To remote sensing scientists, peering directly into the eye of a tropical storm is like hitting a hole in one. That’s exactly what NASA’s CloudSat satellite did on May 16th, completing a stunning overpass of Typhoon Dolphin as the category 4 storm churned across the west Pacific.
CloudSat, which comprises part of NASA’s Earth-orbiting observatory, sends pulses of microwave energy through our planet’s atmosphere, some of which is reflected back to the spacecraft. Conceptually, CloudSat is similar to another tool we looked at last week, RapidScat, which NASA uses for mapping wind speed and direction. The strength of the signal CloudSat receives is related to the amount of ice or water in a cloud, while the time delay can be used to calculate the distance between the cloud and the Earth’s surface.
In the image directly below the aerial view of Typhoon Dolphin, we see the storm in cross section, with darker blues representing heavier precipitation. Combining this data with infrared images collected from Japan’s MTSTAT satellite, researchers produced another cross-sectional view of the storm’s eye and its overall cloud structure:
MTSTAT and CloudSat imagery of Typhoon Dolphin. Image Credit: Natalie D. Tourville/Colorado State University
What’s amazing about these images is that CloudSat, scanning the entire Earth, has a field of view of just 0.5 square miles. Zeroing in on a tropical storm is difficult enough, but most cyclones are over 250 miles wide, while the eye of the storm is a small fraction of that size. A hole in one, indeed.