Climate Sense

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calibration led to refinements in air-sea flux measure-

ment from both ship- and mooring-based platforms.

Experimental devices such as gliders demonstrated

the potential for performing repeated measurements in

regions of the ocean historically difficult to observe.

Ocean modelling efforts – enabled significantly by

advances in computer and information technologies –

have resulted in global ocean models that represent the

energetic nature of boundary currents and associated

processes. They are also capable of providing a dynami-

cally consistent description of many observed aspects of

the ocean circulation that contribute to the formation

and variation of the Earth’s climate system. A combina-

tion of real-time ocean observations and ocean models

offers the possibility of operational oceanography on

a global scale – an important theme of the upcoming

Ocean Observations ’09 Conference, which is to be held

in Venice, Italy. As such, the scientific community is now

on the verge of realizing the oceanographic equivalent

of a World Weather Watch – the system responsible for

modern weather forecasts.

Challenges and opportunities in providing

climate information

Looking to the future, the WCRP Strategic Framework

for the 2005-2015 period aims to facilitate analysis and

prediction of Earth system variability and change for

use in an increasing range of practical applications of

direct relevance, benefit and value to society. A key focus

of the Strategic Framework is the seamless prediction

of weather, climate and, ultimately, the whole Earth

system. There are many theoretical and practical reasons

for adopting this approach. The extension of ‘climate

prediction’ to the more encompassing ‘environmental

prediction’ requires recognition that the climate system

is inextricably linked to the Earth’s biogeochemistry and

to human activities. For the WCRP to achieve its goals of

understanding and predicting climate variability and its

effect on society at large, it must, and will, contribute to

studies of the fully integrated Earth system.

Developing a unified approach to weather, climate,

water and environmental prediction requires a broadened

Earth system perspective beyond the traditional atmos-

pheric science disciplines. The development of climate

prediction, and ultimately environmental prediction,

is not a simple extension of numerical weather predic-

tion. For example, the scientific disciplines required to

support weather, climate and environmental prediction

span meteorology, atmospheric chemistry, hydrology,

oceanography and marine and terrestrial ecosystems.

While atmospheric nowcasting and short-range

weather forecasting are primarily initial value problems,

extension to, medium- and extended-range weather

forecasting brings in the coupling of land surface proc-

esses, as well as the role of soil moisture feedback and

other surface-atmosphere coupled processes. Long-range

forecasting from weeks, to months, to a season involves

atmosphere-ocean coupling, with the initial conditions

of the memory inherent in the upper ocean leading to

Meteorological Congress in May 1979 and lead to the formation

of the WCRP. The major foci of the WCRP are understanding and

predicting the climate system, and assessing the influence of human

activities on it. In its 1984 Scientific Plan the WCRP identified the

complexity and breadth of the scientific challenge at hand – recogniz-

ing clearly the role of radiation, clouds, the oceans, the hydrological

cycle and the biosphere in the formation and variability of the Earth’s

climate. Oceans, land surfaces, the cryosphere and the biosphere all

need to be represented realistically in global climate models for future

projections to be realistic. Today’s four core WCRP projects – Global

Water-Energy Experiment (GEWEX), Climate and Cryosphere,

Climate Variability and Predictability (CLIVAR), and Stratospheric

Processes and their Role in Climate (SPARC) – were established to

achieve this task.

Extensive model development and numerical experimentation

required exploration of climate sensitivity to changes in atmospheric

carbon dioxide concentration (as well as other gases and aerosols).

Early studies on the assessment of the effects of carbon dioxide on

climate accommodated IPCC needs. In view of the critical role of

oceans in the climate system, close cooperation was established with

the oceanographic community – IOC joined as co-sponsor of the

WCRP in 1993. The first WCRP coupled atmosphere-ocean initiative,

the Tropical Ocean and Global Atmosphere (TOGA) project, studied

the influence of the slowly varying thermal inertia of tropical oceans

on large-scale atmospheric circulation. Recognition of the longer

timescale or memory inherent to the oceans enabled short-term

climate forecasts to extend beyond days to weeks. The requirement

for ocean observations to initialize coupled forecasts established the

prototype of the ocean observing system now in place. During the

previous decades, routine observations of the air-sea interface and

upper ocean thermal structure in the tropical Pacific Ocean were

provided in real time by the Tropical Atmosphere Ocean array. These

observations have since been sustained in the Pacific and extended to

the Atlantic and Indian Oceans, thus building a solid foundation for

today’s ocean observing system.

Ocean data assimilation proved to be a key element of the initiali-

zation of seasonal-to-interannual climate forecasts. Coupled ocean

atmosphere prediction models were implemented at many of the

world’s major weather prediction centres. This led to key break-

throughs in seasonal climate forecasts based on observations,

understanding and modelling of worldwide anomalies in the global

atmospheric circulation, temperature and precipitation patterns

linked via teleconnections to El Niño. The WCRP-sponsored CLIVAR,

TOGA and WOCE projects have established a solid foundation to

study the ocean’s role in climate. The ocean observations collected

and disseminated by these projects – supported by more than 30

nations – were fundamental in the development of basin-scale ocean

models and have shaped the current understanding of mixing proc-

esses for energy and nutrients in the oceans. These efforts have had

a positive impact on: knowledge of the global oceans; adoption of

new technology used by oceanographers; and overall changes to the

scientific methods for ocean research.

Advances in ocean technology played a major role in permitting

a global ocean perspective. Continuous observations of global sea

surface height were provided by the TOPEX/Poseidon satellite, the

Jason satellites and the European Remote Sensing satellite radar

altimeters. Active and passive microwave satellite sensors provided

all-weather measurements of the ocean surface wind velocity,

temperature and biological activities. Improved instrumentation and