Jamjareegulgarn, Punyawi

Preferred name

Alternative Name

Jamjareegulgarn, P.

Main Affiliation

KMITL Prince of Chumphon Campus

punyawi.ja@kmitl.ac.th

Now showing 1 - 10 of 11

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Identifying Geomagnetic Storms with Ionospheric Storm Scale for GNSS and Disaster Prevention
(2020-03-01)
Jamjareegulgarn, Punyawi
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Duangsuwan, Sarun
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Supnithi, Pornchai
;
Budtho, Jirapoom
;
Tangtrakunphaisan, Udomsit
This paper proposes an ionospheric storm scale (I-scale) for identifying the impact of geomagnetic or ionospheric storms in the Ionosphere for GNSS (global navigation satellite system) service and disaster prevention. The I-scale in this work is computed based on the observed foF2 at Chumphon station (10.72°N, 99.37°E) over equatorial latitude from January 2004 to July 2018. The results report that the severe geomagnetic storms, i.e., IP3 and IN3, seldom occur at Chumphon with the probabilities of 0.02% and 0.07%, respectively. The probability of quiet ionospheric condition is the maximum value of 70.73%. Meanwhile, the other I-scales sometimes occur and range from 0.60% to 13.97%. The benefits of the foF2-based I-scale are to indicate the violence level of geomagnetic storms and to announce the ionospheric irregularities in practice.
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Improving the modeling of bottomside thickness parameters over midlatitudes and high latitudes
(2020-02-01)
Jamjareegulgarn, Punyawi
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Supnithi, Pornchai
;
Kenpankho, Prasert
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Wichaipanich, Noraset
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Nayak, Chinmaya
This paper investigates bottomside thickness parameters at Digisonde stations over midlatitude and high latitude regions, and compares the diurnal, seasonal, and solar activity variations in 2014 and 2009. The geographic latitudes of high latitude considered in this work are located beyond ±60° and those of midlatitude are located between ±40° and ±60°. The IRI-modeled B0 with ABT-2009 option (B0_IRI) are also examined and compared with four kinds of the B0 values, i.e., the observed B0 (B0_obs) from GIRO, the computed B0 following to Jamjareegulgarn et al. (2017a) (B0_old), the calculated B0 with a correction factor regarding to Jamjareegulgarn et al. (2017b) (B0_new), and the B0 with an average correction factor (B0_new_c_av). The average correction factors are proposed additionally in this work so as to assist occasionally the experimental B0 nonexistence of Digisonde which are equal to 0.2658 and 0.2058 for midlatitudes and high latitudes, respectively. Results show that the diurnal variations of B0_new and B0_new_c_av are in a good agreement with those of B0_obs evidently compared with those of B0_IRI and B0_old at every station during the three seasons over high and middle latitudes. During the three seasons, the diurnal variations of B0_new_c_av show similar trends and are close to one another with the B0_obs and the B0_new with small deviations. The differences between the B0obs and the B0_new_c_av also show similar trends and are close to one another with those between the B0obs and the B0_new. In contrast, the B0_IRI with ABT-2009 option seems to predict the B0 values poorly during the three seasons at high latitudes and some seasons at midlatitudes. The proposed B0_new is useful for computing approximately the observed B0 and the ionogram-based total electron content (ITEC) of Digisonde, and the plasma scale height over midlatitudes and high latitudes.
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Statistical Analysis of Scintillation Index and ROTI based on Multi-GNSS Data at Chumphon, Thailand
(2021-06-27)
Seechai, Khanitin
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Jamjareegulgarn, Punyawi
;
Wang, Ningbo
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Supnithi, Pornchai
Ionospheric scintillation is caused by the fluctuation of electron density in the ionosphere. Severe ionospheric scintillation can degrade the Global Navigation Satellite System (GNSS) signal quality and performance. In low-latitude region, the phenomenon that may cause the ionospheric scintillation, called equatorial plasma bubble or EPB frequently arise. Rate of TEC change Index (ROTI) is utilized to detect the EPB occurrence. In this work, we aim to determine the relationship between the amplitude scintillation index (S4) and the rate of TEC change index (ROTI) at Chumphon, Thailand. The data are collected from a multi-constellation multifrequency GNSS receiver from 11 November to 31 December 2020. From the analysis, the results show that the percentage of enhanced ROTI and S4 events are 21.57% and 17.65%, respectively. Moreover, the statistical number of simultaneous enhancements of ROTI and S4 show the good correspondence. Refer to GALILEO and BeiDou, the S4 index of low frequency signal is disturbed more frequently than that of high frequency signal. However, this phenomenon cannot be seen in GPS.
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A new expression for computing topside scale height for satellite-based communications
(2017-10-19)
Jamjareegulgarn, Punyawi
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Supnithi, Pornchai
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Hozumi, Kornyanat
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Tsugawa, Takuya
It is well-known that the NeQuick 2 model provides analytical expressions showing a relationship between topside and bottomside ionospheres. Its bottomside thickness parameter (B2bot) is a key parameter for studying topside electron density profile (EDP) and topside parameters, and its topside scale height (Hsc) is also used to identify the topside electron density profile. The B2bot computed using ionogram-derived ionospheric parameters can be used to calculate the Hsc. Unfortunately, the Hsc computed by the original B2bot expression (Hsc old) are significantly higher than the scale heights obtained from digisondes (Hm) and the diurnal variations of the Hsc old are quite different from those of the Hm. Hence, a new expression of B2bot for computing the Hsc is suggested in this work relying on the available expressions of the NeQuick 2 model. Our results show that (1) the Hsc computed by the new expression of B2bot (Hsc new) are comparable to the Hm and the diurnal variations in Hsc new are the same trends as those in Hm; (2) all of the scale heights show diurnal variations with higher values during daytime than during nighttime and the secondary peaks can be found different local times relying on the locations; and (3) the peaks of scale height cause higher absolute differences between Hsc new and Hm (D SH).
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A comparative study of ionospheric profile parameters B0 and B1 over Chumphon with IRI-2012
(2015-08-17)
Jamjareegulgarn, Punyawi
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Supnithi, Pornchai
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Wichaipanich, Noraset
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Ishii, Mamoru
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Maruyama, Takashi
Average diurnal variations of ionospheric profile parameters B0 and B1 in 2009 are studied over Chumphon province, Thailand, and compared those variations with IRI-2012 model. The thickness parameter (B0) and the shape parameter (B1) are two main parameters to compute and depict the F2-layer electron density profile. IRI-2012, the latest version of IRI model, offers three options to provide B0 and B1, i.e., Bil-2000, Gul-1987, ABT-2009. Those options have never been taken for studying and comparing with the ionospheric observation data from a FM/CW ionosonde, Chumphon. Moreover, the observed B0 and B1 from Thailand have never been analyzed nor used while establishing the new table of (B0, B1) values of the IRI model. Hence, B0 and B1 observation is necessary as a part of the global validation study of the IRI-2012 model. Our studies show that: (1) In general, the average diurnal variations of B0 for the observation and the IRI-2012 model show the same trends, except B0 of Gul-1987 during 20:00 - 02:00 LT. The observed B0 averages are equal to 166.13 km and 99.18 km in the daytime and nighttime, respectively. (2) The average diurnal variations of B1 for the observation and the IRI-2012 model show the same trends, except B1 of ABT-2009. Average diurnal variations of the observed B1 look like a sine wave where the peak and lowest values can be found around the midnight and the noontime, respectively. For the IRI-2012 model, B1 of Gul-1987 is the same value as B1 of Bil-2000. The observed B1 averages are equal to 1.98 and 2.51 in the daytime and nighttime, respectively. Our observed B0 and B1 results are similar to other studies in equatorial latitude and low latitude stations. Our comparative studies provide some details for improving B0 and B1 parameters of CCIR-based IRI model in the equatorial latitude region.
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A new expression for computing the bottomside thickness parameter and comparisons with the NeQuick and IRI-2012 models during declining phase of solar cycle 23 at equatorial latitude station, Chumphon, Thailand
(2017-07-15)
Jamjareegulgarn, Punyawi
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Supnithi, Pornchai
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Watthanasangmechai, Kornyanat
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Yokoyama, Tatsuhiro
;
Tsugawa, Takuya
This paper proposes a new expression for computing the bottomside thickness parameter at equatorial latitude station, Chumphon (10.72°N, 99.37°E), Thailand. Its diurnal variations from 2004 to 2006 at this location are then studied. The proposed expression is derived based on two experimental data sources: FMCW ionosonde and dual-frequency GPS system, and some expressions of the NeQuick 2 model. Hence, after both the bottomside thickness parameter computed by the proposed equation, B2bot_Pro, and the bottomside shape parameter (namely, B1_Pro in this work) are computed, the bottomside electron density and the height where the bottomside electron density drops down to be 24% of the NmF2 (namely, h0.24) can be computed and shown in this work using the analytical functions of the IRI model. Moreover, the diurnal variations of the B2bot_Pro are compared with those computed from the NeQuick model, B2bot_NeQ, and the predicted B0 of the IRI-2012 model with ABT-2009 and Bil-2000 options (namely, “B0_ABT” and “B0_Bil”, respectively). The averaged, minimum, and maximum values of percentage deviations among these bottomside thickness parameters are also computed and shown in this work. Our results show that the diurnal variations of B2bot_Pro at Chumphon station have the following patterns: they start to increase during nighttime to the first peaks during pre-sunrise hours, and then decrease abruptly to their minimum values during sunrise hours. Afterward, they increase again to reach the second peaks around local noontime and fall gradually to their starting times during 20–04 LT. The diurnal variations of B2bot_Pro follow generally the same trends as those of the B2bot_NeQ and the B0_ABT, except pre-sunrise hours. The pre-sunrise peaks and sunrise collapses in both the B2bot_NeQ and the B0_ABT can be found occasionally. On the other hand, the diurnal variations in B2bot_Pro differ from those in B0_Bil due to the flattened variation in B0_Bil and the pre-sunrise peaks as well as sunrise collapses in B0_Bil disappear. The pre-sunrise peaks of the B2bot_Pro at the Chumphon station are higher than those of the B2bot_NeQ, the B0_ABT, and the observed B0 at other regions. Furthermore, the percentage deviations between the B2bot_Pro and the B0_ABT (PD_B2B0ABT) are mostly lower than 30% for all seasons of the studied years, opposite to the other percentage deviations studied in this work. The proposed B2bot_Pro parameters in this work follow a similar trend to the B2bot_NeQ and the B0_ABT, but it is not conclusive that the proposed values are equivalent to them.
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Investigating the F2-layer peak height of IRI-2016 model at the equatorial station during the deepest solar activity for 70 years ago
(2023-01-01)
Jamjareegulgarn, Punyawi
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Taugtragoonpaisan, Udomsit
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Myint, Lin Min Min
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Supnithi, Pornchai
The paper investigates the F2-layer peak height (hmF2) of IRI-2016 model at Sao Luis on the magnetic Equator in 2019. Since the deepest solar activity occurred surprisingly in year 2019 for 70 years ago, hence, the IRI-2016 model prediction should be investigated to know the anomalous ionosphere and the deviations between the observation and IRI prediction. The hmF2 is selected to be studied in this work. Our studied results show that the observed hmF2 and the three hmF2 models of IRI-2016 prediction generally show the similar variations only about 60% during this deepest solar activity and the variations of the four kinds of studied hmF2 values show the similar trends for all seasons, except June solstice. The diurnal variation of hmF2_Giro show three peaks for December solstice months and the equinoctial months, while they show four peaks amazingly in June solstice. The hmF2_SHU is the best option that can agree reasonably well to the observed hmF2 at Sao Luis, excluding the pre-sunrise hmF2 peak for all seasons and a very deep trough in June solstice.
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Variations of ionospheric slab thickness over the magnetic equator of Southeast Asia
(2016-09-06)
Jamjareegulgarn, P.
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Supnithi, P.
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Watthanasangmechai, K.
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Yokoyama, T.
;
Tsugawa, T.
In this paper, the diurnal and seasonal variations of the ionospheric slab thickness in an ionosonde chain over magnetic equator of Southeast Asia are studied. Three ionosonde stations of SEALION project located along the magnetic meridian of 100°E are selected to investigate, including two stations in Thailand, namely Chumphon and Chiang Mai, and one station in Indonesia, namely Kototabang. The monthly hourly medians of the foF2 from three ionosonde stations in 2010 are used to compute the observed NmF2. Refer to the TEC data; it can be obtained directly from GPS receiver at Chumphon station since the TEC data in 2010 were observed completely. In contrast, the TEC data at Chiang Mai station lost extremely and those at Kototabang station were unavailable. Hence, the TEC data used for these two stations are obtained from the International GNSS service (IGS). Our results show that 1) for all seasons, the NmF2 values during daytime have the successive decreasing values from Chiang Mai, Kototabang, and Chumphon. While the NmF2 values at three stations are almost identical during nighttime; 2) for all seasons at these three stations, the TEC values in the daytime are larger than those in the nighttime and their maximum values in the equinox and winter are higher than those in the summer; 3) the slab thickness values in all seasons during nighttime are generally larger than those during daytime for all three stations. Meanwhile, during daytime for all seasons, the slab thickness at Chumphon station is the highest among these three stations due to the fountain effect over magnetic equator.
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A New Method for Computing Ionogram-Based TEC Based on Digisonde data for Disaster Prevention
(2020-03-01)
Jamjareegulgarn, Punyawi
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Duangsuwan, Sarun
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Supnithi, Pornchai
;
Srisamoodkham, Worachai
This paper presents a new approach for calculating the ionogram-based total electron content so as to be applied alternatively for alarming and preventing the disasters, for example, earthquake, tsunami or other space objectives. The proposed ITEC is estimated using the analytical expression of NeQuick model, the autoscaled Digisonde data, and a new variable "m" of 1. The results are show that 1) the proposed B0 is close to the B0-obs of Digisonde compared to the B0-IRI and the B2bot of the NeQuick model, 2) the diurnal variation of B0-Pro is the same as that of B0-obs compared to those of B0-IRI and B2bot, 3) the proposed ITEC is also close to the ITEC of Digisonde and TEC-iri, excluding the observed GPS TEC, and 4) all of the studied TEC values behave similar diurnal variations. Since the proposed ITEC is based on the analytical functions, the improvement of TEC-B0-Pro can be conducted reliably in order to close to the GPS TEC possibly and apply it optionally to correct the positioning errors for GNSS and aviation systems.
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A correction factor of bottomside thickness parameter for computing TEC in global navigation satellite systems
(2017-10-19)
Jamjareegulgarn, Punyawi
;
Supnithi, Pornchai
;
Hozumi, Kornyanat
;
Tsugawa, Takuya
This paper proposes two new equations for computing the bottomside thickness parameter of the NeQuick 2 model with a correction factor (B2bot Pro2) and the simulated TEC values (TEC Pro). The main contributions of this work are twofold, i.e., 1) the proposed B2bot Pro2 equation can be used to compute the bottomside thickness whose trends and values are close to ones of the observed B0 (B0 obs) obtains from DPS-4 (Digisonde) and 2) the computed B2bot Pro2 are used to compute the TEC values without additional TEC observation by any devices and TEC computation. In this case, it is useful for some locations where there exist only ground-based ionosonde without TEC observation or TEC measurement doesn't work in some situations. The results show that the B2bot Pro2 have the same trends as the B0 obs. They are closer to the B0 obs, except at 13LT in June solstice and September equinox. The averages of absolute differences between B2bot Pro2 and B0 obs (avAD Pro2) are generally lower than about 8 km. They show that the B2bot Pro2 are close to the B0 obs with the improved percentages of higher than 80%. The TEC computed using the B2bot Pro2 equation (TEC Pro) in the nighttime are generally close to the observed TEC (TEC obs) compared with those in the daytime.

Jamjareegulgarn, Punyawi

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