AUSTRALIA - JAPAN SYMPOSIUM
AUSTRALIA - JAPAN SYMPOSIUM ON EARTH SYSTEMS SCIENCE
AND ON NANOMATERIALS
Canberra, 21 November 2006
Australian contribution on oceans: Observations for modelling
Dr Neville R Smith, Chief Research Scientist, Bureau of Meteorology Research Centre
Dr Neville Smith is the Chief Scientist of the Bureau of Meteorology and has been associated with ocean
research in observations and modelling for much of the last two decades. He played a pivotal role in the
development of the initial ocean climate observing system design for GOOS and GCOS, and was Chair of the
Ocean Observations Panel for Climate for six years. He helped convene the seminal OceanObs 99, a Conference
that developed international consensus on the future observing system. He has led the development and
implementation of the Global Ocean Data Assimilation Experiment (GODAE), an initiative to develop
operational ocean prediction as a routine activity and, with colleagues from CSIRO, led the development
of Australia's contribution, BLUElink. He has also been deeply involved in the development of Australia's
contribution to the ocean observing, lately through the National Collaborative Research Infrastructure
Strategy. Dr Smith is currently the National Delegate to the Intergovernmental Oceanographic Commission
and Vice-Chair for the region that includes Australia and Japan.
Over the relatively short history of oceanography as we practice it today, the techniques and practices for observing the ocean and interpreting such data have gone through many small revolutions. In the earliest times, most observations were gathered during voyages of discovery, with the pioneering work of Maury around 150 years ago to establish a systematic program of observation in the North Atlantic being the exception. In the first half of the last century basic models of the ocean circulation and its physics were available and observations also started to be more targeted and, in part, seeking verification of these early theories. Technology progressed rapidly during the middle part of the last century, enabling more systematic surveys of the deep ocean and some of the first insights into the overturning circulation, an aspect that we now know is critical in climate change. By the 1960s and 70s, observations from research vessels were starting to provide a picture of the global circulation though, as we now know, missing much important detail. This period also saw the introduction of the first general circulation models integrated on computers and some of the earliest attempts to constrain ocean models with data. However, for the most part, observations were being used to test and develop theory and early paramaterisations, and being deployed to calibrate simple estimates of ocean circulation using geostrophic theory. The 1980s introduced two international experiments that laid the foundations for the modern revolution in the use of ocean observations in models, namely the Tropical Oceans–Global Atmosphere experiment (TOGA) and the World Ocean Circulation Experiment (WOCE). While both still placed a healthy emphasis on understanding gleaned directly from observations, their strategies explicitly included data assimilation and synthesis as major objectives. TOGA introduced the first effective predictive models of the El Nino–Southern Oscillation, in several cases with ocean data assimilation as part of the initialisation, and a mooring network was deployed expressly for the routine monitoring and prediction of El Niño. WOCE took the observation and simulation of the global ocean circulation to a new level, and introduced global syntheses (inversions) and novel instruments such as the profiling float. This also coincided with the introduction of remote sensing, first for sea surface temperature, but then also for ocean winds and surface elevation (topography) via altimetry. Together, altimetry and autonomous deep-profiling floats represent the most significant advance in our field and have truly revolutionised the way we go about our business. We now have the order 10 ocean model assimilation and prediction systems, either in prototype or operational mode, able to analyses and predict the state of the ocean in real-time, at resolutions relevant to a wide range of applications. Ocean observations play a central role in the regular assessments of climate change, not just for surface temperature, but for sea level and changes in the deep ocean. New approaches to observing and modelling the biogeochemical properties are heralding in a further mini revolution, with immense ramifications for the way we monitor and, perhaps, predict, changes in the ocean carbon cycle and ocean acidification. The last decades have been exciting and rewarding for ocean observations and modelling, and the next promise just as much and more. This paper will highlight contributions of Australia to this endeavour, and opportunities for collaboration.
