(Press-News.org) Shrinking Arctic sea ice grabbed the world's attention again earlier this year with a new record low minimum. Growing economic activity in the Arctic, such as fishing, mineral exploration and shipping, is emphasizing the need for accurate predictions of how much of the Arctic will be covered by sea ice. Every June, an international research group known as the Study of Environmental Arctic Change (SEARCH) publishes a summary of the expected September Arctic sea ice minimum known as the Sea Ice Outlook. The initial reports and monthly updates aim to give the scientific community and public the best available information on sea ice.
Researchers rely on models that use estimated ice thickness data and simulated atmospheric conditions to forecast how sea ice will change during the summer. For the first time, near real-time ice thickness data obtained by NASA's Operation IceBridge has been used to correct a forecast model's initial measurements, which could lead to improved seasonal predictions.
In a paper published last month in the journal Geophysical Research Letters, Ron Lindsay, IceBridge science team member and Arctic climatologist with the Polar Science Center at the University of Washington in Seattle, outlined efforts to use IceBridge data to improve the accuracy of seasonal sea ice forecasts. Lindsay and colleagues used a new quick look sea ice data product that IceBridge scientists released before the end of the Arctic campaign earlier this year. The quick look data, intended for use in time-sensitive applications like seasonal forecasts, supplements the final sea ice data product typically released roughly six months after the campaign. By using new data processing techniques, IceBridge scientists were able to publish the quick look measurements in a matter of weeks. "The idea was to make the data available for anyone to use for the Sea Ice Outlook," said sea ice scientist Nathan Kurtz of NASA's Goddard Space Flight Center in Greenbelt, Md.
The work outlined in Lindsay's paper marks the first use of IceBridge quick look data in an ensemble sea ice forecast (computer) model. "An ensemble forecast is where you run a single forecast model many different times," said Lindsay. In this case, they ran the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) model seven times using conditions from previous summers. PIOMAS uses sea ice extent, the area of sea containing sea ice, and atmospheric data to simulate ice and ocean conditions.
IceBridge data and thickness measurements made by the Seasonal Ice Zone Observing Network (SIZONet), a multidisciplinary project aimed at observing Arctic sea ice, served as a way to correct initial sea ice conditions. These initial measurements come from running the forecast model with historical atmospheric conditions. Lindsay and colleagues used IceBridge and SIZONet data to adjust these measurements and then used the PIOMAS model to create a forecast of September's mean sea ice extent. To make sure what effect the corrected measurements had, they also ran the model as normal, something known as a control run.
Careful Measurements
Before this forecasting work could begin though, the researchers had to gather and process data, something that takes the hard work of many people. During March and April of 2012, IceBridge gathered sea ice thickness data using four different airborne science instruments.
First, researchers measure the surface freeboard, or the amount of ice and snow above the sea level height, using a laser altimeter known as the Airborne Topographic Mapper (ATM). Next, they use snow thickness data derived from airborne snow radar and subtract that to get an accurate ice freeboard measurement. This figure is then combined with known average density measurements to calculate total ice thickness, of which freeboard is typically only 10 percent. One other instrument, the KT-19 temperature sensor, was used to detect leads, or openings, in sea ice, which are used to determine the sea level height.
SIZONet scientists used a different method, measurements from a helicopter-borne electromagnetic sensor that detects differences in how well sea ice and ocean water conduct electricity, giving a distance between the sensor and ocean water below.
Collecting measurements is only the beginning of the work. Measurements from the ATM laser have to be combined with information from the aircraft's GPS and inertial navigation systems and the readings have to be filtered to remove things like false returns from low clouds and fog. Preparing instrument data for release is a labor-intensive and time-consuming process that normally takes six months. With the quick look product, it was done in a matter of weeks.
Producing quality data so quickly is challenging, but the process proved a good test of the instrument team's talents. "We gained some valuable insights into our capabilities," said ATM senior scientist John Sonntag. "This new confidence in the quick data may open new avenues for us in the future."
Looking Forward
The September mean ice extent for the corrected model were slightly closer to the actual result than the control forecast run, but both were fairly far off from the actual record minimum. This may have been due to unusual weather over the summer, including a large Arctic storm in August, or to deficiencies in the model simulation of the new very thin ice conditions of the Arctic. Lindsay said winds have a bigger impact on the thinner ice of recent years than on thick ice. It may be possible to redo this experiment, using this summer's atmospheric conditions in the forecasts. "This would tell us the impact of the observations for the weather we actually experienced," said Lindsay.
As a step in a new direction, the study and quick look data collection could improve sea ice forecasts in the future. Providing near real-time sea ice data may also help in other areas, such as evaluating model performance.
With plans to produce another quick look product in the coming 2013 Arctic campaign, Kurtz is hopeful that IceBridge data will be useful to sea ice forecasters and other researchers. "The question is how will people use it," Kurtz said.
INFORMATION:
For more information about the SEARCH Sea Ice Outlook, visit:
http://www.arcus.org/search/seaiceoutlook/index.php
For more information about IceBridge's quick look sea ice data, read:
http://www.nasa.gov/mission_pages/icebridge/news/spr12/arctic-seaice.html
For more information about Operation IceBridge, visit:
http://www.nasa.gov/icebridge
NASA's Operation IceBridge data brings new twist to sea ice forecasting
2012-12-20
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
LSUHSC research discovery provides therapeutic target for ALS
2012-12-20
New Orleans, LA –Research led by Dr. Udai Pandey, Assistant Professor of Genetics at LSU Health Sciences Center New Orleans, has found that the ability of a protein made by a gene called FUS to bind to RNA is essential to the development of Amyotrophic Lateral Sclerosis (ALS). This discovery identifies a possible therapeutic target for the fatal neurological disease. The research will be available online in the Advanced Access section of the journal Human Molecular Genetics website, posted by December 21, 2012. It will be published in an upcoming issue of the journal.
...
Small changes in eating prompts weight loss
2012-12-20
Making small easy changes to our eating habits on a consistent basis - 25 days or more per month - can lead to sustainable weight loss, according to research by Professor Brian Wansink in Cornell University's Food and Brand Lab. The challenge is to figure out which changes work for specific individuals and how to stick with changes long enough to make them second nature.
To explore this issue, Cornell researchers launched the National Mindless Eating Challenge (NMEC), an online healthy eating and weight loss program that focused on simple eating behavior changes, instead ...
MicroRNAs present exciting opportunities for cancer therapy and diagnosis
2012-12-20
Amsterdam, NL, December 19, 2012 – As many as 50 percent of all human protein-coding genes are regulated by microRNA (miRNA) molecules. While some miRNAs impact onset and progression of cancer, others can actually suppress the development of malignant tumors and are useful in cancer therapy. They can also serve as potential biomarkers for early cancer detection. In a new issue of Cancer Biomarkers, investigators report on non-coding miRNAs as appealing biomarkers for malignancy.
"MiRNA-based therapies are attractive partly due to the fact that these molecules can target ...
California's graduate students in environmental sciences lag behind in technology, computation
2012-12-20
RIVERSIDE, Calif. — Researchers at the University of California, Riverside have conducted a study showing that many skills and practices that could help scientists make use of technological and computational opportunities are only marginally being taught in California's formal graduate programs in the environmental sciences.
The researchers found, too, that graduate students in the state were, in general, not engaged in data management practices. Of the students surveyed who had already completed their graduate degree, only 29.3 percent had made their research data products ...
Delusions of gender: Men's insecurities may lead to sexist views of women
2012-12-20
He loves her, he loves her not.
A new study led by Joshua Hart, assistant professor of psychology, suggests that men's insecurities about relationships and conflicted views of women as romantic partners and rivals could lead some to adopt sexist attitudes about women.
The study was recently published in Personality and Social Psychology Bulletin, a peer-reviewed journal.
Hart and his co-authors, Jacqueline Hung '11, a former student of Hart's, and psychology professors Peter Glick of Lawrence University and Rachel Dinero of Cazenovia College, surveyed more than 400 ...
Young offenders who work, don't attend school may be more antisocial
2012-12-20
Many high school students work in addition to going to school, and some argue that employment is good for at-risk youths. But a new study has found that placing juvenile offenders in jobs without ensuring that they attend school may make them more antisocial.
The study, by researchers at the University of Pittsburgh, Temple University, and the University of California, Irvine, appears in the journal Child Development.
While evidence suggests that working long hours during the school year has negative effects on adolescent antisocial behavior among middle- and upper-income ...
Topics of teen sibling fights affect anxiety, depression, self-esteem
2012-12-20
Fights between siblings about simple things, like whose turn it is to empty the dishwasher, aren't harmless. Rather, such fights are about equality and fairness, and they can lead to depression, according to a new study.
The longitudinal research, by researchers at the University of Missouri, appears in the journal Child Development.
Although teen siblings fight about a lot of different issues, many of their fights can be categorized as being about equality and fairness (for example, whose turn it is to empty the dishwasher) or invasion of personal space (for example, ...
Supportive role models, coping lead to better health in poor teens
2012-12-20
Low-income teenagers who have supportive role models and engage in adaptive strategies have lower levels of a marker for cardiovascular risk than low-income teens without such resources, according to a new study.
The study, by researchers at Northwestern University and the University of British Columbia, is published in the journal Child Development.
"Low socioeconomic status is one of the strongest determinants of chronic disease in developed countries," notes Edith Chen, professor of psychology and faculty fellow at the Institute for Policy Research at Northwestern ...
Motivation, study habits -- not IQ -- determine growth in math achievement
2012-12-20
It's not how smart students are but how motivated they are and how they study that determines their growth in math achievement. That's the main finding of a new study that appears in the journal Child Development.
The study was conducted by researchers at the University of Munich and the University of Bielefeld.
"While intelligence as assessed by IQ tests is important in the early stages of developing mathematical competence, motivation and study skills play a more important role in students' subsequent growth," according to Kou Murayama, postdoctoral researcher of ...
Toddlers' language skills predict less anger by preschool
2012-12-20
Toddlers with more developed language skills are better able to manage frustration and less likely to express anger by the time they're in preschool. That's the conclusion of a new longitudinal study from researchers at the Pennsylvania State University that appears in the journal Child Development.
"This is the first longitudinal evidence of early language abilities predicting later aspects of anger regulation," according to Pamela M. Cole, liberal arts research professor of psychology and human development and family studies at Pennsylvania State University, who was ...