Warming off the Peruvian coast: Potential Consequences and Implications (May, 2012)

Do Peru's Marine Die-Offs Herald the Return of El Nino? (Scientific American, May 8,2012)
Hundreds of birds and dolphins have been washing up dead along the Peru coast against a backdrop of oceanic warming in the region Effects of this warming on the biology are already being observed.  Hundreds of birds and dolphins have been washing up dead along the Peruvian coast.
(News source:http://www.scientificamerican.com/article.cfm?id=do-perus-marine-die-offs-herald-the-return-of-el-nino)

 

At least 1200 dead pelicans have been found along a stretch of northern Peru. Deputy Agriculture Minister Juan Rheineck stated, "We're starting from the hypothesis that it’s because the birds are young and unable to find enough food for themselves, and also because the sea temperature has risen and anchovies have moved elsewhere."
 

However, such deaths have been previously reported during the 1997-98 El Niño.
 

Although it is impossible to determine whether a 2012 El Niño is coming or how strong it would be, the coupling between ocean temperatures and the biology continues to have far reaching consequences that can severely affect coastal regions such as Peru.

References
  • Casey, K. S. and P. Cornillon, 1999, A comparison of satellite and in situ-based sea surface temperature climatologies, J. of Climate, 12 (6),  DOI: 10.1175/1520-0442(1999)012.
  • Donlon, C. J., M. Martin, J. D. Stark, J. Roberts-Jones, E. Fiedler and W. Wimmer, 2011. The Operational Sea Surface Temperature and Sea Ice analysis (OSTIA). Remote Sensing of the Environment. doi: 10.1016/j.rse.2010.10.017.
  • Reynolds, RW, and TM Smith, 1994, Improved global sea-surface temperature analyses using optimum interpolation, J. of Climate, 7, 929-948.
About the Ocean Event
Sea surface temperature anomalies (SSTA) in the Eastern Pacific, specifically off the Peruvian coast, have shown a recent warming. SSTA is defined as the difference between the actual temperature and normal conditions for that time of year. Negative anomalies indicate cooler than normal temperatures, while positive anomalies indicate warmer than normal temperatures. Warm anomalies greater than 2°C have been persistent off the northern to central coast of Peru for over one month. Such warming events off Peru have been historically known to precede El Niño conditions in the Equatorial Pacific.  Although it is too early to determine whether such warm anomalies will lead to a shift to El Niño conditions in the Equatorial Pacific, some local effects have already been seen.
Sea Surface Temperature Anomalies (SSTA) in the eastern Pacific on May 7, 2012.

  Figure 1:
  Sea Surface Temperature Anomalies (SSTA) in the eastern Pacific on May 7, 2012.

 

Figure 1 shows SSTA, using the State of the Ocean (SOTO) tool at the PO.DAAC, in the Pacific for May 7, 2012. Anomalies are based on the difference between the operational sea surface temperature and sea ice analysis (OSTIA) (Donlon et al., 2011) and Pathfinder v5 climatology (Casey and Cornillon, 1999). Warm anomalies over 2°C  are visible off the Peruvian coast.

 

 

SSTA for the week of January 8, 2012. SSTA for the week of March 11, 2012
  Figure 2:
  SSTA for the week of January 8, 2012.		   Figure 3:
  SSTA for the week of March 11, 2012.

 

Figure 2 illustrates NOAA optimum interpolation sea surface temperature analysis (OIv2) (Reynolds and Smith, 1994) that shows conditions off Peru have shifted from neutral/negative anomalies to positive anomalies since January 2012. By March 2012 (Figure 3) warm anomalies over 1°C had appeared off the Peruvian coast. Figures 2 and 3 were taken directly from:  http://www.emc.ncep.noaa.gov/research/cmb/sst_analysis/images/archive/weekly_anomaly/.

 

PO.DAAC Science Team