Stronger storms feared as dry spell forecast in Philippines

Zee News: The disaster-haunted Philippines is likely to be hit by stronger typhoons this year as warming ocean surfaces contribute to a dry spell, the state weather service warned Wednesday.

The Asian archipelago, whipped by about 20 typhoons and storms each year, is now in the grips of the "El Nino" phenomenon that can make storms "stronger" and more "erratic", weather service chief Vicente Malano said.

"El Nino may cause the behaviour of tropical cyclones to become erratic, affecting (their) tracks and intensity," he said in an advisory, adding that the same number of storms are expected.

"The tropical cyclone tracks are expected to shift northward and (their) intensity could become stronger," Malano said.

Super Typhoon Haiyan, the strongest ever to hit land, left more than 7,350 people dead or missing in central regions of the Philippines in November 2013 as it dumped tsunami-like waves on coastlines, wiping out entire towns....

2013's Typhoon Haiyan viewed from a Navy research satellite

Predicting ENSO devastation

Sandhya Sekar in SciDev.net:A new computer model can help forecast the socio-economic devastation caused by rainfall and floods triggered by the El Nino-Southern Oscillation (ENSO) phenomena.  Philip Ward from VU University, Amsterdam, who with his colleagues created the ‘cascade’ modelling framework, says that it is capable of predicting the effect of ENSO on floods at the global and regional scales.

“During El Niño years, the risk is higher than average in north-eastern India, the findings suggest,” says Ward in an interview with SciDev.Net. “On the other hand, some basins in eastern India show lower than average damage during La Niña years.”

ENSO refers to the effects of anomalous sea surface temperatures off the western coast of South America that cause climatic changes across the tropics and subtropics. Southern Oscillation refers to temperature variations on the surface of the tropical eastern Pacific Ocean (warming and cooling known as El Niño and La Niña, respectively) and in  surface  air pressure in the tropical western Pacific.

Ward’s approach, published in September in the Proceedings of the National Academy of Sciences, combines three different models that predict rainfall, water drainage patterns and also the socio-economic impacts of floods, including on GDP.

The models found abnormal flood volumes across more than a third of the earth’s surface during El Nino years when the oceans were warmer than usual, and also during La Nina years when the oceans were colder.  “Our models and results are already at a resolution of one square kilometre which we have found to be very useful for many users of the data in practical applications,” Ward tells SciDev.Net....

Sunrise over the South Pacific, NASA image from the International Space Station

New study explains the role of oceans in global ‘warming hiatus’

A press release from the University of Southampton: New research shows that ocean heat uptake across three oceans is the likely cause of the ‘warming hiatus’ – the current decade-long slowdown in global surface warming.  Using data from a range of state-of-the-art ocean and atmosphere models, the research shows that the increased oceanic heat drawdown in the equatorial Pacific, North Atlantic and Southern Ocean basins has played a significant role in the hiatus.

The new analysis has been published in Geophysical Research Letters by Professor Sybren Drijfhout from the University of Southampton and collaborators from the National Oceanography Centre (NOC) Dr Adam Blaker, Professor Simon Josey, Dr George Nurser and Dr Bablu Sinha, together with Dr Magdalena Balmaseda from the European Centre for Medium Range Weather Forecasting (ECMWF).

Professor Drijfhout said: “This study attributes the increased oceanic heat drawdown in the equatorial Pacific, North Atlantic and Southern Ocean to specific, different mechanisms in each region. This is important as current climate models have been unable to simulate the hiatus. Our study gives clues to where the heat is drawn down and by which processes. This can serve as a benchmark for climate models on how to improve their projections of future global mean temperature.”

Previously, the drawdown of heat by the Equatorial Pacific Ocean over the hiatus period, due to cool sea-surface temperatures associated with a succession of cool-surface La Nina episodes, was thought to be sufficient to explain the hiatus.  However, this new analysis reveals that the northern North Atlantic, the Southern Ocean and Equatorial Pacific Ocean are all important regions of ocean heat uptake. Each basin contributes a roughly equal amount to explaining the hiatus, but the mechanisms of heat drawdown are different and specific in each basin.

...Dr Sinha concluded: “The deeper understanding gained in this study of the processes and regions responsible for variations in oceanic heat drawdown and retention will improve the accuracy of future climate projections.”

Fish at an oil platform, Gulf of Mexico, photo by US Bureau of Ocean Energy Management

Climate researchers discover El Nino's fueling effect on intense hurricanes

A press release from the University of Hawaii-Manoa: El Niño, the abnormal warming of sea surface temperatures in the Pacific Ocean, is a well-studied tropical climate phenomenon that occurs every few years. It has major impacts on society and Earth’s climate – inducing intense droughts and floods in multiple regions of the globe. Further, scientists have observed that El Niño greatly influences the yearly variations of tropical cyclones (a general term that includes hurricanes, typhoons and cyclones) in the Pacific and Atlantic Oceans.

However, there is a mismatch in both timing and location between this climate disturbance and the Northern Hemisphere hurricane season: El Niño peaks in winter and its surface ocean warming occurs mostly along the equator, i.e., a season and region without tropical cyclone (TC) activity. This prompted scientists to investigate El Niño’s influence on hurricanes via its remote ability to alter atmospheric conditions such as stability and vertical wind shear rather than the local oceanic environment.

Fei-Fei Jin and Julien Boucharel at the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), and I-I Lin at the National Taiwan University published a paper today in Nature that uncovers what’s behind this “remote control.” Jin and colleagues uncovered an oceanic pathway that brings El Niño’s heat into the Northeastern Pacific basin two or three seasons after its winter peak – right in time to directly fuel intense hurricanes in that region.

El Niño develops as the equatorial Pacific Ocean builds up a huge amount of heat underneath the surface and it turns into La Niña when this heat is discharged out of the equatorial region.  “This recharge/discharge of heat makes El Niño/La Niña evolve somewhat like a swing,” said Jin, lead author of the study.

Prior to Jin's and colleagues’ recent work, researchers had largely ignored the huge accumulation of heat occurring underneath the ocean surface during every El Niño event as a potential culprit for fueling hurricane activity.

“We did not connect the discharged heat of El Niño to the fueling of hurricanes until recently, when we noticed another line of active research in the tropical cyclone community that clearly demonstrated that a strong hurricane is able to get its energy not only from the warm surface water, but also by causing warm, deep water – up to 100 meters deep – to upwell to the surface,” said Jin....

El Niño’s discharged heat fuels intense hurricanes (historical tracks in black). Credit: Jin/SOEST.

Ocean primed for more El Nino

Space Daily via SPX: The ocean is warming steadily and setting up the conditions for stronger El Nino weather events, a new study has shown. A team of US, Australian, and Canadian researchers sampled corals from a remote island in Kiribati to build a 60-year record of ocean surface temperature and salinity. "The trend is unmistakeable, the ocean's primed for more El Nino events," says lead-author Dr Jessica Carilli, now based at the University of Massachusetts, Boston.

Team member Dr Helen McGregor from the Research School of Earth Sciences at The Australian National University said the change in El Nino patterns could have a major impact on Australia's weather. "During an El Nino event warm waters to the north of Australia move eastward, taking their rainfall with them," she said. "This changes the pattern of Australia's rainfall and droughts significantly."

El Ninos occurs irregularly every two to seven years and have often coincided with severe droughts in Queensland and New South Wales. The current conditions show that a weak El Nin
o has brought warmer and drier conditions to Australia for late 2014.

The team focused on regional differences in sea temperatures that generate the circulating winds known as the Walker Circulation, which drive the trade winds that bring moisture across the Pacific Ocean to the north of Australia.

The island from which the corals were sampled, Butaritari, was chosen for its location at one end of the Walker Circulation....

A causeway on Butaritari, shot by Tauʻolunga, Wikimedia Commons, under the Creative Commons 2.5 license

Drought hits Central America's crops, cattle

Terra Daily via AFP: ... Nicaragua and the rest of Central America has been hit by a major drought that has killed thousands of cattle, dried up crops and forced cities to ration electricity. Costa Rica, Honduras and Guatemala have declared emergencies in the worst affected areas to speed up aid delivery. El Salvador and Nicaragua have opened special funds to help farmers. In northern Nicaragua, vultures are eating the carcasses of cows that are dropping dead in dried out pastures.

Central American agriculture ministers held a videoconference on Wednesday to seek coordinated actions to cope with the drought. The lack of rain has been blamed on the probable arrival of the El Nino weather phenomenon, which is characterized by unusually warm Pacific ocean temperatures that can trigger droughts.

It is the latest trouble to hammer a region already beset by gang violence and poverty, which have driven families and unaccompanied children to migrate illegally to the United States. The drought has swept across a region known as "the dry corridor," which covers nearly a third of Central America, where 10 million people live, according to a 2013 study by the UN Food and Agriculture Organization. Nicaragua's government says the country is enduring its worst drought since 1976.

The first harvest, which takes place between May and August, has yielded nothing, according to Nicaragua's national farmers and ranchers union. Some 2,500 cattle have died and 700,000 more are in critical health as they roam dry pastures.

...El Nino, which occurs every two to seven years, has clobbered Central America 10 times in the past 60 years . "What we are seeing is the consequence of El Nino," Luis Fernando Alvarado, researcher at Costa Rica's Meteorological Institute, told AFP...

Picture by Neil Palmer CIAT. Irrigation of food crops during the dry season in drought-affected Nicaragua, made possible by the use of special reservoirs to capture and store excess rainwater during the country's rainy season. Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Famine in the Horn of Africa (1984) was caused by El Niño and currents in the Indian Ocean

AlphaGalileo via the University of Ghent: Oceanic patterns are important drivers of climatic variability. There is a clear link between periods of drought in the North Ethiopian Highlands and oceanic phases of El Niño, the Indian Ocean Dipole and the Southwestern Monsoons.

In order to prove these links, PhD student Sil Lanckriet (Department of Geography, Ghent University) analyzed weather data since the 1950s, as delivered from a meteorological computer model. He used a procedure known as ‘empirical orthogonal teleconnection analysis’ (EOT). According to Piet Termonia of the Royal Meteorological Institute, such statistical techniques are a clear step forward, since they allow linking oceanic patterns across the planet with the climatic situation at a particular location on the earth surface.

For his PhD, Sil Lanckriet is studying climatic fluctuations in Ethiopia over the past centur
ies, as well as their impact on periods of drought and processes of soil erosion. His study area is located in Korem, the place written in our collective memory by several BBC documentaries, Live Aid and by the pictures of Sebastião Salgado. His promoters Jan Nyssen and Amaury Frankl are well acquainted with the area. They even relocated the exact locations of the pictures and documentaries that were world news at the time. “Our research experience in Ethiopia shows that it is certainly possible that a similar drought will occur again, but this time it will probably not lead to a famine as in 1984. The Ethiopians have been very active on matters such as reforestation and soil and water conservation. We could prove that the land is now much less vulnerable for the occurrence of droughts”.

Enyew Adgo (Bahir Dar University) points out that East African meteorological agencies are well aware of the interactions between the Ethiopian weather and fluctuations of El Niño in the Pacific Ocean. The researchers show that similar patterns in the Indian Ocean should be incorporated by the meteorological models, in order to improve the prediction power of systems for Famine Early Warning...

Approaching Zanzibar, shot by Rob, Wikimedia Commons via Flickr, under the Creative Commons 2.0 license

EN... SO?

Emily Becker at Climate.gov: Forecasters at the Climate Prediction Center haven’t declared El Niño conditions, even though the Niño3.4 index is currently around 0.5°C above normal, and has been for the past two months. What’s the hold up? In short, we’re waiting for the atmosphere to respond to the warmer sea-surface temperatures, and give us the “SO” part of ENSO.

SO what? The Southern Oscillation, that’s what. The Southern Oscillation is a seesaw in surface pressure between a large area surrounding Indonesia and another in the central-to-eastern tropical Pacific; it’s the atmospheric half of El Niño. Since ENSO is a coupled system, meaning the atmosphere and ocean influence each other, both need to meet the criteria for El Niño before we declare El Niño conditions.

During average (non-El Niño) times, the waters of the western tropical Pacific are much warmer than in the east/central area (Figure 1). As warmer water extends out to the east during an El Niño, it warms the air, causing it to rise (lower pressure) (Figure 2). In turn, there is less rising motion (higher pressure) near Indonesia, due to the relatively cooler waters and overlying air.

...As of the end of June, both the SOI and the EQSOI are at +0.2 (they have trended downward over the past few months), and the wind patterns are roughly average over the tropical Pacific, with some slight weakening of the trade winds toward the end of the month. There is increased convection in the central Pacific, but also some over Indonesia… all of which says we’re still waiting for the atmosphere to get dressed in its El Niño clothes and come out to play.

However, we think it’s likely that the atmosphere will get on board soon, and we’re still predicting El Niño, with about a 70% chance that conditions will be met in the next few months, and around an 80% chance by this fall. If you’re interested in how the ocean and atmospheric conditions are evolving, CPC has weekly updates available....

Figure 1. Average state of ocean temperatures, rainfall, pressure, and winds over the Pacific during ENSO-neutral conditions. Figure 2. Generalized state of the ocean and atmosphere during El Niño conditions. NOAA image created by David Stroud.

Indonesia's 'haze' pollution defenses not enough, says green group

Michael Taylor and Kanupriya Kapoor in Reuters: Indonesia's promises to tackle the upcoming annual "haze" season with a $30 million fund and limited military equipment have been called into question by experts anticipating worse pollution levels than last year due to the El Nino weather pattern.

Indonesia has failed in previous attempts to stop the regional haze, with last year giving the worst pollution readings since 1997. Outgoing Indonesian President Susilo Bambang Yudhoyono was forced in mid-2013 to apologize to neighbors Singapore and Malaysia, which were blanketed in thick smog caused by forest fires in Indonesia.

With expectations high that the El Nino dry weather pattern will hit around the middle of the year, the haze could be worse than in 2013, conservation experts told Reuters. "We are talking hundreds of thousands of hectares that will probably burn and I doubt (the government) will be able to cover this much of an area," said David Gaveau, a scientist at the Center for International Forestry Research, a conservation organization based in Indonesia.

"We're expecting El Nino and if it comes, we're going to see much more fires than last year." The heavy smoke from slash-and-burn clearances often comes from the islands of Sumatra and Kalimantan, where large forest concessions are used by pulp and paper and palm oil companies, some of which are listed in Singapore....

NASA image of 2013 haze over southeast Asia

United States El Niño impacts

Mike Halpert at Climate.gov: By this point, most of you have heard that it looks like El Niño is coming, and maybe you’re wondering why you should care.  After all, why should it matter if the tropical Pacific Ocean becomes warmer than average? That’s thousands of miles away from the continental United States.  Well, it turns out that El Niño often results in changes in the patterns of precipitation and temperature across many parts of the globe, including North America (Ropelewski and Halpert 1987, Halpert and Ropelewski 1992).

...By examining seasonal climate conditions in previous El Niño years, scientists have identified a set of typical impacts associated with the phenomenon (Figure 1). “Associated with” doesn’t mean that all of these impacts happen during every El Niño episode. However, they happen more often during El Niño than you’d expect by chance, and many of them have occurred during many El Niño events.

In general, El Niño-related temperature and precipitation impacts across the United States occur during the cold half of the year (October through March). The most reliable of these signals (the one that has been observed most frequently) is wetter-than-average conditions along the Gulf Coast from Texas to Florida during this 6-month period. This relationship has occurred during more than 80% of the El Niño events in the past 100 years.

Over California and the Southwest, the relationship between El Niño and above-average precipitation is weaker, and it depends significantly on the strength of the El Niño. The stronger the episode (i.e., the larger the sea surface temperature departures across the central equatorial Pacific are), the more reliable the signal in this region has been.

...Elsewhere over the United States, El Niño impacts are associated with drier conditions in the Ohio Valley, and there is a less-reliable dry signal in the Pacific Northwest and the northern Rockies. Hawaii also often experiences lower-than-average rainfall totals from the late fall through early spring period.

The climate impacts linked to El Niño help forecasters make skillful seasonal outlooks. While not guaranteed, the changes in temperature and precipitation across the United States are fairly reliable and often provide enough lead time for emergency managers, businesses, government officials, and the public to properly prepare and make smart decisions to save lives and protect livelihoods....

Figure 1. Average location of the Pacific and Polar Jet Streams and typical temperature and precipitation impacts during the winter over North America. Map by Fiona Martin for NOAA Climate.gov.

Third warmest May in satellite record might portend record-setting El Niño

Newswise via the University of Alabama at Huntsville: May 2014 was the third warmest May in the 35-year satellite-measured global temperature record, and the warmest May that wasn’t during an El Niño Pacific Ocean warming event, according to Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville. The global average temperature for May was 0.33 C (about 0.59 degrees Fahrenheit) warmer than seasonal norms for the month. The warmest May was in 1998, during the “El Niño of the century.” Temperatures in May 1998 were 0.56 C (about 1.0 degrees F) warmer than normal. May 2010 — also an El Niño month — was second warmest at 0.45 C (0.81 degrees F).

While May 2014 was not officially an El Niño month, indications are that an El Niño is forming in the eastern central Pacific off the equatorial coast of South America. Even if that El Niño is nothing spectacular, it might become a record setter simply because it is getting a warmer start, Christy said. “The long-term baseline temperature is about three tens of a degree (C) warmer than it was when the big El Niño of 1997-1998 began, and that event set the one-month record with an average global temperature that was 0.66 C (almost 1.2 degrees F) warmer than normal in April 1998.”

January through August of 1998 are all in the 14 warmest months in the satellite record, and that El Niño started when global temperatures were somewhat chilled; the global average temperature in May 1997 was 0.14 C (about 0.25 degrees F) cooler than the long-term seasonal norm for May.

“With the baseline so much warmer, this upcoming El Niño won’t have very far to go to break that 0.66 C record,” Christy said. “That isn’t to say it will, but even an average-sized warming event will have a chance to get close to that level.”...

A thermometer outside the Hotel Baron in Syria, shot by Bernard Gagnon, Wikimedia Commons, under the Creative Commons 3.0 license

Near-normal or below-normal 2014 Atlantic hurricane season predicted

Science Daily: In its 2014 Atlantic hurricane season outlook issued today, NOAA's Climate Prediction Center is forecasting a near-normal or below-normal season.

The main driver of this year's outlook is the anticipated development of El Niño this summer. El Niño causes stronger wind shear, which reduces the number and intensity of tropical storms and hurricanes. El Niño can also strengthen the trade winds and increase the atmospheric stability across the tropical Atlantic, making it more difficult for cloud systems coming off of Africa to intensify into tropical storms.

The outlook calls for a 50 percent chance of a below-normal season, a 40 percent chance of a near-normal season, and only a 10 percent chance of an above-normal season. For the six-month hurricane season, which begins June 1, NOAA predicts a 70 percent likelihood of 8 to 13 named storms (winds of 39 mph or higher), of which 3 to 6 could become hurricanes (winds of 74 mph or higher), including 1 to 2 major hurricanes (Category 3, 4 or 5; winds of 111 mph or higher).

These numbers are near or below the seasonal averages of 12 named storms, six hurricanes and three major hurricanes, based on the average from 1981 to 2010. The Atlantic hurricane region includes the North Atlantic Ocean, Caribbean Sea and Gulfof Mexico.

"Thanks to the environmental intelligence from NOAA's network of earth observations, our scientists and meteorologists can provide life-saving products like our new storm surge threat map and our hurricane forecasts," said Kathryn Sullivan, Ph.D., NOAA administrator. "And even though we expect El Niño to suppress the number of storms this season, it's important to remember it takes only one land falling storm to cause a disaster."...

Image from NOAA

El Niño forecasters must not repeat mistakes of 1997

An editorial in New Scientist: In January, climate researchers warned that extreme El Niño events are likely to become more common as the planet warms. It now seems that the world will have a chance to rehearse for the future as early as the end of this year. A major El Niño is massing in the Pacific Ocean and is likely to cause cyclones, tornadoes, droughts, floods and sea level changes across the world (see "World is unprepared for major El Niño later this year").

Many leading scientists say the approaching El Niño looks similar in magnitude to the huge one that started in 1997 and went on to kill tens of thousands of people and cause tens of billions of dollars of damage. But you won't hear that sort of warning from official forecasters. They agree that an El Niño is likely, but are saying little about its potential strength.

Why is that? One of the key reasons for the devastation of 1997 was excess caution among forecasters. A major UN study published in 2000 revealed that for forecasters, an incorrect prediction is more embarrassing than no prediction at all. We may be seeing the same failings today.

There is still a chance that the threat will dissipate. But we won't know for sure until it is too late to prepare properly. If governments and emergency services are to be given enough time, they need full and frank forecasts now.

Clear forecasting is important for another reason: the response to a big El Niño will be a test of how ready the world is for climate change. The most recent report from the Intergovernmental Panel on Climate Change reiterated that we must prepare for climate variability rather than for any particular threat. El Niño is the biggest source of climate variability we know about....

Friends and neighbors pitch in to save the belongings of a condominium in Laguna Niguel, California, that was heavily damaged in a landslide resulting from El Nino storms. Two luxury homes above the condos collapsed when the hillside gave way. Photo by DAVE GATLEY/FEMA News Photo

Tracking the dynamics of drought

Dawn Fuller at the University of Cincinnati News: University of Cincinnati researchers are at work tracking drought patterns across the United States. Qiusheng Wu, a doctoral student and research assistant for the UC Department of Geography, and Hongxing Liu, a UC professor and head of the Department of Geography, will present details this week at the annual meeting of the Association of American Geographers (AAG) in Tampa, Fla.

To trace the dynamics around agricultural drought, the UC researchers implemented an Event-based Spatial-Temporal Data Model (ESTDM) to detect, track and monitor conditions. The framework organizes data into objects, sequences, processes and events.

The data was collected from the European Space Agency’s (ESA) Soil Moisture and Ocean Salinity (SMOS) satellite, which was the first of its kind dedicated to measure moisture near the surface of the soil. The study focused on four years of data (2010-2014), which included the devastating Texas drought in 2011 and the 2014 California drought.

The satellite uses an L-band (1.4 Ghz) passive microwave radiometer to analyze the spatial and temporal variations of soil moisture and ocean salinity. “Recent studies have shown that many historical drought events in the U.S. are closely related to La Niña, a phenomenon known for its periodic cooling of sea surface temperatures in the tropical Pacific Ocean. So in addition to measuring soil moisture for drought monitoring, it is also important to measure ocean salinity,” explains Wu.

...“By studying the soil moisture data from the satellite, we can see where the droughts begin and end, and what might indicate patterns of how it can spread over one large area. The pattern might be used to predict the drought in another location, so that those areas could take precautions to avoid the impact of an oncoming drought,” says Wu...

Shot by Al Jazeera English, Wikimedia Commons via Flickr,  under the Creative Commons Attribution-Share Alike 2.0 Generic license

No ‘permanent El Niño,’ scientists say — and the tropics may get even hotter

Eric Gershon in the Yale News: New research by Yale University scientists challenges a long-standing paradigm for temperature variability in the Pacific Ocean, casting doubt on the existence of a past period of “permanent” El Niño-like conditions and suggesting that the tropics could grow markedly hotter.

“There’s good news and bad news about future global warming,” said Mark Pagani, professor of geology and geophysics at Yale and an author of the research, published April 4 in the journal Science. “The good news is that global warming does not drive the Pacific Ocean into a permanent El Niño-like condition with all the other regional climate impacts that come with that. The bad news is that the tropics will warm as we continue to add greenhouse gases to the atmosphere — and the recent past was probably much warmer than generally assumed.”

Modern El Niño conditions are characterized by unusually warm surface water in the eastern equatorial Pacific, and a very low overall equatorial Pacific temperature gradient. The quasi-periodic phenomenon’s effects on global weather patterns can be dramatic, including extreme rainfall in some places (Texas, for example) and drought elsewhere (Indonesia and Australia).

A conventional view holds that sea surface temperatures in the warmest part of the equatorial Pacific — the vast western “warm pool” — remained relatively constant for millions of years. Given that ocean temperatures elsewhere rose during this time, the warm pool’s stable temperature implied a tropical ocean “thermostat” or temperature control mechanism, Pagani said.

But in a new reconstruction of ancient Pacific sea surface temperatures covering 12 million years, Pagani and Yale doctoral candidate Yi Ge Zhang found that Pacific warm pool temperatures were notably higher 12 million years ago than previously thought — as much as 4°C warmer. Their results indicate that all parts of the Pacific warmed during past periods of global warming, suggesting greater variability of ancient ocean temperatures and the absence of any tropical temperature control mechanism or  “permanent El Niño-like” conditions....

Ruins at Orongo on Easter Island, shot by TravelingOtter, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license 

Sea-level rise to accelerate as La Nina effect ebbs

The Sydney Morning Herald via Reuters: Heavy rains from the Amazon to Australia have curbed sea level rise so far this century by shifting water from the oceans to land, according to a study that rejects theories that the slowdown is tied to a pause in global warming.

Sea level rise has been one of the clearest signs of climate change - water expands as it warms and parts of Greenland and Antarctica are thawing, along with glaciers from the Himalayas to the Alps. But in a puzzle to climate scientists, the rate slowed to 2.4 millimetres a year from 2003 to 2011 from 3.4 mm from 1994-2002, heartening sceptics who doubt that deep cuts are needed in mankind's rising greenhouse gas emissions.

Writing in the journal Nature Climate Change on Sunday, experts said the rate from 2003-2011 would have been 3.3 mm a year when excluding natural shifts led by an unusually high number of La Nina weather events that cool the surface of the Pacific Ocean and cause more rain over land.

"There is no slowing in the rate of sea level rise" after accounting for the natural variations, lead author Anny Cazenave of the Laboratory for Studies in Geophysics and Spatial Oceanography in Toulouse, France, told Reuters.

In La Nina years, more rain fell away from oceans, including over the Amazon, the Congo basin and Australia, she said. It is unclear if climate change itself affects the frequency of La Ninas...

A generic La Nina: Warm water accumulates in far western Pacific, and equatorial water is cooler than in the normal state. Public domain

Aging El Nino buoys get fixed as weather forecasts at risk

Brian K. Sullvian at Bloomberg News: The National Weather Service is set to start repairing 70 towering buoys used to track El Nino and La Nina patterns, whose damage has led scientists to warn the accuracy of forecasts is in danger.

The Tropical Atmospheric Ocean Array, deployed after a 1982-83 ocean warming caught governments by surprise and caused at least $8.1 billion in damage worldwide, is designed to help predict developments that can alter global weather. The system has degraded to about 40 percent effectiveness, a victim of age, vandalism and neglect, according to the National Oceanic & Atmospheric Administration.

“Having this array in place may give us a few more months extra lead time that otherwise would not occur,” said Kevin Trenberth, distinguished senior scientist in the climate analysis section of the National Center for Atmospheric Research in Boulder, Colorado. “It makes a difference as to what strategy many farmers have in terms of what crops they grow, what water irrigation strategies they use, what fertilizer.”

While maintaining and upgrading the buoys costs about $10 million annually, less than 1 percent of NOAA’s budget, government spending constraints in recent years have limited repairs, said Craig McLean, a deputy assistant administrator for programs and administration at the agency’s office of Oceanic and Atmospheric Research. The weather service’s 2014 budget “offers relief,” and maintenance will begin within the next two weeks, Susan Buchanan, a spokeswoman for the service, said in an e-mailed response to questions yesterday.

...“We are hopeful that we will be able to restore the TAO array to near 80 percent by the end of this year,” she said.

From corn farmers in Iowa to oil-rig operators in the Gulf of Mexico to rubber growers in Indonesia, businesses depend on forecasts generated by data from the equipment. Without that information, there might be less time to prepare for droughts, wildfires, floods and storms, leading to more volatility in commodity prices and the potential for a greater loss of life....

NOAA photo of TAO Buoy Array deployment preparations on board the NOAA Ship GORDON GUNTER. United States, Gulf of Mexico. 2006 August 29.

What is El Nino Taimasa?

EurekAlert via the University of Hawaii: During very strong El Niño events, sea level drops abruptly in the tropical western Pacific and tides remain below normal for up to a year in the South Pacific, especially around Samoa. The Samoans call the wet stench of coral die-offs arising from the low sea levels "taimasa" (pronounced [kai' ma'sa]). Studying the climate effects of this particular variation of El Niño and how it may change in the future is a team of scientists at the International Pacific Research Center, University of Hawai'i at Mānoa and at the University of New South Wales, Australia.

Two El Niño Taimasa events have occurred in recent history: 1982/83 and 1997/98. El Niño Taimasa differs from other strong El Niño events, such as those in 1986/87 and 2009/10, according to Matthew Widlansky, postdoctoral fellow at the International Pacific Research Center, who spearheaded the study.

"We noticed from tide gauge measurements that toward the end of these very strong El Niño events, when sea levels around Guam quickly returned to normal, that tide gauges near Samoa actually continued to drop," recalls Widlansky.

During such strong El Niño, moreover, the summer rain band over Samoa, called the South Pacific Convergence Zone, collapses toward the equator. These shifts in rainfall cause droughts south of Samoa and sometimes trigger more tropical cyclones to the east near Tahiti.

Using statistical procedures to tease apart the causes of the sea-level seesaw between the North and South Pacific, the scientists found that it is associated with the well-known southward shift of weak trade winds during the termination of El Niño, which in turn is associated with the development of the summer rain band.

Looking into the future with the help of computer climate models, the scientists are now studying how El Niño Taimasa will change with further warming of the planet. Their analyses show, moreover, that sea-level drops could be predictable seasons ahead, which may help island communities prepare for the next El Niño Taimasa...

This shows flat-top Porites coral on a shallow reef near American Samoa. Coral heads are fully submerged under normal conditions. During El Niño Taimasa, tops of large flat coral on the reef are exposed to air at low tide. Credit: Image courtesy of the National Park of American Samoa

Major El Nino events likely to double

The Conversation: An international team of researchers have predicted that extreme El Nino events are likely to double in the next century, from once every 20 years to once every ten, thanks to climate change.

Extreme El Nino events occur when more than five millimetres of rain falls a day in the eastern equatorial Pacific region around Central and South America.

These extreme events can severely disrupt global weather patterns, affecting ecosystems, agriculture, tropical cyclones, bushfires, floods and other extreme weather events.

Lead author of the study, Dr Wenju Cai, from CSIRO, said that the further the warming in the east Pacific stretched, and the higher the temperatures reached, the more extreme the El Nino.

They found global warming would alter background climate conditions, meaning it would take weaker changes in ocean temperatures to prompt an extreme El Nino.

A NOAA chart of El Nino conditions

Ecuador in new probe to see if climate change worsens El Nino

Terra Daily via AFP: Think Galapagos and you think nature in its most pristine expression. But the destructive weather phenomenon called El Nino turns coral reefs there a sickly white and sea iguanas scrawny. And now, in an unprecedented experiment, scientists using unmanned submarines in the waters off the Ecuadoran archipelago are probing whether global warming is related to El Nino.

There is not yet conclusive evidence of a link. But experts are very serious about the possibility that climate change is making El Nino -- unusually warm water in the Pacific off the west coast of South America -- more frequent and more intense.

For hundreds of years, the weather system at the Galapagos did not have to worry about global warming, said Eduardo Espinoza, head of maritime research at the Galapagos National Park. But climate change associated with human activity could turn El Nino into a death sentence for several marine species that are unique to the archipelago.

With future studies, it will become clear if global warming is making El Nino nastier and more frequent, said Espinoza. Located 1,000 kilometers (620 miles) off the coast, the Galapagos Islands -- the natural laboratory that inspired Darwin's theory of evolution -- every now and then suffer with the arrival of El Nino. Besides warmer water, the phenomenon is also characterized by heavy rains and weaker winds....

A 2007 shot of the Galapagos, shot by Iris Diensthuber, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license