Clear with a wisp of ground fog this early Friday on California’s north coast — and a cold chill accompanying a brightening sky to the east.
We’re set supposedly for ‘mostly sunny’ through the end of next week before any chance of rain — yesterday afternoon blossomed into another warm, amicable episode in a mostly-dry, strange winter.
And as we bask, across the way of the Great Divide (via Mashable): ‘The eastern U.S. is currently gripped by the most unusually cold air of any region on Earth, based on computer model data showing global temperature departures from average, with temperatures between 25 and 45 degrees below average or more.’
A ‘polar vortex’ of the coldest-cold in two decades.
(Illustration: Detail of M.C. Escher’s ‘Relativity‘ found here).
Yet in utter-ridiculous contrast, yesterday afternoon from Dr. Jeff Masters at WunderBlog:
January 2015 was the second warmest January since record keeping began in 1880, said NOAA’s National Climatic Data Center (NCDC) on Thursday.
NASA also rated January 2015 as the 2nd warmest January on record, behind January 2007, which had the warmest departure from average of any month in recorded history.
January 2015’s near-record warmth continues a trend of very warm months for the planet — December 2014 was the warmest December on record, and 2014 was Earth’s warmest calendar year on record.
Global ocean temperatures during January 2015 were the 3rd warmest on record, and global land temperatures were the 2nd warmest on record.
Global satellite-measured temperatures in January 2015 for the lowest 8 km of the atmosphere were the 7th or 5th warmest in the 37-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH), respectively.
Most-likely, the whiplash weather scenario of climate change.
A few details in this aspect this week from Jennifer Francis, Research Professor in the Institute of Marine and Coastal Sciences at Rutgers University, at Science 2.0 — a few points:
One thing we do know is that the polar jet stream — a fast river of wind up where jets fly that circumnavigates the northern hemisphere — has been doing some odd things in recent years.
Rather than circling in a relatively straight path, the jet stream has meandered more in north-south waves.
In the west, it’s been bulging northward, arguably since December 2013 — a pattern dubbed the “Ridiculously Resilient Ridge” by meteorologists.
In the east, we’ve seen its southern-dipping counterpart, which I call the “Terribly Tenacious Trough.”
This is where climate change comes in: the Arctic is warming much faster than elsewhere.
That Arctic/mid-latitude temperature difference, consequently, is getting smaller.
And the smaller differential in temperatures is causing the west-to-east winds in the jet to weaken.
Strong jets tend to blow straight west to east; weaker jets tend to wander more in a drunken north/south path, increasing the likelihood of wavy patterns like the one we’ve seen almost non-stop since last winter.
When the jet stream’s waves grow larger, they tend to move eastward more slowly, which means the weather they generate also moves more slowly, creating more persistent weather patterns.
At least, that’s the theory.
Proving it is not easy because other changes are happening in the climate system simultaneously.
Some are natural fluctuations, such as El Niño, and others are related to increasing greenhouse gases.
We do know, however, that the Arctic is changing in a wholesale way and at a pace that makes even Arctic scientists queasy.
Take sea ice, for example. In only 30 years, its volume has declined by about 60 percent, which is causing ripple effects throughout the ocean, atmosphere, and ecosystem, both within the Arctic and beyond.
I’ve been studying the Arctic atmosphere and sea ice my entire career and I never imagined I’d see the region change so much and so fast.
No more idle chatter, the weather…