A Mystery In The Mesosphere

This summer, something strange has been happening in the mesosphere. The mesosphere is a layer of the atmosphere so high that it almost touches space. In the rarefied air 83 km above Earth’s surface, summertime wisps of water vapor wrap themselves around specks of meteor smoke. The resulting swarms of ice crystals form noctilucent clouds (NLCs), which can be seen glowing in the night sky at high latitudes.

More Details HERE.

During the first half of August 2018, reports of NLCs to Spaceweather.com have tripled compared to the same period in 2017. The clouds refuse to go away.

Researchers at the University of Colorado may have figured out why. “There has been an unexpected surge of water vapor in the mesosphere,” says Lynn Harvey of Colorado’s Laboratory for Atmospheric and Space Physics (LASP). This plot, which Harvey prepared using data from NASA’s satellite-based Microwave Limb Sounder (MLS) instrument, shows that the days of late July and August 2018 have been the wettest in the mesosphere for the past 11 years:

mls2_strip

In addition to being extra wet, the mesosphere has also been a bit colder than usual, according to MLS data. The combination of wet and cold has created favorable conditions for icy noctilucent clouds.

Water vapor is the primary greenhouse gas, even in the mesosphere.

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Pre-Columbian America was plagued by decades-long megadroughts

Anthony Watts writes at Watts Up With That

In the August issue of Physics Today, climate scientists Toby Ault and Scott St. George share a pair of startling research findings. Between roughly 800 and 1500 CE, the American West suffered a succession of decades-long droughts, much longer than anything we’ve endured in modern history. And statistical models suggest that, as the climate warms, such megadroughts are increasingly likely to return.

western-US-megadroughts

How can scientists be so sure about the duration and extent of droughts that happened long before the era of instrument-based precipitation records? As Ault and St. George explain, the annual growth rings of ancient trees contain a rich paleoclimatic record of precipitation and soil moisture patterns. The width of a tree ring gives clues as to how well nourished the tree was in a given year. The map shows four western US megadroughts predicted from tree-ring data.

Ring-width analyses provide the most complete set of data on past moisture levels. But researchers have other ways of determining those conditions. Here are four of them:

Underwater tree stumps
Archaeological artifacts
Sand-dune cores
Pollen-grain deposits

The Full article is HERE.

Here are some other views of the long-term drought;

Long Drought History

G10b Sac River Flow 30T

 

Sunspot Update for July 2018: The Sun Flatlines!

From Behind the Black, by Robert Zimmerman

Yesterday NOAA posted its monthly update of the solar cycle, covering sunspot activity for July 2018. As I do every month, I am posting it below, annotated to give it some context.

This might be the most significant month of solar activity that has been observed since Galileo. Except for two very short-lived and very weak sunspots that observers hardly noted, the Sun was blank for entire month of July. This has not happened since 2009, during the height of the last solar minimum.

What makes this so significant and unique is that it almost certainly signals the return of the next solar minimum, a return that comes more than a year early. The solar cycle the Sun is now completing has only been ten years long. It is also one of the weakest in more than a hundred years. This combination is unprecedented. In the past such a weak cycle required a long cycle, not a short one.

Read the full post with graphics HERE.

Robert discusses the Next Grand Minimums:

For almost a decade some solar scientists have predicted, based on the Sun’s recent behavior, that we are about to enter an era of little sunspot activity, with the possibility that we could be facing the first Grand Minimum since the Maunder Minimum in the 1600s. During that last grand minimum, named for the man who identified it, the Sun’s solar cycle produced almost no visible sunspots for decades. Though scientists think the eleven-year solar cycle was occurring, sunspot activity was so weak that the solar astronomers at the time, equipped with the very first telescopes, could not see it.

My emphasis added. There is more discussion in the text.

A Solar Activity Update- By Stephanie Osborn

Some informed thoughts for you to think about.

According To Hoyt

A Solar Activity Update- By Stephanie Osborn

http://www.stephanie-osborn.com

My experience

I did my graduate work in spotted variable stars at Vanderbilt University, so in the astronomical community I would be considered a variable star astronomer. Based on our experience, many variable star astronomers consider the Sun to be at least borderline variable, and I am one of these. In point of fact, pretty much across the board, astronomers dropped the “solar constant” years ago, because it simply wasn’t. (Unfortunately, other disciplines have not.)

I personally have been watching solar activity for many years now and have watched the activity gradually decrease. As a consequence, I began keeping a rough spreadsheet in summer 2016 as I watched activity begin to drop dramatically. So I have about 2 years of recorded data. It is fairly simplistic, because I only wanted a snapshot and didn’t have time to do more detail, but it…

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