ESRL Quarterly Newsletter - Fall 2009

Alexander E. MacDonald, Director ESRL

Director’s Corner

Greetings from Venice

Greetings from Venice where I am attending the OceanObs’09 Conference. I am co-author on a white paper on the global ocean observing system, but for me this conference is mainly a chance to understand a part of Earth system science that I have not had much experience with. This is the second OceanObs—the first was held in France 10 years ago, and is credited with propelling the significant increases in ocean observations, assimilation, understanding, and prediction of the last decade. For me, the similarities to the physical atmospheric problem are striking. The moored buoy networks (e.g., TAO, PIRATA, and RAMA) and ARGO floats are now providing, for the first time, the equivalent of the radiosondes for the atmosphere; profiles of state variables at a large number of points over the global ocean. The amazing satellite technology that provides surface altimetry of the ocean to heights of a few centimeters is, in some sense, analogous to the role that surface pressure plays in atmospheric analysis–an indication of the integrated mass field below the ocean surface. (The 30-cm high mound of warm water in the central Gulf of Mexico in late summer of 2005 was an indication of very warm water below, which was important in fueling the surges of Hurricanes Katrina and Rita to Category 5.) Finally, sea surface temperature around the globe constrains the surface thermodynamic field–so combining all three types of observations now gives a relatively complete portrayal of the physical ocean. The ocean community has also made much progress on assimilation with the Global Ocean Data Assimilation Experiment (GODEA).

Like atmospheric science, ocean science can be divided into three domains —physical, chemical, and biological—and understanding has not progressed evenly among all three. In both, initial efforts at full global systems science were primarily in the physical domain. Recently we have seen significant progress in global systems chemistry with, for example, ESRL’s Carbon Tracker. At OceanObs’09, there was much discussion of how to make progress in ocean chemistry. NOAA was well represented with leaders—such as Richard Feely of the Pacific Marine Environmental Laboratory—who have brought ocean chemistry to the forefront of the global change issue. Conference participants discussed proposals to put sensors for carbon dioxide and oxygen onto the ARGO profilers, which would give researchers a global dataset on important ocean chemistry, to the 2000-m depth that the ARGO system samples. Our atmospheric equivalents are aircraft and tall tower chemistry soundings, which ESRL’s Global Monitoring Division is pioneering.

There was a strong feeling at the OceanObs’09 meeting among members of the biological oceanography community that they had not received the needed attention and support that this field deserves. Reasons for this disparity discussed at the meeting include the diversity of biology (for example, there are thousands of species of phytoplankton), the difficulty of observing ocean biology, and the complexity of biological change (e.g., as the ocean becomes warmer and more acidic, determining the resulting Darwinian evolution is very difficult).

At NOAA’s Earth System Research Laboratory, we began with the vision of understanding and predicting the whole Earth system. Our strong capabilities in physical and chemical aspects of the atmosphere could be regarded as encompassing one-third of the Earth system. In addition, the global environmental research community must understand the physics and chemistry of the ocean, and terrestrial and oceanic biology. ESRL is contributing cutting edge efforts to understand the ocean's role in global weather and climate, and in getting that new understanding implemented in the latest generation of computer models. Chris Fairall recently received an AGU medal for his work. He and his team in the Physical Sciences Division (PSD) have garnered wide acclaim for their efforts on air-sea fluxes and how they are parameterized in computer models. A number of other folks in PSD, including Marty Hoerling and CIRES partners Prashant Sardeshmukh and Gil Compo, have been publishing groundbreaking work on the ocean's central role in the climate change we experience on the continents. Dan Murphy led a team, including illustrious Chemical Systems Division colleagues, that published findings in September in the Journal of Geophysical Research. Dan and company put the ocean in the context of radiative forcings and the total Earth system response in "An observationally based energy balance for the Earth since 1950.” ESRL's strengths in atmospheric sciences are clearly multiplied by our growing capacity in understanding the ocean's role, and by the significant progress that I am hearing about at OceanObs’09.

I leave this fascinating week with a main take-home message: The importance of partnerships within the scientific community. No one organization can cover all of Earth system science–we must work together.

—Alexander MacDonald