Monday’s animated Spring Leaf Index (18 March 2019) shows that leaf out was ahead of schedule through late February but fell behind in northern Virginia, the southern Great Plains, and the Pacific Northwest when cold weather hit in early March.
According to the model, spring hasn’t reached Pittsburgh yet but I’m conducting my own Leaf Out Survey in my neighborhood. I took the honeysuckle photos below on 11 March and 16 March 2019. Both were cold days after a spurt of exceptionally warm weather. The tiny leaves on the right show the effect of 77 degrees F on March 14!
Do you have leaves in your neighborhood yet? Is spring on time?
Greater koa finch. Koa forest cut down. Last seen in 1896.
Hawaii mamo. Last seen in 1898.
Greater 'amakihi. Land cleared. Last seen in 1901.
Black mamo. Last seen in 1907.
Laysan honeycreeper. Extinction by rabbit in 1923.
Hawai'i 'o'o. Last seen in 1934.
O'ahu akialo'a. Last seen in 1940.
Maui 'akepa. Last seen in 1988.
Po'ouli (black-faced honeycreeper). Last seen 26 Nov 2004.
By now in my series on Hawaii you’ve probably noticed that the rarest birds on the islands are threatened with extinction. Sadly this situation is normal. So many Hawaiian species have gone extinct and so many are on the edge today that Hawaii is known as the Extinction Capital of the World. The group of forest birds called Hawaiian honeycreepers are a case in point.
Five million years ago a flock of finches similar to redpolls (Carpodacus erythrinus)arrived from Asia, flying non-stop for more than 4,000 miles. When they arrived, Oahu and the Big Island didn’t exist, but over millions of years they spread out and evolved into 59 species of Hawaiian honeycreepers with a wide variety of beaks for exploiting Hawaii’s food sources. They diversified more than Darwin’s finches.
Each bird was perfectly evolved to survive Hawaii’s dangers but had no defense against off-island threats. Their exposure came with the arrival of humans. We came in two waves.
Polynesians arrived in Hawaii around 400AD and were here alone for 1,400 years. During that period 30% of the Hawaiian honeycreepers went extinct.
In 1778 Captain James Cook was the first European to see Hawaii, prompting immigration from the rest of the world. Since then, in just 240 years, another 39% of the honeycreepers have gone extinct. 18 species remain but six are so critically endangered they may be gone soon.
Hawaii’s endemic birds go extinct so easily because of …
Habitat loss: Humans cleared the forest for settlements. Some species had such a small range or specialized food that when their patch was gone, they were too.
Introduced species, especially rats, cats and mongoose: The birds don’t know to move their nests out of reach.
Avian malaria and avian pox: Honeycreepers have no immunity.
Mosquitoes: Avian diseases, carried by mosquitoes, arrived with introduced birds. Honeycreepers don’t know to brush mosquitoes away. They catch malaria easily and it kills them.
Climate change: There’s safety from mosquitoes at high elevation but climate change is heating the mountains. The mosquitoes are moving uphill.
Avian diseases caught from mosquitoes are the big problem. Fortunately there’s a silver lining. One of the honeycreepers, the Hawai’ian amakihi, can now live with avian malaria and is expanding its range within mosquito territory.
This 27-minute video, made in 2005 by Susanne Clara Bard, tells the story of the Hawai’ian amakihi’s survival. Though this video is a lot longer than I normally post, it’s worth even a short look to learn why Hawaiian birds face so many challenges.
The Hawai’ian amakihi evolved to survive malaria in only 200 years.
(images from Wikimedia Commons; click on the links to see the species account at Wikipedia)
Tour Day 9: Leaving the Big Island of Hawai’i for home
Science predicted this more than a generation ago, but most of us couldn’t imagine how it would feel. Now that we’ve seen 30 years of change and more is in store, we’re anxious to know what our climate will be like in the future.
It shows that Pittsburgh’s 2080 climate will feel like Jonesboro, Arkansas does today. Jonesboro is 665 miles away from here, near Memphis, Tennessee. (Click on the image to see the website. Use website controls to see more complex answers.)
The map bubbles explain: Our winters will be 10.8F warmer and 46.8% wetter. Our summers will be 10F warmer and 17.6% drier.
Let’s compare current to future using graphs. Pittsburgh’s current climate averages are shown below from U.S. Climate Data.
Sixty years from now our average winter lows will barely reach freezing. July and August average highs will be 93+ degrees F but watch out for the highest highs. August record temperatures in Jonesboro are all above 103oF!
Our precipitation will be really different. We’ll go from a fairly steady 3 inches of rainfall per month to a rainy season in November-to-May and a dry season June-to-October. This might resemble California’s wet (flood) and dry (fire) seasons.
Climate change is giving us extreme weather, melting glaciers and rising seas. It’s not the first time we humans lived through this but the last event was during the Stone Age and nobody wrote it down.
During the last Ice Age England was connected to Europe. As the glaciers receded people moved to the land between. Dogger Bank was the highest ground, about 100 feet above sea level.
100 feet sounds like a safe height, right? Nope. The glaciers kept melting. Dogger Bank disappeared 8,200 years ago.
Remember how cold it was in January 2014? It’s been five years since we saw extremely cold weather but the jet stream is wobbling again and we’re going to see a smack of subzero temperatures this week. The maps show this week’s forecast lows described by the National Weather Service:
Bitter cold temperatures will give way to a potentially record breaking push of Arctic air this week. Wind chills as low as -40 or colder can be expected across the Northern Plains and Great Lakes. In addition, wide swaths of heavy snow can be expected across the area. This system will push east and south early this week with much below normal temperatures and wintry precipitation.
National Weather Service, 27 Jan 2019, 5am
Crazy as it seems, extreme cold is a sign of climate change. Here’s an explanation from my Polar Vortex article of January 2014:
“In the good old days before climate change, the winter polar vortex in the northern hemisphere was generally well behaved. It was a persistent, strong, cold, low pressure zone surrounding the polar high at roughly the same latitude around the globe. The strong winds kept the jet stream in line. Nobody got too hot or too cold.
“But now as the Earth gets hotter hot air from the troposphere is forced into the stratosphere and disrupts the polar vortex. The vortex weakens, becomes disorganized, and can collapse into smaller pieces. Its winds weaken and the jet stream flaps like a flag in the breeze, as shown in (c) below.”
(a) Strong polar vortex (blue) keeps jet stream (pink) at same latitude.
(b) Polar vortex weakens
(c) Weak vortex lets the jet stream range widely north and south.
Get ready! Arctic air is on its way.
(forecast maps from the National Weather Service. jet stream diagram from Wikimedia Commons; click on the captions to see the originals)
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.
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.
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.
Nowadays the 100th is no longer the rainfall divide.
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.
Two million years ago the Monongahela was a mighty river. Instead of being a short tributary of the Ohio and draining to the Gulf of Mexico, it flowed north to where Lake Erie is today and then to the Atlantic. This stretch of the Ohio River in Pittsburgh was not the Ohio at all. It was the Monongahela.
Here’s how the mighty Mon River lost its crown and the reason why the Ohio turns south at Beaver, Pennsylvania.
Before the Pleistocene era, the Monongahela River drained 75% of today’s Ohio, Allegheny and Monongahela watersheds as it flowed north from West Virginia to the Lake Erie area (roughly the red arrow path below).
Back in those days the Ohio River was just a tributary whose northernmost point was in Pennsylvania where it joined the Mon. The Beaver and Shenango Rivers did not exist as they do today. Their valleys carried the Monongahela north.
But then the climate changed. The Great Ice Age began.
Glaciers blocked the Monongahela’s northward flow so the river backed up and formed Lake Monongahela. The pale dashed lines show the paths of our rivers today bending away from the prehistoric glacier.
Eventually Lake Monongahela rose so high that it breached the lowest barrier in the Ohio valley near present day New Martinsville, WV (see orange arrow).
The Ohio started flowing “backwards.” It cut the Ohio River valley deeper, orphaned the northern Monongahela and reversed its flow, creating the Shenango and Beaver Rivers.
All of this was helped by the huge volume of water joining the Mon from the re-formulated Allegheny River watershed. The Upper and Middle Allegheny river systems used to flow north too, but were also blocked by glaciers. Their proglacial lakes overflowed and joined the Lower Allegheny River flowing into the Ohio watershed.
And so the Monongahela River became a lowly tributary of the Ohio.
Climate change is big stuff. When it gets cold it changes major rivers. When it gets hot … Well, we’ll find out.
UPDATE: See the comments! And here’s a map of the ancient Erigan River drainage from Ohio DNR.
(photo by Kate St. John. Red-arrow map derived from OH & PA river maps at geology.com, map of Lake Monongahela from Wikimedia Commons, annotated map of Erigan River via CVNP; click on the captions to see the originals)
Since then Nature did a 180-degree turn and handed us a series of cold snaps capped by snow. Our wildflowers have not bloomed yet. Last year they were two to three weeks early and had gone to seed by the end of March.
Fortunately NPN tracks first blooms as well, using lilacs as the marker plant.(*) On the map below you can see the Southeast bloomed 20 days early.
But we aren’t on the bloom map yet.
When will our wildflowers bloom? We’ll have to wait and see.
* From the USA NPN website: These models were constructed using historical observations of the timing of first leaf and first bloom in a cloned lilac cultivar (Syringa x chinensis’Red Rothomagensis’) and two cloned honeysuckle cultivars (Lonicera tatarica ‘Arnold Red’ and L. korolkowii ‘Zabelii’).
Yesterday we put on our summer clothes and this honeysuckle bush put out new leaves. It was summer in February.
At 78 degrees F the high temperature broke two Pittsburgh records: a new high for February 20 (formerly 68 degrees in 1891) and a new high for the entire month of February. It was 37 degrees above normal.
When you look at yesterday’s map you can see how it happened. The jet stream dipped across the Northern Rockies and Plains, then abruptly turned north over the Texas Panhandle. It was only 3 degrees F in western Nebraska while we were nearly 80. The narrow temperature gradient — that yellow line across the Midwest — continues to produce heavy rain.
“The Beaufort Gyre is acting strangely,” said the news at Yale Environment 360. “Scientists say it could kick off a period of lower temperatures in Northern Europe.”
The Beaufort Gyre is a wind-driven current in the Arctic Ocean. Traveling clockwise it keeps sea ice contained and moving so slowly that the ice thickens.
Every five to seven years the winds change direction and the gyre spins counter-clockwise, dumping icebergs and cold freshwater into the North Atlantic near Iceland. Then the winds switch back.
But now the winds haven’t changed direction for a long time, arctic ice is melting, and freshwater from the continents is flooding the Beaufort Sea. The surface now holds as much freshwater as the Great Lakes and the gyre is spinning faster, still clockwise.
What will happen next? The past gives us a hint.
Thirty years ago, when the gyre reversed direction for an extra long time, its ice and cold freshwater caused the North Atlantic herring fisheries to collapse and plunged Northern Europe into a temporary deep freeze.
Will the Beaufort Gyre change direction soon? And how long it will spin counter-clockwise? No one knows. Will the change be benign? Probably not.
The globe is warming overall (hence it was called “Global Warming”) but the resulting climate change is both hot and cold, weird and unpredictable.
It’s a bit like watching chaos unfold.
Turning and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world …
— The Second Coming by W. B.Yeats