The purpose of this project is to recover hidden marine weather data recorded in U.S. Navy ships' logbooks during World War II. Like all Old Weather projects, these data will be used to drive sophisticated computer models that help us understand weather and climate in extraordinary detail. But there is another goal that is just as vital - to uncover the source of a mysterious distortion in the Navy temperature data collected during the war.

Service members have been carefully recording marine weather observations since the 1850s. Weather observations were logged on every ship, every hour, almost without fail. This was done even in the midst of battle, in the heart of a typhoon, or in the fatal grip of the Arctic icepack. Now, with the challenge of climate change upon us, it is astonishing that most of this legacy is still unused and unknown. Work you contribute here to recover these hidden data will make a lasting impact on climate science, but also shine a new light on the dedicated work of thousands of service members who collected these observations over nearly two centuries.