Extraction of Ship Elevations from Sea Bird Observation Cruise
Tracks using Gridded Satellite Altimetry Elevation Models

This study was carried out by Diversified Scientific Solutions as part of a contract for Environment Canada under the direction of Dr. Patrick O'Hara in colaboration with Dr. Charles Hannah of the Department of Fisheries and Oceans

Background

The Colorado Center for Astrodynamics Research (CCAR) has developed daily sea surface height grids using multiple satellite altimeter sensors. These grids clearly define mesoscale eddies which are considered to be important vectors that deliver rich coastal water nutrients to the open ocean.  Such nutrients play an important role in supplying a source of vital energy to the water column as well as pelagic birds. Since the mid 1980s, a large database of ship transects have criss-crossed the North Pacific collecting data of bird observations and plankton sampling. Ship elevations were extracted from the available altimeter grids for each cruise date.  In this study, 1120 days of ship observations were examined spanning the years 1992-2015. The positions of each sampling location for this time period has been summarized in the plot below.

Cruise position plot showing sampling locations

(Click on plot to expand)

This work contributes to an integrated study linking DFO’s oceanography work with Environment and Climate Change Canada’s work on seabird foraging ecology.

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