The 100th Meridian Is Moving East

Climate Change, Musings & News, Weather & Sky
North Dakota, riparian wildlife habitat (photo from USDA)

The 100th Meridian West is an imaginary line on the map that happens to mark the climate divide between the humid east and arid west in North America. Or rather, it used to. The rainfall divide is moving east.

Extending from the North to South Poles, the 100th runs longitudinally in the U.S. from North Dakota through Texas.

The 100th meridian is on the upright border of Oklahoma and Texas (image from Wikimedia Commons)

Its coincidence with the rainfall divide was first documented in 1877 by John Wesley Powell who found during his explorations in the Great Plains that the 100th was a visible boundary. Locations to the east of the 100th received 20+ inches of annual rainfall, the west received less.

20 inches is a key number for agriculture and human population. It determines what you can grow, whether you have to irrigate and, thus, how many people can live there. Powell saw the line and told Congress it had implications for settlement of the western plains. Congress didn’t heed him but …

This 2014 map of U.S. Population by County shows that it played out as Powell expected. You can see the rainfall divide in population density. People choose to live where there’s water.

U.S. population by county, 2014 (map from US Forest Service)

You can also see the line from outer space. I’ve marked the 100th (approximately) on this satellite photo of Nebraska. The landscape is deep green to the east though not uniform.

Satellite photo of Nebraska shows it is drier west of the 100th (photo from Wikimedia Commons)

Nowadays the 100th is no longer the rainfall divide.

A study by Columbia University meteorologists found that the aridity line has shifted 140 miles east and is now statistically located at the 98th meridian. Climate change will move it even further as warming evaporates moisture in the northern plains and alters rainfall in the south.

In a hundred years the aridity mark may be firmly inside Minnesota, Iowa and Missouri. Aridity decreases the amount of agriculture and will probably change the population. People choose to live where there’s water.

John Wesley Powell’s “100th meridian” is moving east.

This article was inspired by Yale Climate Connections. Read more here in Yale Environment 360, 11 April 2018.

(photos from USDA, USFS and Wikimedia Commons; click on the captions to see the originals)

Murmurations in Lorain

Bird Behavior, Peregrines

Murmuration of starlings in Lorain, Ohio, 30 Dec 2018 (video by Chad+Chris Saladin)

European starlings (Sturnus vulgaris) are famous for their ability to fly in tight formation. When under attack by a peregrine falcon, they evade him in amazing ways.

Starlings under pressure fly closer together and shape-shift the flock like a giant blob in the sky. This makes it hard for the peregrine to choose a single bird as prey and gives their flocks a special name, a murmuration.

This winter Chad+Chris Saladin have been filming murmurations in Lorain, Ohio. Above on 30 December 2018, below on Christmas Day.

European starling murmuration in Lorain, Ohio on Christmas Day 2018 (video by Chad+Chris Saladin)

Whenever there’s a peregrine, the starlings murmur.

Bonus! Here’s a Facebook album by Chad+Chris with closeups of a peregrine hunting starlings. (click on the “See More” link embedded in the Facebook post)

(videos and photos by Chad+Chris Saladin; click on the captions to visit their Facebook page)

It’s Time To Appreciate Clouds!

Weather & Sky
Wrinkled clouds in Pittsburgh, 7 Jan 2019

A week ago, 7 Jan 2019, the National Weather Service said the sky was clear at Pittsburgh International Airport but I have proof that at that moment it was overcast in the East End.

Not only was it overcast but the clouds were doing something special near the Cathedral of Learning. See that wrinkle? Is that undulation? Or is it the beginning of an asperitas formation?

Asperitas clouds are newly named, the first formation to be added to the International Cloud Atlas in 66 years. They were proposed by the Cloud Appreciation Society in 2009 and accepted in 2017. The atlas goes back to 1896 so this is a big deal.

This video of asperitas clouds in Tenerife, featured by the Cloud Appreciation Society, shows how fascinating these clouds can be.

Thick clouds say “Pittsburgh in winter” all over them. Stratus (low) and altostratus (mid-level) are our specialty but we also have altocumulus undulatus, cumulus fractus and sometimes even mammatus. Click to see what they look like.

Yes, we have overcast skies (tell me about it!) but there are cool things above us if we just take the time to look. Watch the video to get in the mood (exciting background music!).

C’mon, Pittsburgh, it’s time to appreciate clouds!

(photo by Kate St. John, video from skyport.com.es on YouTube)

p.s. Did you know that clouds have a genus and species? At the bottom of this webpage is a cloud diagram that shows genus by height. Explore the International Cloud Atlas.

p.p.s. The sun is at the top edge of my photograph. Do you see it?

Seeing Is Believing

Musings & News

Last year I learned that charts change hearts and minds better than words do. Our brains process visual information better than text.

I was reminded of this human tendency when I read in The New Yorker about the burgeoning Flat Earth movement. Members became believers when they saw YouTube videos claiming there’s been a coverup and that the Earth is actually flat.

This 2017 video sparked controversy as viewers tried to process his intent. Satire or Science?

Seeing is believing.

(video from YouTube; click the YouTube logo to see the original upload)

Truly Sunken Garden Trail

Mammals
Evidence of beavers: downed trees and orange stump, Moraine State Park (photo by Kate St. John)

Last Saturday I tried to enjoy the Sunken Garden Trail at Moraine State Park but there were challenges along the way. The trail was very soggy, trees were down on the Short Loop, and part of the trail was under a few inches of water.

The flood is the work of beavers who backed up water in the wetlands (above) about 600 feet from the trail entrance (below).

Flooded Sunken Garden Trail, 5 Jan 2019 (photo by Kate St. John)

The Sunken Garden Trail is truly sunken here. Fortunately ankle-high muck boots were more than enough to keep me dry.

Be prepared for mud in this winter’s warm weather. And watch out for black-legged ticks. I got one on my pants after I bushwhacked around downed trees. They’re moving around out there, though in slow motion.

(photos by Kate St. John)

Nesting Season Begins for Bermuda Cahow

Nesting & Courtship, Water and Shore
Bermuda cahow returns from the sea for the 2019 nesting season (photo from the Bermuda Cahow Cam at Cornell Lab)

The nesting season began for this Bermuda cahow when she returned to her nest burrow on Wednesday 9 January 2019 at 11:55pm (almost midnight). By 1am she had laid her single egg. Click here for a video.

Cahows or Bermuda petrels (Pterodroma cahow) live on the open ocean and only come to land on dark nights during the nesting season, placing their nests in underground burrows on small inaccessible islands to protect them from predators. Humans used to be one of those predators. We ate them. By 1620 cahows were presumed extinct.

When cahows were rediscovered in 1951 there were only 18 nesting pairs on Earth, but thanks to the conservation efforts of David B. Wingate and the Cahow Recovery Project there are now more than 135. Most of them are on Nonsuch Island where many burrows are man-made to provide additional nesting sites. This burrow has a camera.

The pair that “owns” this burrow came back in November to refurbish the site, court and mate. In December they returned to the sea. Then on Wednesday the female returned to lay her egg and begin incubation. Her mate will arrive and take over incubation so she can go back to the ocean to eat.

Cahows are nocturnal so you’ll see them most active when it’s night in Bermuda. Watch their family life on the Bermuda Cahow Nestcam. Stay up to date on Twitter at @BermudaCahowCam.

(photo from the Bermuda Cahow Cam; click on the caption to see it “Live”)

Orange House Finch

Songbirds
A normal house finch with an orange one (photo by Marcy Cunkelman)

House finches normally have rosy red foreheads, chests, and rumps but occasionally you’ll see an orange one. He’s not a new species, he’s just a color variant.

The orange color might be temporary. Depending on what the house finch eats he could be red next year.

Find out how this happens in this vintage article entitled “Orange?“

(photo by Marcy Cunkelman)

Diamond Dust

Weather & Sky

Here’s a form of ice we’re unlikely to see in Pittsburgh because our weather is rarely cold enough and it’s often overcast.

Diamond dust is clear-sky precipitation that looks like tiny diamonds in the air, falling through a ground-level cloud. The conditions for producing diamond dust are very specific:

  • The temperature has to be well below freezing — best at -13F or lower.
  • The cloud must be made of ice. It’s not a freezing fog that started wet and turned icy.
  • The cloud is in a clear sky and the sun is shining. That’s how you see the diamonds.

The best place to find diamond dust is in Antarctica where it falls 316 days of the year. Otherwise you have to be in the right place at the right time. Bundle up!

Bonus Question: Diamond dust is not associated with a pogonip. What’s a pogonip?

(video “Diamond Dust in Bellevue Washington” from Wikimedia Commons; click here to see the original)

Casting A Pellet

Bird Anatomy, Bird Behavior, Birds of Prey

(Red-tailed hawk casts a pellet, photos by Chad+Chris Saladin)

Why does this red-tailed hawk throw up a long gray lump? Is he sick? Not at all. He’s casting a pellet.

Birds’ digestive systems are very different from ours, beginning with their beaks. Since birds don’t have teeth they swallow most of their food whole. The rest of their digestive system is geared to deal with this.

Birds have little saliva and few taste buds compared with mammals, which chew and physically process food as the first step and then subject it to chemical processing as the second step. Birds reverse this sequence. They start chemical digestion in the proventriculus [then the food] undergoes physical processing in the gizzard.

Ornithology, 3rd Edition by Frank B. Gill, page 164

We chew with our teeth and spit out the bones. Birds chew with their gizzards which then collect the bones, fur, and other indigestible bits into a lump. The bird spits out the lump when it’s a convenient size.

Owls, eagles, hawks and falcons cast pellets but so do many other birds “including grebes, herons, cormorants, gulls, terns, kingfishers, crows, jays, dippers, shrikes, swallows, and most shorebirds.” (quote from Wikipedia)

Scientists examine pellets to find out what the bird ate. One of the long-eared owl pellets below was dissected to reveal the rodent bones inside.

Pellets cast by a long-eared owl, dissected to show rodent bones (photo from Wikimedia Commons)

For whatever reason, it’s rare to see a bird casting a pellet so consider yourself lucky if you witness it, as Chad+Chris Saladin did in the photos above.

A NOTE ABOUT HANDLING OWL PELLETS from Wikipedia: Some rodent viruses and bacteria can survive the owls’ digestive system so wear gloves and sterilize the pellets in a microwave oven before handling. A 2005 study found outbreaks of salmonellosis at elementary schools associated with dissection of owl pellets: Smith KE, Anderson F, Medus C, Leano F, Adams J, 2005. Vector-Borne and Zoonotic Diseases,5, 133–136.

(red-tailed hawk photos by Chad+Chris Saladin; pellet photo from Wikimedia Commons; click on the captions to see the originals)

The Snowman Of The Universe

Musings & News, Weather & Sky
Three images of Ultima Thule, center image is black-and-white (photos from NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute)

Last week the news broke that NASA’s New Horizons spacecraft had flown by and photographed what looks like the “snowman of the universe,” two icy chunks stuck together like a snowman and spinning out there in the Kuiper Belt beyond Neptune.

Yes, this object spins. Here’s a time lapse from NASA on New Years Day 2019.

Polar view of  Ultima Thule’s rotation over 2.5 hours (animation from NASA)

The snowman is reddish and tiny, only 20 miles long, so he can’t be seen from Earth. We wouldn’t even know about him except that a few years ago the New Horizons team looked for something interesting for the spacecraft to explore after it passed Pluto. They saw him as a dot using the Hubble Space Telescope in 2014 and chose him because he’s a classical Kuiper Belt object with low inclination and low eccentricity.

How eccentric is a snowman in outer space? It depends on his orbit.

NASA named his big chunk Ultima and his small one Thule. The combo sounds like a name from science fiction but in fact Ultima Thule was the name ancient geographers gave to the northernmost land in the inhabited world. Back then it was somewhere in Iceland, Norway, or a remote Shetland Island. Now it’s beyond Neptune. (Click here to pronounce Ultima Thule. It’s not what you think.)

Ultima Thule’s real name is (486958) 2014 MU69. It’s just the right number of digits for a phone number, but don’t call it. The long distance charges are astronomical!

For more information, including a diagram showing how the snowman formed, read NASA’s New Horizons Mission Reveals Entirely New Kind of World.

p.s. I’m sure Ultima Thule is not the only snowman out there so he’s actually “A Snowman” in the universe, not “The Snowman.”

(images from NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute)