Aboard A Nasa Research Plane Over Greenland, Aug 16 (AP/UNB) — The fields of rippling ice 500 feet below the NASA plane give way to the blue-green of water dotted with irregular chunks of bleached-white ice, some the size of battleships, some as tall as 15-story buildings.

Like nearly every other glacier on Greenland, the massive Kangerlussuaq is melting. In fact, the giant frozen island has seen one of its biggest melts on record this year. NASA scientist Josh Willis is now closely studying the phenomenon in hopes of figuring out precisely how global warming is eating away at Greenland's ice.

Specifically, he wants to know whether the melting is being caused more by warm air or warm seawater. The answer could be crucial to Earth's future.

Water brings more heat to something frozen faster than air does, as anyone who has ever defrosted a steak under the faucet knows.

If Willis' theory that much of the damage is from the water turns out to be correct, he said, "there's a lot higher potential for Greenland to melt more quickly than we thought." And that means seas rising faster and coastal communities being inundated more.

Greenland contains enough ice to make world sea levels rise by 20 feet if it were all to melt. In a single day this month, it lost a record 13.7 billion tons (12.5 billion metric tons) by one estimate.

"It's a little scary," Willis said as looked down on an area filled with more water than ice. "We're definitely watching the ice sheet disappear in front of us."

Climate change is eating away at Greenland's glaciers in two ways. The most obvious way is from the warm air above, which has been brutal this summer, with a European heat wave in July working like a hair dryer on the ice. The other way is from warm, salty water, some of it from North America's Gulf Stream, nibbling at coastal glaciers from below.

When University of Georgia ice scientist Tom Mote, who isn't part of this project, started studying Greenland's glaciers in the early 1990s, researchers really didn't think the water was a big factor.

Willis' project — called Oceans Melting Greenland, or OMG — is showing that it is. Now the question is how much and how fast.

What Willis is measuring is the water 660 feet (200 meters) or more below the surface, which is warmer and saltier than the stuff that touches the air. It's this deep water that does the major damage.

To measure this, NASA is spending five years crisscrossing the island in a tricked-out 77-year-old DC-3 built for World War II. Willis, project manager Ian McCubbin and mechanic Rich Gill drop long, cylindrical probes through a special tube in the floor of the plane, watching as the sensors parachute down and then dive into the chilly water.

McCubbin then waits for a tone on his computer that tells him the probe is underwater and measuring temperature and salinity. When all of the flight's five probes start signaling — with a sound McCubbin likens to "a fax machine or an AOL modem" — he and Willis high-five.

Meanwhile, pilots Andy Ferguson and Don Watrous bank the plane toward the blue-green spots, looking for the next target and pointing out stunning giant icebergs and signs of glacial retreat over the radio.

As the data is radioed back from one $2,000 probe now deep in the water near Kangerlussuaq in eastern Greenland, it initially looks like the temperature hasn't changed much over the last year or two, which could be good news. But that's just one data point. Each year for the past four years, NASA has been looking at all of Greenland, and the numbers overall haven't been quite as comforting.

If the water is playing a much bigger role than scientists thought, it could mean seas will be rising faster and higher than expected. That's because 90% of the heat energy from climate change goes into the oceans, Willis said. Warm water provides "a bigger bang for the buck" than air when it comes to melting ice, Willis said.

Just how crucial seawater is to melting was illustrated, somewhat paradoxically, by the Jakobshavn glacier, the fast-shrinking glacier on Greenland's more populated west coast. In recent years, it suddenly started to grow a bit, probably because of a cooling of waters as a result of a temporary shift in weather and water-current patterns, Willis said.

In general, oceans warm up much more slowly than the air, yet they stay warmer longer. The water weakens glaciers and causes icebergs to break loose. Those icebergs eventually melt, adding to the seas.

"Some of them are as big as a city," Willis said.

A 2019 study by Danish climate scientist Ruth Mottram looked at 28 glaciers in Greenland with long-term data. Nearly all are melting, with only one or two that could be considered somewhat stable.

"One glacier retreating looks like carelessness, but 28 retreating is the sign of something going on," Mottram told The Associated Press.

A 2017 study concluded that coastal glaciers and icecaps — what Willis is studying — reached a "tipping point" for ice loss in 1997 and since then have been rapidly deteriorating. A NASA satellite found that Greenland's ice sheet lost about 255 billion metric tons a year between 2003 and 2016, with the loss rate generally getting worse.

It will take centuries for all of Greenland's massive ice sheet to melt, but how fast is the key question. If warm water plays a bigger role than scientists suspect, by the year 2100, Greenland alone could cause 3 or 4 feet (more than 1 meter) of sea level rise, Willis said.

Other scientists, such as the University of Colorado's Ted Scambos, say Greenland's contribution to sea level rise by 2100 would probably be closer to 1 foot (30 centimeters).

That's a big spread.

"I tend toward the higher number, but I'm hoping for a lower number," said University of Maryland Baltimore County glaciologist Christopher Shuman, whose family owns property along the coast.

New Orleans, Aug 16 (AP/UNB) — NASA's top official says the rocket expected to power the next mission to the moon is about 90 percent complete.

NASA administrator Jim Bridenstine spoke during a visit Thursday to a facility in New Orleans where the core stage is being built.

The 212-foot-tall (65-meter-tall) core stage is made up of two liquid propellant tanks and four RS-25 engines.

In the months to come, the engine section will be attached to the rest of the core section. If all goes well, it will power the Artemis 1 test flight in 2020.

Plans call for the rocket to carry a crewless Orion capsule in a double loop around the moon during 25½ days in flight.

Future missions are expected to carry U.S. astronauts, including the first female astronaut to land on the moon.

San Francisco, Aug 15 (AP/UNB) — Hundreds of Google employees are calling on the company to pledge it won't work with U.S. Customs and Border Protection or Immigration and Customs Enforcement. It's the latest in a year full of political and social pushback from the tech giant's workforce.

A group of employees called Googlers for Human Rights posted a public petition urging the company not to bid on a cloud computing contract for CBP, the federal agency that oversees law enforcement for the country's borders. Bids for the contract were due Aug. 1. It is not clear if Google expressed interest. The company did not return a request for comment.

More than 700 Google employees had signed the petition by Tuesday afternoon. Citing a "system of abuse" and "malign neglect" by the agencies, the petition demands Google not provide any technical services to CBP, ICE or the Office of Refugee Resettlement (ORR), which provides services for refugees, until the agencies "stop engaging in human rights abuses."

"In working with CBP, ICE, or ORR, Google would be trading its integrity for a bit of profit, and joining a shameful lineage," the organizers wrote. They cited federal actions that have separated migrant children from parents and set up detention centers with poor conditions .

Google employees have led a growing trend in which some tech-company employees have taken public stances against their employers' policies. Thousands of Google employees walked out last fall to protest the company's handling of sexual misconduct claims. Employees also protested a Pentagon contract last year over work that used artificial intelligence technology to analyze drone footage.

The protests have chalked up some success. After the walkout , Google announced new sexual misconduct guidelines, although some employees say they don't go far enough. And the company did not renew the Pentagon contract after significant pushback.

Responding to some employee pressures has added fuel to claims from Republican pundits and lawmakers that the company is building its products to be biased against conservatives — an unfounded claim that has spawned multiple congressional hearings, although none that have produced evidence of bias.

Google was hit with criticism by President Donald Trump last week when the president tweeted he was "watching Google very closely" after a former employee claimed on Fox News — without evidence — that the company would try to influence the 2020 election against Trump.

Google has denied claims of political bias in its popular search service and other products.

Dhaka, Aug 15 (UNB) - It's raining plastic -- that's what a survey of rainfall in Denver and Boulder, Colorado, concluded recently, reports CNN.

The rainfall survey, titled "It is raining plastic," was put together by scientists at the US Department of the Interior and US Geological Survey.

They couldn't see the plastic with their naked eyes, but found it using a binocular microscope fitted with a digital camera.

They found plastic showed up in 90% of the samples, mostly in fiber form, and came in a variety of colors. Blue was most prevalent, followed by red, silver, purple, green, yellow and other colors, the study says.

It's unclear where the plastic is coming from, but plastic contamination has been a growing problem throughout the world.

Scientists have found microplastic particles in rain before. They saw it in the rain falling in the Pyrenees in southern France. It has wound up in remote and otherwise pristine islands. Trillions of pieces of plastic litter float through the ocean, killing fish and other animals. An earlier study found that people are swallowing an average of 5 grams of plastic every week, about the weight of a credit card.

It's unclear what the health effects of living with all this plastic will be, scientists say, although several studiesare underway.

Some cities have tried to cut back on plastic by banning plastic bags. Boulder, one of the sites for the rain survey, has a plastic bag ban.

While some companies have made it a goal to scale back their use of plastic, President Donald TrumpTuesday made an appearance at a Pennsylvania plastic manufacturing plant to promote plastic. When asked by a reporter about how he felt about the world being "awash in plastic," the president blamed China for the problem.

"Well, we have tremendous plastics coming over from Asia, from China, and various others," Trump said. "It's not our plastic. It's plastic that's floating over in the ocean and the various oceans from other places. No, plastics are fine, but you have to know what to do with them. But other countries are not taking care of their plastic use and they haven't for a long time. And the plastic that we're getting is floating across the ocean from other places, including China."

Greeley, Aug 14 (AP/UNB) — A drone soared over a blazing hot cornfield in northeastern Colorado on a recent morning, snapping images with an infrared camera to help researchers decide how much water they would give the crops the next day.

After a brief, snaking flight above the field, the drone landed and the researchers removed a handful of memory cards. Back at their computers, they analyzed the images for signs the corn was stressed from a lack of water.

This U.S. Department of Agriculture station outside Greeley and other sites across the Southwest are experimenting with drones, specialized cameras and other technology to squeeze the most out of every drop of water in the Colorado River — a vital but beleaguered waterway that serves an estimated 40 million people.

Remote sensors measure soil moisture and relay the readings by Wi-Fi. Cellphone apps collect data from agricultural weather stations and calculate how much water different crops are consuming. Researchers deliberately cut back on water for some crops, trying to get the best harvest with the least amount of moisture — a practice called deficit irrigation.

In the future, tiny needles attached to plants could directly measure how much water they contain and signal irrigation systems to automatically switch on or off.

"It's like almost every month somebody's coming up with something here and there," said Don Ackley, water management supervisor for the Coachella Valley Water District in Southern California. "You almost can't keep up with it."

Researchers and farmers are running similar experiments in arid regions around the world. The need is especially pressing in seven U.S. states that rely on the Colorado River: Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming.

The river has plenty of water this summer after an unusually snowy winter in the mountains of the U.S. West. But climatologists warn the river's long-term outlook is uncertain at best and dire at worst, and competition for water will only intensify as the population grows and the climate changes.

The World Resources Institute says the seven Colorado River states have some of the highest levels of water stress in the nation, based on the percentage of available supplies they use in a year. New Mexico was the only state in the nation under extremely high water stress.

The federal government will release a closely watched projection Thursday on whether the Colorado River system has enough water to meet all the demands of downstream states in future years.

The river supplies more than 7,000 square miles (18,000 square kilometers) of farmland and supports a $5 billion-a-year agricultural industry, including a significant share of the nation's winter vegetables, according to the U.S. Bureau of Reclamation, which manages most of the big dams and reservoirs in the Western states.

The Pacific Institute, an environmental group, says the river also irrigates about 700 square miles (1,820 square kilometers) in Mexico.

Agriculture uses 57% to 70% of the system's water in the U.S., researchers say. The problem facing policymakers is how to divert some of that to meet the needs of growing cities without drying up farms, ranches and the environment.

The researchers' goal is understanding crops, soil and weather so completely that farmers know exactly when and how much to irrigate.

"We call it precision agriculture, precision irrigation," said Huihui Zhang, a Department of Agriculture engineer who conducts experiments at the Greeley research farm. "Right amount at the right time at the right location."

The Palo Verde Irrigation District in Southern California is trying deficit irrigation on alfalfa, the most widely grown crop in the Colorado River Basin.

Alfalfa, which is harvested as hay to feed horses and cattle, can be cut and baled several times a year in some climates. The Palo Verde district is experimenting with reduced water for the midsummer crop, which requires more irrigation but produces lower yields.

Sensors placed over the test plots indirectly measure how much water the plants are using, and the harvested crop is weighed to determine the yield.

"The question then becomes, what's the economic value of the lost crop versus the economic value of the saved water?" said Bart Fisher, a third-generation farmer and a member of the irrigation district board.

Blaine Carian, who grows grapes, lemons and dates in Coachella, California, already uses deficit irrigation. He said withholding water at key times improves the flavor of his grapes by speeding up the production of sugar.

He also uses on-farm weather stations and soil moisture monitors, keeping track of the data on his cellphone. His drip and micro-spray irrigation systems deliver water directly to the base of a plant or its roots instead of saturating an entire field.

For Carian and many other farmers, the appeal of technology is as much about economics as saving water.

"The conservation's just a byproduct. We're getting better crops, and we are, in general, saving money," he said.

But researchers say water-saving technology could determine whether some farms can stay in business at all, especially in Arizona, which faces cuts in its portion of Colorado River water under a drought contingency plan the seven states hammered out this year.

Drone-mounted cameras and yield monitors — which measure the density of crops like corn and wheat as they pass through harvesting equipment — can show a farmer which land is productive and which is not, said Ed Martin, a professor and extension specialist at the University of Arizona.

"If we're going to take stuff out of production because we don't have enough water, I think these technologies could help identify which ones you should be taking out," Martin said.

Each technology has benefits and limits, said Kendall DeJonge, another Agriculture Department engineer who does research at the Greeley farm.

Soil moisture monitors measure a single point, but a farm has a range of conditions and soil types. Infrared images can spot thirsty crops, but only after they need water. Agricultural weather stations provide a wealth of data on the recent past, but they can't predict the future.

"All of these things are tools in the toolbox," DeJonge said. "None of them are a silver bullet."