Monday, August 17, 2015

I predict - that TLT will rise

I've tweeted to a few people that the denier village is clinging to a final wall against the scientific certainty that the Earth's temperature is rising. This final wall is the temperature of the lower troposphere (TLT), measured by instruments on satellites, which has not shown much of a rise above the heights it reached following the 1997-1998 El Niño. It is on this basis that Denierville claims that there has been "no global warming" and that there's still a pause. If it goes higher than the 1997-1998 El Niño peak, they're done. Toast, as it were.

Well, if you haven't been paying attention, the slow-to-start El Niño  is now in full "ON" mode, and is being predicted to be one of the strongest (even perhaps THE strongest) ever observed. It's capable of becoming a definite rival to 1997-1998. I think that this is the warming that has been stored in the ocean for a few years coming back to the surface (as I thought it might) but I will wait for a more professional statement of that. Now there are some predictions it's going to last into and maybe through the Northern Hemisphere winter, and that might mean some extra needed precipitation in California.

But I keep looking around to try and figure out why the TLT hasn't moved much yet. It's frustrating, because it truly is the denier's firewall. And I have enough confidence in the way the world works that with El Niño's warmth blasting away at the atmosphere, it's going to go up.

But when? Well, I might have my answer here:

Is there a pause in the temperature of the lower troposphere?

It's a good analysis. It's also from last December, before El Nino got going for real. So here's what I found:
"The global mean TLT differs from the global mean near-surface temperature in a few key aspects. One of them is that the influence of El Niño is much larger, as can be seen from, e.g., the height of the peak in 1998, which is about 0.4 K above the trend line, against about 0.2 K in the near-surface temperature. Note that strongest effects of El Niño on temperature lag the event itself by about half a year. The 2010 peak is also higher, about 0.2 K versus only 0.1 K. On a map, this can be seen as a stronger and broader response to El Niño and La Niña in the tropics, see Fig. 2. The amplification can easily be understood due to the stronger warming at height caused by the heat of condensation of the higher rainfall. This is the upper tropospheric warming that accompanies an increase in SST in the tropics. In the deep tropics, near the equator, this causes heating well above the lower troposphere and hence is not clearly visible in the TLT, but away from the equator the warmer air descends in the Hadley circulation and enters the heights to which the TLT is more sensitive."

Note what I've underlined above. He says there's a HALF-YEAR lag. El Niño really started kicking into gear about April, and accelerated into May and June. So half a year from that is --- November. It's August now and it's really warm - the anomalies have been climbing for months. So if the half-year lag is right, then we ought to see the TLT start to climb around October, and keep going into the New Year.

And boy is that an outcome devoutly to be wished for!

I'm not a fan of global warming. It's not good for the Earth. But the discussion/debate needs this to happen. The 2015 (and possibly 2015-2016) El Niño has got to knock the TLT wall down.

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