Distinct patterns of shallow cumulus clouds can sometimes be seen from the distance of a satellite. The clouds may form rows called cloud streets when winds are much the same at various heights and there is an unstable layer under a stable layer, e.g. when polar air blows over a warm ocean (Section 7.4). The rows of cloud are parallel to the wind and perhaps hundreds of kilometres long, with a distance between adjacent rows equal to about five times the depth of the convective layer. A glider pilot can fly a long way in the updraughts just below a cloud street.
Other patterns resemble a honeycomb, with numerous open cells or closed cells, each with a diameter of 50-1,600 km. An open cell involves subsidence in the middle surrounded by gently ascending air, whereas it is the other way round in a closed cell.
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