Floods paralyze Indonesian capital, heavy rains continue

Fergus Jensen and Rieka Rahadiana in Reuters: Heavy monsoon rain triggered severe flooding in large swathes of the Indonesian capital, Jakarta, on Thursday, bringing the city to a halt with many government offices and businesses forced to close because staff could not get to work. At least 20,000 people were forced from their homes in the capital and weather officials warned the rain could get worse over the next few days.

"Rain will continue to fall in the greater Jakarta area ... the potential for flooding remains," a spokesman for the Meteorology Climatology Meteorology and Geophysics Agency told Reuters. He said rain was expected to remain heavy in mountains above Jakarta, often the source of floodwater.

Four people were reported to have been killed, according to the National Disaster Prevention Agency, which urged residents to stay at home to reduce traffic congestion on blocked roads. Torrential rain was reported across much of the country, including the main island of Java and heavily agricultural area of southern Sumatra....

From a 2007 flood in Jakarta, shot by gajah mada, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Tel Aviv will flood again

Green Prophet: It’s warming up again this week in Israel, just after a series of storms last week that began with major flooding on the Mediterranean Coast and ended with Jerusalem of Gold turned to white after a serious snowstorm. Reports on the flooding of the Yarkon River, which shut down large sections of Tel Aviv for a day, including its major highway, have addressed the insufficient drainage system, but little has been made of the connection between climate change and severe weather events.

Professors Pinhas Alpert and Colin Price, lecturers at the Porter School of Environmental Studies’ International MA Program at Tel Aviv University, have predicted that increased flooding will result from global climate change. Alpert helped to pioneer the use of cellular phone networks for monitoring the amount and intensity of precipitation and water vapor – measurements which are virtually free of charge and can be used for studying global climate systems.

Prof. Colin Price, Head of the Department of Geophysical, Atmospheric and Planetary Sciences, researches the Earth’s changing climate and what impact it will have on global thunderstorms. He predicts that a relatively small change in global temperatures – a one degree rise – will result in a significant increase in lighting activity. He expects that in drier climates like Israel the storms may become fewer in number, but more intense with stronger and more rainfall and lightning.

This is precisely what happened last week in Israel, when the largest storm since 2003 hit the country and provided as much rain as certain cities see in an entire winter, according to the Israel Meteorological Service.

“Intense rainstorms in Israel can cause flash flooding, which causes increased runoff that doesn’t reach the aquifers,” says Price. “The water scarcity problem in this region is exacerbated when rainfall doesn’t recharge the groundwater supply and precious drinking water flows out to sea.”...

The harbor in Tel Aviv, shot by Daniel winter, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Zimbabwe ill-prepared for rainfall extremes, farmers say

Madalitso Mwando in the Zimbabwe Mail: Thumeliso Matshobana knows what the devastation of too much water looks like. A smallholder farmer in Zimbabwe’s Midlands, he watched helplessly last year as floods destroyed crops, livestock, homes and schools. The heavy rains, he says, came as “a total surprise.”

The floods left a trail of destruction in traditionally dry and impoverished rural areas of the Midlands and Matebeleland, and rebuilding has been a slow and painful process. “We want rain but not the kind that kills us and destroys our livelihoods. But no one ever seems to know exactly the kind of rains we will have,” Matshobana lamented.

That “makes it hard for us villagers to make necessary preparations,” he said, expressing what has become a common sentiment about unpredictable rain patterns that seem to vex even the country’s meteorological services department.

The Met office, as it is known in Zimbabwe, issued a flood advisory in late November, predicting heavy downpours. But because the Met office has been off the mark many times in the past with its weather predictions, which are now questioned by farmers and disaster preparedness organizations, farmers such as Matshobana find themselves with little idea what to expect or what to do to prepare for floods.

Japhet Hadebe, a climate change researcher working with the Zimbabwe Environment Research Organisation (ZERO) says climate change monitoring remains “a complicated issue in Zimbabwe.”...

Cloud forest trees drink water through their leaves

Robert Sanders in the University of California-Berkeley News Center: Tropical montane cloud forest trees use more than their roots to take up water. They also drink water from clouds directly through their leaves, University of California, Berkeley, scientists have discovered.

While this is an essential survival strategy in foggy but otherwise dry areas, the scientists say that the clouds the trees depend on are now disappearing due to climate change.

“The study highlights the vulnerability of this rare and already endangered ecosystem to climate change,” said Todd Dawson, senior author of the study and UC Berkeley professor of integrative biology. Changes in cloud cover have already been correlated to declines and disappearances of cloud forest animal populations, such as frogs and salamanders.

The new study will be published next year in the journal Ecology Letters and is available online this month.

In tropical montane cloud forests, leaves are constantly bathed in clouds, making them wet. The leaves of the most common cloud forest trees drink this cloud water when water from the soil just isn’t enough, said Greg Goldsmith, lead author of the study and a graduate student in Dawson’s lab.

“Many cloud forests experience an annual dry season when the primary water source isn’t rain, but rather, the moisture from the clouds,” he said. “This is when the trees are most likely to draw water in through their leaves.”...

Graduate student Greg Goldsmith in the montaine cloud forest of Monteverde Cloud Forest Reserve, Costa Rica. Photo courtesy of Drew Fulton (Canopy in the Clouds)

Physicist happens upon rain data breakthrough

NASA: A physicist and researcher who set out to develop a formula to protect Apollo sites on the moon from rocket exhaust may have happened upon a way to improve weather forecasting on Earth.

Working in his backyard during rain showers and storms, John Lane, a physicist at NASA's Kennedy Space Center in Florida, found that the laser and reflector he was developing to track lunar dust also could determine accurately the size of raindrops, something weather radar and other meteorological systems estimate, but don't measure.

The special quantity measured by the laser system is called the "second moment of the size distribution," which results in the average cross-section area of raindrops passing through the laser beam.

"It's not often that you're studying lunar dust and it ends up producing benefits in weather forecasting," said Phil Metzger, a physicist who leads the Granular Mechanics and Regolith Operations Lab, part of the Surface Systems Office at Kennedy.

Lane said the additional piece of information would be useful in filling out the complex computer calculations used to determine the current conditions and forecast the weather. "We may be able to refine (computer weather) models to make them more accurate," Lane said. "Weather radar data analysis makes assumptions about raindrop size, so I think this could improve the overall drop size distribution estimates."...

John Lane looks over data recorded from his laser system as he refines his process and formula to calibrate measurements of raindrops. Photo credit: NASA/Jim Grossmann

New evidence links Mayan collapse to climate change

Voice of America: The ancient Mayan civilization, which developed a sophisticated culture in the Central American rainforests, vanished mysteriously a thousand years ago.  Now, an international team of anthropologists, archeologists, chemists and climatologists says it has identified the cause of the Mayan collapse: climate change.

To create a weather record for the past 2,000 years, the scientists analyzed a natural mineral formation called a stalagmite from a cave in Belize, using oxygen-isotope dating to determine how much rain fell on the region over the centuries. Stalagmites build up incrementally, like tree rings, as water drips through the cave ceiling, preserving an accurate climate record.

Mayan rulers commissioned stone monuments to record important events such as their rise to power, major battles, civic unrest and strategic alliances.  Pennsylvania State University Anthropology professor Douglas Kennett, the study's co-author, says the team was able to compare changes in the society documented on those monuments with their new climate timeline.

On a podcast for the journal Science, he said the team saw a relationship between rainfall levels and political stability. "The growth of Maya civilization and increases in population and levels of sophistication actually correlate with a very wet interval that spans several hundred years and the decline of the Maya actually appeared to correlate with a downturn generally in climate and climate drying," he said....

A Mayan zodiac circle, shot by theilr, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license