Meteorological data from various ships that were bombed by the Japanese in Pearl Harbor were retrieved with the aim of helping scientists understand how the global climate changes.
The crew members on various warships, such as the USS Pennsylvania and USS Tennessee, lost their lives when their ships were targeted in December 1941. Despite the losses, many ships returned to the front lines during World War II, and American sailors continued their daily duties. These duties included recording meteorological data.
Meteorological data from 19 U.S. Navy ships
A new study published in the “Geoscience Data Journal” narrates the story of the recovery of meteorological data from 19 U.S. Navy ships, including battleships, aircraft carriers, destroyers, and cruisers, that participated in World War II. Their rescue was made possible through the work of more than 4,000 volunteer citizen-scientists who transcribed over 28,000 logbook pages from the U.S. Navy fleet stationed in Hawaii during the period 1941-1945.
Previous studies have suggested that these years were unusually warm. The new dataset, which includes over 630,000 records with more than three million individual observations, will help determine if this was the case. The logbooks contain millions of entries related to surface air and sea temperatures, atmospheric pressure, wind speed, and wind direction.
Data providing a window into the past
As noted by Pravin Telte, a researcher at the University of Reading who led the study, “Disruptions to shipping lanes during World War II led to a significant reduction in maritime weather observations. Until recently, records from that era were still only available on paper in classified documents. The scanning and rescue of this data provides a window into the past, allowing us to understand how the global climate behaved during a period of significant upheaval.”
Observations from warships were the primary sources of maritime weather observations during World War II, but many records were destroyed as acts of war or simply forgotten due to the lengthy period during which they were classified. The recovered dataset reveals that the war imposed changes in observation practices. For example, more observations were made during the day instead of at night to reduce exposure to enemy ships and avoid detection. It is believed that such changes could have led to slightly warmer temperature recordings, thus explaining why historical climate records show a period of unusual warmth during World War II. The new data will help investigate this uncertainty.
Filling gaps in existing data
Since few or no digitized observations exist from the Indian-Pacific and Far East regions during World War II, the surviving records will help scientists fill gaps in existing datasets and ensure that they can better understand how the global climate evolved from the early 20th century onwards.