ANNUAL AND SEMI-ANNUAL VARIATIONS OF THE GPS-DERIVED PRECIPITABLE WATER VAPOR OVER SUMATRA ISLAND

Dudy D. Wijaya (Institut Teknologi Bandung (ITB))
Nabila S.E. Putri (Institut Teknologi Bandung (ITB))
Yan A. Rahmawan (Badan Informasi Geospasial (BIG))
Sidik T. Wibowo (Badan Informasi Geospasial (BIG))
Akhmad Y. Basuki (Badan Informasi Geospasial (BIG))
Muhammad S. Fathulhuda (Institut Teknologi Bandung (ITB))
Vera Sadarviana (Institut Teknologi Bandung (ITB))

JURNAL METEOROLOGI DAN GEOFISIKA
Vol 22, No 2 (2021)

We have utilized the Global Positioning System (GPS) data at 57 stations distributed over Sumatra Island to investigate spatio-temporal variations of the atmospheric precipitable water vapor (PWV). We focused on the annual and semi-annual cycles of the PWV. Our results show that Sumatra Island is divided into two distinct areas of annual and semi-annual cycles, where the boundary line between the areas is approximately at 2oS. While the annual cycle dominates the area over the southern side of 2oS, the semi-annual cycle is dominant over the northern side. Our results have further shown that the maximum phase of annual cycle occurs between January-March with considerably large amplitudes (10-15 mm). On the other side, the maximum phase of the semi-annual cycle in general occurs around November and May, whose amplitude is approximately between 1-5 mm. Our results are consistent with other results using rainfall data.