2-D lidar scans at Makapuu, Hawaii

This figure shows the color coded scattering coefficient at 532 nm (in m-1) in the area surrounding Manana and Kaahikaipu islands, off Makapuu on the northeast shore of O'ahu, Hawaii (the vertical axis is oriented at 60 deg. E) taken on 10/16/97. This data was obtained by inverting the PMT signals obtained in ~100 stacked profiles (10 laser shots per profile), while scanning horizontally at 1 deg/sec. The laser beam was kept at an elevation of 5 m above the ocean surface. The two blank sections are due to the laser hitting the islands. Plumes of water/salt spray appear as red patches due to waves breaking on rocks on the edges of the islands. The plumes are drifting with the trade winds which are from 56.6 degrees east at 2.6 m/s.

This scan, taken 40 minutes later, shows turbulent vortices appearing on the leeward side of Manana island. The vortices are due to the zones of shear between the stationary air behind the island and the faster moving air on either side.

This figure shows the results of a vertical scan made about 2 hours later with the laser pointed in the wind direction at elevations of 0-90 degrees. The red patches at an altitude of ~700 m are clouds.

The link below is a GIF movie made of 17 similar images taken at ~30 sec. intervals 10 days earlier than the image above (the scattering coefficient color coding in the movie is different from the coding used in the above two figures)

movie.gif(556 KB)