Interannual Variability in Biological Responses
How will climate change alter California Current ecosystems, through
changes in the length, strength, frequency and timing of ENSO cycles and
other interannual variations?
The latter question encompasses long time frames as well as short, and
therefore relates to issues discussed below under "Interdecadal
Variability" as well. The ENSO cycle and especially warm phase (El
Nino) events may serve as useful proxies for examining ecosystem
responses to longer-term, more gradual climate change because of their
dramatic impacts on both the physical environment and biological
populations of the CCS. A U.S. GLOBEC study of the CCS should be
prepared to determine how ecosystem responses to warm ENSO events differ
between regions of the CCS. Finally, given the relatively short-term
physical impact of warm ENSO events (1-3 years), one might be able to
address the following questions:
- What are the natural modes of variability and covariability between components of the ecosystems in the CCS on interannual and longer time scales and what is the relation between these modes, past climate variability and potential future climate change?
- Is the response to perturbed forcing during ENSO events more complex than simple expansions and contractions of range? Can these more complex changes serve as analogs for responses to longer climatic changes?
How does the generation time of marine
animals influence the impact of warm events?
How does the recovery rate
of populations perturbed by an ENSO event differ for benthic versus
How would these populations be affected by changes
in the frequency or intensity of warm ENSO events?