Tag Archives: Extreme weather

Saving lives via mobile phone weather warnings

FOR IMMEDIATE RELEASE As extreme weather events become more common because of climate change, the mobile phone is increasingly being recognised as an important tool for warnings that can not only save lives – but also, in Brazil, the coffee crop. SAO PAULO, 19 June – Over the last few years, violent storms, leading to flooding and mudslides, have become more frequent in Brazil.   In 2011, violent rainstorms wreaked havoc in and around Rio. Houses built on steep hillsides were swept away by devastating mudslides. An entire shantytown built on top of a former rubbish dump in Niteroi collapsed, killing over 50 inhabitants. In Novo Friburgo, a mountainous town settled by 265 Swiss families in 1820, and the surrounding region, over 1000 people died in January 2011, after several days of violent rains. Sirens had sounded to warn people to evacuate, but many people either did not hear them, or ignored them. The permanent solution of course, would be to provide better housing in safer areas, but that is still many years away. Now a scheme successfully tried on the other side of the Atlantic is to be launched in the region. The scheme was piloted on Lake Victoria, a giant lake the size of Ireland, which is shared by three countries, Uganda, Kenya and Tanzania.   Five thousand die Its size makes it large enough to create its own weather, and conditions can change suddenly, with winds quickly whipping up six-foot waves capable of capsizing ferries and fishing boats.  Up to five thousand of the Lake’s estimated 200,000 fishermen were dying every year due to these freak storms. The African scheme is a joint initiative between the UK’s Met Office, the Ugandan Department of Meteorology, and the telecommunications company Ericsson. Text messages are sent to the mobile phones of local fishermen, warning them of changes in the weather. Before, there were no forecasting services relevant to fishermen in the region, making access to weather information almost impossible. To capture more accurate information about the local weather conditions, the Met Office set up a 4 km resolution weather forecast model over Lake Victoria. Tom Butcher, External Relations Manager at the Met Office explained:  “A lot of the weather patterns on the lake happen on quite a small scale and are driven by the difference in temperature between the lake’s water and the surrounding land. You get warm moist air at night, rising above the lake and sucking in colder air from over the land surface – a convective process that creates a lot of storms.”   Red means danger To get round the problem of illiteracy among the fishermen, the forecasters at Uganda`s Department of Meteorology adopted the Met Office’s traffic light system of colour-coded weather warnings. Green means winds of less than five knots and no significant weather conditions predicted, therefore a very low hazard threshold, no advice needed. Red means a high likelihood of 20 knots+ winds, or severe thunderstorms, therefore a high hazard threshold and advice to ‘take action’. The project was enthusiastically received by the fishermen and within a few weeks it was saving lives. In Rio, the scheme involves attaching rain gauges (pluviometers) to mobile phone masts to give warnings in real time of extreme weather and high rainfalls to mobile phone users with 3G, via their providers. The scheme will eventually be extended to 19 Brazilian states, with the attachment of rain gauges to 1500 masts.  Experience has shown that sirens are often ignored, or not heard, but a direct message aimed at a phone user personally is much more effective.   Four hours warning This is the first scheme to use a direct link between rain gauges and the mobile phone users.  A small-scale scheme, based on information collected via satellite and from a network of meteorological radars maintained by the administration, is already in use, under a partnership between the Rio city authorities, the Civil Defence department and four major mobile phone operators. The warnings of high rainfall are transmitted by SMS about four hours before they are due. The Civil Defence also has a special warning programme for 3,500 health agents who work in 117 risk areas. The agents, each responsible for about 100 families, are then expected to spread the warnings by word of mouth. When the rainfall tops 40mm in an hour, or 125 mm in 24 hours, then the agents receive messages telling them to evacuate people. Mobile phone weather warnings are not only being used for rainfall. It may surprise some readers, who think of Brazil only as a tropical country, to know that in the southern state of Paraná, frost alerts for the region’s coffee farmers are also being sent by SMS to mobile phones. The initiative, which began in 2012, is the result of a partnership between IAPAR, Parana’s Agricultural Institute and the state’s meteorological system, SIMEPAR. Paulo Henrique Caramori, coordinator of Iapar’s Agrometeorology department, said: “the SMS service is direct and very quick and enables the coffee growers to speed up protection measures for their trees”. – Climate News Network  

FOR IMMEDIATE RELEASE As extreme weather events become more common because of climate change, the mobile phone is increasingly being recognised as an important tool for warnings that can not only save lives – but also, in Brazil, the coffee crop. SAO PAULO, 19 June – Over the last few years, violent storms, leading to flooding and mudslides, have become more frequent in Brazil.   In 2011, violent rainstorms wreaked havoc in and around Rio. Houses built on steep hillsides were swept away by devastating mudslides. An entire shantytown built on top of a former rubbish dump in Niteroi collapsed, killing over 50 inhabitants. In Novo Friburgo, a mountainous town settled by 265 Swiss families in 1820, and the surrounding region, over 1000 people died in January 2011, after several days of violent rains. Sirens had sounded to warn people to evacuate, but many people either did not hear them, or ignored them. The permanent solution of course, would be to provide better housing in safer areas, but that is still many years away. Now a scheme successfully tried on the other side of the Atlantic is to be launched in the region. The scheme was piloted on Lake Victoria, a giant lake the size of Ireland, which is shared by three countries, Uganda, Kenya and Tanzania.   Five thousand die Its size makes it large enough to create its own weather, and conditions can change suddenly, with winds quickly whipping up six-foot waves capable of capsizing ferries and fishing boats.  Up to five thousand of the Lake’s estimated 200,000 fishermen were dying every year due to these freak storms. The African scheme is a joint initiative between the UK’s Met Office, the Ugandan Department of Meteorology, and the telecommunications company Ericsson. Text messages are sent to the mobile phones of local fishermen, warning them of changes in the weather. Before, there were no forecasting services relevant to fishermen in the region, making access to weather information almost impossible. To capture more accurate information about the local weather conditions, the Met Office set up a 4 km resolution weather forecast model over Lake Victoria. Tom Butcher, External Relations Manager at the Met Office explained:  “A lot of the weather patterns on the lake happen on quite a small scale and are driven by the difference in temperature between the lake’s water and the surrounding land. You get warm moist air at night, rising above the lake and sucking in colder air from over the land surface – a convective process that creates a lot of storms.”   Red means danger To get round the problem of illiteracy among the fishermen, the forecasters at Uganda`s Department of Meteorology adopted the Met Office’s traffic light system of colour-coded weather warnings. Green means winds of less than five knots and no significant weather conditions predicted, therefore a very low hazard threshold, no advice needed. Red means a high likelihood of 20 knots+ winds, or severe thunderstorms, therefore a high hazard threshold and advice to ‘take action’. The project was enthusiastically received by the fishermen and within a few weeks it was saving lives. In Rio, the scheme involves attaching rain gauges (pluviometers) to mobile phone masts to give warnings in real time of extreme weather and high rainfalls to mobile phone users with 3G, via their providers. The scheme will eventually be extended to 19 Brazilian states, with the attachment of rain gauges to 1500 masts.  Experience has shown that sirens are often ignored, or not heard, but a direct message aimed at a phone user personally is much more effective.   Four hours warning This is the first scheme to use a direct link between rain gauges and the mobile phone users.  A small-scale scheme, based on information collected via satellite and from a network of meteorological radars maintained by the administration, is already in use, under a partnership between the Rio city authorities, the Civil Defence department and four major mobile phone operators. The warnings of high rainfall are transmitted by SMS about four hours before they are due. The Civil Defence also has a special warning programme for 3,500 health agents who work in 117 risk areas. The agents, each responsible for about 100 families, are then expected to spread the warnings by word of mouth. When the rainfall tops 40mm in an hour, or 125 mm in 24 hours, then the agents receive messages telling them to evacuate people. Mobile phone weather warnings are not only being used for rainfall. It may surprise some readers, who think of Brazil only as a tropical country, to know that in the southern state of Paraná, frost alerts for the region’s coffee farmers are also being sent by SMS to mobile phones. The initiative, which began in 2012, is the result of a partnership between IAPAR, Parana’s Agricultural Institute and the state’s meteorological system, SIMEPAR. Paulo Henrique Caramori, coordinator of Iapar’s Agrometeorology department, said: “the SMS service is direct and very quick and enables the coffee growers to speed up protection measures for their trees”. – Climate News Network  

Once in a century floods due every ten years

For immediate release Some parts of the world face frequent catastrophic floods by the end of this century while other regions could get less hazardous. LONDON, 10 June – Floods during the 21st century are expected to get worse. Really calamitous floods that, during the 20th century were considered once-in-a-century events could come round ever 10 years or so by the end of the 21st century, according to Japanese scientists. Yukiko Hirabayashi of the University of Tokyo and colleagues report in Nature Climate Change that they looked at the likely pattern of hazard in 29 of the world’s great river basins. They considered the risk in those places where greater numbers of people were settled, and used 11 global climate models to project flood dangers by the end of this century. They warn that the frequency of floods will increase in Southeast Asia, Peninsular India, eastern Africa and the northern half of the Andes of South America. More at stake Conditions in northern and eastern Europe – the scene of recent and current calamitous flooding – could get less hazardous, along with Anatolia, central Asia, North America and southern South America. The predictions, of course, come with the usual caveat: that the real exposure to flooding will depend to a great extent on what governments finally decide to do about greenhouse emissions, how much the world warms, what water management or flood control plans are put in place and on population growth in the regions at risk. But those lower latitude countries where both population and economic investment are on the increase will have more at stake in the decades to come, and should prepare for greater flood risks.  Floods in the last three decades have claimed 200,000 lives and caused around $400 billion in economic damage: they have also cost an estimated three billion people their homes, farms, businesses and livestock. Great river basins The most recent assessment by the Intergovernmental Panel on Climate Change said that overall, there was a “low confidence in projections of changes in fluvial floods. Confidence is low due to limited evidence and because the causes of regional changes are complex.” The Tokyo team took a detailed look at all the available data for the world’s great river basins, from the Yukon, the Mackenzie and the Columbia in the North American west to the Mississippi and the St Lawrence; the Rhine, the Danube and the Volga in Europe; the Ob, the Yenisei and the Amur in Siberia; the Orinoco, Parana and Amazon in South America; the Euphrates, the Indus, the Ganges, the Mekong and the Yangtze in Asia: the Niger, Nile, Zambezi and Congo in Africa and even the Murray in Australia. Their projections are just that: projections, to be tested by outcomes long after some of the authors have died. The researchers acknowledge the limitations in their methodology “The 20C 100-year flood event is projected to occur about every 10-50 years in many of these rivers in the 21C. Such a large change in return period is caused by a 10-30% increase in flood discharge,” they warn. “Major attention should be paid to low-latitude countries where flood frequency and population are both projected to increase.” – Climate News Network

For immediate release Some parts of the world face frequent catastrophic floods by the end of this century while other regions could get less hazardous. LONDON, 10 June – Floods during the 21st century are expected to get worse. Really calamitous floods that, during the 20th century were considered once-in-a-century events could come round ever 10 years or so by the end of the 21st century, according to Japanese scientists. Yukiko Hirabayashi of the University of Tokyo and colleagues report in Nature Climate Change that they looked at the likely pattern of hazard in 29 of the world’s great river basins. They considered the risk in those places where greater numbers of people were settled, and used 11 global climate models to project flood dangers by the end of this century. They warn that the frequency of floods will increase in Southeast Asia, Peninsular India, eastern Africa and the northern half of the Andes of South America. More at stake Conditions in northern and eastern Europe – the scene of recent and current calamitous flooding – could get less hazardous, along with Anatolia, central Asia, North America and southern South America. The predictions, of course, come with the usual caveat: that the real exposure to flooding will depend to a great extent on what governments finally decide to do about greenhouse emissions, how much the world warms, what water management or flood control plans are put in place and on population growth in the regions at risk. But those lower latitude countries where both population and economic investment are on the increase will have more at stake in the decades to come, and should prepare for greater flood risks.  Floods in the last three decades have claimed 200,000 lives and caused around $400 billion in economic damage: they have also cost an estimated three billion people their homes, farms, businesses and livestock. Great river basins The most recent assessment by the Intergovernmental Panel on Climate Change said that overall, there was a “low confidence in projections of changes in fluvial floods. Confidence is low due to limited evidence and because the causes of regional changes are complex.” The Tokyo team took a detailed look at all the available data for the world’s great river basins, from the Yukon, the Mackenzie and the Columbia in the North American west to the Mississippi and the St Lawrence; the Rhine, the Danube and the Volga in Europe; the Ob, the Yenisei and the Amur in Siberia; the Orinoco, Parana and Amazon in South America; the Euphrates, the Indus, the Ganges, the Mekong and the Yangtze in Asia: the Niger, Nile, Zambezi and Congo in Africa and even the Murray in Australia. Their projections are just that: projections, to be tested by outcomes long after some of the authors have died. The researchers acknowledge the limitations in their methodology “The 20C 100-year flood event is projected to occur about every 10-50 years in many of these rivers in the 21C. Such a large change in return period is caused by a 10-30% increase in flood discharge,” they warn. “Major attention should be paid to low-latitude countries where flood frequency and population are both projected to increase.” – Climate News Network

Climate change 'causes wild weather'

EMBARGOED until 2000 GMT on Monday 25 February
Extreme weather is often the result of climate change, according to scientists in Germany, who say they have found how greenhouse gases are helping to trap the jet stream and the weather patterns it brings.

LONDON, 25 February – The cause of much of the recent extreme weather across the world is climate change triggered by human activities, scientists say.

The Earth has experienced a range of severe regional weather extremes in recent years, including the heat waves of 2011 in the US and 2010 in Russia, a year that also brought the unprecedented Pakistan floods.

Behind these distinct events, though, there is a common physical cause, according to a team at the Potsdam Institute for Climate Impact Research (PIK), Germany.

Their paper, which helps to explain the mechanism that is causing an increasing number of weather extremes, has the less than catchy title of Quasi-resonant amplification of planetary waves and recent Northern Hemisphere weather extremes, and will be published this week in the US Proceedings of the National Academy of Sciences (link provided on publication).

The paper suggests that man-made climate change is repeatedly disturbing the patterns of airflow around the northern hemisphere, bringing extreme conditions.

This airflow has always travelled in waves round the planet, the wave movements caused by the difference in temperature between the oceans and land surfaces. These in turn cause changes in the high altitude air currents, particularly the jet stream.

Lead author Vladimir Petoukhov explains: “An important part of the global air motion in the mid-latitudes of the Earth normally takes the form of waves wandering around the planet, oscillating between the tropical and the Arctic regions.

“So when they swing up, these waves suck warm air from the tropics to Europe, Russia, or the US, and when they swing down, they do the same thing with cold air from the Arctic.

“What we found is that during several recent extreme weather events, these waves almost freeze in their tracks for weeks. So instead of bringing in cool air after having brought warm air in, the heat just stays. In fact we observe a strong amplification of the usually weak, slow-moving component of these waves.”

Tested against the data

 

Time is critical here: two or three days of 30˚C are no problem, but 20 days or more lead to extreme heat stress, the authors say. Since many ecosystems and cities are not adapted to temperatures this high, prolonged hot periods can cause many deaths, as well as forest fires and serious crop losses.

Climate change caused by greenhouse gas emissions from the burning of fossil fuels does not mean uniform warming – in the Arctic the relative rise in temperatures, amplified by the loss of snow and ice, is higher than average.

This in turn reduces the temperature difference between the Arctic and, for example, Europe. Yet it is this temperature difference that is normally a main driver of airflow, including the jet streams.

Additionally, continents generally warm and cool more readily than the oceans. They always have. But, coupled with the new changes to the jet streams, the net result is to trap the energy of the slow-moving parts of the waves.

“These two factors are crucial for the mechanism we detected,” says Petoukhov. “They result in an unnatural pattern of the mid-latitude airflow, so that for extended periods the slow waves get trapped.”

The authors tested their assumptions using standard daily weather data from the US National Centers for Environmental Prediction (NCEP). During recent periods in which several major weather extremes occurred, they did observe the trapping and strong amplification of particular waves.

‘A breakthrough’

 

The data show an increase in the occurrence of these specific atmospheric patterns which is statistically significant at the 90% confidence level.

“Our dynamical analysis helps to explain the increasing number of novel weather extremes. It complements previous research that linked such phenomena to climate change, but had not yet identified a mechanism behind it”, says Hans Joachim Schellnhuber, director of PIK and co-author of the study.

“This is quite a breakthrough, even though things are not at all simple – the suggested physical process increases the probability of weather extremes, but additional factors certainly play a role as well, including natural variability.”

The 32-year period of the project provides a good indication of the mechanism involved but is too short to allow definite conclusions.

Still, scientists are surprised by how far beyond experience some of the recent extremes have been. The new data show that the emergence of extraordinary weather is not just a straightforward linear response to the average warming trend, and the proposed mechanism could explain that. – Climate News Network

EMBARGOED until 2000 GMT on Monday 25 February
Extreme weather is often the result of climate change, according to scientists in Germany, who say they have found how greenhouse gases are helping to trap the jet stream and the weather patterns it brings.

LONDON, 25 February – The cause of much of the recent extreme weather across the world is climate change triggered by human activities, scientists say.

The Earth has experienced a range of severe regional weather extremes in recent years, including the heat waves of 2011 in the US and 2010 in Russia, a year that also brought the unprecedented Pakistan floods.

Behind these distinct events, though, there is a common physical cause, according to a team at the Potsdam Institute for Climate Impact Research (PIK), Germany.

Their paper, which helps to explain the mechanism that is causing an increasing number of weather extremes, has the less than catchy title of Quasi-resonant amplification of planetary waves and recent Northern Hemisphere weather extremes, and will be published this week in the US Proceedings of the National Academy of Sciences (link provided on publication).

The paper suggests that man-made climate change is repeatedly disturbing the patterns of airflow around the northern hemisphere, bringing extreme conditions.

This airflow has always travelled in waves round the planet, the wave movements caused by the difference in temperature between the oceans and land surfaces. These in turn cause changes in the high altitude air currents, particularly the jet stream.

Lead author Vladimir Petoukhov explains: “An important part of the global air motion in the mid-latitudes of the Earth normally takes the form of waves wandering around the planet, oscillating between the tropical and the Arctic regions.

“So when they swing up, these waves suck warm air from the tropics to Europe, Russia, or the US, and when they swing down, they do the same thing with cold air from the Arctic.

“What we found is that during several recent extreme weather events, these waves almost freeze in their tracks for weeks. So instead of bringing in cool air after having brought warm air in, the heat just stays. In fact we observe a strong amplification of the usually weak, slow-moving component of these waves.”

Tested against the data

 

Time is critical here: two or three days of 30˚C are no problem, but 20 days or more lead to extreme heat stress, the authors say. Since many ecosystems and cities are not adapted to temperatures this high, prolonged hot periods can cause many deaths, as well as forest fires and serious crop losses.

Climate change caused by greenhouse gas emissions from the burning of fossil fuels does not mean uniform warming – in the Arctic the relative rise in temperatures, amplified by the loss of snow and ice, is higher than average.

This in turn reduces the temperature difference between the Arctic and, for example, Europe. Yet it is this temperature difference that is normally a main driver of airflow, including the jet streams.

Additionally, continents generally warm and cool more readily than the oceans. They always have. But, coupled with the new changes to the jet streams, the net result is to trap the energy of the slow-moving parts of the waves.

“These two factors are crucial for the mechanism we detected,” says Petoukhov. “They result in an unnatural pattern of the mid-latitude airflow, so that for extended periods the slow waves get trapped.”

The authors tested their assumptions using standard daily weather data from the US National Centers for Environmental Prediction (NCEP). During recent periods in which several major weather extremes occurred, they did observe the trapping and strong amplification of particular waves.

‘A breakthrough’

 

The data show an increase in the occurrence of these specific atmospheric patterns which is statistically significant at the 90% confidence level.

“Our dynamical analysis helps to explain the increasing number of novel weather extremes. It complements previous research that linked such phenomena to climate change, but had not yet identified a mechanism behind it”, says Hans Joachim Schellnhuber, director of PIK and co-author of the study.

“This is quite a breakthrough, even though things are not at all simple – the suggested physical process increases the probability of weather extremes, but additional factors certainly play a role as well, including natural variability.”

The 32-year period of the project provides a good indication of the mechanism involved but is too short to allow definite conclusions.

Still, scientists are surprised by how far beyond experience some of the recent extremes have been. The new data show that the emergence of extraordinary weather is not just a straightforward linear response to the average warming trend, and the proposed mechanism could explain that. – Climate News Network