scholarly journals Mapping the cloud-to-ground lightning occurrence in Fiji

2006 ◽  
Vol 24 (1) ◽  
pp. 32
Author(s):  
V Ramachandran ◽  
A Kishore ◽  
S Kumar
Keyword(s):  
Seasonal Variation ◽  
Diurnal Variation ◽  
Tropical Rainfall Measuring Mission ◽  
Peak Activity ◽  
Annual Average ◽  
Tropical Rainfall ◽  
Group Arrival ◽  
Cloud To Ground Lightning ◽  
A Site ◽  
Imaging Sensor

Using the Time Of Group Arrival (TOGA) of sferics two year (Jan2003-Dec2004) annual average of about 3,200 and 1,200 cloud-to-ground (CG) flashes were recorded in the two larger islands, Viti Levu and Vanua Levu, Fiji. A two year average CG flash density showed maxima of 0.80 and 0.35 flashes/km2 per year in two islands. The diurnal variation showed peak activity between 14:00 hrs- 16:00 hrs LT and the seasonal variation showed enhanced lightning incidences during November-April. Data from Lightning Imaging Sensor (LIS) aboard the NASA Tropical Rainfall Measuring Mission (TRMM) satellite are also presented for the same period at the two locations. Lightning in a 10 km �10 km area was compared with total rain accumulation at a site midway in the area which shows good correlation.

scholarly journals Diurnal Variation of TRMM/LIS Lightning Flash Radiances

2017 ◽  
Vol 98 (7) ◽  
pp. 1453-1470 ◽  
Author(s):  
Themistoklis Chronis ◽  
William J. Koshak
Keyword(s):  
Diurnal Variation ◽  
Mesoscale Convective System ◽  
Tropical Rainfall Measuring Mission ◽  
The United States ◽  
Global Scale ◽  
Diurnal Variations ◽  
Convective System ◽  
Lightning Flash ◽  
Mesoscale Convective ◽  
Imaging Sensor

Abstract This study provides, for the first time, an analysis of the climatological diurnal variations in the lightning flash radiance data product ε from the Tropical Rainfall Measuring Mission Lightning Imaging Sensor (TRMM/LIS). The ε values over 13 years (2002–14), and over a global scale (∼38°S–38°N), reveal novel and remarkably consistent regional and seasonal patterns as a function of the local solar time (LST). In particular, the diurnal variation of ε (over both continental and oceanic regions) is characterized by a monotonic increase from late afternoon (∼2000 LST), attaining a maximum around 0900 LST, followed by a decreasing trend. The continental (oceanic) ε values reach a broader minimum spanning from ∼1500 to 1900 LST (∼1800 to 2000). The relative diurnal amplitude variation in continental ε is about 45%, compared to about 15% for oceanic ε. This study confirms that the results are not affected by diurnal biases associated with instrument detection or other statistical artifacts. Notable agreement is shown between the diurnal variations of ε and the global-scale (∼38°S–38°N) mesoscale convective system areal extent. Comparisons with recently published diurnal variations of cloud-to-ground lightning peak current over the United States also exhibit a marked similarity. Given the novelty of these findings, a few tentative hypotheses about the underlying physical mechanism(s) are discussed.

scholarly journals Distribusi Spasial dan Temporal Petir di Sumatera Barat

2016 ◽  
Vol 5 (4) ◽  
pp. 303-312
Author(s):  
Elfira Saufina ◽  
Marzuki Marzuki
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
Tropical Rainfall ◽  
Imaging Sensor

Distribusi spasial dan temporal petir di Sumatera Barat telah diteliti dengan menggunakan data satelit Tropical Rainfall Measuring Mission-Lightning Imaging Sensor (TRMM-LIS) selama 16 tahun pengamatan (1998-2013). Hubungan antara petir dan curah hujan diteliti dengan memanfaatkan data TRMM 3B43. Hasil penelitian menunjukkan bahwa petir di Sumatera Barat banyak terjadi di darat dengan densitas tertinggi terjadi pada bulan Desember, Januari dan Februari (DJF). Petir di darat banyak terjadi pada sore hari mulai jam 17.00 LST hingga tengah malam dan kabupaten Dharmasraya merupakan daerah yang memiliki densitas kilatan petir tertinggi terutama selama periode DJF. Siklus diurnal petir konsisten dengan siklus migrasi awan dari laut ke daratan Sumatera yang ditemukan oleh peneliti sebelumnya. Hubungan curah hujan dan petir di Sumatera Barat bervariasi antara satu kabupaten dengan kabupaten lainnya. Berdasarkan nilai regresi linier antara petir dan curah hujan terlihat bahwa daerah yang memiliki korelasi yang cukup kuat antara densitas petir dan curah hujannya adalah Kabupaten Solok,  Solok Selatan, Padang Pariaman, dan 50 Kota sedangkan daerah yang memiliki korelasi yang rendah adalah Kepulauan Mentawai, Pesisir Selatan, dan Agam. Dengan demikian, di beberapa kabupaten petir dapat menjadi indikator untuk penentu curah hujan tetapi tidak untuk beberapa kabupaten yang lain.Kata kunci: distribusi petir, Sumatera Barat, TRMM

scholarly journals Observed and predicted characteristics of equatorial F1 layer during solar minimum

2014 ◽  
Vol 32 (5) ◽  
pp. 571-580 ◽  
Author(s):  
C.-C. Lee
Keyword(s):  
Seasonal Variation ◽  
Diurnal Variation ◽  
Solar Minimum ◽  
Shape Parameter ◽  
Early Morning ◽  
Peak Height ◽  
Time Range ◽  
Occurrence Probability ◽  
Peak Density

Abstract. This study aims to assess the predictability of IRI-2012 on the equatorial F1 layer during solar minimum. The observed characteristics of F1 layer by the Jicamarca digisonde are compared with the model outputs. The results show that the time range for F1-layer appearance of observation is longer than that of IRI-2012, by at least 1 h in the early morning and later afternoon. In IRI-2012, there are three options for the occurrence probability of F1 layer: IRI-95, Scotto-97 no L, and Scotto-97 with L options. The first option predicts the probability well, but the last two underestimate the probability. The peak density of F1 layer (NmF1) of observation is very close to that of IRI-2012. For the F1 peak height (hmF1), the modeled values are smaller than the observed ones. The observed seasonal variation of hmF1 is not found in the modeled results. Nevertheless, the observed diurnal variation of hmF1 is similar to the modeled results with the B0 choices of Bil-2000 and ABT-2009. Regarding the shape parameter, the values of D1 (the shape parameter of F1 layer in observation) are much greater than the values of C1 (the shape parameter of F1 layer in IRI-2012). The D1 values are 3–6 times the C1 values. The diurnal variation of D1 is similar to that of C1, but the seasonal variation of D1 is not.

Comparison Between Estimated Rainfall Estimated by the Tropical Rainfall Measuring Mission (TRMM) Satellite and Data Observed in the Lagoa Mirim/RS Basin, Brazil

INCREaSE 2019 ◽  
2019 ◽  
pp. 97-110
Author(s):  
Géri Eduardo Meneghello ◽  
Letícia Burkert Méllo ◽  
Ritâ De Cassia Fraga Damé ◽  
Francisco Amaral Villela ◽  
Maria Clotilde Carré Chagas Neta ◽  
...  
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
Tropical Rainfall
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