The weather came out of the northwest bringing cooler temperatures on Tuesday and Wednesday and smoke from the Canadian wildfires more than 1,000 miles away. Even when the air quality was bad this week I went outdoors. Perhaps I was fooled that it was OK since it didn’t have that sulfur smell typical of Pittsburgh pollution.
This week I went further afield than Schenley Park. Here are highlights from Frick, Schenley, Aspinwall Riverfront Park and Moraine State Park. The captions tell the story.
Common mullein (Verbascum thapsus) has small flowers that we rarely see up close because they bloom on a six foot spike.
We definitely notice the spike. And then the rest of the plant.
Meanwhile, my namesake plant is still blooming. This one was at Moraine State Park.
As unpleasant as this summer has been in the Northern Hemisphere we comfort ourselves that better weather will arrive with autumn in September. But even that is changing. A new study published in Geophysical Research Letters predicts that by the end of this century winter, spring and fall will retreat while summer will last nearly half the year.
During those sixty years, summers got longer while the other seasons shrank. The slides below show the historical seasons 1952 and 2011 plus the study’s prediction for the year 2100. By then summer will run from May to October.
For those of you who don’t like winter this sounds like a great idea but the reality will be unsettling. The long summers and short winters will continue to have extreme temperature and precipitation swings with stunning storms like those we’ve seen in recent years. Imagine the heat of July lasting three months or more.
Meanwhile pleasant days will become scarce. My favorite seasons, spring and fall, will be shorter.
Our great-grandchildren will live in a very different world.
Consequently the Colorado River is running very low and Lake Mead reached a crisis point last month. The Guardian reports:
In June , the level of Lake Mead plunged below 1,075ft, a point that will trigger, for the first time, federally mandated cuts in water allocations next year. …
Should second tier cuts occur, Arizona will lose nearly a fifth of the water it gets from the Colorado River. Nevada’s first-round cut of 21,000 acre-ft (an acre-ft is an acre of water, one foot deep) is smaller, but its share is already diminutive due to an archaic allotment drawn up a century ago when the state was sparsely populated.
The crisis is due to lack of precipitation but we learned in 2014 that loss of rain and snow is dwarfed by the depletion of groundwater.
Using nine years of NASA’s GRACE satellite data from the Colorado River Basin, UC Irvine and NASA scientists made an alarming discovery. From December 2004 to November 2013 the watershed lost 53 million acre-feet of water, an amount almost twice the size of Lake Mead. More than 75% of that loss was from groundwater. No one knows how much water is underground but it’s going fast.
At 3pm on Wednesday 7 Jul 2021 a heavy downpour in the Nine Mile Run watershed caused a flash flood recorded by Upstream Pittsburgh‘s stream cam (video below, blurry because it’s raining). The downpour was so localized to the East End that it did not register on Pittsburgh’s official weather gauges. Flood debris showed that if I’d been on the Nine Mile Run Trail the water would have been up to my ears! (photo at top taken at 40.4263341,-79.9068387).
On Thursday 8 July at 7pm a downpour over Pleasant Hills had devastating results as reported by CBS Pittsburgh.
And on Friday 9 July another localized thunderstorm let loose for half an hour in Squirrel Hill. I have no photos because I was driving down Braddock Avenue in the downpour, hoping the river on the road would not become a car-swallowing lake under the Parkway bridge. Fortunately the water ran off into Nine Mile Run. Another flash flood. I’m glad I was not on the trail.
We don’t need a particularly wet year for this to happen. Pittsburgh’s 2021 rainfall is actually 0.93 inches below normal as of today. The problem is that the rain falls all at once, especially in June and July.
Climate change is making the problem worse. A 2019 study found that extreme precipitation has increased 55% in the Northeastern US in my lifetime.
Brace yourself, Pittsburgh, for a lot of flash floods in the future. Sometimes every day.
About Nine Mile Run per Upstream Pgh (formerly Nine Mile Run Watershed Association): “Nine Mile Run is a small stream that flows through Pittsburgh’s East End, mostly underground. The 7 square mile Nine Mile Run watershed is home to the largest urban stream restoration in the United States, completed by the U.S. Army Corps of Engineers in 2006.” Upstream Pgh got its start with this project and now works throughout the region on community-oriented stormwater management projects, large and small, plus much more. Click here for their website.
The State of the Air Report doesn’t even measure the rotten egg smell — hydrogen sulfide, H2S — that’s produced by U.S. Steel’s Clairton Coke Works and Edgar Thompson Works in Braddock.
High concentrations of H2S (widely recognized by its foul, rotten-egg odor) are registered all too often in the Mon Valley. In fact, so far this year there have already been 21 exceedances of Pennsylvania’s 24-hour average H2S standard – 13 at the Liberty monitor and eight more at the North Braddock monitor.
About once a week I look back seven years to highlight an old blog post that is still interesting today. This morning when I looked back, I was stunned at how different spring is now in southwestern PA compared to April 2014. A lot has changed in seven years. Migrating ducks, singing frogs and flowers are showing up earlier in 2021. For instance …
Have you seen a lot of ruddy ducks lately? Seven years ago the bulk of their migration through Moraine State Park began on 5 April 2014. This year it started almost a month earlier on 11 March 2021 and is basically over now. Here’s the 2014 blog post that caught my attention: Ruddy Bubbles. Click on the hotspot icons here to see this year’s ruddy duck activity at Moraine.
Have you heard spring peepers or wood frogs calling lately? Seven years ago they were loud on 6 April 2014 (Jeepers Creepers) but this year their peak was on 12 March 2021 at Racooon Wildflower Reserve: Sights and Sounds of Early Spring. When I returned to Raccoon twelve days later the frogs were quieter. They were silent on 4 April 2021.
In the early 1900’s Joseph Grinnell made extremely detailed records of flora and fauna in California’s Mojave Desert for the Museum of Vertebrate Zoology. A century later the average temperature in the Mojave is now 2oC (3.6oF) higher. Using Grinnell’s records a team led by Eric Riddell resurveyed Grinnell’s locations to find out how birds and mammals fare in hotter, drier conditions.
If you like birds, you won’t like the news.
[In the Mojave Desert] Over the past century, occupancy of small mammals remained stable while birds severely declined.
On average, every spot surveyed had lost more than 40% of its desert bird species, such as American kestrels or mountain quail. At most sites, even the remaining species were scarcer.
Seven years ago I wrote about an endangered member of the crow family in Ethiopia whose range is small and shrinking. Similar in size and sociability to our Florida scrub-jay, Stresemann’s bush-crow (Zavattariornis stresemanni or Ethiopian bush-crow) lives in just 6,000 square miles of southern Ethiopia’s Borana rangelands in an area smaller than New Jersey.
Has the bird’s status changed in the last seven years? No, but we know more.
A 2012 study found that his range was limited by daily high temperature. In 2018 a team of scientists investigated further, taking temperatures throughout the region and comparing the bush-crow’s range to two other local species — white-crowned and superb starlings. Their report at the British Ornithological Union blog showed that Stresemann’s bush-crow has a narrow favorite temperature range and is heat intolerant.
The starlings don’t care how hot it gets but the bush-crow won’t live where the maximum daily temperature is over 30 degrees C (86 degrees F). (Graphs embedded below from bou.org)
This wouldn’t be a problem except that it’s getting hotter.
Every November air pollution spikes in India as farmers in the Punjab burn their fields in preparation for the next crop. Because the practice causes terrible air pollution it was outlawed in 2015, but small farmers cannot afford to buy the machines needed to clear the fields so the practice continues year after year.
When the stubble burns Delhi is smothered in dangerous air pollution. The smoke from thousands of fires swirls high in the atmosphere and can be seen from satellites.
Meanwhile glaciers in the Himalayas have been retreating for the past decade. Scientists wondered if atmospheric carbon air pollution, landing on the white ice, was a factor in their warming. A team led by Yuan Q placed air pollution monitors in remote locations on the northern side of the Himalayas. Their report, published by the American Chemical Society on 4 November 2020, found an amazing thing:
Using electron microscopy, the researchers unexpectedly found that about 28% of the thousands of particles in the air samples from the Himalayan research station were tarballs, and the percentage increased on days with elevated levels of pollution.
Microscopic tarballs form from brown carbon in the smoke of organic fires — in this case, stubble burning. They are so lightweight that they travel far, rising over the Himalayas to deposit on the other side. Their dark color absorbs sunlight and causes the glaciers to melt faster.
Stubble burning is a persistent annual problem in India as shown in the 2018 video from France 24 below.
Dec 2018: Crop burning crisis: India chokes as farmers set fields on fire, France 24 News
As India’s government provides community-shared machines for clearing stubble, the burning will come to an end. Will it be soon enough for the glaciers? Probably not.
(photos from Wikimedia Commons, chart embedded from acs.org; click on the captions to see the originals)
The study is here: Yuan Q et al. Evidence for Large Amounts of Brown Carbonaceous Tarballs in the Himalayan Atmosphere. Environmental Science & Technology Letters. Published 4 November 2020. https://doi.org/10.1021/acs.estlett.0c00735
As temperatures soared this week from 9 to 19 degrees above normal, I remembered the time when our furnace broke in late September 2009. We thought we could tough it out while we waited for the new furnace to arrive but it was cold! The temperature went down on 25 September 2009 and never came up again. Like ducklings, we huddled inside to stay warm.
This graph shows how much we needed the furnace in the fall of 2009. The higher the blue line, the more we needed heat. We didn’t need air conditioning (orange line) after 25 Sept 2009.
Not so this year! Every 10 days or so the temperature climbs so high that we’d benefit from air conditioning. Rather than flipping the thermostat from heat (blue line) to A/C (red line), I wear my summer clothes again. Climate change makes the temperature fluctuate widely.
For five days this month it was summertime even though the trees couldn’t provide much shade.
Today the weather will turn cold. The furnace is ready. No need to huddle this year.
p.s. Read about our no-furnace adventure in this vintage article: Huddle!
(photos from Wikimedia Commons and by Kate St. John)