decision making

California Flooding | Earth Wise

February 2, 2023 By EarthWise Leave a Comment

Starting in December, a series of “atmospheric rivers” brought record storms to California producing as much rain in three weeks in some areas as they normally have in an entire year. The historic levels of rain (and snow in the mountains) have swollen rivers, flooded roads and homes, forced evacuations, knocked out electric power for millions of people, and resulted in more than 20 deaths.

Atmospheric rivers are air currents that carry large amounts of water vapor through the sky. They are not unusual for California but recurrent waves of them like those that have happened recently are very infrequent. Studies by the U.S. Geological Survey have shown that such a phenomenon recurs in California every 250 years. There were a series of storms causing disastrous floods in California in 1861-62.

The atmospheric rivers are born in the warm waters of the tropical Pacific. During La Nina phases, the atmospheric rivers typically make landfall on the northern West Coast. During El Nino phases, atmospheric rivers are more likely to end up in Southern and Central California. During transitions between the phases, as is happening now, the storms can cover large parts of the state.

Modern forecasting is pretty good at predicting the forthcoming occurrence of these storms and has led to some helpful actions, such as reservoir operators preventing dams from overflowing or bursting. But there is a gap between science and decision-making. It is pretty clear what needs to be done when tornados or hurricanes are on the way. It is less clear what actions are appropriate when there are going to be repeated heavy rainstorms.

These storms will have an effect on California’s megadrought, but just how much of an effect remains to be seen.

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Flooding in California: What Went Wrong, and What Comes Next

Photo, posted January 5, 2023, courtesy of Sarah Stierch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Ocean Currents And Climate Change | Earth Wise

September 22, 2020 By EarthWise Leave a Comment

Oceans cover more than 70% of the earth and absorb 94% of incoming solar radiation. As a result, oceans play a major role in the climate system. With their massive size and capacity to store heat, oceans help keep temperature fluctuations in check. But oceans also play a more active role. Ocean currents are responsible for moving vast amounts of heat around the planet.

According to a paper recently published in the journal Nature Communications, the world’s strongest ocean currents will experience more intense marine heatwaves than the global average in the coming decades. These strong ocean currents play key roles in fisheries and ocean ecosystems.

Sections of the Gulf Stream near the United States, the Kuroshio Current near Japan, the East Australian Current near Australia, and the Antarctic Circumpolar Current will all see more intense marine heatwaves over the next 30 years.

Scientists from the University of Tasmania and CSIRO in Australia relied on high-resolution ocean modeling to carry out their research. They confirmed the model’s accuracy by comparing outputs with observations from 1982-2018. They then used the same model to project how marine heatwaves would alter with climate change out to 2050.

The model projects, for example, that intense marine heatwaves are more likely to form well off the coast of Tasmania, while more intense marine heatwaves along the Gulf Stream start to appear more frequently close to the shore from Virginia to New Brunswick, Canada.

Marine heatwaves are on the rise globally, but knowing where they will occur and how much hotter they will be will help policymakers, ecologists, and fisheries experts in their regional decision-making.

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Where marine heatwaves will intensify fastest: New analysis

Photo, posted April 17, 2016, courtesy of Nicolas Henderson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Oil Platforms And Fish | Earth Wise

July 16, 2020 By EarthWise Leave a Comment

It is well-known that offshore oil platforms become major habitats for fish. Their support structures rise hundreds of feet through the water column and basically create a prefabricated reef for marine life. Many of these platforms will soon be decommissioned and government agencies are considering the consequences to undersea life when this happens.

Researchers at the University of California Santa Barbara have looked at how various decommissioning scenarios would affect undersea ecosystems. They found that completely removing a platform could reduce fish biomass by an average of 95%. In contrast, removing just the top part of the rig could keep losses to around 10%.

California is looking at several possibilities for decommissioning 27 oil platforms off of its coast. The three options are: leave the platform in place, remove all of it, or remove just the top part of it. Each option entails its own economic and ecological consequences.

The research team studied the size and composition of fish communities at 24 platforms and created models for each of the decommissioning scenarios. The partial removal approach involved stripping away all structures within 26 meters of the surface. This number would eliminate the need for a lighted buoy where the support structure remained according to U.S. Coast Guard guidelines.

For the 24 structures studied, leaving them entirely in place would support over 29,000 kilograms of fish biomass. Removing just the top 26 meters would support nearly 28,000 kilograms. Removing the platforms entirely would support only 500 kilograms of fish biomass.

As California weighs how to decommission its oil platforms, studies like this will be critical to making informed decisions.

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Web Links

Oil Platforms’ Fishy Future

Photo, posted June 4, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Animals And Social Distancing | Earth Wise

June 16, 2020 By EarthWise Leave a Comment

As the spread of COVID-19 continues throughout the U.S. and around the world, health officials continue to ask people to keep physical space between themselves and others outside their homes. It’s an important and effective way to slow down and prevent the spread of disease.

But it’s not just humans who can benefit from social distancing. It turns out that animals can, too.

Microorganisms living on or inside our bodies are important for both our health and for the development of disease. Researchers from the University of Texas at San Antonio have found evidence for the importance of social distancing to minimize the spread of microbes among individuals. The researchers studied wild monkeys to find out what role diet, genetics, social groupings, and distance in a social network play when it comes to the microbes found inside the gut. The gut microbiome refers to all the microorganisms living in the digestive tract.

The research team studied the fecal matter of 45 female colobus monkeys that congregated in eight different social groups in a small forest in Ghana. The researchers observed major differences in gut microbiomes between the eight social groups. But individual monkeys from different groups that were more closely connected to the population’s social network had more similar gut microbiomes. The findings, recently published in the journal Animal Behaviour, indicate that microbes may be transmitted between monkeys during occasional encounters with other monkeys from different social groups.

Learning how microorganisms pass among monkeys can help researchers understand how diseases spread. Understanding how diseases spread can help guide decision making during this pandemic and any future disease outbreaks.

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Even animals benefit from social distance to prevent disease, research shows

Photo, posted January 10, 2007, courtesy of Silke Baron via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.