National Research and Development Agency Disaster Prevention Science and Technology Research Institute
497ｍ
480ｍ
458ｍ
450ｍ
445ｍ
375ｍ
345ｍ
Around 300m
Around 250m
458m altitude
Cloud particle observation (National Research Institute for Earth Science and Disaster Resilience)
From June 2016 to December 2022, observations were conducted at a height of 458 meters to measure the size and number of cloud droplets. By utilizing the height of the TOKYO SKYTREE to observe conditions within clouds, which are usually difficult to observe except from airplanes, the obtained data is being used in the development of cloud radar for the early detection of sudden heavy rainfall.
Aerosol observation (National Institute of Polar Research, Hiroshima University, etc.)
The observation was conducted at an altitude of 458 meters with the aim of analyzing atmospheric particulate matter (aerosols) collected, primarily focusing on particles that become nuclei for cloud droplets (cloud droplet condensation nuclei) and particles that have the property of freezing cloud droplets (ice crystal nuclei).
About the Research
There are three reasons why observing cloud droplets and aerosol particles at TOKYO SKYTREE is significant:
1. Elucidating the impact of human activities on the occurrence of sudden heavy rain
Aerosol particles released by human activities act as condensation nuclei (cloud condensation nuclei) when water vapor condenses to form cloud droplets, and it has been pointed out that this can intensify sudden, heavy downpours. In places with high levels of human activity, such as Tokyo, the number of aerosol particles is very high, so it is thought that many small cloud droplets are formed, which are then carried to the upper atmosphere by cumulonimbus clouds, freeze, and cause heavy rain. Through observations at TOKYO SKYTREE, we clarified the extent to which cloud condensation nuclei and ice crystal nuclei exist in the atmosphere above Tokyo, and obtained basic data to elucidate the impact of human activities on sudden, heavy downpours.
2. Understanding the impact of clouds on climate change
Clouds reflect solar radiation and absorb infrared radiation from the ground, thus possessing both cooling and warming effects on the Earth. The extent to which clouds reflect solar radiation depends on the size and number of cloud droplets. Through observations at TOKYO SKYTREE, we aim to clarify the actual state and seasonal changes of clouds and use this information to validate climate change prediction models.
3. Verification of Earth observation satellites and cloud radar
Currently, there are plans to launch an Earth observation satellite equipped with cloud radar (radar that observes cloud droplets) to observe clouds from space. The National Research Institute for Earth Science and Disaster Resilience has also conducted test operations of cloud radar to detect cumulonimbus clouds at an early stage. Ground truth (data for comparative verification) is necessary for observations using cloud radar, so it is hoped that cloud and aerosol data acquired from TOKYO SKYTREE will be utilized.
Entering the clouds to conduct observations has been a long-held dream of mine as a meteorologist. Thanks to TOKYO SKYTREE, I was able to conduct observations from within the clouds myself, and I am very happy about that. I have been able to obtain a lot of data that I could not get before, and I am happily overwhelmed with excitement as I analyze it.
(Professor Ryohei Misumi, College of Liberal Arts and Sciences, Nihon University; Visiting Researcher, National Research Institute for Earth Science and Disaster Resilience)