Remote Sensing the Ocean Biosphere

This article reviews the broad range of contemporary remote sensing technologies that can access the ocean, while emphasizing next-generation ones that might revolutionize the field. Significant challenges remain in studying the largest part of Earth's biosphere. As of 2022, less than 10% of the ocean has been imaged at a comparable resolution to the surface of the moon and Mars, despite comprising more than 90% of the habitable volume of our planet. Within the past five years, phenomena as modest as refractive ocean-wave distortion have finally been addressed, but steep technology maturation and challenges persist in remote sensing life in our oceans, hampering our understanding of rapidly changing ecosystems at a crucial inflection point in our history. We survey the field and share emerging technologies and trends, while motivating the case for a future Sustained Marine Imaging Program for the next decade in remote sensing the ocean biosphere. Expected final online publication date for the Annual Review of Environment and Resources, Volume 47 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.