This chapter includes an overview of the current state of knowledge about ocean climate, including anomalies, placed in historical context. Expert scientists who monitor, observe, and analyze the ocean products described in this chapter (e.g., sea level, ocean carbon, SST) have produced concise summaries describing why it is important to monitor these variables. Climate applications are presented along with an explanation of how the observing system needs to be enhanced to improve ocean analysis and reduce present uncertainties. This chapter focuses primarily on decision makers and non-scientists interested in, and concerned about, ocean research.

A performance measure is a structured statement describing how progress will be evaluated. Performance measures consist of four parts: indicator, unit of measure, baseline and target. An indicator defines the attribute or characteristic to be measured. The unit of measure describes what is to be measured. A baseline establishes the basis for comparison through an initial collection and analysis of data. A baseline should include both a starting date and level. A target establishes the desired level to be reached in a defined period, usually stated as an improvement over the baseline. Targets are based on research and a thorough understanding of the goal/program and are challenging, worthwhile and achievable (NOAA definition). A metric is any type of measurement used to gauge some quantifiable component of an agency's performance. Currently, the following performance measures exist for the ocean observation program.

Present Performance Measure:

1. Reduce the uncertainty in projections of sea level rise during the 21st century. Metric – the range between credible estimates of sea level rise (centimeters):
   

   	2002	2003	2004	2005	2006	2007	2008	2009	2010
   	80 cm	80 cm	70 cm	60 cm	50 cm	40 cm	30 cm	25 cm	25 cm

2. Reduce the uncertainty in estimates of the increase in carbon inventory in the global ocean. Metric – uncertainty in estimates of anthropogenic change per decade (Gigatons):
   

   	2002	2003	2004	2005	2006	2007	2008	2009	2010
   	10 Gt	10 Gt	10 Gt	8 Gt	8 Gt	7 Gt	6 Gt	4 Gt	4 Gt

3. Reduce the error in global measurement of sea surface temperature. Metric – estimated maximum monthly mean error in 5° regions (degrees Celsius).
   

   	2002	2003	2004	2005	2006	2007	2008	2009	2010
   	1.3 C	1.3 C	1.0 C	0.8 C	0.6 C	0.5 C	0.4 C	0.3 C	0.3 C

The short articles presented in this chapter describe the products listed in Table 2.1 and are the result of ocean projects funded, in whole or in part, by NOAA’s Office of Climate Observation.

Table 2.1. Products

2.1 Sea level to identify changes resulting from climate variability – Laury Miller, Bruce Douglas, Robert Cheney
2.2 Ocean carbon content every ten years and the air-sea exchange seasonally – Rik Wanninkhof, Richard Feely
2.3 Sea surface temperature to identify significant patterns of climate variability – Richard Reynolds
2.4 Surface currents to identify significant patterns of climate variability – Peter Niiler, Nikolai Maximenko
2.5 Sea surface pressure to identify changes in forcing functions driving ocean conditions and atmospheric conditions – Ed Harrison
2.6 Air-sea exchange of heat, fresh water, momentum to identify changes in forcing functions driving ocean conditions and atmospheric conditions – Bob Weller
2.7 El Niño and heat content variations – Michael McPhaden