Actinae in the North Pacific Ocean

March 29th, 2008 |

AVHRR false color images (Animated GIF)

AVHRR false color imagery (above; viewed using Google Earth) and GOES-11 visible channel imagery (below) revealed a family of cyclonic vorticies  propagating westward across the eastern North Pacific Ocean on 29 March 2008. The radially-banded cloud features that form such cloud “swirls” are known as actinae or actinoform clouds, and they are seen occasionally in the marine stratocumulus cloud field over the Pacific Ocean (for example, other similar cases were observed in March 2007 and June 1997). This type of cloud pattern was first observed on TIROS V imagery way back in August 1962 and October 1962.

GOES-11 visible images (Animated GIF)

2 Responses to “Actinae in the North Pacific Ocean”

  1. Joel Gratz says:

    The Actinae look amazing, but can you comment on what appears to be NE-to-SW oriented waves the propogate ESE through the entire cloud field? This is most evident on the visible animation…thanks!

  2. scott.bachmeier says:

    Good observation, Joel — gravity waves such as those you point out are observed quite frequently in the marine stratucumulus cloud field over the eastern Pacific. The strong marine layer temperature inversion acts as a “duct” to allow these waves to propagate for long distances, relatively unperturbed.

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