Temperature of atmospheric layers as determined by MSU (Microwave Sounding Unit) NASA satellites. El Chichón and Pinatubo were volcanic eruptions, while El Niño is a periodic event from ocean variability.
NASA, Robert Simmon
<a rel="nofollow" class="external free" href="http://earthobservatory.nasa.gov/Features/GlobalWarming/images/msu_1978-2010.png">http://earthobservatory.nasa.gov/Features/GlobalWarming/images/msu_1978-2010.png</a>