I didn’t check eligibility – some of them may be available for international participants.
Center for Western Weather and Water Extreme, SIO (Climate Science, Hydrology)
Woods Hole Oceanographic Institution (Oceanography)
中谷医工計測技術振興財団 中谷RIES (Any STEM topic, depending on the lab matching)
ヴルカヌス研修 (More focused on Engineering and not on Earth Science topics, but I list here. It’s a great program)