The Tiki mask and caffeine halo let me know it’s name! Hunga Tonga-Hunga Ha’apai! What that means is everything is now amped to Black Swan level!
The Hunga Tonga-Hunga Ha-apai volcano erupted this last January. It was the largest explosion on the planet ever recorded by instruments. It was an undersea eruption from a pre-existing caldera at the perfect depth to vaporize the entirety of the underwater caldera and direct the force of explosion through the Troposphere and into the Stratosphere. This was unique from all prior volcanic eruptions, which usually push sulphur dioxide and other particulates into the lower atmosphere and can result in cooling, NASA’s recent report shows that instead this eruption “may” cause warming. The Stratosphere is waay up there, and generally very low water density only as micro-ice crystals. I wondered what the huge volume of water vapor injected into Stratosphere might do, and if any past studies had been done.
Turns out (academic publication is linked below), just the increasing amount of CO2 in the Troposphere is enough to cause more water vapor in the Stratosphere, of such significance that it should be considered a distinct “individual physical entity controlled, at least in part, by essentially different mechanisms than tropospheric water vapor, we conclude that the Stratospheric Water Vapor (SWV) feedback is of suﬃciently large amplitude to deserve dedicated attention”.
The authors conclude: “We wish to emphasize that although the SWV climate feedback calculated here (“here” is the lowermost stratosphere (LMS), which is mainly located in the extratropics, and the key region of emphasis) is small compared to global mean estimates of the tropospheric water vapor feedback from the CMIP5 models, it is of the same order of magnitude as the multi-model mean surface albedo feedback (0.3 ±0.1 Wm−2K−1) and the cloud feedback.
When the researchers say extratropics, they mean the mid-latitudes. This is the area where up to 95% of the forced heating is expressed, and happens to align nicely with the extreme spike of temperature and rainfall across the northern & southern hemispheres. The water vapor may persist in the Stratosphere for up to 10 years, as an anomalous forcing event. Bonus, it strips away at the ozone layer as well.
After the eruption it took just a few weeks for the stratospheric Polar Vortex of the northern hemisphere to collapse and split. This article from last spring summarizes the phenomena, and predicts this summer’s heat. NASA published their satellite findings of the eruption in early August, so the warming agent that collapsed the polar vortex was considered an anomalous spike- maybe not so anomalous?