among molecules are considered to be relatively unimportant in the far-field plume region. A reasonable number of simulated molecules is also employed to reproduce the fluid behaviour in the macroscopic level. The predicted disturbance torques and thrust loss are found to be much less than the design control torques and the nominal thrust force for ROCSAT-1 satellite, indicating that the plume impingement effect will not cause any performance deterioration of the propulsive function.

Storm time plasma irregularities in the pre‐dawn hours observed by the low‐latitude ROCSAT‐1 satellite at 600 km altitude

Large scale ion density depletions were detected in the nighttime sector by ROCSAT‐1 for over 10 hours during the 22 October 1999 geomagnetic storm. Prominent depletion structures (bubbles) that are characterized by large‐amplitude density decrease (N/No ≤ 1%) with rapid horizontal ion drift (600 ∼ 800 m/s) are found to cluster in the 03:00 ∼ 04:30 local time sector and at magnetic latitudes 14° ∼ 20° S when the storm was in its early recovery phase. These presunrise bubbles are positively correlated to the enhanced eastward electric fields of greater than 1 ∼ 2 mV/m, which were in response to the storm‐time disturbances resulting from the in‐phase contributions of the prompt penetration magnetospheric and the long lasting ionospheric disturbance dynamo electric fields. Further analyses of the field‐aligned and cross‐field ion drifts within the depletions reveal that bubble plasma were driven by the eastward polarization electric fields to move upward, but these upward velocities were compensated by large downward field‐aligned diffusive motions. These features confirm that the disturbance electric fields produced during a great magnetic storm can significantly affect the occurrence timing and spatial extent of severe plasma irregularities in low‐latitude ionosphere. The spatial dimensions of the pre‐sunrise irregularities may exceed the large region observed by the 35° inclined circular orbiting ROCSAT‐1.

ROCSAT-1 Satellite Observations of Magnetic Anomaly Density Structures During the Great Magnetic Storm of July 15-16, 2000

Large scale ion density structures were observed by ROCSA T -1 at 630 km altitude over the South Atlantic anomaly (SAA) region during the great magnetic storm of July 15-16,2000. The observed density structures were confined within 30° in longitude east of the SAA, and co-rotated with the SAA for Over 8 hours. The magnetic anomaly density structures (MADS) observed during several successive orbits in the nighttime sector, contained density holes and density pile-ups adjacent to each other. The density holes had a density drop of one to two orders of magnitude below the ambient level and a spatial size of 800 - 1800 km along the satellite path. The density pile-ups typically spanned a spatial size of 2000 - 3000 km were characterized with a density enhancement, large density fluctuations and upward drift velocity. In contrast to density pile-ups, density holes did not exhibit noticeable density fluctuations nor upward drift velocity. A common feature of large poleward drifts was noticeable inside both density hole and pile-up structures. The ion drift measurements thus indicate that ions inside the density holes drifted away in the poleward direction rather than the upward direction. The successive observations of density holes on six orbits suggest that the density hole might be initially created near the center of SAA region and then expanded equatorward. We interpret the magnetic anomaly density pile-up to be the ionospheric F2 peak layer raised to the satellite altitude by storm enhanced eastward electric fields. It is speculated that energetic particle precipitation might have occurred in the region of magnetic anomaly density structures, increasing locally ionospheric conductivity in the E region and producing eastward polarization electric fields in the precipitation region. The combination of localized polarization electric fields and storm time electric fields at low latitudes in the night-side might be responsible for the ion drifts and the associated anomalous density structures observed by ROCSA T -1 in the F region.

Ocean Color Imager:Instrument Description and Its Performance

The Ocean Color Imager is an electro-optic remote sensing instrument to be flown on the ROCSAT-1 satellite, scheduled to be launched in January 1999. It is a push-broom type spectral-radiometer with 702 km swath width and 800 m resolution for measuring radiances of water-leaving from ocean surfaces and atmospheric scattering in six visible and near infrared bands. The OCI's missions, architecture, function, and pre-launch performance test results are described here.

System Architecture of the IPEI Payload on ROCSAT-1

The Ionospheric Plasma and Electrodynamics Instrument (IPEI) is one of the three payloads on the ROCSAT-1 satellite. The IPEI consists of two major packages: Sensor Electronics Package (SEP) and Main Electronics Package (MEP). The SEP carries four sensors: an Ion Trap (IT), Horizontal and Vertical Drift Meters (HDM and VDM), and a Retarding Potential Analyzer (RPA). These sensors measure ion concentration, ion temperature, cross-track ion velocity, and major ion composition at the satellite position along the ROCSAT-1 orbit. This will nominally yield coverage at600km altitude within the latitude band of ±35°.The MEP contains four major parts: a digital processing unit (DPU), command interface, science data interface, and power supplies. The MEP provides the electrical interface between IPEI and the spacecraft. Also, the MEP implements the operational modes of IPEI: NORMAL, FAST, and AUTO. In the NORMAL mode the IT, HDM, and VDM provide measurements of the total ion concentration and the cross-track ion drift velocity at 32Hz, while the RPA provides the in-track ion drift, the ion temperature and the major ion composition at a nominal 1/2 Hz rate. In the FAST mode these sample rates are 1024 Hz and 1/4 Hz respectively. The AUTO mode enables IPEI to switch from the default NORMAL mode to the FAST mode when sudden large changes in the ion concentration, commonly associated with plasma structures called bubbles, are detected. The unique feature of the AUTO mode allows the scientists to investigate spatial structures with scale sizes as small as 16 meters.