The climate science community tells us that the El Nino/Southern Oscillation (ENSO) is merely a redistribution of heat. Sea level data tells us otherwise. The graph below shows detrended sea level data from the University of Colorado, which is available for the period 1993-2008.
If ENSO is non-radiative, it should not influence sea level, which is a metric of the heat content of the oceans (in addition to glacial melt). However, the graph above clearly shows that ENSO is influencing the heat content of the oceans. Very basic analysis of sea level data makes it incredibly obvious that ENSO is a radiative oscillation that has the potential to cause long-term climate change.
In this past, I have suggested that only the 1976/7, 1986/7, and 1997/8 El Nino events were radiative, a position that I now believe is false. This point of view came from the examination of gridded sea surface temperature data. Erl has, through an examination of gridded atmospheric data, always contended that ENSO is always radiative. Gridded sea level data resolves the seeming discontinuity between these two viewpoints. As Nino 3.4 anomalies swing between negative and positive values, the tropical ocean integrates the values as cloud cover rises and falls. This has produced consistently increasing sea levels in the tropics as El Nino conditions have been prevalent, as shown in the graph below.
However, the increasing heat remains mostly in the tropics until it is released poleward by strong El Ninos, like the 1986/7 and 1997/8 El Ninos. The effect of the 1997/8 El Nino on the poleward transport of heat can be seen in the graphs below.
Once the heat is released from the tropics, it appears at the surface and in the temperature record, creating the observed “step-changes” in global temperature.
You’d think that after $79 billion dollars of government-funded research just in the United States, someone would have bothered to detrend sea level data to discover that ENSO is radiative. The apocalyptic conclusions of climate scientists have come before a serious effort has been put into understanding the basics of climate. Climate science truly needs to be rebuilt from the bottom up.
Global Sea Level Timeseries: University of Colorado
Gridded Sea Level: CLS ENACT Analysis
Nino 3.4 Timeseries: ERSST.v3b
Gridded Sea Surface Temperature: ERSST.v3b
All data available at KNMI Climate Explorer.