UCTD and EM/APEX measurements in support of the April 2015 AirSWOT Campaign : cruise and data report

Abstract

AirSWOT is an aircraft mounted instrument for measuring and imaging sea surface height (SSH), and it is similar to the SWOT (Surface Water Ocean Topography) instrument that will be deployed on a satellite in 2020. A field campaign was conducted in April 2015 to examine the performance of AirSWOT and to better understand how the measurement is affected by surface waves and currents. Supporting measurements were collected from the R/V Shana Rae, the R/V Fulmar, and a second aircraft (a Partenavia P68 operated by Aspen Helicopter, Oxnard,CA for UCSD/SIO). From 17-20 April 2015, the R/V Shana Rae, a 50-foot research vessel, was used for collection of Underway CTD (or UCTD) measurements and for deployment and recovery of three EM/APEX floats in a study area off the central California coast. The UCTD measurements are being used to estimate the sea surface height signal associated with variations in ocean density structure. The EM/APEX floats provide time series of the same, as well as vertical profiles of ocean velocity. The purpose of this report is to document the shipboard operations on the R/V Shana Rae and the resulting UCTD and EM/APEX data sets.