By Brendan O'Brien
A magnitude-5.8 earthquake hit western Montana early on Thursday, the U.S. Geological Survey reported, and people felt the tremor hundreds of miles away. Map Courtesy USGS Montana Earthquake Map
Just in case you slept through it, summer officially began at 3:24 am PDT this morning (12:24 am EDT)
What does the first day of summer have to do with Stonehenge?
No one really knows whyStonehengewas built some 5,000 years ago (at least I don’t, sorry). But one possibility is that it was used to mark solstices and equinoxes. That’s because during the summer solstice, the sun rises just over the structure’s Heel Stone and hits the Altar Stone dead center.
Here’sa graphicfrom NASA imagining what a summer solstice sunrise might’ve looked like back when Stonehenge was fully intact:
Nowadays, humans still gather to pay homage to the summer solstice at Stonehenge — they just use modern technology, like so:
(NASA/Goddard/SDO AIA Team) I’m a
huge fan of NASA’s graphics and real pics – so cool!
The summer solstice is upon us: June 20th and the 21st will be
the longest days of 2017 for anyone living north of the equator. If pagan
rituals are your thing, this is probably a big moment for you.
If not, the solstice is still pretty neat.
Technically
speaking, the summer solstice occurs when the sun is directly overhead the
Tropic of Cancer, or 23.5° north latitude. In 2017, this will occur at exactly
12:24 am (Eastern) on the 21st. (But we can celebrate on either day.)
Below is a
short scientific guide to the longest day of the year (though not, as we’ll
see, the longest day in Earth’s history — that happened back in 1912).
2)
Why do we have a summer solstice, anyway?
Okay, most
people know this one. Earth orbits around the sun on a tilted axis
(probably because our planet collided with
some other massive object billions of years ago, back when it was still being
formed).
So between
March and September, Earth’s Northern Hemisphere gets more exposure to direct
Tauʻolunga) sunlight over the course of a day. The rest of the year, the Southern
Hemisphere gets more. It’s the reason for the seasons.
In the
Northern Hemisphere, "peak" sunlight usually occurs on June 20, 21,
or 22 of any given year. That’s the summer solstice. By contrast, the Southern
Hemisphere reaches peak sunlight on December 21, 22, or 23 and the north hits
peak darkness — that’s our winter solstice.
3) How many hours of
sunlight will I get on Tuesday?
That depends on where you live. The further north you are, the
more sunlight you’ll see during the solstice. Alaska-based climatologistBrian
Brettschneidercreatedthis terrific guide:
In our part of
North Idaho we’ll enjoy about 16 hours of sunlight today!
On the off chance you live near the Arctic Circle, the sun never
really sets during the solstice.
(By contrast, during the winter solstice, Fairbanks only gets
about three hours of sunlight.)
March Equinox in the Lewiston/Clarkston Valley was this morning, Monday, March 20, 2017 at 3:29am
. The March equinox marks the moment the Sun crosses the celestial equator – the imaginary line in the sky above the Earth’s equator – from south to north and vice versa in September.
The word equinox was formed by two Latin words: "Equi" is the Latin prefix for "equal" and "nox" is the Latin word for "night." The equal refers to the fact that the amount of daylight and darkness on this day are almost equal. – 12 hours – all over the world. (For all practical purposes, the amount of daylight and darkness on the equinox can be considered equal. Scientists are quick to point out it is not exactly the same – but, let’s face it scientists are famous for splitting hairs and atoms and they want all of their science nerd friends to know that they know it’s not technically exact.)
The September equinox occurs the moment the Sun crosses Earth’s Equator – from north to south.
On any other day of the year, either the southern hemisphere or the Northern Hemisphere tilts a little towards the Sun. But on the 2 equinoxes, the tilt of Earth's axis is perpendicular to the Sun's rays, like the illustrations shows
Earth orbits the Sun at a slant, which is why equinoxes and solstices happen.
Shorter days ahead…The days (length of daylight) will now grow shorter until the Winter Solstice – the shortest day of the year, become equal at the Vernal (spring) equinox in March, then grow longer until the Summer Solstice – the longest day of the year in June.
The Autumnal equinox is known by many names - Fall Equinox, September Equinox, the beginning of fall. Keep in mind the Northern Hemisphere’s Autumnal Equinox is the Southern Hemisphere’s Vernal Equinox- but it is the September equinox for the whole planet.
The “Meteorological Seasons”. Meteorologists and climatologists have come up with their own calendar and named it after themselves.They don’t recognize the “astronomical seasons” like rest of the world -so they don't consider today the first day of fall. Heaven’s no – They have to start early. How else would they “predict” the weather and tell us what’s happening before it happens?
Weather folks start autumn on Sept. 1, the first day of winter Dec. 1, the first day of spring March 1 and the first day of summer June 1. Each of those seasons, known as "meteorological seasons," runs three full months and they are based on the annual temperature cycle instead of the earth's rotation around the sun.
The snake of sunlight at Chichen Itza, Mexico.The snake of sunlight on the stairs of the main pyramid at Chichen Itza, Mexico.
A famous ancient equinox celebration was the Mayan sacrificial ritual by the main pyramid at Chichen Itza, Mexico.
The pyramid, known as El Castillo, has 4 staircases running from the top to the bottom of the pyramid's faces, notorious for the bloody human sacrifices that used to take place here. The staircases are built at a carefully calculated angle which makes it look like an enormous snake of sunlight slithers down the stairs on the day of the equinox.
The U.S. snow depth analysis shows a dramatic picture this morning: huge amounts of snow over the Northwest U.S., but virtually nothing over the Northeast U.S. (see below). Washington State has greater depths than any other state (mainly in the Cascades), with amounts exceeded only by British Columbia, the Saudi Arabia of water resources. British Columbia snow is a big positive for us, of course, since the Columbia drains southward and many of us head to Whistler or other south BC ski areas.
Serious folks in the snow business like to look at snow water equivalent (SWE) instead of snow depth. SWE tells us the liquid water equivalent (the depth of water if the snowpack was melted) of the frozen water in the snowpack and is a better measure of the water availability when the snowpack melts during the spring. The SWE for this AM (see below) shows massive amounts in our area, with substantial SWE in the northern and central Rockies. Bad news over the eastern U.S., where preternatural warmth--reaching the lower 70s was enjoyed during Christmas Eve and Christmas Day.
The temperatures back east were simply startling and opposite of the severe cold they experienced the last two winters. Take a look at the max temperatures on Christmas Eve Day. 72F in New York City and Albany. 69F in Boston.
Saturday, December 26, 2015
The Pacific Northwest: Snow Capital of the U.S.
The U.S. snow depth analysis shows a dramatic picture this morning: huge amounts of snow over the Northwest U.S., but virtually nothing over the Northeast U.S. (see below). Washington State has greater depths than any other state (mainly in the Cascades), with amounts exceeded only by British Columbia, the Saudi Arabia of water resources. British Columbia snow is a big positive for us, of course, since the Columbia drains southward and many of us head to Whistler or other south BC ski areas.
Serious folks in the snow business like to look at snow water equivalent (SWE) instead of snow depth. SWE tells us the liquid water equivalent (the depth of water if the snowpack was melted) of the frozen water in the snowpack and is a better measure of the water availability when the snowpack melts during the spring. The SWE for this AM (see below) shows massive amounts in our area, with substantial SWE in the northern and central Rockies. Bad news over the eastern U.S., where preternatural warmth--reaching the lower 70s was enjoyed during Christmas Eve and Christmas Day.
The temperatures back east were simply startling and opposite of the severe cold they experienced the last two winters. Take a look at the max temperatures on Christmas Eve Day. 72F in New York City and Albany. 69F in Boston.
Eastern U.S temperatures have been much warmer than normal all fall. Here is the anomaly (difference from normal) of max temperature for the past 90 days. Western WA has actually been a bit below normal.
Why? The proximate reason is unusually persistent high pressure over the eastern U.S.. Here is the anomaly (in tens of meters) of the heights at a mid-level of the atmosphere (500hPa) for the past 90 days. . Red means higher heights (pressure) than normal. High heights are associated with warmer temperatures below.
This is probably the result of natural variability, no reason to expect it is connected with global warming. What about El Nino? Probably not at this point. We have yet to see the normal El Nino circulation changes, which generally are most profound after January 1st and certainly our recent weather in the Northwest is not El Nino-like.
Finally, some folks in the lowlands may enjoy some snow tomorrow: those on the Kitsap and SE of the Olympics. Here is the 24 snowfall ending 4 AM Monday. Some snow extending over the the Hood Canal area and over parts of Kitsap. Light snow in the Cascades (few inches). None over Seattle, so our mayor can relax.
Most of the Kitsap snow will fall tomorrow morning as a modest front crosses our region
Incredible photos from the International Space Station
Hurricane Danny. Keeping an eye on you from the International Space Station. Looks like you're 1st in the Atlantic this year. Stay safe below! (Photo courtesy Scott Kelly / NASA)
Been hanging out with the Bahamas again, it never gets old. (Photo courtesy Scott Kelly / NASA)
#GoodMorning to those in the western #USA. Looks like there's a lot going on down there. #YearInSpace (Photo courtesy Scott Kelly / NASA)Kelly / NASA)
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