Clouds are not holding in heat. They are emitting it!
Clouds absorb heat during the day just as the earth does. When the temperature falls clouds emit heat in all directions including downward to us below. Their warmth can be just enough to keep us above freezing.
On a clear night there is nothing to warm us so we have frost in the morning.
Did you know you can avoid frost on your windshield if you park beneath a tree on clear, near-freezing nights? The tree is emitting heat, too. No frost in the morning.
Either it is very cold in this picture or the car was not parked under a tree.
Quiz! Where is the largest desert on Earth? What continent is it on?
By “largest” I mean square miles. By “desert” I mean …
A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of denudation. About one-third of the land surface of the world is arid or semi-arid.
Did you know that the majority of deserts are not composed of sand dunes?
To get you in the mood, here are photos of deserts around the world.
Leave a comment with your answer. I’ll post the answer later today (see below).
Click here for a map (By the way, this map includes the answer but it doesn’t look that way!)
ANSWER: Antarctica! In fact both poles are deserts. The Antarctica Polar Desert is 5.5. million square miles, the Arctic Polar Desert is 5.4 million sq mi and the Sahara is 3.5 million sq mi. Read more about the largest deserts at geology.com.
It cannot be too cold to snow some. It can be too cold to snow a lot. As air gets colder, it can hold less moisture. This is why the Antarctic is the greatest desert on Earth. It’s drier in many places than the Sahara! Climate change is expected to cause more snow in polar regions, not less. Now you know why. (warmer air means it can snow more)
Back in 2018 astronomers discovered a planet 200 light-years away and five times the size of Earth. K2-141b is a lava planet so close to its sun that its rotation and orbit are in lock step; the same side always faces the sun. It also moves really fast completing an orbit in only 0.28 days. Earth’s orbit takes a year. On K2-141b a “year” lasts 6.7 hours!
All of this was so intriguing that astronomers from York University, McGill University, and the Indian Institute of Science Education and Research decided to model K2-141b’s atmosphere. Published in the Monthly Notices of the Royal Astronomical Society, their report attracted attention because K2-141b is so unbelievably hellish. For instance:
The planet rains rocks, has an enormous lava ocean over 60 miles deep, and winds whip across its surface at speeds more than four times the speed of sound. And, because of how the small planet moves around its sun, one part of it experiences permanent daylight and reaches temperatures up to 5,432 degrees Fahrenheit, while the other side exists in permanent darkness, and temperatures drop to negative-328 degrees.
Put all that together and you get a place hot enough to evaporate rock, windy enough to transport the evaporated minerals rapidly to the other side of the planet, and cold enough on the dark side for minerals to condense quickly and fall as a rain of rocks!
Halloween is almost here. Who has the largest jack o’ lantern?
Two pumpkins in Jersey would like to win the honor. They’re nearly as wide as a picnic table.
They would lose to this 905.5 pound pumpkin from Ohio. Even if scooped out it would break the picnic table.
No squash can match the Ericsson Globe in Stockholm, Sweden when dressed for Halloween. At 360 feet in diameter it’s wider than a football field, the largest jack o’ lantern in the world.
However, the universe wins the prize for size. The Jack O’ Lantern nebula is a cosmic cloud of radiation and particles emitted by a huge star 15-20 times heavier than our sun. This 2019 animation from NASA/JPL-Caltech shows why it’s called The Jack O’ Lantern.
These arborvitae cones were on the ground at a pine siskin hotspot. Three stages are pictured: Top = Spent cones as much as one year old, Middle = Opened cones that were emptied by pine siskins, Bottom = a mix of closed, opened and spent cones.
The huge acorn crop in Schenley Park is attracting many blue jays, squirrels and chipmunks. Here’s what the ground looks like below the oaks at Bartlett Shelter.
In other delights October trees, sky and shadows are spectacular.
All summer we noticed curly dock (Rumex crispus) leaves and not the flowers. Now our attention is reversed because the seeds have turned a rich brown. The stalk is ugly, however the seeds are fascinating up close, each one surrounded by the calyx that produced them. The papery wings allow them to float on water and fly a bit in the wind.
The most obvious sign of fall is the temperature. 43 degrees F at dawn today. Speaking of gloves, you’ll need them when you go birding in the morning.
This week’s spooky sunsets and hazy skies in eastern North America are due to smoke from the massive wildfires in Washington, Oregon and California. The smoke is so intense that it’s dispersing across the continent and across the Atlantic, causing haze in Europe.
Near sunset on Monday 14 September the sun was a strange shade of pink in Pittsburgh, captured above in true color by Jonathan Nadle.
We can’t see the smoke coming but the satellites do, blowing eastward in two paths on Tuesday 15 September: one over the Northern Plains and Great Lakes, the other over Nebraska to Kentucky and Virginia.
The haze is inconvenient for us but truly hazardous on the West Coast. The dark brown colors on the map below are the worst air quality in the world. The air is so bad that people are leaving the area. I know of at least one person who’s fleeing from San Francisco to Pittsburgh.
Last night two hours after sunset bird migration was intense over the southeastern United States. The birds showed up as blue blobs on Doppler weather radar but there was a noticeable gap over Louisiana, southern Mississippi and southeastern Alabama. The birds were avoiding Hurricane Laura.
This National Weather Service radar map from 26 Aug 2020, 9:48pm EDT shows where the birds won’t go. (I’ve added a pink line to illustrate their self-imposed boundary.) I believe the small blue blob south of the pink line –at Jackson, Mississippi — is a sign of birds leaving for safer locations.
Humans were urged to leave too because of the coming storm surge, 20 feet high, as illustrated in the Weather Channel video below.
The National Hurricane Center has forecasted “unsurvivable storm surge” from Hurricane #Laura in parts of Louisiana and Texas. Do NOT underestimate this storm.