Click on a segment of research vessel track to select it and view the ADCP backscatter intensity data collected during that segment. Use the right/left arrow keys or arrow buttons to move the selection forward/backwards along the track.

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ADCP backscatter intensity along Palmer LTER research cruises

Information on the project | Video tutorial of viz (Python vers.)

Data originators: ADCP - Dr. Teresa Chereskin | Net tows - Dr. Debbie Steinberg

This visualization allows exploration of ADCP backscatter intensity data collected by annual Palmer LTER research cruises along the western Antarctic Peninsula. (The project is explained in more depth here.) In short, areas of very high backscatter intensity indicate dense aggregations of organisms, so we can use the backscatter data to observe the horizontal and vertical distribution of creatures in this region. Net tows are also performed at intervals along the cruise track; the contents of the nets give us a sense of which species are present where.

Instructions

Click and drag to move the map, and zoom in/out with the +/- buttons in the upper left. Click on a segment of ship track to select it. To move the selection forward/backwards along the track, use your right/left arrow keys or the arrow buttons in the top center of the screen. Use the dropdown in the lower left to select the year of the cruise to view. The Palmer LTER performs sampling cruises once a year (in Jan/Feb) and ADCP data are available starting in 2005; data from 2005 through 2016 are available in this tool.

How to read ADCP backscatter images

When a track segment is selected, its ADCP backscatter data will be shown in the upper right. Cooler colors indicate lower backscatter, while warmer colors indicate higher backscatter. Big blobs of warm colors indicate an aggregation of organisms. Bright yellow lines indicate the seafloor (which has a very loud echo). Here's an example image, showing 2 hours of data as the ship transited:

When a segment of the ship track is lined in pink, it indicates that a net tow was performed there to sample organisms in the water. When a segment of track with a net tow is selected, the count of organisms in the tow is shown in the bottom left. The area of the water column sampled with the net is indicated in the backscatter figure as a red rectangle.

Purple lines indicate temperature profiles taken with a CTD. Temperature profiles are depicted as oceanographic profiles, in which a position further left indicates a lower temperature at that depth, and a position further right indicates a warmer temperature at that depth; small gray numbers along the profile indicate temperature in C.

The sun elevation angle is shown along the top x-axis of the figure. Some organisms perform a diel vertical migration, moving deeper into the water column during daylight and up towards the surface at night. However, as these data are collected during Antarctic summer, the sun spends very little time below the horizon.

Here's an example of 2 hours of ADCP data with a net tow and a temperature profile:

See links at top of pop-up for more information on the project and a walk-through of the Python version of this interactive map.