Global rainfall satellites require massive overhaul

Space Daily via SPX: Circling hundreds of miles above Earth, weather satellites are working round-the-clock to provide rainfall data that are key to a complex system of global flood prediction. A new Cornell University study warns that the existing system of space-based rainfall observation satellites requires a serious overhaul. Particularly in many developing countries, satellite-based flood prediction has weak spots, which could lead to major flooding that catches people by surprise. What's more, four of the 10 dedicated rainfall satellites are past their warranty, further increasing risk of disaster.

The study, published online Feb. 11 in Environmental Research Letters, is led by Patrick Reed, professor of civil and environmental engineering, in collaboration with researchers at Princeton University and the Aerospace Corporation.

"It's important for us to start thinking as a globe about a serious discussion on flood adaptation, and aiding affected populations to reduce their risks," Reed said. "We want to give people time to evacuate, to make better choices, and to understand their conditions."

In their study, Reed and colleagues showed that even assuming all 10 satellites are working well and perfectly coordinated, rainfall data still has many deficits across the globe, including in areas vulnerable to flood risk. Removing the four satellites that have surpassed their design life dramatically increases these deficits, possibly leading to high-intensity flood events to go unobserved.

The study was not all bad news. Reed and colleagues also demonstrated that replacing as few as two of the four satellites past their design life could help close these gaps considerably....

Typhoon Songda in 2011, via NASA

Rwanda fills climate data gap to protect against storms

Paula Park in SciDev.net: Rwanda’s weather service is now better able to forecast floods and other natural disasters after scientists bridged climate-data gaps left by the 1994 genocide.  The collection of national rainfall and temperature records lapsed for after the genocide, and the absence of reliable records had hampered the Rwanda Meteorology Agency’s ability to forecast threats such as torrential rain or flooding that damaged homes and crops, and caused fatalities.

But researchers have now combined Rwandan weather station observations from before and after the 15 year gap with satellite data on rainfall patterns over the past 30 years. It has enabled the Rwanda Meteorology Agency to fill hole in its observations, says Marcellin Habimana, a climate processing officer at the agency.

Rwanda’s data gap is typical of many Sub-Saharan African countries. “Africa is very sparsely sampled,” Elfatih Eltahir, a civil engineer at the Massachusetts Institute of Technology, United States, tells SciDev.Net.

There are just 1,152 stations in Africa within the World Weather Watch programme that reports to the World Meteorological Organisation (WMO), so each covers 27,347 square kilometres, according to German NGO the Institute Water for Africa.  In comparison, it says, the 287 WMO weather stations in Germany each cover an area about 20 times smaller than that....

Mt. Katsimbi in Rwanda, shot by Micah Zarnke, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Get ready for hotter summers and more flooding in the UK

Roz Pidcock in the Carbon Brief: Weather-wise, the UK saw it all last year. The coldest spring for 50 years, a sweltering summer heat wave and the wettest winter since records began. Today, a new report examines whether climate change is upping the odds of these events occurring.

The collection of papers, published in a bumper edition of journal Bulletin of the American Meteorological Society, looks at 16 weather events that took place last year across the world. From Colorado to Korea, the scientists examine heatwaves, droughts, heavy rain and storms.

Globally, there is evidence for changes in some types of extreme weather, and evidence for a human fingerprint in those changes. But different types of event are affected differently. Climate change is greatly increasing the odds of heatwaves worldwide, today's report concludes. For storms, rainfall and drought the picture is less clear, however. Big differences between regions, natural variability in the climate and limited data make detecting changes over time far more difficult.

The science of disentangling human and natural influences on our climate is known as attribution. Dr Peter Stott, head of the climate change detection and attribution team at the Met Office and an editor on the report, explained more in a recent guest blog  for us: "[The aim is] to compare what actually happened with what might have happened in a world without anthropogenic climate change."

Understanding how our activities are changing the risk of some types of extremes is important for making decisions about how we can prepare for the future.,,,

Beach volleyball at the 2012 Summer Olympics in London, shot by cdephotos - DSC02805, Wikimedia Commons via Flickr, under the Creative Commons 2.0 license

Why global warming is taking a break

Fabio Benjamin at the ETH (Switzerland): ...Global warming is currently taking a break: whereas global temperatures rose drastically into the late 1990s, the global average temperature has risen only slightly since 1998 – surprising, considering scientific climate models predicted considerable warming due to rising greenhouse gas emissions. Climate sceptics used this apparent contradiction to question climate change per se – or at least the harm potential caused by greenhouse gases – as well as the validity of the climate models. Meanwhile, the majority of climate researchers continued to emphasise that the short-term ‘warming hiatus’ could largely be explained on the basis of current scientific understanding and did not contradict longer term warming.

Researchers have been looking into the possible causes of the warming hiatus over the past few years. For the first time, Reto Knutti, Professor of Climate Physics at ETH Zurich, has systematically examined all current hypotheses together with a colleague. In a study published in the latest issue of the journal Nature Geoscience, the researchers conclude that two important factors are equally responsible for the hiatus.

One of the important reasons is natural climate fluctuations, of which the weather phenomena El Niño and La Niña in the Pacific are the most important and well known. "1998 was a strong El Niño year, which is why it was so warm that year," says Knutti. In contrast, the counter-phenomenon La Niña has made the past few years cooler than they would otherwise have been.

...According to the study, the second important reason for the warming hiatus is that solar irradiance has been weaker than predicted in the past few years....Furthermore, several volcanic eruptions, such as Eyjafjallajökull in Iceland in 2010, have increased the concentration of floating particles (aerosol) in the atmosphere, which has further weakened the solar irradiance arriving at the Earth's surface.

The scientists drew their conclusions from corrective calculations of climate models. In all climate simulations, they looked for periods in which the El Niño/La Niña patterns corresponded to the measured data from the years 1997 to 2012. With a combination of over 20 periods found, they were able to arrive at a realistic estimate of the influence of El Niño and La Niña. They also retroactively applied in the model calculations the actual measured values for solar activity and aerosol concentration in the Earth's atmosphere. Model calculations corrected in this way match the measured temperature data much more closely.

...Despite the warming hiatus, Knutti is convinced there is no reason to doubt either the existing calculations for the climate activity of greenhouse gases or the latest climate models. "Short-term climate fluctuations can easily be explained. They do not alter the fact that the climate will become considerably warmer in the long term as a result of greenhouse gas emissions," says Knutti. He believes that global warming will recommence as soon as solar activity, aerosol concentrations in the atmosphere and weather phenomena such as El Niño naturally start returning to the values of previous decades....

NASA image of a sunspot

Cooler temperatures, lighter winds could help firefighters with Washington wildfires

US News and World Report via AP: Cooler temperatures and lighter winds are forecast to descend on a wildfire-stricken Washington state, helping firefighters battle flames that have been growing unfettered for a week and have covered hundreds of square miles.

While Sunday's weather has slight improvements on the hot temperatures and gusty winds that have fueled the wildfires, the forecast for Monday and Tuesday calls for lighter winds and temperatures, said Spokane-based National Weather Service meteorologist Greg Koch. "Overall, it looks like the weather scenario is improving," Koch said.

Then on Wednesday a "vigorous" front is expected to cover Washington, bringing rain to much of the state. But it will also bring lighting, he added. "The benefits of the system are still up in the air," Koch said. "We may get some rain where we need it, but we may also experience some lighting that could cause some new ignitions."

Sunday's official estimate puts the wildfire burning in north-central Washington at more than 370 square miles. It measured 260 square miles on Friday. Okanogan County Sheriff Frank Rogers estimates that 150 homes have been destroyed, but suspects that number could be higher. His deputies haven't been able to search parts of the county where homes are spread miles apart. No serious injuries have been reported, Rogers said.

There are nearly 1,400 firefighters battling the flames, assisted by more than 100 fire engines, helicopters dropping buckets of water and planes spreading flame retardant...

An archival shot of a 1973 fire in Washington state

Weather info project aims to help African farmers adapt

Kizito Makoye at the Thomson Reuters Foundation: Farmers facing long periods of dry weather and floods have expressed hope that a new climate change adaptation initiative being rolled out in Tanzania and Malawi will spell an end to dismal crop yields.

The Climate Services Adaptation Programme launched in November 2013 by the World Meteorological Organization (WMO) presents a window of opportunity for African farmers to use scientific knowledge to battle weather challenges.

With $10 million in funding pledged by Norway, the pilot project is expected to equip thousands of farmers in Malawi and Tanzania with skills to combat extreme weather, especially drought and floods. Farmers will be taught ways to boost the resilience of their crops and protect their farms, such as using drought-tolerant crop varieties, changing planting dates to cope with shifting rainfall patterns and planting barrier crops to reduce pest infestations.

Other techniques include using drains to avoid water runoff in their fields, and other harvesting and irrigation systems to cope with fluctuations in the availability of water. Farmers will also learn how to plant tree nurseries to increase carbon sequestration.

“Every one of us has in one way or another been affected by bad weather. When the experts are empowered, they should help us with skills to prevent unnecessary losses,” said Hamisi Ali, a farmer from Matombo village in Tanzania’s Morogoro region.

“This is a pilot project, but the ultimate goal is to see (that) every single farmer across the country is able to use these skills to deal with the effects of climate change,” said Richard Muyungi, director of climate change in the office of Tanzania’s vice president....

A farm in Mwanza, Tanzania, shot by Hansueli Krapf, Wikimedia Commons,  under the Creative Commons Attribution-Share Alike 3.0 Unported license

Financial decision-makers need weather and climate information to manage risks

Science Daily: Maximizing returns on financial investments depends on accurately understanding and effectively accounting for weather and climate risks, according to a new study by the American Meteorological Society (AMS) Policy Program.

The study also found that weather events create and exacerbate risks to financial investments by causing

1. direct physical impacts on the investments themselves,
2. degradation of critical supporting infrastructure,
3. changes in the availability of key resources,
4. changes to workforce availability or capacity,
5. changes in the customer base,
6. supply chain disruptions,
7. legal liability,
8. shifts in the regulatory environment,
9. reductions in credit ratings, and
10. additional impacts that alter competitiveness (e.g., shifts in consumer preferences).

The study is based on a recent AMS Policy Program workshop, Climate Information Needs for Financial Decision Making, held in Washington, DC earlier this year and conducted in partnership with the University Corporation for Atmospheric Research (UCAR). Financial analysts, investors, academicians, and key leaders from the business, financial, and climate research communities convened to examine the role of climate science in financial analysis.

The purpose of the study was to assist with societal decision-making by examining the implications of climate variability and change on near-term financial investments....

A weather vane in Portugal, shot by Joseolgon, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Melting Arctic sea ice could increase summer rainfall in northwest Europe

A press release from the University of Exeter: A new study offers an explanation for the extraordinary run of wet summers experienced by Britain and northwest Europe between 2007 and 2012. The study found that loss of Arctic sea ice shifts the jet stream further south than normal resulting in increased rain during the summer in northwest Europe.

Dr James Screen from Mathematics at the University of Exeter used a computer model to investigate how the dramatic retreat of Arctic sea ice influences the European summer climate. He found that the pattern of rainfall predicted by the model closely resembles the rainfall pattern of recent summers. The study is published in the journal Environmental Research Letters.

Dr Screen said: “The results of the computer model suggest that melting Arctic sea ice causes a change in the position of the jet stream and this could help to explain the recent wet summers we have seen. “The study suggests that loss of sea ice not only has an effect on the environment and wildlife of the Arctic region but has far reaching consequences for people living in Europe and beyond.”

Jet streams are currents of strong winds high in the atmosphere – around the height at which aeroplanes fly. These winds steer weather systems and their rain. Normally in summer the jet stream lies between Scotland and Iceland and weather systems pass north of Britain. When the jet stream shifts south in summer, it brings unseasonable wet weather to Britain and northwest Europe causing havoc for tourism and farming.

The model suggests that while summer rainfall increases in northwest Europe, Mediterranean regions will receive less rain. The effects are not limited to Europe - weather systems as far as North America could also be influenced....

Arctic ice, shot by Patrick Kelley, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

China creates 50 billion tonnes of artificial rain annually

Space Daily via Xinhua: A report submitted to China's top legislature on Monday said the country creates about 50 billion tonnes of artificial rain each year, but extra efforts are needed during natural disasters.

The report on the implementation of China's meteorological law, was submitted to the bi-monthly session of the Standing Committee of the National People's Congress, which runs from Monday to Friday.

The report said a total of 2,266 counties in the country use weather modification, with artificial rain used across an area covering 5 million square kilometers, about half of China's land area. The State Council, or the cabinet, has actively promoted a system of artificial weather, which has operated on a large-scale, coordinated and regular way, the report said.

In the meantime, the country has established a geosynchronous satellite and sun-synchronous satellite system to monitor weather. A total of seven meteorological satellites are in orbit, five of them operating normally. However, present meteorological systems do not meet the demands for disaster prevention and relief, especially in grassroots and rural areas, added the report...

Piloting agro-meteorological early warnings for Nepal’s farmers

IRIN: The Nepalese government is planning to pilot the country’s first weather warnings for farmers, something it is hoped will stem agricultural losses during the June-August monsoon.  Thousands of hectares of arable land are damaged during this period; in 2013 alone an estimated 10,000 hectares were lost to land erosion, floods and water-logging, according to the Ministry of Agricultural Development (MOAD).

..."We cannot avert natural disasters but we can make the farmers better prepared with the help of timely information through an efficient communication system,” MOAD’s senior official Shib Anand Shah told IRIN in Kathmandu.

For the first time, the Nepal government (with US$31 million from the World Bank) is expected to create an agricultural information management system tailored for farmers, said Shah.  According to almost all major risk analyses, Nepal is among the most climate-vulnerable countries worldwide.

MOAD is preparing to launch the system in collaboration with the semi-governmental Nepal Agricultural Research Council (NARC) and the Department of Hydrology and Meteorology (DHM) by early 2014 in 25 of the country’s 75 districts judged to be most vulnerable to natural disasters. The goal is to pilot the system in four districts by the end 2013.

Until now, the government has only monitored water levels in rivers through real-time, manual data collection, which limited its capacity to issue timely accurate warnings for hydro-meteorological hazards, according to the World Bank.

The new information system will see the installation of three Doppler weather monitoring radars nationwide (WSR-88D - costing $2 million each) capable of forecasting heavy rainfall and drought through DHM...

Sunset on the flood-prone Rapti River in Nepal, shot by Ashokdhamala,Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

India's Meteorological Department gets its act right as cyclone strikes the coast

Dinesh C. Sharma in India Today: The Indian Meteorological Department (IMD), often a butt of jokes and wisecracks as well as a whipping boy for other government agencies, has emerged as the unexpected hero in the Phailin cyclone disaster that hit the East coast this weekend.

The British era scientific agency which was in news for corruption and maladministration just a decade back has made a spectacular turnaround. In 2004, director general of the met office was sacked for alleged graft in awarding of contracts to firms he favoured and for owning assets disproportionate to his income. He was arrested and is facing prosecution. Internal government investigations had found that the agency had hired non-scientific staff - arts and commerce graduates - for handling scientific work relating to weather forecasting. The agency, then working under the Department of Science and Technology (DST), was a perfect picture of a white elephant though it had some excellent scientific workforce in centres such as the Indian Institute of Tropical Meteorology, Pune.

A modernisation plan was prepared and implemented after the agency was shifted in 2006 from DST to the newly created Ministry of Earth Sciences. Daily weather forecasting, monsoon prediction, cyclone early warning, weather services for farmers, fog prediction at airport runways - all services were revamped with induction of new supercomputing capacity, radars, satellite data flow and better coordination among various agencies involved in met operations. A tsunami warning system is also now in place. The National Centre for Medium Range Weather Forecasting in Noida (NCMRWF) claims the capability to predict weekly weather forecast for any location in the world. Cyclone tracking and landfall forecasts have improved due to improvements in space, land and seabased data collection as well real time computation of this data. The way Indian scientists remained stuck to their prediction on Phailin shows their new found confidence. Though Met office modernization is a work in progress we can already see the results...

The track of Cyclone Phailin, created and updated by Keith Edkins, public domain

Smartphones could provide weather data in poor nations

Laura Garcia in SciDev.net: Smartphones can now be used to collect weather data such as air temperatures through WeatherSignal, a crowdsourcing app developed by UK start-up OpenSignal.   This helps crowdsource real-time weather forecasts and could one day help collect climate data in areas without weather stations, its developers say.

Once installed, the app automatically collects data and periodically uploads them to a server. The app's ability to record air temperature is based upon the discovery that the temperature of a smartphone battery correlates closely to the surrounding air temperature, published in Geophysical Research Letters this month (13 August).

"Lithium ion batteries have temperature sensors to prevent damage caused by attempts to charge them when the battery is too hot," the paper says. But these sensors do not provide a direct air temperature measurement — due to heat being emitted by both the smartphone and its user. So the researchers used a model that estimates the outside temperature based on smartphone readings. The fact that battery temperature correlates with ambient air temperature was discovered by accident, James Robinson, one of the authors of the paper and co-founder of OpenSignal, tells SciDev.Net. 

The team was researching energy consumption in relation to poor mobile network signal, a condition that is known to reduce battery performance. "We started playing with the data and decided to look at average battery temperature versus historic weather temperature, and we found a really strong correlation," says Robinson....

An Ubuntu smartphone (in an attempt not to be outdated), shot by Cartmanland, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license

Britain 'faces decade of bad weather'

Terra Daily via AFP: Britain was set to enjoy its hottest day of the year so far on Wednesday but woke up to the gloomy news that it could be in the middle of a decade-long bad weather cycle. National weather and climate experts met on Tuesday to discuss Europe's run of unusually wet and cold conditions, and were told the cause could be Atlantic currents that move in cycles of 10 years or more.

Climate change is likely also a factor, scientists at the meeting said. "The workshop heard new evidence from the University of Reading suggesting that long-term Atlantic currents may be playing an important role," said a statement from national weather service the Met Office.

"These are understood to operate on cycles of a decade or more, which suggests that we may see their influence on our summers for a few more years to come." The currents could be influencing the position of the jet stream, a ribbon of very strong winds over the Atlantic which in turn affects weather patterns in Britain and its European neighbours.

But the bad weather might also be affected by declining Arctic ice, solar variations and long-term ocean cycles, the Met Office said. It sought to soften the blow by adding: "It doesn't rule out the possibility of decent summers over the next few years."...

A gloomy day in Gateshead, on Carr Hill Road, shot by C Baldwin, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Ebbs and flows in 'atmospheric rivers' and their impact

Vinson Kurian in Business Line in the Hindu (India): An important part of 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.  The waves travel from west to east and often call on the northern and northwestern parts of India, which we know as western disturbances.

These waves have quite in the news in recent years - down to this year, as recently as last week, when they set off an unprecedented late-spring snowstorm over northwestern Europe.  Earlier in February, a train of western disturbances rolling into Northwest India had ventured unusually south of their usual paths to dip into Central and adjoining Peninsular India to create freaky weather – hailstorm in Central India and untimely string of thundershowers all over the place.

Now, there is study material available that seeks to link the sudden change in weather – snowing wet or bone dry – from scientists of Potsdam Institute for Climate Impact Research. They have attributed it to fluctuations in the course of the ‘atmospheric rivers’ that flow around the northern latitudes and close to polar region.

The world suffered from severe regional weather extremes in recent years - a heat wave in the US in 2011 preceded by the one in Russia 2010. To complete the riddle, the latter coincided with an unprecedented Pakistan flood.  The Potsdam study suggests that man-made climate change repeatedly disturbs the patterns of atmospheric flow around the globe’s Northern hemisphere through a subtle resonance mechanism.

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, lead researcher Vladimir Petoukhov said….

Diagram of breeze formation, designed by Jesús Gómez Fernández, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

'India needs micro-level data for climate action'

Archita Bhatta and Athar Parvaiz in SciDev.net: India needs micro-level scientific assessment at the state, district and village levels for effective planning and implementation of measures to combat climate change, a national workshop has highlighted.

The workshop on  climate-resilient development, organised last month (13 February), discussed integrating climate change into development programmes in semi-arid regions like Bundelkhand in central India. Participants pointed to how lack of micro-level climate change information at the state and district level was affecting planning and implementation of climate resilient development in Bundelkhand.

"We need scientific assessment of the vulnerabilities of each state that can predict weather and climate impacts, and also greenhouse gas inventories," said Lokendra Thakkar, general manager and coordinator at the climate change division of the Madhya Pradesh state government.

India launched a National Action Plan on Climate Change (NAPCC) in 2008, but translating the policy into ground-level action depends to a large extent on states that are developing individual climate action plans. India needs models that can predict, with reasonable certainty, long-term climatic conditions that will prevail over a state over a specific time period, said Ashwani Kulkarni, scientist at the Indian Institute of Tropical Meteorology (IITM), Pune.

"We have not been able to scale down the climate prediction models to predict long-term climatic conditions in a state," Kulkarni told SciDev.Net, adding that the IITM is developing a model to predict long- term climatic conditions over individual Indian states...

The western state of Rajasthan hosts the large Thar desert in northern India. Shot by sushmita balasubramani, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

NOAA and NASA's next generation weather satellite may provide earlier warnings

NASA: A new satellite that will detect the lightning inside storm clouds may lead to valuable improvements in tornado detection. The GOES-R satellite is currently being built with new technology that may help provide earlier warnings for severe weather. The national average is a 14-minute lead time to warn residents of a tornado, but NASA and NOAA scientists are looking to improve severe weather detection to save lives and property. They are developing the Geostationary Operational Environmental Satellite-R Series, or GOES-R, to observe thunderstorm development with much greater spatial and temporal detail than ever before. Severe weather knows no specific season and the new technology aboard GOES-R is expected to help provide earlier detection for warnings, whatever the time of year.

On Jan. 29 and 30, 2013, a winter-time tornado outbreak produced multiple tornadoes from the southern Plains states, across the Mississippi River Valley, eastward to the Mid-Atlantic. On Feb. 10, several tornadoes touched down in Mississippi, destroying 200 homes, damaging and causing injuries near Hattiesburg.

"These storms can spin up pretty quickly which limits warning lead-time," said NOAA scientist Steve Goodman. "The radar and storm spotter’s view of tornadoes reaching the ground can be blocked by terrain, or visibility is very poor when the tornado is wrapped in rain. And it's certainly more challenging for storm spotters to observe and confirm tornadoes occurring at night. Sometimes it's just plain hard to come up with enough advance warning."

For the first time, scientists will be able to detect the lightning occurring inside storm clouds, and thus better track how developing storms are moving and intensifying before and during the occurrence of severe weather, Goodman said, all of which will help meteorologists better predict weather disasters...

A powerful cold front moving from the central United States to the East Coast wiped out spring-like temperatures and replaced them with winter-time temperatures. On Jan. 30 at 1825 UTC (1:25 p.m. EST), NOAA's GOES-13 satellite captured an image of clouds associated with the strong cold front. The visible GOES-13 image shows a line of clouds that stretch from Canada to the U.S. Gulf Coast and contain powerful thunderstorms with the potential to be severe. Credit: NASA GOES Project

Pacific locked in 'La Nada' limbo

 NASA: Sea-surface height data from NASA's Jason-2 satellite show that the equatorial Pacific Ocean is still locked in what some call a neutral, or 'La Nada' state. This condition follows two years of strong, cool-water La Niña events.

A new image, based on the average of 10 days of data centered on Jan. 26, 2013, shows near-normal conditions (depicted in green) across the equatorial Pacific. The image is available at: http://sealevel.jpl.nasa.gov/images/latestdata/jason/2013/20130126P.jpg.

This latest image highlights the processes that occur on time scales of more than a year, but usually less than 10 years, such as El Niño and La Niña. These processes are known as the interannual ocean signal. To show that signal, scientists refined data for this image by removing trends over the past 20 years, seasonal variations and time-averaged signals of large-scale ocean circulation.

The height of the water relates, in part, to its temperature, and thus is an indicator of the amount of heat stored in the ocean below. As the ocean warms, its level rises; as it cools, its level falls. Yellow and red areas indicate where the waters are relatively warmer and have expanded above normal sea level, while green (which dominates in this image) indicates near-normal sea level, and blue and purple areas show where the waters are relatively colder and sea level is lower than normal. Above-normal height variations along the equatorial Pacific indicate El Niño conditions, while below-normal height variations indicate La Niña conditions. The temperature of the upper ocean can have a significant influence on weather patterns and climate. For a more detailed explanation of what this type of image means, visit: http://sealevel.jpl.nasa.gov/science/elninopdo/latestdata/.

"This past spring, after two years of La Niña, the expected El Niño was a no-show," says Bill Patzert, climatologist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "La Niña faded and 'La Nada' conditions locked in. This absence of El Niño and La Niña, termed 'neutral' by some, has left long-range climate forecasters adrift," Patzert added. "Seasonal, long-range forecasting works best when signals like El Niño and La Niña are strong."

Patzert calls the present condition 'La Nada,' because the word 'neutral' misleadingly implies to some that weather will be 'normal.'....

The latest image of sea surface heights in the Pacific Ocean from NASA's Jason-1 satellite shows that the equatorial Pacific Ocean is now in its 10th month of being locked in what some call a neutral, or "La Nada" state. "La Nadas" make long-range climate forecasting more difficult due to their greater unpredictability. Yellows and reds indicate areas where waters are relatively warmer and have expanded above normal sea level, while blues and purple areas show where waters are relatively colder and sea level is lower than normal. Green indicates near-normal sea level conditions. Image credit: NASA-JPL/Caltech/Ocean Surface Topography Team

Smartphones, tablets help researchers improve storm forecasts

Hannah Hickey in University of Washington News: The next advance in weather forecasting may not come from a new satellite or supercomputer, but from a device in your pocket. University of Washington atmospheric scientists are using pressure sensors included in the newest smartphones to develop better weather forecasting techniques.

“With this approach we could potentially have tens or hundreds of thousands of additional surface pressure observations, which could significantly improve short-term weather forecasts,” said Cliff Mass, a UW professor of atmospheric sciences.

Owners of certain new Android smartphones and tablet computers can now download the PressureNet app, which measures atmospheric pressure and provides the data to UW researchers. When some smartphone manufacturers recently added pressure sensors, to estimate the phone’s elevation and help pinpoint its location, Mass saw an opportunity to enhance weather prediction. In the autumn he approached Cumulonimbus, a Canadian app company that developed a barometer application for smartphones that collects all the data and shares it back with users.

The PressureNet app this week collected about 4,000 observations per hour, with users clustered in the northeastern United States and around some major cities. “We need more density,” Mass said. “Right now it’s a matter of getting more people to contribute.”

Android devices equipped with pressure sensors include Samsung’s Galaxy S3, Galaxy Nexus, Galaxy Note and Nexus 4 smartphones, and the Nexus 10 and Motorola Xoom tablet computers.

Atmospheric pressure is the weight of the air above, and includes information about what is happening as air masses collide. Precise tracking of pressure readings and pressure changes could help weather forecasters to pinpoint exactly where and when a major storm will strike.

Mass is particularly interested in the center of the country, which is prone to severe storms but includes fewer weather observation stations. “Thunderstorms are one of the areas of weakest skill for forecasting,” Mass said. “I think thunderstorms in the middle part of the country could potentially be the biggest positive for this approach. They are relatively small-scale, they develop over a few hours, they can be severe and can affect people significantly.”...

Photo by Harald Hoyer, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

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

Bangladesh experts fear climate change link to erratic rainfall pattern

The Financial Express (Bangladesh): Despite intense rainfall within a short span of time in the total quantum of downpour appeared much less than the usual in the past several years, a phenomenon which experts feared is a backlash of change of global climate pattern, reports BSS.

Weather and climate experts said impact of climate change could be manifested in the form of temperature extremes and frequent floods, droughts and cyclones. But in Bangladesh the data of rainfall, a crucial climate change indicator, showed the region appeared a victim of the phenomenon.

"We earlier saw protracted monsoon downpour for three or four consecutive days but the trend disappeared now, intense rainfall in a short period of time triggers flash floods nowadays," Professor Umme Kulsum Navera of Department of Water Resources Engineering of Bangladesh University of Engineering and Technology (BUET) told the news agency.

Meteorologists said they recorded 47,447milimetres rainfall in June, July, August and September in 2010, which was less compared to the average of the last 15 years. The country experienced less rainfall in the last year, Meteorologist SM Quamrul Hassan said adding that ten per cent less rainfall was recorded from June to September this year....