adplus-dvertising
Connect with us

Science

Parts of North America Are Currently Heading For a Megadrought, Study Finds – ScienceAlert

Published

 on


Even though air pollution levels have been dropping in the wake of the coronavirus outbreak, the climate crisis isn’t going to go away. In fact, parts of the US and Mexico could be in line for a “megadrought” in the very near future, scientists warn.

Based on an analysis of precipitation levels since the turn of the century, and how they match up with soil moisture levels recorded by tree rings over the last 1,200 years, future modelling suggests the southwestern North American (SWNA) region could see a drought that’s worse than any in recorded history.

The conditions we’ve seen in the SWNA region since 2000 match up with times of severe drought in the past, the researchers say. It’s possible that a megadrought has already started, though 2019 precipitation levels did offer some respite.

300x250x1

The area covered by the study. (Adapted from Williams et al., Science, 2020)

“Earlier studies were largely model projections of the future,” says bioclimatologist Park Williams, from Columbia University. “We’re no longer looking at projections, but at where we are now.”

“We now have enough observations of current drought and tree-ring records of past drought to say that we’re on the same trajectory as the worst prehistoric droughts.”

Reliable weather records only go back to around 1900, but the researchers studied the ring patterns in thousands of trees to calculate soil moisture levels – and therefore rainfall – right back to 800 CE.

They identified four megadroughts that were particularly severe, and the 19 years from 2000-2018 is outdoing three of those droughts in terms of lack of moisture, and is closely tied with the fourth (1575 to 1603).

The analysis also showed that this current drought is affecting wider areas, and affecting them more consistently, which the team attributes to climate change.

While the current drought may have happened anyway, the researchers estimate global warming is responsible for half of the drought’s pace and half of its severity, producing hotter air that can hold more moisture pulled out of the ground.

“It doesn’t matter if this is exactly the worst drought ever,” says environmental scientist Benjamin Cook, from Columbia University. “What matters is that it has been made much worse than it would have been because of climate change.”

The earlier droughts were brought on by natural factors such as cooling ocean temperatures that blocked storms from reaching the west coast of the US. Add those factors to human-caused temperature rises of about 1.2 degrees Celsius (2.2 degrees Fahrenheit) and it’s a scary picture.

That temperature rise could cancel out the natural variability in precipitation seen in past centuries, making droughts longer, drier, and more widespread. The signs of this shift are appearing everywhere, not just in North America.

The study also showed that the 20th century was the wettest of all from the 1,200-year period covered – which may have lulled us into a false sense of security about how hard we would need to work to protect water supplies.

“The 20th century gave us an overly optimistic view of how much water is potentially available,” says Cook. “It goes to show that studies like this are not just about ancient history. They’re about problems that are already here.”

The research has been published in Science.

Let’s block ads! (Why?)

728x90x4

Source link

Continue Reading

Science

NASA's Voyager 1 resumes sending engineering updates to Earth – Phys.org

Published

 on


NASA’s Voyager 1 spacecraft is depicted in this artist’s concept traveling through interstellar space, or the space between stars, which it entered in 2012. Credit: NASA/JPL-Caltech

For the first time since November, NASA’s Voyager 1 spacecraft is returning usable data about the health and status of its onboard engineering systems. The next step is to enable the spacecraft to begin returning science data again. The probe and its twin, Voyager 2, are the only spacecraft to ever fly in interstellar space (the space between stars).

Voyager 1 stopped sending readable science and engineering data back to Earth on Nov. 14, 2023, even though mission controllers could tell the was still receiving their commands and otherwise operating normally. In March, the Voyager engineering team at NASA’s Jet Propulsion Laboratory in Southern California confirmed that the issue was tied to one of the spacecraft’s three onboard computers, called the flight data subsystem (FDS). The FDS is responsible for packaging the science and engineering data before it’s sent to Earth.

300x250x1

The team discovered that a responsible for storing a portion of the FDS memory—including some of the FDS computer’s software code—isn’t working. The loss of that code rendered the science and engineering data unusable. Unable to repair the chip, the team decided to place the affected code elsewhere in the FDS memory. But no single location is large enough to hold the section of code in its entirety.

So they devised a plan to divide affected the code into sections and store those sections in different places in the FDS. To make this plan work, they also needed to adjust those code sections to ensure, for example, that they all still function as a whole. Any references to the location of that code in other parts of the FDS memory needed to be updated as well.

NASA’s Voyager 1 resumes sending engineering updates to Earth
After receiving data about the health and status of Voyager 1 for the first time in five months, members of the Voyager flight team celebrate in a conference room at NASA’s Jet Propulsion Laboratory on April 20. Credit: NASA/JPL-Caltech

The team started by singling out the responsible for packaging the spacecraft’s engineering data. They sent it to its new location in the FDS memory on April 18. A radio signal takes about 22.5 hours to reach Voyager 1, which is over 15 billion miles (24 billion kilometers) from Earth, and another 22.5 hours for a signal to come back to Earth. When the mission flight team heard back from the spacecraft on April 20, they saw that the modification had worked: For the first time in five months, they have been able to check the health and status of the spacecraft.

During the coming weeks, the team will relocate and adjust the other affected portions of the FDS software. These include the portions that will start returning science data.

Voyager 2 continues to operate normally. Launched over 46 years ago, the twin Voyager spacecraft are the longest-running and most distant spacecraft in history. Before the start of their interstellar exploration, both probes flew by Saturn and Jupiter, and Voyager 2 flew by Uranus and Neptune.

Provided by
NASA

Citation:
NASA’s Voyager 1 resumes sending engineering updates to Earth (2024, April 22)
retrieved 22 April 2024
from https://phys.org/news/2024-04-nasa-voyager-resumes-earth.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Osoyoos commuters invited to celebrate Earth Day with the Leg Day challenge – Oliver/Osoyoos News – Castanet.net

Published

 on


Osoyoos commuters can celebrate Earth Day as the Town joins in on a national commuter challenge known as “Leg Day,” entering a chance to win sustainable transportation prizes.

The challenge, from Earth Day Canada, is to record 10 sustainable commutes taken without a car.

300x250x1

“Cars are one of the biggest contributors to gas emissions in Canada,” reads an Earth Day Canada statement. “That’s why, Earth Day Canada is launching the national Earth Day is Leg Day Challenge.”

So far, over 42.000 people have participated in the Leg Day challenge.

Participants could win an iGo electric bike, public transportation for a year, or a gym membership.

The Town of Osoyoos put out a message Monday promoting joining the national program.

For more information on the Leg Day challenge click here.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Science

Early bird may dodge verticillium woes in potatoes – Manitobe Co-Operator

Published

 on


Verticillium wilt is a problem for a lot of crops in Manitoba, including canola, sunflowers and alfalfa.

Read Also

Field stress can translate to potato skin flaws.

In potatoes, the fungus Verticillium dahlia is the main cause of potato early die complex. In a 2021 interview with the Co-operator, Mario Tenuta, University of Manitoba soil scientist and main investigator with the Canadian Potato Early Dying Network, suggested the condition can cause yield loss of five to 20 per cent. Other research from the U.S. puts that number as high as 50 per cent.

It also becomes a marketing issue when stunted spuds fall short of processor preferences.

Verticillium in potatoes can significantly reduce yield and, being soil-borne, is difficult to manage.

Preliminary research results suggest earlier planting of risk-prone fields could reduce losses, in part due to colder soil temperatures earlier in the season.

Unlike other potato fungal issues that can be addressed with foliar fungicide, verticillium hides in the soil.

“Commonly we use soil fumigation and that’s very expensive,” said Julie Pasche, plant pathologist with North Dakota State University.

There are options. In 2017, labels expanded for the fungicide Aprovia, Syngenta’s broad-spectrum answer for leaf spots or powdery mildews in various horticulture crops. In-furrow verticillium suppression for potatoes was added to the label.

There has also been interest in biofumigation. Mustard has been tagged as a potential companion crop for potatoes, thanks to its production of glucosinolate and the pathogen- and pest-inhibiting substance isothiocyanate.

Last fall, producers heard that a new, sterile mustard variety specifically designed for biofumigation had been cleared for sale in Canada, although seed supplies for 2024 are expected to be slim. AAC Guard was specifically noted for its effectiveness against verticillium wilt.

Timing is everything

Researchers at NDSU want to study the advantage of natural plant growth patterns.

“What we’d like to look at are other things we can do differently, like verticillium fertility management and water management, as well as some other areas and how they may be affected by planting date,” Pasche said.

The idea is to find a chink in the fungus’s life cycle.

Verticillium infects roots in the spring. From there, it colonizes the plant, moving through the root vascular tissue and into the stem. This is the cause of in-season vegetative wilting, Pasche noted.

As it progresses, plant cells die, leaving behind tell-tale black dots on dead tissue. Magnification of those dots reveals what look like dark bunches of grapes — tiny spheres containing melanized hyphae, a resting form of the fungus called microsclerotia.

The dark colour comes from melanin, the same pigment found in human skin. This pigmentation protects the microsclerotia from ultraviolet light.

Adblock test (Why?)

728x90x4

Source link

Continue Reading

Trending