Hostetler, Chris: NASA Langley Research Center (Project Lead)
Project Funding:
2016 - 2019
NRA: 2015 NASA: Ocean Biology and Biogeochemistry
Funded by NASA
Abstract:
The Cloud-Aerosol Lidar with Orthogonal Polarization on the CALIPSO satellite has shown that ocean subsurface retrievals are possible from space. However, the CALIOP instrument was not designed for ocean profiling and has limitations for this application. Interest in space-based ocean lidar measurements is increasing and was called for by the Aerosols-Clouds-Ecosystems Science Working Group and white paper inputs to the current Decadal Survey. Our studies show that such measurements can penetrate through up to 70% of the ocean euphotic zone to characterize biomass features far out of reach of traditional passive sensors and would therefore dramatically enhance the accuracy of global plant biomass and carbon estimates. Our team at NASA Langley Research Center has developed an airborne prototype atmosphere and ocean profiling lidar (HSRL-1) and deployed it on the SABOR mission in 2014 as part of our Ocean Biology and Biogeochemistry (OBB) project funded in FY13-15 (Proposal number 12-OBB12- 0063). This successful OBB project proved that the high spectral resolution lidar (HSRL) technique that we employed on that instrument could indeed provide accurate profiles of diffuse attenuation and particulate backscatter measurements at 532 nm. The diffuse attenuation profile provides information on the availability of light for photosynthesis as a function of depth, and the particulate backscatter profile can be used to derive vertically resolved profiles of phytoplankton biomass and particulate organic carbon. Since submitting that proposal, our team was also funded to upgrade our more advanced HSRL-2 instrument to enable ocean profiling at 355 and 532 nm and add fluorescence channels for chlorophyll and colored dissolved organic matter (cDOM). This project is submitted as a successor to our earlier OBB-funded project (Proposal number 12-OBB12-0063) in response to Section 2.4 in the A.3 Appendix to the ROSES announcement. Under this project, we will (1) refine the retrievals developed and demonstrated under our earlier award and conduct comprehensive comparisons of the retrieved products against in situ and remote sensing measurements, (2) develop ocean-relevant retrieval algorithms for our more advanced HSRL-2 instrument, (3) assess the benefits and capabilities of a future spaceborne ocean-profiling HSRL instrument, including sampling studies and expected random and systematic errors, and (4) provide consultation to the OBB community on the capabilities and applications of airborne and spaceborne lidar for ocean applications.
More details may be found in the following project profile(s):
