Watershed Info No 1104

Daniel Salzler                                                                                                          No. 1104 EnviroInsight.org                                   Five  Items                                         May 28, 2021

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If your watershed is doing something you would like others to know about, or you know of something others can benefit from, let me know and I will place it in this Information newsletter.

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Enhance your viewing by downloading the pdf file to view photos, etc. The attached is all about improving life in the watershed. If you want to be removed from the distribution list, please let me know. Please note that all meetings listed are open.                                       

Enhance your viewing by downloading the attached pdf file to view photos, etc. 

The attached is all about improving life in the watershed.

Read this newsletter at EnviroInsight.org



1. Solving A Natural Riddle Of Water Filtration

Date: May 20, 2021

Source: University of Texas at Austin

For many engineers and scientists, nature is the world’s greatest muse. They seek to better understand natural processes that have evolved over millions of years, mimic them in ways that can benefit society and sometimes even improve on them.

An international, interdisciplinary team of researchers that includes engineers from The University of Austin has found a way to replicate a natural process that moves water between cells, with a goal of improving how we filter out salt and other elements and molecules to create clean water while consuming less energy.

In a new paper published today in Nature Nanotechnology, researchers created a molecule-sized water transport channel that can carry water between cells while excluding protons and undesired molecules. These channels mimic the water transport functions of proteins in our bodies known as aquaporins. In our cells, uncontrolled transport of protons alongside water can be harmful because they can change the pH of cells, potentially disrupting or killing them.


Civil, Architectural and Environmental Engineering. “These channels facilitate speedy transport of molecules you want, like water, and block those you don’t want, like salt.”

The research team’s artificial water channels can perform the same functions as aquaporins, which are crucial at a larger level for desalination, water purification and other processes for separating molecules. And they do so while transporting water 2.5 times faster compared to aquaporins.

The artificial channels are three nanometers in width by three nanometers in length. If densely packed into the correct size membrane, the channels can pass roughly 80 kilograms of water per second per square meter of membrane, while rejecting salts and protons at rates much higher than current commercial desalination membranes are capable of.

This is the first instance of an artificial nanometer-sized channel that can truly emulate the key water transport features of these biological water channels. And it could improve the ability of membranes to efficiently filter out unwanted molecules and elements, while speeding up water transport, making it cheaper to create a clean supply.”It copies nature, but it does so by breaking the rules nature has established,” said Manish Kumar, an assistant professor in the Cockrell School of Engineering’s Department.


“These artificial channels in essence solve the critical technical challenges of only allowing water molecules to pass while excluding other solutes like salt and protons,” said professor Huaqiang Zeng of Department of Chemistry at Hainan University and the Institute of Advanced Synthesis at Northwestern Polytechnical University in China. “Their extraordinary water transportation speed and the fact that these channels allow for simpler membrane fabrication suggest they will become a crucial component of next-generation membranes for producing clean water to address severe scarcity facing human beings in this century.”

Aquaporin-based channels are so small that they only allow a single molecule of water through at a time, like a single-lane road. A unique structural feature in these new channels is a series of folds in the channels that create additional “lanes,” so to speak, allowing water molecules to be transported faster.


These folding channels help transport water while blocking unwanted molecules like salt. Credit: The University of Texas at Austin/Cockrell School of Engineering.


“You’re going from a country road to a highway in terms of water transport speed, while still keeping out other things by putting little bumps in the road,” said Aleksei Aksimentiev, a professor of biological physics at the University of Illinois at Urbana-Champaign who collaborated on the research.Earlier this year, Kumar teamed with Penn State University researchers on a discovery that shed new light on how traditional water desalination membranes work. They found that uniformity throughout the membrane speeds up transporting water and improves the process of filtering out salt. These channels can only be one size to fit the desired water molecules through while squeezing out other unwanted molecules.

Going forward, the team plans to use these artificial water channels to fabricate next-generation reverse-osmosis membranes to convert seawater to drinkable water.



2. Gulf Stream System At Its Weakest In Over A Millennium – Not A Good Thing

  February 25, 2021 Potsdam Institute for Climate Impact Research (PIK)

Summary:

Never before in over 1000 years the Atlantic Meridional Overturning Circulation (AMOC), also known as Gulf Stream System, has been as weak as in the last decades. Researchers compiled proxy data, reaching back hundreds of years to reconstruct the AMOC flow history. They found consistent evidence that its slowdown in the 20th century is unprecedented in the past millennium.

Never before in over 1000 years the Atlantic Meridional Overturning Circulation (AMOC), also known as Gulf Stream System, has been as weak as in the last decades. This is the result of a new study by scientists from Ireland, Britain and Germany. The researchers compiled so-called proxy data, taken mainly from natural archives like ocean sediments or ice cores, reaching back many hundreds of years to reconstruct the flow history of the AMOC. They found consistent evidence that its slowdown in the 20th century is unprecedented in the past millennium; it is likely linked to human-caused climate change. The giant ocean circulation is relevant for weather patterns in Europe and regional sea-levels in the US; its slowdown is also associated with an observed cold blob in the northern Atlantic.

“The Gulf Stream System works like a giant conveyor belt, carrying warm surface water from the equator up north, and sending cold, low-salinity deep water back down south. It moves nearly 20 million cubic meters of water per second, almost a hundred times the Amazon flow,” explains Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research PIK, initiator of the study to be published in Nature Geoscience. Previous studies by Rahmstorf and colleagues showed a slowdown of the ocean current of about 15 percent since the mid-20th century, linking this to human-caused global warming, but a robust picture about its long-term development has up to now been missing: This is what the researchers provide with their review of results of proxy data studies.

“For the first time, we have combined a range of previous studies and found they provide a consistent picture of the AMOC evolution over the past 1600 years,” says Rahmstorf. “The study results suggest that it has been relatively stable until the late 19th century. With the end of the little ice age in about 1850, the ocean currents began to decline, with a second, more drastic decline following since the mid-20th century.” Already the 2019 special report on the oceans of the Intergovernmental Panel on Climate Change (IPCC) concluded with medium confidence “that the Atlantic Meridional Overturning Circulation (AMOC) has weakened relative to 1850-1900.” “The new study provides further independent evidence for this conclusion and puts it into a longer-term paleoclimatic context,” Rahmstorf adds.




From temperature to flow speed changes: the art of reconstructing past climate changes 

Because ongoing direct AMOC measurements only started in 2004, the researchers applied an indirect approach, using so-called proxy data, to find out more about the long-term perspective of its decline. Proxy data, as witnesses of the past, consist of information gathered from natural environmental archives such as tree rings, ice cores, ocean sediments, and corals, as well as from historical data, for instance from ship logs.

“We used a combination of three different types of data to obtain information about the ocean currents: temperature patterns in the Atlantic Ocean, subsurface water mass properties and deep-sea sediment grain sizes, dating back from 100 to ca. 1600 years. While the individual proxy data is imperfect in representing the AMOC evolution, the combination of them revealed a robust picture of the overturning circulation,” explains Levke Caesar, part of the Irish Climate Analysis and Research Unit at Maynooth University and guest scientist at PIK.

As proxy records in general are subject to uncertainties, statistician Niamh Cahill from Maynooth University in Ireland tested the robustness of the results in consideration of these. She found that in 9 of the 11 data sets considered, the modern AMOC weakness is statistically significant. “Assuming that the processes measured in proxy records reflect changes in AMOC, they provide a consistent picture, despite the different locations and time scales represented in the data. The AMOC has weakened unprecedentedly in over 1000 years,” she says.

Why is the AMOC slowing down?

An AMOC slowdown has long been predicted by climate models as a response to global warming caused by greenhouse gases. According to a number of studies, this is likely the reason for the observed weakening. The Atlantic overturning is driven by what the scientists call deep convection, triggered by the differences in the density of the ocean water: Warm and salty water moves from the south to the north where it cools down and thus gets denser. When it is heavy enough the water sinks to deeper ocean layers and flows back to the south. Global warming disturbs this mechanism: Increased rainfall and enhanced melting of the Greenland Ice Sheet add fresh water to the surface ocean. This reduces the salinity and thus the density of the water, inhibiting the sinking and thus weakening the flow of the AMOC.

Its weakening has also been linked to a unique substantial cooling of the northern Atlantic over the past hundred years. This so-called cold blob was predicted by climate models as a result of a weakening AMOC, which transports less heat into this region.

The consequences of the AMOC slowdown could be manifold for people living on both sides of the Atlantic. The northward surface flow of the AMOC leads to a deflection of water masses to the right, away from the US east coast. This is due to Earth’s rotation that diverts moving objects such as currents to the right in the northern hemisphere and to the left in the southern hemisphere. As the current slows down, this effect weakens and more water can pile up at the US east coast, leading to an enhanced sea level rise. Other studies found possible consequences being extreme heat waves or a decrease in summer rainfall. Exactly what the further consequences are is the subject of current research; scientists also aim to resolve which components and pathways of the AMOC have changed how and for what reasons.

“If we continue to drive global warming, the Gulf Stream System will weaken further — by 34 to 45 percent by 2100 according to the latest generation of climate models,” concludes Rahmstorf. This could bring us dangerously close to the tipping point at which the flow becomes unstable.


Story Source:Materials provided by Potsdam Institute for Climate Impact Research (PIK)Note: Content may be edited for style and length.Journal Reference:L. Caesar G. D. McCarthy, D. J. R. Thornalley, N. Cahill, S. Rahmstorf. Current Atlantic Meridional Overturning Circulation weakest in last millenniumNature Geoscience, 2021; DOI: 10.1038/s41561-021-00699-z


3. Upper Agua Fria Watershed Partnership

Please join my meeting from your computer, tablet or smartphone.

https://global.gotomeeting.com/join/555529925


You can also dial in using your phone.
United States: +1 (312) 757-3121

Access Code: 555-529-925

Upper Agua Fria Watershed Partnership June 1, 2021, 10 am

Draft Agenda

1.      Introductions and Announcements

2.      Judy Burges, Legislative District 1 Representative

3.      Solar Farm Proposals: Updates                     

Solar Frontier/Idemitsu Renewables:

Candela 

Pronghorn, Connectivity: Central AZ Grasslands Conservation Strategy

ASLD and Yavapai County Review process

4.        FAFNM:  upcoming events, Wet/Dry Mapping?

5.        CALT: Agua Fria Green Ribbon Concept/Goal – 2021 Efforts: March 2,   

           2021Committee Meeting Report, rural planning area concept, 

6.        Other Business: July 7, 2021 Next Meeting



4. 1.9 meters (6.2339 feet): Average amount of water, measured vertically across the entire reservoir, that evaporates from Lake Mead each year, according to a U.S. Geological Study report. [Click to go to the report] The measurements will improve understanding of the lake’s annual water balance, said Katherine Earp, a study co-author.



5. 208: Disease outbreaks in the U.S. between 2015 and 2019 that were linked to swimming pools, hot tubs, and other treated recreational waters, according to a Centers for Disease Control and Prevention report. The pathogens causing the most outbreaks were Cryptosporidium and Legionella. Just over half of the outbreaks began in June, July, or August. One-third were traced to a hotel or resort.

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