Tags Posts tagged with "Climate"

Climate

Xiaoning Wu at her recent PhD graduation with Kevin Reed. Photo by Gordon Taylor

By Daniel Dunaief

If they build it, they will understand the hurricanes that will come.

That’s the theory behind the climate model Kevin Reed, Associate Professor at the School of Marine and Atmospheric Sciences at Stony Brook University, and his graduate student Xiaoning Wu, recently created.

Working with Associate Professor Christopher Wolfe at Stony Brook and National Center for Atmospheric Research scientists, Reed and Wu developed an idealized computer model of the interaction between the oceans and the atmosphere that they hope will, before long, allow them to study weather events such as tropical cyclones, also known as hurricanes.

In his idealized program, Reed is trying to reduce the complexity of models to create a system that doesn’t require as much bandwidth and that can offer directional cues about coming climate change.

“When you’re trying to build a climate model that can accurately project the future, you’re trying to include every process you know is important in the Earth’s system,” Reed said. These programs “can’t be run” with university computers and have to tap into some of the biggest supercomputers in the world.

Reed’s work is designed to “peel back some of these advances that have happened in the field” which will allow him to focus on understanding the connections and processes, particularly between the ocean and the atmosphere. He uses fewer components in his model, reducing the number of equations he uses to represent variables like clouds.

“We see if we can understand the processes, as opposed to understanding the most accurate” representations possible, he said. In the last ten years or so, he took a million lines of code in a climate model and reduced it to 200 lines.

Another way to develop a simpler model is to reduce the complexity of the climate system itself. One way to reduce that is to scale back on the land in the model, making the world look much more like something out of the 1995 Kevin Costner film “Waterworld.”

About 30 percent of the world is covered by land, which has a variety of properties.

In one of the simulations, Reed reduced the complexity of the system by getting rid of the land completely, creating a covered aqua planet, explaining that they are trying to develop a tool that looks somewhat like the Earth.

“If we could understand and quantify that [idealized system], we could develop other ways to look at the real world,” he said.

The amount of energy from the sun remains the same, as do the processes of representing oceans, atmospheres and clouds.

In another version of the model, Reed and Wu represented continents as a single, north-south ribbon strip of land, which is enough to change the ocean flow and to create currents like the Gulf Stream.

The expectation and preliminary research shows that “we should have tropical cyclones popping up in these idealized models,” Reed said. By studying the hurricanes in this model, these Stony Brook scientists can understand how these storms affect the movement of heat from around the equator towards the poles.

The weather patterns in regions further from the poles, like Long Island, come from the flow of heat that starts at the equator and moves to colder regions.

Atlantic hurricanes, which pick up their energy from the warmer waters near Africa and the southern North Atlantic, transfer some of that heat. Over the course of decades, the cycling of that energy, which also reduces the temperature of the warmer oceans, affects models for future storm systems, according to previous studies.

Reed said the scientific community has a wide range of estimates for the effect of hurricanes on energy transport, with some researchers estimating that it’s negligible, while others believing it’s close to 50 percent, which would mean that hurricanes could “play an active role in defining” the climate.

Reed’s hypothesis is that a more rapid warming of the poles will create less of an energy imbalance, which will mean fewer hurricanes. This might differ in various ocean basins. He has been studying the factors that control the number of tropical cyclones.

Reed and Wu’s research was published in the Journal of Advances in Modeling Earth Systems in April.

Wu, who is completing her PhD this summer after five years at Stony Brook, described the model as a major part of her thesis work. She is pleased with the work, which addresses the changing ocean as the “elephant in the room.”

Oftentimes, she said, models focus on the atmosphere without including uncertainties that come from oceans, which provide feedback through hurricanes and larger scale climate events.

Wu started working on the model in the summer of 2019, which involved considerable coding work. She hopes the model will “be used more widely” by the scientific community, as other researchers explore a range of questions about the interaction among various systems.

Wu doesn’t see the model as a crystal ball so much as a magnifying glass that can help clarify what is happening and also might occur in the future.

“We can focus on particular players in the system,” she said.

A native of central China, Wu said the flooding of the Yangtze River in 1998 likely affected her interest in science and weather, as the factors that led to this phenomenon occurred thousands of miles away.

As for her future, Wu is intrigued by the potential to connect models like the one she helped develop with applications for decision making in risk management.

The range of work she has done has enabled her to look at the atmosphere and physical oceanography and computational and science communication, all of which have been “useful for developing my career.”

Results from a study of clouds and aerosols conducted in the Azores revealed that new particles can seed the formation of clouds in the marine boundary layer—the atmosphere up to about a kilometer above Earth's surface—even over the open ocean, where the concentration of precursor gases was expected to be low. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

Understanding previously undocumented source of new particle formation will improve models of aerosols, clouds, and their impact on Earth’s climate

New results from an atmospheric study over the Eastern North Atlantic reveal that tiny aerosol particles that seed the formation of clouds can form out of next to nothingness over the open ocean. This “new particle formation” occurs when sunlight reacts with molecules of trace gases in the marine boundary layer, the atmosphere within about the first kilometer above Earth’s surface. The findings, published in the journal Nature Communications, will improve how aerosols and clouds are represented in models that describe Earth’s climate so scientists can understand how the particles—and the processes that control them—might have affected the planet’s past and present, and make better predictions about the future.

“When we say ‘new particle formation,’ we’re talking about individual gas molecules, sometimes just a few atoms in size, reacting with sunlight,” said study co-author Chongai Kuang, a member of the Environmental and Climate Sciences Department at the U.S. Department of Energy’s Brookhaven National Laboratory. “It’s interesting to think about how something of that scale can have such an impact on our climate—on how much energy gets reflected or trapped in our atmosphere,” he said.

Using an aircraft outfitted with 55 atmospheric instrument systems, scientists traversed horizontal tracks above and through clouds and spiraled down through atmospheric layers to provide detailed measurements of aerosols and cloud properties. The aircraft data were supplemented by measurements made by ground-based radars and other instruments. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

But modeling the details of how aerosol particles form and grow, and how water molecules condense on them to become cloud droplets and clouds, while taking into consideration how different aerosol properties (e.g., their size, number, and spatial distribution) affect those processes is extremely complex—especially if you don’t know where all the aerosols are coming from. So a team of scientists from Brookhaven and collaborators in atmospheric research around the world set out to collect data in a relatively pristine ocean environment. In that setting, they expected the concentration of trace gases to be low and the formation of clouds to be particularly sensitive to aerosol properties—an ideal “laboratory” for disentangling the complex interactions.

“This was an experiment that really leveraged broad and collaborative expertise at Brookhaven in aerosol observations and cloud observations,” Kuang said. Three of the lead researchers—lead authors Guangjie Zheng and Yang Wang, and Jian Wang, principal investigator of the Aerosol and Cloud Experiments in the Eastern North Atlantic [https://www.arm.gov/publications/backgrounders/docs/doe-sc-arm-16-020.pdf] (ACE-ENA) campaign—began their involvement with the project while working at Brookhaven and have remained close collaborators with the Lab since moving to Washington University in St. Louis in 2018.

Land and sea

Brookhaven Lab atmospheric scientist Chongai Kuang (center) with Art Sedlacek (left) and Stephen Springston (right) aboard ARM’s Gulfstream-159 (G-1) aircraft during a 2010 atmospheric sampling mission that was not part of this study. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

The study made use of a long-term ground-based sampling station on Graciosa Island in the Azores (an archipelago 850 miles west of continental Portugal) and a Gulfstream-1 aircraft outfitted with 55 atmospheric instrument systems to take measurements at different altitudes over the island and out at sea. Both the ground station and aircraft belong to the DOE Office of Science’s Atmospheric Radiation Measurement (ARM) user facility [https://www.arm.gov/], managed and operated by a consortium of nine DOE national laboratories.

The team flew the aircraft on “porpoise flights,” ascending and descending through the boundary layer to get vertical profiles of the particles and precursor gas molecules present at different altitudes. And they coordinated these flights with measurements taken from the ground station.

The scientists hadn’t expected new particle formation to be happening in the boundary layer in this environment because they expected the concentration of the critical precursor trace gases would be too low.

“But there were particles that we measured at the surface that were larger than newly formed particles, and we just didn’t know where they came from,” Kuang said.

The aircraft measurements gave them their answer.

Many of the choreographed flight paths for this study traversed the open ocean and also crossed within the ranges of the ground-based scanning radars at DOE’s Atmospheric Radiation Measurement (ARM) Climate Research Facility on Graciosa Island in the Azores. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

“This aircraft had very specific flight patterns during the measurement campaign,” Kuang said. “They saw evidence that new particle formation was happening aloft—not at the surface but in the upper boundary layer.” The evidence included a combination of elevated concentrations of small particles, low concentrations of pre-existing aerosol surface area, and clear signs that reactive trace gases such as dimethyl sulfide were being transported vertically—along with atmospheric conditions favorable for those gases to react with sunlight.

“Then, once these aerosol particles form, they attract additional gas molecules, which condense and cause the particles to grow to around 80-90 nanometers in diameter. These larger particles then get transported downward—and that’s what we’re measuring at the surface,” Kuang said.

“The surface measurements plus the aircraft measurements give us a really good spatial sense of the aerosol processes that are happening,” he noted.

At a certain size, the particles grow large enough to attract water vapor, which condenses to form cloud droplets, and eventually clouds.

Both the individual aerosol particles suspended in the atmosphere and the clouds they ultimately form can reflect and/or absorb sunlight and affect Earth’s temperature, Kuang explained.

Study implications

Framed by a brilliant rainbow, ARM’s Gulfstream-159 (G-1) research aircraft sits on the tarmac on Terceira Island during the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) winter 2018 intensive operation period in the Azores. Image courtesy of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility.

So now that the scientists know new aerosol particles are forming over the open ocean, what can they do with that information?

“We’ll take this knowledge of what is happening and make sure this process is captured in simulations of Earth’s climate system,” Kuang said.

Another important question: “If this is such a clean environment, then where are all these precursor gases coming from?” Kuang asked. “There are some important precursor gases generated by biological activity in the ocean (e.g., dimethyl sulfide) that may also lead to new particle formation. That can be a nice follow-on study to this one—exploring those sources.”

Understanding the fate of biogenic gases such as dimethyl sulfide, which is a very important source of sulfur in the atmosphere, is key to improving scientists’ ability to predict how changes in ocean productivity will affect aerosol formation and, by extension, climate.

The research was funded by the DOE Office of Science, DOE’s Atmospheric System Research, and by NASA. In addition to the researchers from Brookhaven Lab and Washington University, the collaboration included scientists from Pacific Northwest National Laboratory; Missouri University of Science and Technology; the University of Washington, Seattle; NASA Langley Research Center; Science Systems and Applications Inc. in Hampton, Virginia; the Max Planck Institute for Chemistry in Mainz, Germany; and the Scripps Institution of Oceanography, University of California, San Diego.

Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy.  The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time.  For more information, please visit science.energy.gov [https://www.energy.gov/science/office-science].

By Emma Collin

The Eiffel Tower is surrounded by protesters at the United Nations Climate Change Conference in Paris. Photo by Emma Collin
The Eiffel Tower is surrounded by protesters at the United Nations Climate Change Conference in Paris. Photo by Emma Collin

It’s the morning of Dec. 12 as I hurriedly make my way across Paris. Today will be my first real engagement with civil disobedience. Under a broad state of emergency, French President François Hollande has banned demonstrations, which the state defines as “more than two people sharing a political message.” In the weeks leading up to today, citizens who publicly criticized the egregiously dangerous deal brewing in the 21st United Nations Conference of the Parties climate talks were confronted with state-sanctioned violence, tear gas, and arrest. I emerge from the metro and scan the scene. Imposing graffiti on the bank of the Seine River nearby reads “L’état d’urgences pour faire oublier les tas d’urgences,” or “A state of emergency to ensure other emergencies are forgotten”.

Let’s back up. From Nov. 30 to Dec. 12, the United Nations Framework Convention on Climate Change convened heads of state in an old airport hanger in a suburb north of Paris. World leaders were tasked with drafting and signing a binding agreement that would prevent the most catastrophic effects of climate change. COP21 comes after years of unproductive conversation around climate; e.g. the notorious COP15 in Copenhagen 2009 produced only a vague document with no legal standing.

After an emotional and exhausting two weeks, not to mention an extended deadline and a few all-nighters, a deal heralded by most major news outlets as “historic” and “groundbreaking” was signed.

In many ways, the deal is historic. World leaders unanimously signing a deal at all signals progress. This forward movement is undoubtedly a testament to grassroots power built by communities around the world who are demanding action — for example, the more than 400,000 people who took to the streets of New York City last September for the People’s Climate March.

Emma-Collin-w
The author holds a monkey. Photo from Emma Collin

While acknowledging that victory, here are some things you should understand about the Paris climate accord. For one, it is functionally unenforceable. Emission reductions are based on voluntary commitments by each nation. To adhere to the desperately needed 1.5°C warming limit that appears repeatedly in the document’s text, we need to stop extracting and burning fossil fuels almost immediately. Instead, the tangible commitments to emission-reduction lock us into 3.0°C warming or more, which spells catastrophe, especially for the global south. Furthermore, language on indigenous and human rights were stripped completely from the body of the document. The words “fossil fuels,” “coal,” or “oil” don’t appear once.

One of the most debated and divisive sections of the document is called “loss and damage.” It outlines the idea that compensation should be paid to vulnerable states to aid adaptation to climate change. In a predictable move, representatives of developed countries like the United States fought hard to make this section non-binding. This strips poor nations — those already feeling the brunt of the consequences of climate change despite a historically negligible contribution to emissions — of any mechanism for claiming damages or compensation. Contrast this with international free trade agreements, which give corporations concrete mechanisms to sue nations for projected loss of profits. I know this deal is inadequate, and I know others know it too.

So when I exit the metro on Dec. 12 and quietly walk past swarms of Parisian police officers in full riot gear, I find myself in a crowd 15,000 people. I stand with people peacefully singing and chanting and defying a protest ban because they understand that we can do better. I stand next to my family and fellow delegates of Gulf South Rising, an inspirational group of community and indigenous leaders from the five southern states on the Gulf of Mexico, who are uniting to build just economic, political, and energy systems that heal their communities. And I stand with the understanding that what happened this month is just the beginning — that we must operate from a framework of resistance where we demand the healthy and safe communities we know we deserve.

The Paris Climate Accord will not get us there, but with world leaders committing, however theoretically, to action, it is a tool we can leverage as we continue this fight.

Emma Collin, a Centerport native, graduated from Harborfields High School. She recently moved to New Orleans, La., and is a senior project manager at Gulf Coast Center for Law & Policy and a community organizer with Gulf South Rising.

by -
0 2071
Hydrangea macrophylla. Photo by Ellen Barcel

By Ellen Barcel

Many Long Islanders have noted the change in Long Island’s climate. Old photos of the Great South Bay, the Long Island Sound and Peconic Bay taken during winters past show the amount of ice around. I’ve even seen an old photo that shows a car being driven on Peconic Bay in the early 1900s.

That was a long time ago, and despite the last two winters’ unusual cold and snow, we haven’t seen that much ice in years. So, yes, our island is definitely in a period of warmer winters. Officially, the U.S. Department of Agriculture’s Hardiness Zone map puts us squarely in zone 7, where in the past we were sort of borderline.

How does the gardener deal with Long Island’s climate? And, what do microclimates mean?

First, microclimates refer to a small area, within a larger one, that has different temperature, rainfall or humidity than the rest of the area. A friend of mine planted some gladiolus in an area near to her house, with two side walls, facing south. These are not hardy glads, but the regular, old-fashioned kind that need to be lifted each fall and stored. Yet, year after year, her glads return, even through unusually cold winters. She has a microclimate, one that is substantially warmer than the rest of her garden.

In our area, Easter lillies, above, should be mulched or lifted in the fall. Photo by Ellen Barcel
In our area, Easter lillies, above, should be mulched or lifted in the fall. Photo by Ellen Barcel

Microclimates can be one-half to one zone either warmer or colder than the surroundings. Another gardener of my acquaintance had a flowering shrub that she moved and moved repeatedly, until she found a location that was ideal for it. There’s a fruit orchard out east that can grow one type of tender tree in a small hollow but nowhere else. And we all know that the pine barrens tend to be colder than the rest of the island.

So, as a gardener, you may need to:

* Move certain plants more than once until you find the ideal location. I had to move a hydrangea several times until I found the perfect, shady and moist spot in my garden for it to thrive.

* Put plants only rated for zone 7 and warmer in a protected area. This could be behind a fence or in a little nook near the house, in a warmer microclimate. Remember that the past two winters we’ve had unusually cold weather.

* Make sure to mulch any plants in fall that are iffy, since they might not make it through a cold winter. Easter lilies, for example, are rated for zone 7 and warmer, yet frequently do not make it through Long Island winters. Lift them in fall or mulch them to make sure they survive.

* Grow iffy plants in containers that can be moved into a shed or garage over winter for a bit of added protection.

* Replace plants that bloom on old wood with rebloomers or everbloomers. For example, Hydrangea macrophylla, the old-fashioned kind, booms on old wood. Most of us saw few flowers last growing season and can expect very few this season as a result of the cold. So replace the older ones with Endless Summer or another rebloomer so that even if old wood dies back to the ground, new wood will produce beautiful flowers later in the season.

Ellen Barcel is a freelance writer and master gardener. To reach Cornell Cooperative Extension and its Master Gardener program, call 631-727-7850.