Study of contrails observed from the ERTS 1 satellite imagery

This is the authors' abstract. We don't add key points for this paper.

The ERTS 1 maps the surface of the earth in several spectral bands with ground resolution of approximately 80 m. On two images taken October 23, 1972, over the southern shores of Cyprus, several contrails could be easily discerned. The pressure at the contrail height is inferred here to be 280 ± 60 mbar. The meteorological conditions prevailing at the estimated height of the contrails were found to favor the formation of contrails. An upper limit of the lateral diffusion rates of (9.6 ± 2.4) × 105 cm2/s is obtained from measurements of the variation of the width of one of the trails over distances of the order of 100 km. An attempt to infer the optical depth τc of the contrail in the two bands MSS5 and MSS7 resulted in 0 < τc (MSS5) < 0.025 and 0 < τc (MSS7) < 0.08. The largest possible average number densities in the contrail are 0.12 cm−3 if the ice crystals have bases with radii of 10 μm and 0.005 cm−3 if the ice crystals have large base radii (∼50 μm) as reported in recent literature.