Photos: Early week flooding leaves 70 percent of Venice underwater, more flooding possible Thursday

Photos: Early week flooding leaves 70 percent of Venice underwater, more flooding possible Thursday


https://www.accuweather.com/en/weather-news/photos-early-week-flooding-leaves-70-percent-of-venice-underwater-more-flooding-possible-thursday/70006490

More than 70 percent of Venice, Italy, was under water after strong winds flooded the area by raising the water level by more than 5 feet earlier this week.

The flooding has been described as the worst to hit the city in at least a decade, according to CNN. This same storm system has been linked to at least 11 deaths across Italy.

"Geography of Venice is key to its storm-tide problem. It is nested within a lagoon at the far-northwest end of the Adriatic Sea," AccuWeather Meteorologist Jim Andrews said.

Due to this extreme flooding, tourists and residents were seen wading in nearly waist-deep water.

St Mark’s Basilica was flooded for just the second time in the past 100 years, according to The Guardian.

Fears were rising that the damage to the historic landfall could be severe due to the extent of the flooding.

According to Andrews, wind direction has been southeasterly, as would be expected.

"Another factor is the air pressure difference between Venice and the southern end of the Adriatic Sea. Monday, this difference has reached 0.44 to 0.59 inches of mercury (15 to 20 millibars), which is quite significant. This pressure difference tends to lift water at the north end of the Adriatic Sea (thus Venice), contributing to the lift caused by the 'wind set' (southeasterly onshore winds)," Andrews said.

More unsettled weather is on the way for Venice and surrounding parts of Italy as a storm arrives from Thursday into Friday.

A brief period of southeasterly winds could result in renewed flooding problems Thursday into Thursday evening corresponding with high tides.

Rainfall of 13-38 mm (0.5-1.5 inches) will accompany the gusty winds and further elevate the risk for flooding.

FIRST ALERT WEATHER DAY: Potential for severe weather this evening and overnight

There will be some strong to potentially severe weather this evening and overnight

FIRST ALERT WEATHER DAY: Potential for severe weather this evening and overnight

http://www.kplctv.com/2018/10/31/first-alert-weather-day-potential-severe-weather-this-evening-overnight/

LAKE CHARLES, LA (KPLC) - Today is First Alert Weather Day. There is potential for severe weather during the evening and overnight tonight. All forms of severe weather are possible from the early evening to the early morning hours on Thursday. That includes hail, tornadoes, flash flooding, and damaging winds. Now is the time to download the KPLC 7Stormteam weather app so you will be alerted if there is severe weather in your area.

During the day, the winds will be gradually increasing, and the clouds will thicken up. There could be a few showers as well. At times, there may be a little sunshine, which would help the storms later this evening.

As the kids try to go trick-or-treating, the sooner they go, the better. The rain will be arriving later after sunset along with a few storms. If there are storms in the area, I would try to keep the kids inside. Check the radar before you head out the door.

Overnight is when the stronger storms will arrive. This is when everyone will need to be inside ahead of the potential severe weather. There will be heavy rain and some storms could produce tornadoes. Make sure to stay away from windows and inside as the weather passes. Keep your alerts turned on, on your weather app to stay up to date on the storms.

Once that cold front passes Wednesday night, it will push all of the rain and clouds away from Southwest Louisiana. There could be a few showers and maybe a storm or two in the morning, but all of the rain will move out by lunchtime at the latest. The temperature will be much cooler as well. Highs will be in the lower 70s.

Then Friday and through the weekend, it will go back to being nice and sunny with no chance of rain! It will be perfect fall weather where it is cool in the morning, then warms up in the afternoon. As mentioned, it will be sunny with no rain around, so any outdoor plans should be good to go!

Later, Sunday there could be a few clouds that build their way back up. Another cold front will be on its way. The rain chances will stay at 20% Sunday but will increase on Monday and Tuesday. It is unknown if there will be severe weather with this system next week since it is too far out.

CODE RED WEATHER: Tracking Thursday Thunderstorms

CODE RED WEATHER: Tracking Thursday Thunderstorms
 https://mynbc15.com/news/local/code-red-weather-tracking-thursday-thunderstorms

A warm Wednesday morning will turn into a hot Halloween afternoon. While temperatures in the low to middle 80s aren’t necessarily hot, they are 10 degrees above normal.

A few showers are possible during the heat of the day, but most of us will remain dry through this evening.

4PM: 82° 6PM: 76° 8PM: 73°

Storms are a safe bet on Thursday and some may be severe.

While the higher risk of damaging wind and isolated tornadoes is to our north and west, the Storm Prediction Center has our area under a level 2 threat so please stay weather alert tomorrow.

If the storm system tracks farther south and or slows down, our risk of rough weather will increase. Locally, the main weather worry is heavy rain followed by damaging wind.

An isolated tornado is also possible.

The line of storms should move through the region between 8 am and 2 pm.

Behind the weather maker, Friday and the weekend look dry and cooler with lows in the 40s and highs in the upper 60s to low 70s.

The Tropics:

Hurricane Oscar is moving through the central Atlantic Ocean. This storm is far from land and the forecast track keeps it away from land until it dissipates across the north Atlantic by the end of the week.

Tornado warning for Fort Bend County until 3:45 p.m.

Tornado warning for Fort Bend County until 3:45 p.m.

https://www.chron.com/news/houston-weather/article/Trick-or-treaters-to-encounter-severe-weather-13350826.php

Much of Fort Bend county is under a tornado warning until 3:45 p.m. as law enforcement fields call for a possible touchdown.

The Fort Bend County Sheriff's Office tweeted that they are working on unconfirmed reports of a tornado touchdown at FM 2759 and Agnes Road.

All of southeast Texas is under a tornado watch until 10 p.m. Wednesday.

SEVERE WEATHER ON HALLOWEEN: 

Spooky weather is in the forecast this Halloween, with trick-or-treaters expected to encounter severe thunderstorms later tonight.

Kids might have their best shot at raking in the candy before 6 p.m., according to the National Weather Service. A cold front should move through the area around that time, bringing the strongest storms along and on the south side of the front.

SWEET RELIEF FROM RAIN: Houston's indoor trick-or-treating events to avoid getting wet

The Houston area will see an 90 percent chance of scattered showers and thunderstorms this afternoon, with a quarter to a half-inch of rain forecast.

Later tonight, expect severe thunderstorms, which should cause rainfall of 1 to 2 inches.

The most favorable time for storms is between 4 p.m. and 10 p.m., meteorologists say.

The National Weather Service warns that rain could cause roadways to pond and flood cars in low-lying areas. Creeks and bayous could rapidly rise but aren’t expected to exceed their banks.

Severe storms could produce tornadoes, wind damage, large hail and locally heavy rainfall, according to the National Weather Service’s Houston/Galveston office.

Highs are forecast at 84 degrees today, with lows reaching 59 degrees. High temperatures will dip to the high 60s on Thursday.

 

 

Nine dead and one missing after storms batter Italy

Nine people are reported dead and one missing today after storms swept across Italy, destroying roads and flooding towns and cities.

 

Much of northern Italy remains under red alert today, after two days of severe storms in which much of the country was lashed by torrential rains. Winds of up to 180 kilometers an hour have been reported in Liguria, and waves up to seven meters high.

So far the storm has reportedly left nine people dead, one missing and dozens injured.

Two people were killed when a tree hit a car they were travelling in near Frosinone, south of Rome.

A volunteer firefighter was reportedly killed by a falling tree in Alto Adige. Falling trees also killed a man in Terracina south of the capital, and another in the Naples region, authorities said.

5.800 firefighters responded to over 7,000 incidents yesterday, the Italian fire service said.

More than 3500 calls were for fallen or dangerous trees, the main cause of fatal accidents.

Near Savona in the northwest, a falling piece of cornice struck and killed a woman.

A boat owner is still missing after a storm-tossed sailboat was smashed against a pier in Calabria on Sunday. He was the owner of the Canadian-flagged vessel, from which others may also be missing.
Authorities said today that a woman died when her home was engulfed by a mudslide and rocks in the northern region of Trentino.

A man was killed while kitesurfing on Monday afternoon near the town of Cattolica on the Adriatic coast, with the local press saying strong winds had blown his board into the rocks.

Italian media have also reported that around 170 people, tourists and hotel staff, were stranded by heavy snowfall at the Stelvio Pass on the Swiss border.

Dozens of people are reported wounded, among which there are also several firefighters.

There was widespread damage to roads and property across many regions. A bridge collapsed due to heavy rains at Ovaro, Friuli on Monday.

Record high winds were recorded in Liguria, with the highest at 180 kilometers per hour in Savona.

 https://www.thelocal.it/20181029/eight-dead-and-many-missing-after-severe-storms-batter-italy

CDOT plow tips over during storm

 

WOODLAND PARK, Colo. (KKTV) - The storm Tuesday night caused problems for some drivers, including a Colorado Department of Transportation snow plow operator.

CDOT told 11 News the driver lost control on a snowy part of Highway 24 between Woodland Park and Divide.

Eastbound Highway 24 had to be closed while crews cleaned up all the sand the truck was carrying.
CDOT said, while firefighters were on the way to the crash, another driver ran into the firetruck.

 https://www.kktv.com/content/news/CDOT-plow-tips-over-during-storm-499107711.html

Arizona storm chaser publishes incredible video highlighting the desert monsoon season

PHOENIX, Ariz. -- One of my favorite storm chasers is at it again.

Mike Olbinski, who focuses most of his chases on capturing the beauty of the Arizona thunderstorms during the summer monsoon season, has released his annual video compilation.

"Monsoon V" features "a pretty dang good show in 2018, starting off with a decent dust storm on July 5th, then the best haboob chase I've ever had on July 9th, an epic green hail core on July 11th and finally another fantastic dust storm day on August 2nd," Olbinski wrote on his Vimeo page.

"Sprinkled in there...more dust storm, some at night, spectacular lightning, and tons of microbursts and stormy clouds, plus a few rotating supercells to put some icing on the cake. It was one of the best monsoon seasons I've chased..."

This year's treks totaled 15,000 miles zig-zagging across Arizona over 32 days.

"I love doing these films so much. So much hard work for months on end goes into capturing them," he said. "Sleep deprivation, tons of gas money, crappy food and yes, sometimes missing storms I wish I had been on... But the highs were amazing."

This year his three kids came along on some of the chases.

"Chasing with my kiddos...sharing the July 9th haboob bonanza with Lyla and Eli...or an all-night chase with my youngest, Asher. They were so awesome to have along."

Enjoy!






 https://komonews.com/weather/scotts-weather-blog/arizona-storm-chaser-publishes-incredible-video-highlighting-the-desert-monsoon-season

Mother of 1-year-old swept away in hurricane flood waters faces criminal charges

MONROE, N.C. —
The mother of a 1-year-old who was swept into floodwaters created by Hurricane Florence has been charged in the boy's death.

The Union County Sheriff's Office said on its Facebook page 20-year-old Dazia Ideah Lee of Charlotte is charged with involuntary manslaughter and driving on a closed or unopened highway.

Lee told news outlets she wasn't from the area and was unfamiliar with the roads. Authorities said the water from a rain-swollen creek pushed her car off the road as she tried to cross a bridge and left her stuck in a group of trees on the night of Sept. 16. Lee said she was able to get Kaiden Lee-Welch out of the car, but the water caused her to lose her grip.

"I couldn't hold on anymore, and he let go," Lee told Fox 46. 

Multiple law enforcement teams searched for Kaiden that night and again in the morning, when his body was found.

Lee told the Washington Post that she had seen people successfully crossing the bridge, although she also saw barricades nearby.

“I can tell you that the barricades were up there,” Union County Sheriff Eddie Cathey said the day after Kaiden was swept away, according to the Charlotte Observer. “Whether someone else moved those barricades and she drove around ‘em, I can’t say.”

Lee tearfully spoke to reporters after her son's body was found, desperately explaining how hard she tried to save him.

“I did everything I could,” Lee said. “From the moment I was pregnant until the moment I lost him. I did everything I could to save and protect him.”

She noticed that much of the response to Kaiden's death on social media was critical of her.

Comments included: “Mom made a bad decision,” “Although I feel for this child, I do not feel for the mother,” and “Negligence."

Cathey defended the decision to charge Lee.

“The tragic death of this child and the circumstances surrounding this case are heartbreaking,” Cathey said. “We continue to pray for all those suffering as a result of this child’s death. However, after a very thorough investigation and taking all facts into consideration and applying the law, we feel that these charges are appropriate.”

https://www.wesh.com/article/mother-of-1-year-old-swept-away-in-hurricane-flood-waters-faces-criminal-charges/24465378

Venice Flooding Is Worst in a Decade; Severe Weather in Italy Kills at Least 11

 

ROME — Violent thunderstorms, small tornadoes that blew roofs off homes, and hurricane-force winds lashed Italy from Piedmont to Sicily early this week, leaving at least 11 people dead, many more injured and firefighters and other rescue workers scrambling to respond to emergency calls.

In Venice, ferocious winds drove the high tide to more than 61 inches, or 156 centimeters, above average sea level on Monday, one of the highest levels ever recorded, plunging much of the city under water. It was the highest flood in a decade in Venice, though far short of the record, more than 76 inches above level, set in November 1966.

Venetians and tourists tottered on raised walkways throughout the city, while others waded through thigh-high water. Many shops and restaurants flooded when barriers across doorways failed to keep the water out.

Near the covered entrance to the basilica, the mosaic floor was under as much as 35 inches of water, it said, “soaking the monumental bronze doors, columns and marble.” Water levels remained above ground in the basilica for 16 hours.

“It may not be visible to the eye, but structures age because of the salt water drenching the bricks, which were not meant to remain underwater for long; that goes for bronze, too,” said Pierpaolo Campostrini, one of the board members. “The bricks are like sponges, and if the water levels don’t drop, the water rises several meters to the mosaic level.”

“In one day, the basilica aged 20 years,” he said.

 https://www.nytimes.com/2018/10/30/world/europe/venice-floods-italy.html

Carbon emissions from Amazonian forest fires up to 4 times worse than feared

Carbon losses caused by El Niño forest fires of 2015 and 2016 could be up to four times greater than thought, according to a study of 6.5 million hectares of forest in Brazilian Amazonia.

New research, published in a special issue of the journal Philosophical Transactions of the Royal Society B, has revealed that the aftermath of 2015 and 2016 forest fires in the Amazon resulted in CO2 emissions three to four times greater than comparable estimates from existing global fire emissions databases.

The finding is part of a series of results published this week by Lancaster University researchers who were working in the heart of the site of one of the worst forest fires the Amazon has seen in a generation.

Researchers say uncontrolled wildfires in the understorey -- or ground level -- of humid tropical forests during extreme droughts are a large and poorly quantified source of CO2 emissions.

The study 'Quantifying immediate carbon emissions from El Niño-mediated wildfires in humid tropical forests' looked at a 6.5 million hectare region, of which almost 1 million hectares of primary and secondary forests burned during the 2015-2016 El Niño (an area approximately the size of half of Wales).

Although the area analyzed covers less than 0.2% of Brazilian Amazonia, these wildfires resulted in expected immediate CO2 emissions of over 30 Million tonnes, three to four times greater than comparable estimates from global fire emissions databases.

Lead author Kieran Withey of Lancaster University said : "Uncontrolled understorey wildfires in humid tropical forests during extreme droughts are a large and poorly quantified source of CO2 emissions . These u¬nderstory fires completely consumed leaf litter and fine woody debris, while partially burning coarse woody debris; resulting in high immediate CO2 emissions. This analysis covers an area of just 0.7% of Brazil, but the amount of carbon lost corresponds to 6% of the annual emissions of the whole of Brazil in 2014."

https://www.sciencedaily.com/releases/2018/10/181008083517.htm

Predicting an El Niño or La Niña year 17 months in advance

https://www.sciencedaily.com/releases/2018/10/181015084633.htm

Changes in Atlantic Ocean sea surface temperatures can be used to predict extreme climatic variations known as El Niño and La Niña more than a year in advance, according to research conducted at Korea's Pohang University of Science and Technology and published in the journal Scientific Reports.

The El Niño Southern Oscillation (ENSO) is an irregular, periodic variation in trade winds and sea and air temperatures in the equatorial region of the Pacific Ocean, . Its warming phase of sea surface temperatures, called El Niño, and cooling phase, called La Niña, affects weather and climate around the world. For example, El Niño conditions typically generate more typhoons in the Pacific Ocean and fewer hurricanes in the Atlantic Ocean, while La Niña conditions usually reverse the trend.

Extensive studies have been conducted to better understand what triggers a distinct oscillation in order to predict associated climatic events. But accurate predictions are still limited to about a year or less before an ENSO swing. For example, studies have found that a peak in warm water in the equatorial Pacific precedes El Niño by about eight months. Also, an abnormal drop in sea surface temperatures in the tropical North Atlantic in early spring precedes El Niño conditions in the Pacific within about nine months.

Now, researchers at Pohang University of Science and Technology and colleagues in Hawaii and Japan have found that an abnormal rise in sea surface temperatures in a large body of warm water, called the Atlantic Warm Pool -- comprising the Gulf of Mexico, the Caribbean Sea, and the western tropical North Atlantic -- triggers La Niña about 17 months later.

The team analysed observational (1985-2016) and model simulation (1970-2000) data and found an unusual rise of sea surface temperature in the Atlantic Warm Pool in mid-summer to early fall leads to the formation of a northerly wind over the North Pacific. This generates cold sea surface temperatures, high sea level pressure, and a low-level high-pressure area called an anti-cyclone in the subtropical north-eastern Pacific that persist through the subsequent winter and spring. The cold sea surface temperature extends toward the equator. Together, these events lead to a coupling between sea surface temperature and surface winds in the equatorial Pacific in the spring, triggering La Niña. Falling sea surface temperatures in the Atlantic Warm Pool ultimately trigger El Niño. Both ENSO events are triggered 17 months after the initial changes in Atlantic Warm Pool sea surface temperatures.

The robust relationship between these events can provide a longer lead time for ENSO predictions compared to those reported in previous studies, the researchers say. This relationship has only become strong enough for the purpose of these predictions in the past three decades. Before this, it was not statistically significant. Average rising sea surface temperatures in the Atlantic Warm Pool above 28°C seem to be responsible for this, the researchers say.

Wind farms and reducing hurricane precipitation

With the United States being pummeled over the last couple of years with several high-category, high-damage hurricanes, the University of Delaware's Cristina Archer recently published a paper that discovered an unexpected benefit of large-scale offshore wind farms: they lessen the precipitation caused by these devastating storms.

Archer said that while previous studies have shown that hypothetical offshore wind farms can harness the kinetic energy from hurricanes and lessen the effects of wind and storm surge, this study showed that offshore wind farms can also have an impact on precipitation. The paper demonstrates a clear decrease in precipitation for onshore locations that are downstream of a wind farm and an increase in precipitation in offshore areas that are upstream or within the wind farms themselves.

Archer, professor in UD's College of Earth, Ocean and Environment and the Wind Power Associate Director of the Center for Carbon-free Power Integration (CCPI), worked with Yang Pan and Chi Yan, both former doctoral students of Archer's while at UD, on the paper that was recently published in the Environmental Research Letters journal.

The researchers used Hurricane Harvey as an example because it brought possibly the heaviest rain ever recorded in United States history to the Texas coast and caused unprecedented flooding.

Unlike Hurricanes Katrina or Sandy, for which storm surge was one of the biggest problems, Hurricane Harvey flooded Houston because of the amount of rain that it dropped on the city.

Archer explained that wind farms can help mitigate the precipitation by affecting two large factors that cause precipitation: wind convergence and divergence.

The strong hurricane winds slow down when they hit wind turbines, which is an effect known as convergence and enhances precipitation.

"Think about convergence like when there's traffic on a freeway and everybody is going fast and then all of a sudden, there's an accident and everybody slows down. You get a convergence of cars that backs up because everybody slows down. That's the convergence upstream of the offshore wind farms," said Archer.

This leads to increased precipitation because when the winds converge at a point on the surface, they have no other place to go except up, and that vertical motion brings more moisture into the atmosphere.

Using the accident on the freeway metaphor again, Archer said that divergence is similar to what happens when cars finally get past the accident: everybody speeds up.

"Divergence is the opposite effect. It causes downward motion, attracting air coming down, which is drier and suppresses precipitation. I was wondering what if that would also happen when there is an offshore farm?" said Archer.

https://www.sciencedaily.com/releases/2018/10/181017141024.htm

US tornado frequency shifting eastward from Great Plains

A new study finds that over the past four decades, tornado frequency has increased over a large swath of the Midwest and Southeast and decreased in portions of the central and southern Great Plains, a region traditionally associated with Tornado Alley.

The study, by meteorology professor Victor Gensini of Northern Illinois University and Harold Brooks of NOAA's National Severe Storms Laboratory in Norman, Okla., found significant decreasing trends in frequencies of both tornado reports and tornado environments over portions of Texas, Oklahoma and northeast Colorado.

Tornado Alley remains the top zone for tornadoes in the United States, but other areas, including the so-called Dixie Alley that includes much of the lower Mississippi Valley region, are catching up.

The researchers identified significant increasing trends of tornado reports and tornado environments in portions of Mississippi, Alabama, Arkansas, Missouri, Illinois, Indiana, Tennessee and Kentucky.

"Regions in the Southeast and Midwest are closing the gap when it comes to the number of tornado reports," said Gensini, who led the study published Oct. 17 in the Nature partner journal, Climate and Atmospheric Science.

"It's not that Texas and Oklahoma do not get tornadoes," Gensini said. "They're still the number one location in terms of tornado frequency, but the trend in many locations is down over the past 40 years."

The study examined tornado frequency trends in fine-scale resolution using two separate approaches, Gensini said.

The researchers tracked the number of tornado reports from 1979 to 2017, while also investigating regional trends in the daily frequency of tornado-environment formation over the same time period, using an index known as the Significant Tornado Parameter (STP). Frequently used for predicting severe weather, the index captures the coexistence of atmospheric ingredients favorable for producing tornadoes.

Both the number of actual tornado reports and the historical STP analysis showed the eastward uptick in tornado frequency.

"One could argue that because a region's population has increased, more tornadoes are sighted and reported," Gensini said. "But we also identified this eastward trend when using the STP index, which looks at the frequency of tornado environments and has nothing to do with people. This increases our confidence in the reporting trend that we're seeing."

https://www.sciencedaily.com/releases/2018/10/181017172846.htm

World Heritage Sites threatened by rising sea levels

https://www.sciencedaily.com/releases/2018/10/181017111022.htm

In the Mediterranean region, there are numerous UNESCO World Heritage Sites in low-lying coastal areas. These include, for example, the Venetian Lagoon, the Old City of Dubrovnik and the ruins of Carthage. In the course of the 21st century, these sites will increasingly be at risk by storm surges and increasing coastal erosion due to sea-level rise. This is the conclusion of one of the first large-scale studies, carried out by doctoral researcher Lena Reimann from the Department of Geography at Kiel University (CAU), together with Professor Athanasios Vafeidis and international partners. The team published their results in the current issue (Tuesday 16 October) of the journal Nature Communications.

Already today, a large number of the altogether 49 World Heritage Sites investigated are at risk due to rising sea levels. Up to 37 of these sites are at risk from a so-called 100-year storm surge, which has a 1 percent chance of being exceeded in any given year. 42 of the 49 sites are at risk from coastal erosion. If sea levels continue rising further, "in the Mediterranean region, the risk posed by storm surges, which are 100-year storm surges under today's conditions, may increase by up to 50 percent on average, and that from coastal erosion by up to 13 percent -- and all of this by the end of the 21st century under high-end sea-level rise. Individual World Heritage Sites could even be affected much more due to their exposed location," said Lena Reimann to explain the study results.

In order to be able to evaluate the potential risks, the research team created a spatial database of all UNESCO World Heritage Sites in low-lying coastal areas of the Mediterranean region. In addition to the location and form of the sites, the study also included the heritage type, the distance from the coastline, and its location in urban or rural surroundings. "Using this database and model simulations of flooding, taking into account various scenarios of sea-level rise, we were able to develop indices: the index for flood risk and for erosion risk," said Reimann. The flood risk index takes into account the potentially-flooded area and the maximum flood depth of each World Heritage Site. The erosion risk index is based on the distance of each site from the coastline and the physical properties of the coast, which largely determine the degree of erosion. These include, among others, the material properties of the coast, from sandy through to rocky, and the availability of new sediment.

The increase in flood risk of up to 50 percent and erosion risk of up to 13 percent are based on an assumed average sea-level rise in the Mediterranean region of 1.46 meters by the year 2100. This increase could occur with a five percent probability (95th percentile) under a high-end climate change scenario (RCP8.5). "Even if such a high sea-level rise has a low probability of occurring by the year 2100, this scenario cannot be ruled out, due to the high uncertainties in relation to the melting of the ice sheets," said Professor Vafeidis. "In addition, such a scenario is quite relevant from a risk management perspective, since a 5% probability in this context is not low."

Scientists find missing piece in glacier melt predictions

https://www.sciencedaily.com/releases/2018/10/181015100508.htm

Stanford scientists have revealed the presence of water stored within a glacier in Greenland, where the rapidly changing ice sheet is a major contributor to the sea-level rise North America will experience in the next 100 years. This observation -- which came out of a new way of looking at existing data -- has been a missing component for models aiming to predict how melting glaciers will impact the planet.

The group made the discovery looking at data intended to reveal the changing shape of Store Glacier in West Greenland. But graduate student Alexander Kendrick figured out that the same data could measure something much more difficult to observe: its capacity to store water. The resulting study, published in Geophysical Research Letters, presents evidence of glacier meltwater from the surface being stored within damaged, solid ice. While ice melting at the surface has been well documented, little is known about what happens below glacier surfaces, and this observation of liquid water stored within solid ice may explain the complex flow behavior of some Greenland glaciers.

"Things like this don't always come along, but when they do, that is the real 'joy of the discovery' component of Earth science," said co-author Dustin Schroeder, an assistant professor of geophysics at Stanford University's School of Earth, Energy & Environmental Sciences (Stanford Earth). "This paper not only highlights this component's existence, but gives you a way to observe it in time."

Surface meltwater plays an important role in Greenland by lubricating the bottoms of ice sheets and impacting how retreating glaciers are affected by the ocean. The process of how the glaciers melt and where the water flows contributes to their behavior in a changing climate, as these factors could alter glaciers' response to melting or impact the timeline for sea-level rise. Knowing that some liquid is intercepted within glaciers after melting on the surface may help scientists more accurately predict oceanic changes and help people prepare for the future, Schroeder said.

Rising temperatures and human activity are increasing storm runoff and flash floods

https://www.sciencedaily.com/releases/2018/10/181022085820.htm

Hurricanes Florence and Michael in the U.S. and Super Typhoon Mangkhut in the Philippines have shown the widespread and harmful impact of weather extremes on both ecosystems and built communities, with flash floods causing more deaths, as well as property and agriculture losses than from any other severe weather-related hazards. These losses have been increasing over the past 50 years and have exceeded $30 billion per year in the past decade. Globally, almost one billion people now live in floodplains, raising their exposure to river flooding from extreme weather events and underscoring the urgency in understanding and predicting these events.

Columbia Engineering researchers have demonstrated for the first time that runoff extremes have been dramatically increasing in response to climate and human-induced changes. Their findings, published today in Nature Communications, show a large increase in both precipitation and runoff extremes driven by both human activity and climate change. The team, led by Pierre Gentine, associate professor of earth and environmental engineering and affiliated with the Earth Institute, also found that storm runoff has a stronger response than precipitation to human-induced changes (climate change, land-use land-cover changes, etc). This suggests that projected responses of storm runoff extremes to climate and anthropogenic changes are going to increase dramatically, posing large threats to the ecosystem, affecting community resilience and infrastructure systems.

The researchers discovered that changes in storm runoff extremes in most regions of the world are in line with or higher than those of precipitation extremes. They noted that different responses of precipitation and storm runoff to temperature can be attributed not only to warming, but also to factors like land-use and land-cover changes, water and land management, and vegetation changes that have altered the underlying surface conditions and hydrological feedbacks that have, in turn, increased storm runoff.

Climate stress will make cities more vulnerable

https://www.sciencedaily.com/releases/2018/10/181018095435.htm

Built upon on a complex system of canals, water catchments and embankments, Angkor was once the largest city in the world, covering an area of approximately 1000km2. However, in the 15th Century it saw a massive population fall.

The multidisciplinary team of academics, researchers and students led by Professor Mikhail Prokopenko, Director of the Complex Systems Research Group, and Associate Professor Daniel Penny, Director of the Greater Angkor Project, found that the medieval city suffered external climate stress coupled with overloaded infrastructure within the canal system, which through in-depth mapping showed evidence of a vulnerability to catastrophic failures.

Professor Prokopenko believes that the study is crucial to improving infrastructure in an era of increasing frequent extreme weather events which are creating new and pressing risks to urban environments.

He said, "Complex infrastructural networks provide critical services to cities but can be vulnerable to external stressors, including climatic variability.

"The cascading failure of critical infrastructure in Angkor which resulted from climate extremes re-emphasises the importance of building resilience into modern networks."

Having worked on the Greater Angkor Project for 18 years, Professor Daniel Penny said, "For the first time, identifying a systemic vulnerability in Angkor's infrastructural network has provided a mechanistic explanation for its demise, which comes with an important lesson for our contemporary urban environments."

Both of the researchers believe that the risks of network collapse have become more acute as urban conglomerations become larger, more complex, and have more people living in them.

"The water management infrastructure of Angkor has been developed over centuries, becoming very large, tightly interconnected, and dependent on older and ageing components. The change in the middle of the 14th Century C.E., from prolonged drought to particularly wet years, put too much stress on this complex network, making the water distribution unstable," said Professor Prokopenko.

The factors behind Angkor's demise are also comparable to the challenges faced by modern urban communities that are struggling with complex critical infrastructure and extreme weather events, such as floods and drought.

Professor Prokopenko continued, "We found that infrastructural networks in preindustrial urban environments in fact share very common topological and functional characteristics with modern complex networks."

In complex systems, catastrophic responses and cascading failures, such as an abandonment of a city, can also be caused by very small changes or even a series of accumulated changes which cause a system or network to reach a 'tipping point'.

There are several examples of tipping points faced by the modern world, such as the Amazon die-back, the 2016 South Australian power outage and the El Niño-Southern Oscillation.

Professor Prokopenko believes the team's research emphasises the need for governments and communities to focus on building resilience into modern urban networks, particularly in the face of a changing climate.

"Not only is it possible that catastrophic, infrastructural failure may also have occurred in the past, but the results from this research are critical to our community's understanding of how climate and distributed resources affect the functioning of our cities and societies.

"If we don't build resilience into our critical infrastructure, we may face severe and lasting disruptions to our civil systems, that can be intensified by external shocks and threaten our environment and economy," he concluded.

The research was conducted as part of the Greater Angkor Project in conjunction with the University of Sydney's CRISIS initiative which models social risks and extreme events.

The Greater Angkor Project is a collaborative research program between the University of Sydney (Archaeology and Geosciences), the APSARA National Authority and the École Française d'Extrême-Orient, that has attempted to explain the demise and abandonment of Angkor for the past 16 years