Thursday, November 1, 2018

Violent migrants attack Mexico police and break down border between Guatemala and Mexico-10/28/2018, Reuters…(Hurry up, we need more cheap labor says entire US political class)

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You’re a racist unless you say these are just poor people looking for jobs. You’re a racist if you don’t invite them into your home with your children and pets and hire them in your company. 

10/29/18, “Migrants clash with police at Guatemala-Mexico border,” Reuters

















Above, 10/28/18, “Bienvenidos a Mexico:” “Migrants try to climb the Mexican border gate on the bridge between Guatemala and Mexico in Tecun Uman. REUTERS/Carlos Garcia Rawlins”



Above, 10/28/18, “Migrants throw stones at Mexican Police in Tecun Uman. REUTERS/Carlos Garcia Rawlins”



Above, 10/28/18, “Migrants throw stones at riot police as they try to break through the border gate to cross into Mexico in Tecun Uman. REUTERS/Carlos Garcia Rawlins”



Above, 10/28/18, “A man throws a stone at Mexican Police in Tecun Uman. REUTERS/Carlos Garcia Rawlins” 

Below: Earlier caravan en route 10/21/18:



Above, Oct. 21, 2018: “A migrant caravan, which has grown into the thousands, walks into the interior of Mexico after crossing the Guatemalan border on Oct. 21, 2018, near Ciudad Hidalgo, Mexico. (John Moore / Getty Images)“
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Added: US government has lost the basis for collecting taxes. The US is no longer a country:



10/21/18, “If there’s nothing our own government can do to stop this, really don’t see why we have to pay for a military or another “national security” bureaucracy. Stop pretending our country still exists and save us the tax payments.” Virginia Dare twitter via Ann Coulter twitter

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Added: Entire US political class would be thrilled if Central American population replaced US population. Just before 2006 midterms–Oct. 26, 2006–Republicans passed a fake border fence act which they cancelled in 2007-Politifact, 5/16/2011. The Oct. 26, 2006 Secure Fence Act of 2006, was quietly altered [by Republicans] in a significant way the following year (2007)….The law was amended to read, “nothing in this paragraph shall require the Secretary of Homeland Security to install fencing.”… 

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Politifact on “border fence:”

5/16/2011, “Obama says the border fence is ‘now basically complete’,“ PolitiFact, Robert Farley

“Sections of the fence on the Mexico border, like this one near San Miguel, Ariz., are designed primarily to stop vehicles.” Politifact photo

 “In his speech in El Paso on immigration reform on May 10, 2011, President Obama declared that the fence along the border with Mexico is “now basically complete."

Still, he predicted that many Republican opponents won’t be satisfied.

“We have gone above and beyond what was requested by the very Republicans who said they supported broader reform as long as we got serious about enforcement,” Obama said. “All the stuff they asked for, we’ve done. But even though we’ve answered these concerns, I’ve got to say I suspect there are still going to be some who are trying to move the goal posts on us one more time.”

“They’ll want want a higher fence,” Obama said. “Maybe they’ll need a moat. Maybe they want alligators in the moat. They’ll never be satisfied. And I understand that. That’s politics.”

Fencing along the U.S.-Mexico border has long been a thorny political issue, so with Obama declaring mission accomplished, we decided to check it out…. 

DHS reports that there is now fencing for 649 of the 652 miles described in the Secure Fence Act of 2006. But the vast majority of the requirement was met with vehicle barriers and single-layer pedestrian fence. The original act specifically called for double-layer fencing, and only 36.3 miles of double-layered fencing currently exist. However, the act was later amended to allow Border Security the discretion to determine which type of fencing was appropriate for different areas.…

You need to go back to the Secure Fence Act of 2006, which was passed by a Republican Congress and signed by President George W. Bush [on Oct. 26, 2006]. It authorized the construction of hundreds of miles of additional fencing along the border with Mexico. The act specified “at least two layers of reinforced fencing.”

But the law was quietly altered in a significant way the following year….

Sen. Kay Bailey Hutchison, R-Texas,  proposed an amendment to give DHS the discretion to decide what type of fence was appropriate in different areas. The law was amended to read, “nothing in this paragraph shall require the Secretary of Homeland Security to install fencing, physical barriers, roads, lighting, cameras, and sensors in a particular location along an international border of the United States, if the Secretary determines that the use or placement of such resources is not the most appropriate means to achieve and maintain operational control over the international border at such location.”

In other words, Border Patrol would have the leeway to decide which type of fencing was appropriate in various regions. The amendment was included in a federal budget bill in late 2007 despite being condemned by legislators such as Reps. Peter King, R-N.Y., and Duncan Hunter, R-Calif., who argued the amendment effectively killed the border fence promised in the 2006 bill.

At the time, Hutchison told the San Antonio Express-News, “Border patrol agents reported that coyotes and drug-runners were altering their routes as fencing was deployed, so the amendment gives our agents discretion to locate the fence where necessary to achieve operational control of our border.”

DHS reports there are currently 36.3 miles of double-layered fencing, the kind with enough gap that you can drive a vehicle between the layers. But the majority of the fencing erected has been vehicle barriers, which are designed to stop vehicles rather than people (see here), and single-layer pedestrian fencing (see here). [Links go to generic Border Patrol site with pictures, not to specific picture of fences].

The design specifications vary depending on geography and climate characteristics, but according to the Customs and Border Patrol website, it includes “post on rail” steel set in concrete; steel picket-style fence set in concrete; vehicle bollards similar to those found around federal buildings; “Normandy” vehicle fence consisting of steel beams; and concrete jersey walls with steel mesh….

“They are interpreting the requirements of the Secure Fence Act in a way that is clearly contrary to what Congress intended,” said Mark Krikorian, executive director of the Center for Immigration Studies, which favors tougher enforcement against illegal immigration.

There may be a role for the vehicle barriers, but “your grandmother could hop over them,” he said, and “that’s not what Congress thought it was voting for.”…

A Government Accountability Office report on border security, issued in February 2011…acknowledges progress on the fences…but “DHS reports that the southwest border continues to be vulnerable to cross-border illegal activity, including the smuggling of humans and illegal narcotics.”…

It is estimated that for every person caught (Border Patrol reported apprehending over 445,000 illegal entrants in 2010) two more get by, [retired president of National Border Patrol Concil T.J.] Bonner said. “To me, that doesn’t seem like border security.”…

So Obama can make a case that the vehicle barriers and single-layer pedestrian fences meet the amended letter of the law. But we also think Obama misleads, particularly when he mocks Republican opponents, saying that even though the fence has been built, “They’ll want want a higher fence. Maybe they’ll need a moat. Maybe they want alligators in the moat.” The Border Patrol has not gone “above and beyond” what Republicans requested, as Obama claimed. What they originally requested was a double-layer fence, and they didn’t get much of it. And so we rate Obama’s statement Barely True. [Changed to “Mostly False” per Editor’s note below]
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“Editor’s note: This statement was rated Barely True when it was published. On July 27, 2011, we changed the name for the rating to Mostly False.”
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Added:

2006 Fence Act didn’t require fences, merely “authorized” them: 

10/26/2006, “Fact Sheet: The Secure Fence Act of 2006″ 

“Authorizes the construction of hundreds of miles of additional fencing along our Southern border"…

But...

The Fence Act also authorized “adding thousands of new beds” at detention facilities.
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7/11/2007, “Border Fence Construction Not Moving Fast Enough for Rep. Hunter,“ NY Times, by Eleanor Stables, Congressional Quarterly


“The Secure Fence Act (PL 109-367), passed just before the 2006 midterm elections, authorizes 700 miles of fencing along the Mexican border. Then-House Homeland Security Chairman Peter T. King, R-N.Y., sponsored the bill, and Hunter was an original cosponsor and author of its fencing provisions. The bill passed after a [so-called] comprehensive immigration overhaul failed last session; the defeat of the Senate immigration bill (S 1639) late last month means a [so-called] comprehensive immigration overhaul is also unlikely this session.

The Secure Fence Act says “the Secretary of Homeland Security shall provide for least 2 layers of reinforced fencing, the installation of additional physical barriers, roads, lighting, cameras and sensors” at five specific stretches of border totaling approximately 700 miles.”...
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Added: US government has ceded at least a quarter of the 2000 mile southern border land to drug cartels. Easiest way to illegally cross US border is Texas Big Bend area, few patrols. What’s to stop them, says border agent-LA Times, 12/16/2017

12/16/2017, “Could the Big Bend in Texas be the border’s weakest link? Smuggling of drugs and migrants is on the rise,” LA Times, Molly Hennessy-Fiske














“Just yards from the Rio Grande, Agent Lee Smith pointed to footprints and scraps of carpet. Smugglers tie carpet to their shoes in hopes of covering their tracks, he said. Smith followed the rough trail through thick brush, his fellow agent close behind, wearing a bulletproof vest and carrying a long gun. They saw no one. But the agents sensed smugglers watching, waiting.

“They come right across. What’s here to stop them?” Smith said.

Sometimes smuggler scouts cross on horseback: The muddy banks are pocked with human and horse tracks. The river here, about 60 miles east of El Paso, is just a few yards wide, one of the reasons Border Patrol agents in Texas’ Big Bend region have seen troubling increases in smuggling, attacks on agents and migrant deaths in recent years.

“There’s hundreds of these crossings just in our area of operation,” Smith said. “The drug cartels, they own this part of the land. We have conceded large swaths of the border. There are areas where there are not agents for days.”

He called the vast Big Bend “the absolute weakest link on the southern border.”

The natural barriers beyond the river that made the landscape a stunning backdrop for “No Country for Old Men,” “There Will Be Blood” and “Giant” were also supposed to protect it. Or at least that was long the assumption of U.S. officials. There’s the river. There are mountains–the snow-covered Chinati, Chisos and Davis ranges….

But smuggling routes shift according to the dictates of criminal organizations, often in response to border enforcement. In the late 1990s, border traffic moved from Southern California to remote desert stretches of Arizona; by 2013, it moved east again to Texas’ Rio Grande Valley, the epicenter of migration and enforcement ever since. But now new routes are opening up to the west, in Big Bend.

“As things in the Rio Grande Valley get tougher to cross, they’re looking for other places, and this is a spot that over the past few years has become established for smuggling,” said Border Patrol Agent Rush Carter, a spokesman for the agency in Big Bend.

Just as migrants once tried to cross the Arizona desert unprepared, Central Americans are arriving in Big Bend without cold weather gear, abandoned to the elements by smugglers. Migrants tell agents that smugglers advertise the area as an easy crossing, the least patrolled stretch of border.

U.S. Customs and Border Protection divides the southern border into nine sectors. Big Bend is the largest: 135,000 square miles, 510 miles of river, a quarter of the entire southern border. 

The sector stretches north to include 118 counties in Texas and all of Oklahoma. Yet it has the smallest staff of any southern border sector, about 500 agents assigned to a dozen stations and several highway checkpoints including one in Sierra Blanca, notorious for large drug busts. That’s fewer agents than have been assigned to a single station in the Tucson sector, Smith said.

President Trump has promised to add 5,000 Border Patrol agents, potentially doubling Big Bend staffing, but with high turnover, agents said that they would still be spread thin.

With such a small staff, agents usually patrol alone, with hand-me-down technology from other areas, including radios so spotty agents have erected makeshift cell towers in the brush to boost reception. Sometimes they just yell.

They don’t have observation towers along the border as in the Rio Grande Valley, and their single aerostat blimp hovering overhead, unlike those used in the Valley, is not equipped with infrared technology, Smith said.

“You know what it [the blimp] helps?” Smith said. “Migrants. They use it as a guide: Go that direction.”

The only time they received drones, agents complained, was when the devices were sent west from southeast Texas for safekeeping before Hurricane Harvey hit in August.

Since the summer [2017], Big Bend saw the biggest increase in unaccompanied youth caught on the border, mostly Central Americans:

278 since the federal fiscal year that began in October, up 74% from last year. By contrast, the number of youths caught in the Rio Grande area dropped 64% during the same period.

At the same time, Big Bend saw drug seizures drop, Smith and other agents said. That’s because smugglers use the migrants as decoys, they said, and abandon dozens at a time to overwhelm agents, before sending drug mules with 50-pound backpacks of marijuana in their wake.

Big Bend agents caught 6,000 people last fiscal year, which ended in September. During the next two months, they caught 1,646 people, putting them on pace to far exceed last year’s total.

Big Bend agents seized 40,852 pounds of marijuana last fiscal year, but 4,211 pounds in the first two months of this year. That’s more than a thousand pounds less per month.

As conditions deteriorated, some agents said they feared a death was inevitable….Last month, the agents’ worst fears were realized.

Two Border Patrol agents were injured [one of whom died] while investigating smugglers who had reached a culvert under Interstate 10, about 55 miles north of Porvenir. Both agents were fathers with years of experience. Both suffered serious head injuries. Agent Rogelio Martinez died. Agent Stephen Garland is still recovering and has trouble remembering what happened, said Smith, who spoke recently to the agent, who declined interviews. 

The FBI is still investigating the incident, and there have been no arrests.

Walking the 9-foot-deep concrete culvert where Martinez, 36, was found fatally injured, Smith pointed out signs of recent smuggling:

A gray backpack, a man’s black-and-white checked shirt, an empty water jug in a holder sewn from a pair of blue jeans.

Up on the highway, traffic zoomed past a lighted sign advertising “Reward for information Border Patrol agent death.”

Days after the agents were injured [one agent was actually murdered–not just “injured”], another was sent to investigate potential smuggler activity in a culvert farther south, alone. The agent, who asked not to be named because he was not authorized to speak, didn’t encounter anyone, but he was nervous: His two backup agents at a nearby station has been sent north to help after the attack.

“If it picks up here, we’re just going to be unprepared,” Smith said. He and other agents said they need more staff, improved radios, cameras and other equipment. Otherwise, they worry they may become overwhelmed the way Rio Grande Valley agents were by tens of thousands of Central American youth and families in 2014.

They also worry for the migrants unprepared for the harsh conditions of Big Bend. This month, agents patrolling by air spotted 15 Guatemalan men lost in the desert. The agents caught and brought them to a station, but the migrants were already suffering hypothermia. One died. Migrant families often turn themselves in, Smith said, but agents are increasingly discovering skeletons in the desert.

Recently a group of 50 migrants–mostly Guatemalan families and a couple of Hondurans–turned themselves in at Presidio, about 250 miles east of El Paso. Across from the bustling Mexican town of Ojinaga, connected by an official bridge and makeshift river crossings marked by guide wires, Presidio has become a hot spot for families who claim asylum [to be paid for by struggling US taxpayers], agents said.

On the Mexican side stands a roughly 50-foot-high retention wall topped with razor wire, set back from the river, built after a flood in 2008. Agents said it may be time to build a similar wall on the U.S. side. [It “may be" time?] 

A day after the Central American group arrived, a half dozen agents were still processing them in the Presidio station, a collection of trailers with reward posters on the door for Martinez….

They lined up a dozen of the migrants…outside where Border Patrol vans waited to take them to two other Big Bend stations. Agents there would have to interrupt other duties to help process the latest arrivals."


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Florida toxic algae is caused by millions of tons of Sahara dust that travels across the Atlantic yearly as it has for thousands of years. The same dust that causes Florida toxic algae provides nutrients to Amazon soil-NASA, PNAS, UK Independent

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Africa dust travels across Atlantic, across Florida, causes toxic algae blooms sometimes known as red tides. This natural phenomenon has been happening for thousands of years:




Image caption: Satellites can track African dust clouds as they migrate across the Atlantic Ocean. This NASA TOMS aerosol movie, which spans the interval June 13 through 21, 2001, shows such a cloud raining bits of the Sahara Desert over the Caribbean and the Gulf of Mexico. [more information] NASA tested 8,100 sq. mile region between Tampa Bay and Fort Myers, Florida-Aug. 2001 study

8/30/2001, “Desert Dust Kills Florida Fish,” “New research links huge African dust clouds with the “red tides” that kill millions of fish along the Florida coast each year,” science.nasa.gov

“Without warning, the sea turns a shade of reddish brown, killing scores of fish and other marine life — and making the water an unwelcome place for humans.

Such “red tides” have, from time to time, plagued coastal communities for centuries. Now a new study, partially funded by NASA, has revealed a surprising connection between red tides in the Gulf of Mexico and giant dust clouds that blow across the Atlantic Ocean from the distant Sahara Desert. NOAA and NASA satellites can spot such dust clouds en route from Africa to the Americas, raising hopes that space-based data could help scientists predict when red tides will strike the Gulf coast….

“The West Florida shelf is a hot spot for fishing, aquaculture and tourism, all of which can be drastically affected by a surprise visit from a red tide,” said Jason Lenes, a graduate student at University of South Florida’s College of Marine Science, and the lead author in the study. 
Red tides, which are actually blooms of toxic algae, have in the past killed huge numbers of fish, shellfish, marine mammals, and birds. They can also trigger skin and respiratory problems in humans. 
 
Storm activity in the Sahara Desert region kicks up fine particles from the arid topsoil there, generating vast clouds of dust. Easterly trade winds carry the dust across the Atlantic Ocean and into the Gulf of Mexico. 
The new study shows that these clouds fertilize the water off the West Florida coast with iron. Plant-like bacteria use that iron to set the stage for red tides. When iron levels go up, these bacteria, called Trichodesmium, fix nitrogen in the water, converting it to a form usable by other marine life.

The addition of biologically usable nitrogen in the water makes the Gulf of Mexico a friendlier environment for toxic algae.

“This is one of the first studies that quantitatively measured iron from the dust and [linked] it to red tides through Trichodesmium,” said Lenes. The research was partially funded by a NASA grant as part of ECOHAB: Florida (Ecology and Oceanography of Harmful Algal Blooms), a multi-disciplinary research project designed to study harmful algae. 

The study used satellite and ground based measurements to track large dust clouds leaving Africa on June 17, 1999. Lenes and his colleagues followed the clouds using data from the Advanced Very-High-Resolution Radiometer (AVHRR), an imager aboard the NOAA’s Polar Orbiting Environmental Satellites (POES).

The Saharan dust reached the West Florida shelf around July 1st, increasing iron concentrations in the surface waters by 300 percent. As a result, Trichodesmium counts shot up to 10 times what they had been prior to this event. Through a complex process involving a special enzyme called nitrogenase, the Trichodesmium used the iron to convert nitrogen in the water to a form more usable for other marine life. 

In October, after a 300 percent increase of this biologically-accessible nitrogen, a huge bloom of toxic red algae (Karenia brevis) had formed within the study area, an 8,100 square mile region between Tampa Bay and Fort Myers, Florida….

Scientists have labored for several years to develop a reliable method to predict red tides, particularly because the results of these blooms can be both physically and economically devastating to a region.

Humans who swim in the Gulf during a red tide can experience respiratory problems by breathing toxins from K. brevis that get in the air. Also, eating shellfish poisoned by red tides can lead to paralysis and memory problems. Around the Gulf of Mexico, scientists and others have recorded fish kills totaling in the millions and manatee deaths in the hundreds resulting from a single red tide bloom. 

By using satellites to monitor dust arrivals and Trichodesmium blooms, Lenes said this research could lead to forecasting of red tides. “If you could predict when a red tide is coming, you could close beaches and fisheries ahead of time,” Lenes said. 

Note: The research reported here appears in the September [2001] issue issue of the scientific journal Limnology and Oceanography. The paper was funded through a number of grants connected with the ECOHAB program. Other funding for this study included grants from the National Oceanic and Atmospheric Administration, the Office of Naval Research and the Environmental Protection Agency. The ECOHAB: Florida Mission is to better understand the factors involved in the occurrence and dispersal of Florida’s predominant red tide algae, K. brevis, and to predict and manage harmful algal bloom events.”
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Added: Toxic red tides in Florida caused by Sahara dust:
 
Sahara Dust travels across the Atlantic Ocean, across the state of Florida, across the Gulf of Mexico, PNAS peer reviewed study, 5/9/2016



May 9, 2016, “Saharan dust nutrients promote Vibrio bloom formation in marine surface waters,“ PNAS.org https://doi.org/10.1073/pnas.1518080113
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May 11, 2016, “How dust from the Sahara fuels poisonous bacteria blooms in the Caribbean,” Washington Post, Sarah Kaplan

“Leave your car parked outside in Miami for too many days in August, and you’re likely to see a fine film of orange powder coating the windshield.

It’s dust — African dust — carried thousands of miles across the Atlantic to parking lots in Florida.

This phenomenon, known as the Saharan Air Layer, brings several hundred million tons of dust to the Americas each year. 

It helps build beaches in the Caribbean and carries nutrients that fertilize the Amazon rainforest. The dust is also thought to help suppress hurricanes along the coast.

It has been happening for thousands of years, but in the past few decades, scientists have become concerned about the effects of this dust on coral reef ecosystems in the Caribbean. Studies have linked the dust plumes to toxic “red tides” — huge algae blooms that poison fish and trigger skin and breathing problems in people. There’s also some evidence suggesting that African microbes may be hitching rides on the dust and poisoning corals on the other side of the sea. 

But what about the bacteria that already live in the ocean? In a study published this week in the Proceedings of the National Academy of Sciences, scientists examined how one genus of bacteria, a pathogen called Vibrio, responded to the influx of dust that rains down on the Caribbean in the late summer months.”…
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Added: Sahara dust also reaches UK:

4/2/2014, “Saharan dust: Six things you didn’t know about red dust storms,” Independent UK, Heather Saul

Red dust in Perth, Australia
 
“Dust all the way from Africa has reached Britain after unusual weather patterns”

“Motorists across the country awoke to grains of dust coating their cars on Monday, which had travelled all the way from the Saharan desert to leave a little piece of North Africa on their vehicles.

But the dust has also triggered fears it may cause health problems for people across Britain. The Government issued warnings of “very high” levels of air pollution across parts of England and Wales, after the dust and winds combined to create a potentially toxic storm.

Here are six other things you may not have known about Saharan dust:

1. Red dust storms can cause air pollution to increase to “very high levels” and can aggravate breathing problems. Health professionals warn the dust may irritate lung tubes and cause asthma to flare up.

2. While it may not be healthy for humans, Saharan dust can prove beneficial for the environment. Trees and plants in the Amazon Rainforest rely on the nutrient-rich dust, which helps to keep the area fertile, New Scientist reported.

3. However, researchers have also linked Saharan dust to coral disease. Coral reefs in the Caribbean have been in a state of decline since the 1970s. Scientists from the US Geological Survey (USGS) Centre for Coastal Geology believe this decline in the Caribbean is a result of pathogens transported in dust from North Africa.

4. The dust clouds can literally turn the sea from blue to a reddish brown by encouraging the growth of algae blooms in a phenomenon known as red tides.The toxic blooms have been responsible for the deaths of huge numbers of fish, marine mammals and birds in the past. They can also have an impact on human health by causing respiratory problems for those living near a shoreline.

5. Dust clouds from the Sahara are often so big they can be seen from space. Space station crew members frequently report seeing Saharan dust masses as very widespread atmospheric haze, according to Nasa.

6. These dust palls blowing from Africa can be lifted as high as 15,000 feet and transported across the Atlantic Ocean. Scientists found dust from the Sahara influences levels of precipitation as far as California because of a hot, dry, dusty layer of air known as the Saharan Air Layer.” (image above: “A towering red dust storm in Perth, Australia (Twitter/ National Geographic"))
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Added: Map, African dust also travels to UK:

4/2/2014, “Deadly smog leaves us gasping for breath: Millions of asthmatics struggle as giant cloud of Saharan sand and toxic air covers Britain,” UK Daily Mail, Ben Spicer


 
“Journey: The dust has been blown across from the Sahara over mainland Europe and into Britain,” image from UK Daily Mail
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Added: Sahara dust keeps Amazon alive:

1/3/2007, “Amazon forest relies on dust from one Saharan valley,“ newscientist.com, Richard Fisher 

“The trees and plants in the Amazon rainforest rely on nutrient-rich dust from a single valley in the Sahara desert for sustenance, researchers have discovered.


Scientists know that millions of tonnes of mineral dust are blown from the Sahara desert to the Amazon basin each year. The dust helps keep the Brazilian rainforest soils fertile.

Now, researchers have found that 56% of this dust comes from one place: the Bodélé depression in Chad, Africa. They also showed that three times more dust than previously thought is transported each year from the Sahara to the Amazon – over 40 million tonnes.

The team, led by Ilan Koren at the Weizmann Institute in Israel, used satellite and geological data to track the “dust parcel” across the Atlantic ocean….

The Bodélé valley is 200 times smaller than the Amazon basin, and forms only 0.2% of the Sahara itself. The reason the valley supplies so much dust is its location between two mountain ridges. It forms a funnel that accelerates the flow of air, not unlike a wind tunnel, allowing more dust to be carried. In winter, the valley produces an average of 700,000 tonnes of dust per day.

Journal reference: Environmental Research Letters (DOI: 10.1088/1748-9326/1/1/014005)”
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Added: CO2 is trapped on ocean floors as result of dust storms:

4/20/2016, “Explainer: What Dust From The Sahara Does To You And The Planet,“ theconversation.com

(subhead): “The ocean floor”

“Saharan dust that settles on the Atlantic Ocean and the Mediterranean is also likely to be a significant contributor of iron to marine algae. When this algae sinks to the ocean floor, or is eaten by planktonic organisms, whose carbonate shells also sink, carbon dioxide is sequestered into sea floor sediments. The distribution of iron in the oceans is likely to be a way of trapping excess atmospheric CO2. On the one hand, global warming could increase winds and therefore dust production, but then more dust could enter the ocean, potentially providing a natural mitigator to those effects.”
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Added: More: Africa dust keeps Amazon alive:

8/9/2010, “African dust keeps Amazon blooming,” Nature.com, Richard Lovett

“Plumes of dust that cross the Atlantic are richer in nutrients than previously thought.”

dust research team  Charlie Bristow’s team in Chad found significant micronutrient levels in dust heading for the Atlantic.

Dust from one of the world’s most desolate places is providing essential fertilizer for one of the most lush, scientists have discovered. Significant amounts of plant nutrients have been found in atmospheric mineral dust blowing from a vast central African basin to the Amazon, where it could compensate for poor rainforest soils.

 The basin, known as the Bodélé depression, is the site of a once-massive lake in Chad. Bodélé is thought to be the dustiest place on Earth.

Scientists went to Bodélé in 2005 and took atmospheric measurements to learn how the dust travels1. They also took dust samples to learn about its composition (see ‘Climate science: The dustiest place on Earth’). 

With chemical analyses now complete, the dust turns out to contain substantial amounts of the key plant nutrients iron and phosphorus. Although the abundances are not unusually high, prior estimates of the dust plume’s nutrient content were very low, particularly for phosphorus. The team estimates the dust to be 38 times richer in this mineral than formerly thought. 

The dust in any case is unusual in the sandy Sahara, as it is essentially lakebed sediment originating from the shells of freshwater diatoms, and so richer in nutrients, including iron.

The results were reported in Geophysical Research Letters on 30 July2. Charlie Bristow, a sedimentologist at Birkbeck, University of London, and lead author of the study, says, “A hypothesis we are investigating at the moment is that because it’s coming from the lakebed, this iron is going to be more bioavailable than if it were coming from the deeply weathered surface of the Sahara.”

“The Amazon is essentially a leached or leaching system,” says Bristow. Nutrients in the soil are washed away by rains. “So although it is very productive, it is actually quite nutrient-poor.”

So nutrient input is vital to the rainforest. Phosphorus, a major element of commercial fertilizer, is essential for plant growth, respiration and energy transfer and storage. Iron is a micronutrient that plants use to make an enzyme critical for photosynthesis….   

Dried mega-lake  

But it is more nutrient-rich than simple sand and, crucially, there is a lot of it….
 
Bodele depression
The Bodélé depression in central Africa is part of a vast dried-up lakebed. Modis/NASA… 

Joseph Prospero, an atmospheric chemist at the University of Miami, Florida, is in Barbados studying the dust blown across the Atlantic.

 “Looking at satellite images, day after day you see these huge plumes coming out of that region,” he says. The dust takes two seasonal routes across the ocean, in the summer passing by the Caribbean and in the winter swinging further south to the Amazon.

 At current rates of dispersal, the dust in the basin will last for perhaps another 1,000 years or more, assuring Amazon fecundity if weather patterns do not change. But what about changes in precipitation, which could have an effect on the amount of dust produced? 

Unfortunately, even the latest climate models can’t agree on whether that part of Africa will get wetter or drier, says Prospero. “If it becomes drier, we can expect more dust.” 

That might be bad for nearby residents, leading to more dust storms, but it could be a good thing globally. More dust means more nutrients for the Amazon, which means greater plant growth. Plants in the Amazon help to remove excess carbon dioxide from the atmosphere, which could mitigate global warming by slowing its rate…. 

Dust in the atmosphere, or the lack of it, may have even wider implications. It increases the amount of sunlight reflecting off Earth into space, potentially offsetting global warming. It could also affect cloud formation, and even tropical storms. “It gets pretty complicated,” says Prospero. 

“One of the primary areas of [global climate] research today is understanding the global cycle of dust.”…




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