In 1965, the first "anomalous cloud lines" were observed in images from the TIROS VII satellite. It was hypothesized that the most likely cause was from the exhaust from ships. Many studies since have confirmed the cause, and they are now referred to as ship tracks. Scientists soon realized that the climatic impacts from aerosols could have a large effect on climate through the Twomey effect, and that ship tracks provided an excellent laboratory for their studies.
