by Judith Curry
A few things that caught my eye this past week.
The only critique of my testimony that i’ve encountered (beyond tweets from Mann and Colose) [link]. I’m being attacked for thinking volcanoes and the sun could be important (wasn’t volcanoes and the sun Gavin Schmidt’s explanation for the pause in a paper published last year?)
Excellent discussion of climate and other effects of big volcanoes [link]
3D Cryosat tracks winter sea ice [link]
BBC News: Warning over aerosol climate fix [link]
Russian temperatures “warmer & drier than present” fr 7500-5000 years ago [link]
Model Fail: Iceberg Armadas Didn’t Cause North Atlantic Cooling [link]
“An Honest Climate Scientist: Hans von Storch.” [link]
What’s going on in the Pacific?
This topic probably deserves its own post, but no time right now, here are some relevant links.
New Scientist: Mystery blob in the Pacific messes up weather and ecosystems [link]
The Pacific Ocean may have entered a new warm phase – and the consequences could be dramatic [link] . Chris Mooney (and some scientists) think it is the PDO, but I think it is something else.
Two new journal publications that I find significant on the Pacific:
Pacific sea surface temperature and the winter of 2014
Abstract: It is shown from historical data and from modeling experiments that a proximate cause of the cold winter in North America in 2013–2014 was the pattern of sea surface temperature (SST) in the Pacific Ocean. Each of the three dominant modes of SST variability in the Pacific is connected to the tropics and has a strong expression in extratropical SST and weather patterns. Beginning in the middle of 2013, the third mode of SST variability was two standard deviations positive and has remained so through January 2015. This pattern is associated with high pressure in the northeast Pacific and low pressure and low surface temperatures over central North America. A large ensemble of model experiments with observed SSTs confirms that SST anomalies contributed to the anomalous winter of 2014. [link] to abstract
Additional details are given in this weather.com article, which argues for a new mode of variability in the Pacific.
Decadal modulation of global surface temperature by internal climate variability
Aiguo Dai, John Fyfe, Shang-Ping Xie, Xingang Dai
Abstract. Despite a steady increase in atmospheric greenhouse gases (GHGs), global-mean surface temperature (T) has shown no discernible warming since about 2000, in sharp contrast to model simulations, which on average project strong warming1, 2, 3. The recent slowdown in observed surface warming has been attributed to decadal cooling in the tropical Pacific1, 4, 5, intensifying trade winds5, changes in El Niño activity6, 7, increasing volcanic activity8, 9, 10 and decreasing solar irradiance7. Earlier periods of arrested warming have been observed but received much less attention than the recent period, and their causes are poorly understood. Here we analyse observed and model-simulated global T fields to quantify the contributions of internal climate variability (ICV) to decadal changes in global-mean T since 1920. We show that the Interdecadal Pacific Oscillation (IPO) has been associated with large T anomalies over both ocean and land. Combined with another leading mode of ICV, the IPO explains most of the difference between observed and model-simulated rates of decadal change in global-mean T since 1920, and particularly over the so-called ‘hiatus’ period since about 2000. We conclude that ICV, mainly through the IPO, was largely responsible for the recent slowdown, as well as for earlier slowdowns and accelerations in global-mean T since 1920, with preferred spatial patterns different from those associated with GHG-induced warming or aerosol-induced cooling. Recent history suggests that the IPO could reverse course and lead to accelerated global warming in the coming decades. [link] to abstract
Washington Post has an article on the paper The Pacific Ocean has been slowing global warming down – that could be about to change.
Misc topics of interest
Interesting study on risks of groupthink: [link]
Victoria Stodden: “How Computational Science is Changing the Scientific Method” [link]