Extreme Temperature Diary- Monday October 4th, 2021/ Main Topic: Global Dimming…Another Negative Feedback Loop

The main purpose of this ongoing blog will be to track planetary extreme or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉

Main Topic: Global Dimming…Another Negative Feedback Loop

Dear Diary. Let’s discus simple physics to start today’s main subject. A blacker or darker object can absorb more incoming radiation than its whiter or brighter counterpart. That’s why climate scientists are very concerned about the loss of sea ice, reduction of snow cover, and loss of vegetation occurring around the planet due to climate change. Also, it has been demonstrated that as the Earth warns there will be less cloudiness. As we know, clouds deflect some incoming solar radiation.

What we have here is a negative feedback loop in which global warming leads to more global warming the dimmer the planet gets. On the bright side, pardon the pun, global dimming is one more facet that climate scientists can point to as proof of man induced climate change.

Here are many more details from a recently written article from Live Science:


Climate change is making Earth dimmer

By Meghan Bartels 10/3/2021

An image taken from the International Space Station in 2011 shows Earthshine on the moon.

An image taken from the International Space Station in 2011 shows Earthshine on the moon. (Image credit: NASA)

Earth is reflecting less light as its climate continues to change, new research suggests.

A beautiful phenomenon connects climate and brightness: clouds. Clouds are a notoriously complicated piece of the climate puzzle — scientists struggle to model how clouds will respond to climate change and how those responses in turn will shape the future climate. But the scientists behind the new study think that the reflectivity finding hinges on the dynamics of clouds over the Pacific Ocean.

The research relies on two decades’ worth of observations of a phenomenon called “earthshine,” which is the light that Earth reflects onto the surface of the dark side of the moon, combined with satellite observations of Earth’s reflectivity, or albedo, and the sun’s brightness.

RelatedThe top 10 views of Earth from space

Different features on Earth reflect different amounts of light: the oceans very little, land about twice as much. Meanwhile, clouds reflect about half the sunlight that hits them, and snow and ice reflect the majority of light they receive.

Scientists at Big Bear Solar Observatory in Southern California have been studying how earthshine fluctuates since 1998, looking for changes at time scales from daily to decadal. (The researchers note that these measurements are only relative and call for more robust observations, perhaps even from cubesats or a lunar observatory.)

In the new research, scientists combined that data with observations from NASA’s Clouds and the Earth’s Radiant Energy System (CERES) project, which has been operating since 1997 with instruments on a host of NASA and National Oceanic and Atmospheric Administration (NOAA) satellites.

The researchers pulled together the two datasets to get a sense of whether and how Earth’s brightness has been changing. Over the full two-decade span, the amount of light Earth reflected dropped about 0.5% — or about half a watt less light per square meter. (One square meter is a little less than 11 square feet.) Most of the change comes in the last three years of the earthshine data set, which the researchers analyzed through 2017; the CERES data continues until 2019 and shows an even starker decline at its end.

And during that time, the researchers determined, the brightness of the sun — which went through two periods of maximum activity and one quiet period during the course of the study — didn’t meaningfully connect to the dip in reflectance. So a change in the amount of light Earth is reflecting must come from a change in Earth itself, the scientists reasoned.

In particular, the CERES data noted a loss of bright low-altitude clouds over the eastern Pacific Ocean, off the west coast of the Americas, where scientists are also registering stark temperature increases at the ocean surface.RELATED STORIES

— 10 out-of-this-world images of Earth taken by Landsat satellites
— Earth Day: These amazing NASA images show Earth from above
— The world turns sideways in trippy, glowing Earth photo from the International Space Station

And because light not reflected out to space is trapped in the Earth system, the change in brightness also has implications for the future of climate, potentially increasing the pace of human-caused climate change.

The research is described in a paper published Aug. 29 in the journal Geophysical Research Letters.

Email Meghan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

Here are some “ET’s” from Monday:

Here is some September 2021 climatology:

Here is more climate and weather news from Monday:

(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)

Now here are some of today’s articles and notes on the horrid COVID-19 pandemic:

(If you like these posts and my work please contribute via the PayPal widget, which has recently been added to this site. Thanks in advance for any support.) 

Guy Walton “The Climate Guy”

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