JpGU-AGU Joint Meeting 2020

講演情報

[E] 口頭発表

セッション記号 A (大気水圏科学) » A-AS 大気科学・気象学・大気環境

[A-AS14] Extreme Events: Observations and Modeling

コンビーナ:Sridhara Nayak(Disaster Prevention Research Institute, Kyoto University)、JAGABANDHU PANDA(National Institute of Technology Rourkela)

[AAS14-11] Detection and Possible Interpretation of Tropospheric Dispersive Phase Associated with Heavy Rain Events

*Naufal Setiawan1Masato Furuya1 (1.Space Geodesy Research Section, Department of Earth and Planetary Sciences, Hokkaido University, Japan)

キーワード:Heavy rain event, InSAR, Split-spectrum method

Hanssen et al., 1999 demonstrated the ability of Interferometric Synthetic Aperture Radar (InSAR) in the detection of water vapor associated with rain, using during the European Remote Sensing (ERS) satellite tandem mission. Furthermore, taking the advantage of the Advanced Land Observing Satellite (ALOS) satellite emergency observation, a localized signal related to water vapor during Seino heavy rain event was identified (Kinoshita et al., 2013). There were no surface deformation events during these former studies.

Utilizing the dispersive nature of the ionospheric layer, the range split spectrum method (SSM) separates InSAR phase into non-dispersive and dispersive phase, and thus ionospheric delay could be mitigated (Brcic et al., 2010; Rosen et al., 2010; Gomba et al., 2016). Additionally, higher-order ionospheric effects, such as geomagnetic and geometric ray-bending could be revealed using different frequency dependence of InSAR phase (Furuya et al., 2017). In contrast, tropospheric/ neutral atmospheric delay has a non-dispersive nature. Thus, if during heavy rain case, no surface deformation occurred and ionospheric contribution were negligible, water vapor can be detected in the non-dispersive phase accompanied by a virtually no dispersive phase.

In this presentation, we will show our detection results on ; (i) InSAR phase anomaly related to the water vapor during heavy rain episodes during ALOS-2 normal observation mode, (ii) unknown dispersive phase in SSM, and (iii) possible interpretation of the unknown dispersive phase during heavy rain cases.