The group, led by Lisa Beal, professor of ocean sciences at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, provides a road map for an enhanced IndOOS to better meet the scientific and societal needs for more reliable environmental forecasts in the next decade. The 136 actionable recommendations from the three-year, internationally coordinated review were published in the Bulletin of the American Meteorological Society.

The scientists call for four major improvements to the current observing system:

1) more chemical and biological measurements in at-risk ecosystems and fisheries;

2) expansion into the western tropics to improve understanding of the monsoon;

3) better-resolved upper ocean processes to improve predictions of rainfall, drought, and heat waves; and

4) expansion into key coastal regions and the deep ocean to better constrain the basin-wide energy budget.

Although the smallest of the major oceans on Earth, the Indian Ocean is home to roughly one-third of the global population living among the 22 countries that border its rim. Many of these countries are developing or emerging economies vulnerable to climate changes such as sea level rise and more extreme weather events. The Indian Ocean also influences climate globally and is thought to have played a key role in regulating global mean surface temperatures.

The Indian Ocean Observing System, established in 2006, is a multinational network of sustained oceanic measurements that underpin understanding and forecasting of weather and climate for the Indian Ocean region and beyond. IndOOS is part of the Global Ocean Observing System (GOOS) which is coordinated through the World Meteorological Organization and the Intergovernmental Oceanographic Commission of the United Nations.

IndOOS-2 will require new agreements and partnerships with and among Indian Ocean rim countries, creating opportunities for them to enhance their monitoring and forecasting capacity, said the authors.

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Materials provided by University of Miami Rosenstiel School of Marine & Atmospheric Science. Original written by Diana Udel. Note: Content may be edited for style and length.

Conservation ecologist Rebecca Brunner, a Ph.D. candidate at the University of California, Berkeley, has discovered that the glass frog Sachatamia orejuela can be added to the list of species that make use of visual cues in response to their acoustic environments. This is the first time a member of the glass frog family (Centrolenidae) has been observed using visual communication in this manner.

“A handful of other frog species around the world use visual signaling, in addition to high-pitched calls, to communicate in really loud environments,” Brunner said. “What’s interesting is that these species are not closely related to each other, which means that these behaviors likely evolved independently, but in response to similar environments — a concept called convergent evolution.”

Sachatamia orejuela glass frogs are native to the rainforests of Ecuador and Colombia. They are especially unique because they are almost exclusively found on rocks and boulders within the spray zones of waterfalls, where rushing water and slippery surfaces offer some protection against predators, and their green-gray color and semi-transparent skin make them nearly impossible to spot. As a result, little is known about this species’ mating and breeding behavior.

Brunner, who studies the bioacoustics of different ecological environments, was chest-deep in an Ecuadorean rainforest stream recording the call of a Sachatamia orejuela when she first observed this visual signaling behavior. As soon as she saw the frog repeatedly raising its front and back legs, Brunner climbed a slippery rock face and balanced on one foot to get video footage of the behavior.

“I was already over the moon because I had finally found a calling male after months of searching. Before our publication, there was no official record of this species’ call, and basic information like that is really important for conservation,” Brunner said. “But then I saw it start doing these little waves, and I knew that I was observing something even more special.”

While she filmed, the frog continued to wave its hands and feet and bob its head. She also observed another male Sachatamia orejuela glassfrog a few meters away performing the same actions.

“This is a really exhilarating discovery because it’s a perfect example of how an environment’s soundscape can influence the species that live there. We’ve found that Sachatamia orejuela has an extremely high-pitched call, which helps it communicate above the lower-pitched white noise of waterfalls. And then to discover that it also waves its hands and feet to increase its chances of being noticed — that’s a behavior I’ve always loved reading about in textbooks, so it is beyond thrilling to be able to share another amazing example with the world,” said Brunner.

Though the COVID-19 pandemic has put a pause on Brunner’s fieldwork, she hopes to return to Ecuador soon to continue her research, which links bioacoustics and conservation.

“One of the best things about fieldwork is that nature is always full of surprises — you never know what discoveries you may happen upon,” Brunner said. “I hope our findings can serve as a reminder that we share this planet with incredible biodiversity. Conserving ecosystems that support species like Sachatamia orejuela is important not only for our well-being, but also for our sense of wonder.”

Video: https://www.youtube.com/watch?v=U6prmVIyxXI&feature=emb_logo

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Materials provided by University of California – Berkeley. Original written by Kara Manke. Note: Content may be edited for style and length.

The researchers are the first to observe metallic lines in a perovskite crystal. Perovskites abound in the Earth’s center, and barium stannate (BaSnO3) is one such crystal. However, it has not been studied extensively for metallic properties because of the prevalence of more conductive materials on the planet like metals or semiconductors. The finding was made using advanced transmission electron microscopy (TEM), a technique that can form images with magnifications of up to 10 million.

The research is published in Science Advances.

“The conductive nature and preferential direction of these metallic line defects mean we can make a material that is transparent like glass and at the same time very nicely directionally conductive like a metal,” said Mkhoyan, a TEM expert and the Ray D. and Mary T. Johnson/Mayon Plastics Chair in the Department of Chemical Engineering and Materials Science at the University of Minnesota’s College of Science and Engineering. “This gives us the best of two worlds. We can make windows or new types of touch screens transparent and at the same time conductive. This is very exciting.”

Defects, or imperfections, are common in crystals — and line defects (the most common among them is the dislocation) are a row of atoms that deviate from the normal order. Because dislocations have the same composition of elements as the host crystal, the changes in electronic band structure at the dislocation core, due to symmetry-reduction and strain, are often only slightly different than that of the host. The researchers needed to look outside the dislocations to find the metallic line defect, where defect composition and resulting atomic structure are vastly different.

“We easily spotted these line defects in the high-resolution scanning transmission electron microscopy images of these BaSnO3 thin films because of their unique atomic configuration and we only saw them in the plan view,” said Hwanhui Yun, a graduate student in the Department of Chemical Engineering and Materials Science and a lead author of the study.

For this study, BaSnO3 films were grown by molecular beam epitaxy (MBE) — a technique to fabricate high-quality crystals — in a lab at the University of Minnesota Twin Cities. Metallic line defects observed in these BaSnO3 films propagate along film growth direction, which means researchers can potentially control how or where line defects appear — and potentially engineer them as needed in touchscreens, smart windows, and other future technologies that demand a combination of transparency and conductivity.

“We had to be creative to grow high-quality BaSnO3 thin films using MBE. It was exciting when these new line defects came into light in the microscope,” said Bharat Jalan, associate professor and Shell Chair in the Department of Chemical Engineering and Materials Science, who heads up the lab that grows a variety of perovskite oxide films by MBE.

Perovskite crystals (ABX3) contain three elements in the unit cell. This gives it freedom for structural alterations such as composition and crystal symmetry, and the ability to host a variety of defects. Because of different coordination and bonding angles of the atoms in the line defect core, new electronic states are introduced and the electronic band structure is modified locally in such a dramatic way that it turns the line defect into metal.

“It was fascinating how theory and experiment agreed with each other here,” said Turan Birol, assistant professor in the Department of Chemical Engineering and Materials Science and an expert in density functional theory (DFT). “We could verify the experimental observations of the atomic structure and electronic properties of this line defect with first principles DFT calculations.”

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Materials provided by University of Minnesota. Note: Content may be edited for style and length.