Perpustakaan Digital ITB

Atmosphere dynamics monitoring is essential for hazard assessment of hidrometeorological disasters. In this research, the altimetry satellite performance for atmosphere dynamics observation is going to be examined. Altimetry satellite has an on-board microwave radiometer for water vapor measurement which originally used to provide the wet path delay correction for the altimeter range measurement. This microwave radiometer has been assessed in many studies and was already verified for having good precision on measuring the integrated water vapor thus offers the potential for altimetry satellite to also be utilized for atmosphere observation, specifically on the water vapor distribution. The altimetry satellite mission which are going to be studied is the Jason altimetry satellite series which includes the TOPEX/Poseidon, Jason-1, OSTM/Jason-2 and Jason-3. The specification of the observation is analyzed, such as its spatiotemporal resolution and coverage on how it would comply for atmosphere dynamics monitoring. Comparison with other atmosphere observation satellites in terms of resolution and instruments for observing the atmosphere are also provided. Furthermore, the water vapor radiometer data are assessed on how it could capture atmosphere phenomena along the equator such as the monsoon, El Niño Southern Oscillation (ENSO), Indian Ocean Dipole (IOD) and climate changes. Lastly, the water vapor data are going to be compared to the GSMaP rainfall data to see if the altimetry-based data can be a good estimator for rainfall. For the examination of the altimetry microwave radiometer data on capturing the monsoon and other seasonal variation on the equator, the author generated a monthly climatology water vapor maps from the data. From the maps, the Indonesia and American monsoon characteristics are apparent also with other seasonal variation such as the shifting of Intertropical Convergence Zone (ITCZ) and South Pacific Convergence Zone. For the examination of the data on capturing the ENSO and IOD signal, the data are compared to the climate indices for the ENSO and IOD monitoring. The comparison yields high correlation coefficient (CC) value of more than 0.75 with the ENSO indices, i.e. ONI and EQSOI and 0.6 with the IOD indices, the DMI (the CC value is lesser when the averaged over area water vapor data is compared instead). For the examination on the monitoring of climate changes, decadal mean maps are generated. From the maps, similar feature of climate changes with other studies are portrayed, such as the increasing of water vapor in Indonesia, Indian Ocean and the ITCZ region in Pacific at 1990-2011 time period. The comparison with GSMaP monthly rainfall data yields >0.6 CC value. From all the results the author concludes that the altimetry water vapor radiometer data can be utilized for atmosphere dynamics monitoring in monthly time-scale.