Feng, L., T. Zhang, T.-Y. Koh, and E. M. Hill, 2021: Selected years of monsoon variations and extratropical dry-air intrusions compared with the Sumatran GPS array observations in Indonesia. J. Meteor. Soc. Japan, 99,
Special Edition on Years of the Maritime Continent (YMC),
Early Online Release Graphical Abstract NEW GA
Plain Language Summary: Although the Global Positioning System (GPS) has been widely used to study long-term trends or diurnal and subdiurnal cycles of precipitable water vapor (PWV), it has been rarely used for the intra-seasonal scale. We used the zenith wet delay (ZWD) data from the Sumatran GPS Array (SuGAr) in Indonesia, with help from reanalysis data, to study the summer intra-seasonal variability of PWV over Sumatra in years without strong inter-annual variability, and to probe the underlying atmospheric processes that control the variability.
- The summer intra-seasonal variability of daily ZWD over Sumatra in 2008, 2016, and 2017 is dominated by the South Asian Summer Monsoon, and further influenced by dry-air intrusions associated with eastward-propagating Rossby waves in the Southern Hemisphere midlatitudes.
- As the first ground-based GPS data used for studying dry-air intrusions, the SuGAr data provide new in-situ evidence that extratropical dry-air intrusions reach the deep tropics within 5° south of the equator over the Maritime Continent.