In my 40 years as a scientist focusing on global ocean circulation and air-sea interaction, I’ve learned that there is a strong link between technological developments and the degree to which we can answer our scientific questions. Many of the questions we ask are timeless, but our ability to answer them arrives when the right tools emerge. In my career, a few opportunities have arisen where I could use and promote new tools to solve the fundamental questions of physical oceanography.
In my mind, there have been several dramatic shifts in answering these questions during my lifetime. Only 100 years ago, in the early part of the 20th century, our ocean science depended on lowering wires and ropes from ships, attaching bottles to wires, and men on ships to use these tools to describe the depth of the ocean, the water properties, and weather at sea. Virtually all of these measurements were “firsts” and viewed as an initial description of an unchanging ocean. These techniques were still taught to me as a student in the 1970s.
By the time I was a graduate student in the 1970s, science had graduated to sensors lowered on conducting cables, to a capability to moor current meters in the open ocean, and the advent of the first weather satellites. This moved the science toward a view of the ocean as a turbulent fluid with changes over time and space scales (in other words a vast challenge!). The idea emerged that we (humanity) should map the global ocean circulation—a snapshot to baseline change over the long term. As planned and conducted in the 1990s, this World Ocean Circulation Experiment (WOCE) would take men and women on ships ten years to complete. In the 1980s, I threw myself behind this mission—using the latest in water profiling and sampling from ships to attain deeper answers to the timeless questions of physical oceanography. I loved the sea-going life in this first part of my career!
As WOCE was completed in the 1990s, the “golden age” of oceanography from space began. Satellites for imaging properties of the ocean surface, to probe properties with active radars, and to provide unprecedented new location information (Global Positioning System) changed our ability to describe the ocean. Also, autonomous platforms such as the neutrally buoyant Argo floats perfected in WOCE provided the ability to continuously monitor the temperature and salinity of the upper ocean on a global basis. I joined NASA in 1997 to help use these new tools to probe more deeply again into the timeless, fundamental questions of physical oceanography. This second phase of my career was all about ocean science with a new idea—a sustained Global Ocean Observing System (GOOS). While WOCE took a decade to map the global ocean circulation, GOOS has the capability to deliver maps of the ocean surface circulation every 10 days!
Last month, I retired from NASA after 22 awesome years. While there are many innovations yet to come in satellite oceanography, I felt that the “game changer” in the 2020s would be the growth and development of the in situ sustained ocean observing system—the expansion and stabilization of GOOS. Because the ocean is virtually opaque to electromagnetic radiation, satellite remote sensing is largely confined to the description of properties at the ocean surface. This is incredibly valuable for ocean science, especially when combined with in situ measurements such as profiles from Argo floats or detailed air-sea interaction measurements from Saildrone. For this third and final phase of my career, I want to provide the scientific rationale for a fleet of at least 1,000 saildrones monitoring and mapping the ocean circulation and air-sea interaction. There are many people and sectors that support this mission.
The United Nations have declared the 2020s to be a Decade of Ocean Science in support of Sustainable Development goals. This is also the decade of a challenge, Seabed 2030, to map the global ocean topography at high resolution before the end of the decade. The US National Academy of Science in their recent decadal guidance to NASA Earth Sciences has set forth a challenge to remotely sense the “planetary boundary layer”—the interface between the ocean and atmosphere (which is a tough remote-sensing challenge). In situ data from the interface of the ocean and atmosphere will be crucial to the success of this challenge.
I see this technology as the next innovation that, when used with other evolving observing systems, will revolutionize answering our fundamental questions in physical oceanography. Saildrones will have the capability to economically map the seabed of the entire ocean. Saildrones will have the capability to map ocean surface currents that, when used with next-generation satellite technology, will illuminate the detailed physics of the surface circulation of the ocean. Saildrone will have the capability to improve weather and climate forecasts by providing data to weather models where little is available now. It is especially heartening for a physical oceanographer that all these capabilities are proven—all that is needed is the will to “scale-up” from demonstrating Saildrone’s platform to making it a permanent, valuable part of the Global Ocean Observing System. It will join ships, moorings, floats, drifters, satellites, models, and other autonomous platforms to take oceanography to the next level—the level that society needs when we see rapid changes in weather, climate, and the ocean as a challenge before us.
At the dawn of this new year 2020, I thank my lucky stars that I have another opportunity to contribute to the advancement of ocean science. As a physical oceanographer, I love the fact that Saildrone can make such a large impact on our timeless science questions. I also recognize that Saildrone is so much more—contributing to our understanding of ocean ecosystems and fisheries, contributing to our knowledge of the fate of carbon dioxide in the ocean and ocean acidification, and contributing much-needed eyes and ears in the ocean space for our security.