Abstract. We search for lost bodies of water in the cities of Manila, Tacloban, Iloilo, Cebu, Davao, and Naga by aligning their digitized Spanish-era and American-era maps to Google maps. These vanished ancient waterways can either become flooding hazards in case of extreme weather events, or liquefaction hazards, in case of earthquakes. Digitized historical maps of the cities were georectified, overlaid on current Google maps, and checked for potential missing bodies of water. Inspection through field visits and interviews with locals were conducted to verify the actual status of suspected sites. The validation identified lost, found, and even new bodies of water. There was also evidence of affected buildings, rainless flooding, and a “new normal” for the meaning of flooding among frequently inundated residents.

<p>In order to predict the intensity and location of extreme weathers, such as torrential rainfall by individual thunderstorm or typhoon, we are developing the new methodology of weather monitoring using a ground AWS network with lightning sensors and micro-satellites weighting about 50kg, which will realize quasi-real-time thunderstorm monitoring with broad coverage. Based on the AWS network data, we plan to operate micro-satellites in nearly real-time, manipulating the attitude of satellite for capturing the most dangerous or important cloud images for 3D reconstruction. We have developed and launched several micro-satellites and been improving the target pointing operation for this decade. We succeeded in obtaining the images of the typhoon center at a resolution of 60-100 m for Typhoon Trami in 2018 and Typhoon Maysak in 2020. Using 4 or a few 10s images captured from different angles by one micro-satellite when it passed over the typhoon area, 3D models of typhoon eye were reconstructed, which have a ground resolution of ~100 m. Due to the unusual temperature profile around typhoon eye, it’s very difficult to estimate the heigh distribution of cloud top only with a thermal infrared image at a resolution of 2 km taken by geostationary meteorological satellite. This is one of the biggest limitations in estimating the precise intensity of typhoons, namely, the center pressure or the maximum wind velocity. The on-demand flexible operation of micro-satellite will achieve the high accuracy estimation of typhoon intensity as well as the speed estimation of individual thunderstorm development, which can be applied to disaster management. This research was conducted by a mixed team of Japan and the Philippines, supported by Science and Technology Research Partnership for Sustainable Development (SATREPS), which is funded by Japan Science and Technology Agency (JST) / Japan International Cooperation Agency (JICA).</p>

<p>Typhoons are extreme weather phenomena that inflict damages and casualties around globe. These phenomena are difficult to study because of their chaotic behaviour but the capacity to measure their intensity can help mitigate the hazards that they bring. In the past, several attempts have been done to relate typhoon's intensity with the structural evolution of its eye. This suggests the possible relation between the typhoon intensity with typhoon eye altitude. In this research, we visualize Typhoon Trami’s structure by reconstructing the three-dimensional model inside its eye and analyze the information of its cloud top altitude. An experiment was conducted under the SATREPS/ULAT project (SATREPS: Science and Technology Research Partnership for Sustainable Development, ULAT: Understanding Lightning and Thunderstorm) where images of Typhoon Trami were taken from an aircraft last September 26, 2018. Aircraft images were used to reconstruct the 3D model inside the typhoon eye because they provide closer views of the typhoon than that of geostationary satellite images, making it easier to reconstruct a 3D model. The 3D reconstruction generated covers 43 km region of the typhoon eye at 20.2 m/pixel spatial resolution. Three cross-sections of the 3D model were analyzed, and the resulting altitude distribution was compared with the cloud-top altitude estimated by mapping the brightness temperature of the Himawari Thermal Infrared Band 13 with cloud-top height as measured by NOAA sonde data. From the 3D model, the altitude distribution ranges from 5.3 km to 14.3 km which corresponds with the altitude estimated from the brightness temperature of 6.5 km to 14.3 km. However, regions of altitude difference can also be observed between the two methods. This study shows that a three-dimensional model could be a good mode of typhoon visualization as it shows a more detailed typhoon structure such as the stairstep structures that was detected at some regions within the typhoon eye. This research was supported by SATREPS, funded by Japan Science and Technology Agency (JST) / Japan International Cooperation Agency (JICA).</p>

<p>We have been developing a ground-based lightning and AWS network system under the projects of a SATREPS “ULAT” and e-ASIA in order to realize precise real-time monitoring and issuing alert for torrential rainfall and typhoon extreme based on international cooperation among Japan, Philippines, Indonesia and other SE-Asian countries supported by JST, JICA, PHL-Microsat and other funding. The intensification of lightning activity is precursor of typhoon growth. In these projects, we are constructing ground-based lightning and AWS—automated weather station—network system with 12 sites for VLF radio wave measurement in nation-wide of Philippines and with 50 sites for electrostatic field measurement in Metro Manila together with infrasound sensor. We are going to complete the installation of the sensors at most of the planned ~60 sites by the end of this year. We already started with installed sensors and achieved preliminary results for typhoon and thunderstorm measurement. We are also doing practice in operating our micro-satellite which can make rapid target pointing at high accuracy. Using the photos captured from the satellite, now we can reproduce the detailed 3-D structure of the cloud at best quality even compared to the latest radar system.</p>

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