Ocean variablity and its influence on the detectability of greenhouse warming signals

Journal Article · Thu Jun 15 04:00:00 EDT 1995 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/95JC00683· OSTI ID:114915

Santer, B D ^[1]; Mikolajewicz, U; Maier-Reimer, E ^[2]

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1. Lawrence Livermore National Lab. CA (United States)
2. Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); and others

Recent investigations have considered whether it is possible to achieve early detection of greenhouse-gas-induced climate change by observing changes in ocean variables. In this study the authors use model data to assess some of the uncertainties involved in estimating when one could expect to detect ocean greenhouse warming signals. They distinguish between detection periods and detection times. As defined here, detection period is the length of a climate time series required in order to detect, at some prescribed significance level, a given linear trend in the presence of the natural climate variability. Detection period is defined in model years and is independent of reference time and the real time evolution of the signal. Detection time is computed for an actual time-evolving signal from a greenhouse warming experiment and depends on the experiment`s start date. Two sources of uncertainty are considered: those associated with the level of natural variability or noise, and those associated with the time-evolving signals. The authors analyze the ocean signal and noise for spatially averaged ocean circulation indices such as heat and fresh water fluxes, rate of deep water formation, salinity, temperature, transport of mass, and ice volume. The signals for these quantities are taken from recent time-dependent greenhouse warming experiments performed by the Max Planck Institute for Meteorology in Hamburg with a coupled ocean-atmosphere general circulation model. 75 refs., 20 figs., 3 tabs.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 114915
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: C6 Vol. 100; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CLIMATIC CHANGE
DETECTION
GENERAL CIRCULATION MODELS
GLOBAL ASPECTS
GREENHOUSE EFFECT
SEAS
VARIATIONS