Actively addressing inequalities promotes social change

UMass Amherst social scientist part of global research team studying group interactions

UNIVERSITY OF MASSACHUSETTS AMHERST

Research News

 

IMAGE: LINDA TROPP, PROFESSOR OF SOCIAL PSYCHOLOGY AT UMASS AMHERST, LED THE MULTINATIONAL STUDY IN THE U.S. view more 

CREDIT: UMASS AMHERST

What does it take for people to commit to take action to promote social equality? And how might this differ for people from advantaged and disadvantaged groups?

An international team, including Linda Tropp at the University of Massachusetts Amherst and researchers in 23 countries, finds more mutual support for social change among advantaged and disadvantaged groups when inequality is actively addressed and the psychological needs of each group are met. The new research, led by the University of Zurich (UZH), was published in the Journal of Personality and Social Psychology.

"What this research is showing is that people on both sides really need to acknowledge that they have different motivations and concerns when they interact with each other," says co-author Tropp, the lead researcher in the U.S. who has examined how members of different groups experience intergroup contact for more than 20 years.

Prior research has shown that advantaged groups prefer to discuss commonalities among groups rather than differences between groups, at the same time as they desire to feel accepted and not be labeled as biased. But if members of socially disadvantaged groups simply have pleasant, positive exchanges with people who are not themselves targets of discrimination, they may emerge from those contact experiences even less committed to fighting for social justice and improving their own group's social position.

As first author Tabea Hässler of UZH says, "They get the deceptive impression that their own group no longer suffers so much discrimination... It is therefore important that social inequalities and discrimination between different social groups are actively addressed and named." This helps to meet the needs of disadvantaged group members, such as racial minorities and LGBTIQ+ individuals, who are motivated to have a voice and feel empowered in their relations with advantaged groups.

Each group's psychological needs are therefore an important part of the equation. "If contact situations are structured where members of disadvantaged groups or minority groups feel empowered, that they have a voice and are being listened to and heard, that's the time when contact with members of advantaged groups may support their interest in collective action to challenge the status quo," says Tropp, professor of social psychology at UMass Amherst.

Similarly, when members of majority groups "feel welcome as allies in that cause and not presumed to be racist, then that can bolster their willingness to use some of their time and energy to try to promote social equality," she says.

To gather their data, 43 researchers around the world conducted a survey with more than 11,000 individuals from a range of identity groups, including heterosexual individuals and members of sexual or gender minorities, migrants and members of their respective host societies, as well as indigenous groups and religious minorities.

"Overall, our findings suggest that contact across group boundaries fosters social change when it meets the targeted needs of disadvantaged and advantaged groups," says Johannes Ullrich, professor of social psychology at UZH.

Tropp says one next step is to help prepare members of advantaged groups to engage in difficult conversations about power relations and discrimination.

"To the extent that the advantaged engage in those conversations with disadvantaged groups, talking about the structural inequalities that do exist and need to be addressed, then it's likely that both members of disadvantaged groups as well as advantaged groups will be more prepared to engage in efforts to challenge the inequalities that we have in our society," she says.

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People across the world favor paid parental leave, study finds

Americans are also supportive, but with some caveats

OHIO STATE UNIVERSITY

Research News

 

COLUMBUS, Ohio - Although the United States is the only wealthy nation that doesn't guarantee paid leave to mothers or fathers after the arrival of a new child, Americans endorse providing paid time off for parents nearly as much as people from other countries.

About 82% of Americans support paid maternity leave, just slightly less than the 86% who support it in 26 wealthy nations, a new study shows.

Where Americans differ from the rest of the world is that they are less supportive of government funding for paid leaves, prefer shorter leave times and are less supportive of paid leave for fathers.

"We find marked differences in how Americans want paid leave administered compared to the rest of the world - but very similar desires to have leave available," said Chris Knoester, co-author of the study and associate professor of sociology at The Ohio State University.

Knoester conducted the study with Richard Petts, professor of sociology at Ball State University, and Amelia Li, a doctoral student in sociology at Ohio State. Their findings were published this week in the International Journal of Comparative Sociology.

The researchers analyzed data from 35,488 people who participated in the International Social Survey Programme 2012. The participants come from 26 wealthy countries, including the United States, that belong to the OECD, the Organisation for Economic Co-Operation and Development.

Overall, the study found high levels of support for paid leave across the developed world, as well as support for relatively long paid leave periods and government funding for the time off, Knoester said.

Worldwide, about 75% of people wanted government support for paid maternity leave. In a previous study the authors published in Social Science Research, they found that about half wanted it for paternity leave.

Support for government funding was much lower in the United States - about half endorsed it for maternity leave, and only a third wanted it for paternity leave. And very few Americans wanted government funding leave by itself, Knoester said. Most wanted the government and private employers to share the costs.

"This may be a major reason why we don't have more widespread and generous leave offered in the United States, even though most people support it," he said.

"If we don't have leave provided through the federal government, we get what we have now, which is a patchwork of states and employers offering different leave policies."

Americans also didn't want as much paid leave as did those from other countries in the survey. People in the United States wanted about four months of leave allocated to new parents. Worldwide, people supported close to 13 months.

Support for paid leave for fathers is lower than for maternity leave, both in the United States and in the rest of the countries surveyed.

Overall, about 60% of people surveyed wanted paid paternity leave, compared to just over half of Americans.

While a lack of support for government funding may be one reason why the U.S. is the only major country without paid maternity leave, there are other reasons, the researchers said.

In another new study by the researchers, forthcoming in Sociological Focus, findings showed that older white people with more conservative political views in the United States were least supportive of paid parental leave.

"These tend to be the people in the elite positions in our society who make those policy decisions about paid leave," Li said. "That makes it difficult to enact leave policies."

Petts noted another reason why political elites in the United States may be less supportive of government-supported leave.

"These are the people who already largely have access to paid leave through their employers. They would not directly benefit from it, because they already have it," Petts said.

"It is a story of the haves and the have-nots."

The international study also showed other factors that affect people's support of paid leave.

As expected, women were generally more likely to support paid leave and wanted longer time off.

Also, people who were strong supporters of traditional gender roles, in which men focus on paid work and women focus on the home and family, were less supportive of paid leave than people who advocated more egalitarian gender roles.

"Relatedly, when people endorse both members of a couple working, they are more supportive of paid leave and this shows up particularly for support of paid leave for fathers in the U.S.," Knoester said.

In addition, individuals who felt more conflict between their home and job responsibilities were more likely to endorse paid leave.

While the survey that this study was based on was done 10 years ago, the researchers said more recent surveys suggest people's views have not changed much. If anything, people may have become slightly more supportive of paid leave, particularly in the United States.

"We are still seeing very high support of paid maternity leave, and there are some indications that support for paternity leave has increased since 2012," Knoester said.

In addition, signs point toward more Americans being in favor of government support of parental leave. Nine states and Washington, D.C., have enacted paid parental leave programs. Last November, Colorado voters passed a ballot measure that allows for up to 12 weeks of leave.

"I would never have guessed that the kind of measure enacted in Colorado would pass in the U.S. It suggests Americans are becoming more open to government support," Petts said.

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Association of Childcare Facility Closures With Employment Status of US Women vs Men During the COVID-19 Pandemic

Research Letter

June 25, 2021

Yevgeniy Feyman, BA¹; Naomi E. Fener, NP, MPH²; Kevin N. Griffith, PhD³

Author Affiliations Article Information

JAMA Health Forum. 2021;2(6):e211297. doi:10.1001/jamahealthforum.2021.1297

COVID-19 Resource Center

Introduction

In the US, policy responses to COVID-19 have varied across states, with some states requiring closures of childcare facilities to reduce population mobility and contact among households. Such policies may have been associated with reductions in the growth rate of the pandemic but may also have had unintended consequences. Women perform more unpaid labor than men in couples with children.¹ Because of these inequities, negative outcomes associated with lack of childcare options, such as reductions in hours worked, may be concentrated among working mothers. A study in Italy² found that the amount of household labor remained greater for women during the early period of the COVID-19 pandemic. We investigated the association between childcare facility closures and employment status among women vs men with children during the first year of the COVID-19 pandemic (January to December 2020) in the US.

Methods

For this cross-sectional study, we obtained employment and demographic data from the Integrated Public Use Microdata Series, Current Population Survey from January to December 2020. The number of deaths from COVID-19 per month was obtained from the Johns Hopkins Coronavirus Resource Center.³ Childcare closure data were obtained from the COVID-19 US State Policy Database.⁴ Our unit of observation was the person-month, restricted to individuals aged 18 to 64 years in households with children. This study was deemed to be exempt from review and informed consent by the Boston University institutional review board because it involved nonhuman subjects research. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

We used a triple differences approach with a linear probability model to estimate the association between childcare facility closures and overall changes in employment stratified by sex. Interrupted time series models were then used to assess changes in employment by race/ethnicity, sex, and state childcare facility closure status. Models controlled for individual-level demographic characteristics (eg, age, family size) and state-level COVID-19 case loads, with fixed effects for industry, occupation, month, state, and household. We controlled for race/ethnicity to improve model precision and stratify our findings. We used Stata, version 16-MP (StataCorp LLC) for statistical analysis. Additional information is given in the eMethods in the Supplement.

Results

This study included 48 920 individuals (13 307 in states with childcare closures and 35 613 in states without closures), of whom 24 452 (49.98%) were women and 24 648 (50.02%) were men; the mean SD age was 43.3 (9.6) years. The sample comprised 165 158 individual-months, including 44 925 individual-months in 15 states that closed childcare facilities by April 2020. All closures were rescinded by June 2020. Employment decreased for both men and women beginning in April 2020 (Figure). Estimates from the triple differences analysis showed that compared with men, the likelihood of a women being employed was −2.6 percentage points (95% CI, −4.3 to −1.0 percentage points) in closure states while closures were in effect. Nationally, this equated to a reduction of approximately 611 000 workplace positions among 23.5 million working mothers.⁵ Estimates were similar when controlling for the number of adults (vs men) in the household and greater when restricting to households with children younger than 6 years (−3.3 percentage points; 95% CI, −6.2 to −0.5% percentage points).

Interrupted time series models indicated that the largest differences in employment were observed in households with Hispanic and Black individuals, although differential estimates by sex in closure states were greatest in households with Hispanic and White individuals (Table). In a falsification test for households without children, there was no association of sex with employment status (estimate, −0.8 percentage points; 95% CI, −2.2 to 0.4 percentage points), and there was also no association in a test for households with only children of middle school age (11 years to <18 years) (estimate, −1.1 percentage points; 95% CI, −3.5 to 1.3 percentage points).

Estimates from the interrupted time series model for hours worked were greater for both men (−3.9; 95% CI, −4.9 to −3.0) and women (−5.8; 95% CI, −6.5 to −5.0) in closure states than for those in nonclosure states (men: −3.5 [95% CI, −4.2 to −2.8]; women −4.3 [95% CI, −5.2 to −3.5]). Women in closure states had a differential reduction of approximately 1 hour worked unconditional on employment.

Discussion

In this cross-sectional analysis, state-level childcare facility closures were associated with greater reductions in employment among women compared with men. This association was limited to parents of children younger than 6 years. Our results comport with prior estimates⁶; however, the longer study period allowed us to evaluate whether these associations dissipated by December 2020. We also found that the sex-differential associations were strongest in households with White and Hispanic individuals. In addition, we observed a differential association of sex with hours worked.

Our study has several limitations. First, we could not observe actual childcare service use. Second, because of our observational study design, all findings should be treated as associations. Third, other simultaneously enacted policies (eg, business closures) may have moderated the primary associations, but such policies were not included in this study.

Labor market outcomes may differ by sex, and well-intentioned policies may exacerbate existing inequities. Our findings suggest that additional policy interventions to support women in families with children are needed.

Back to top

Article Information

Accepted for Publication: April 30, 2021.

Published: June 25, 2021. doi:10.1001/jamahealthforum.2021.1297

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2021 Feyman Y et al. JAMA Health Forum.

Corresponding Author: Yevgeniy Feyman, BA, Department of Health Law, Policy, and Management, Boston University School of Public Health, 715 Albany St, Talbot Bldg. T2-West, Boston, MA 02118 (yfeyman@bu.edu).

Author Contributions: Mr Feyman and Dr Griffith had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: All authors.

Acquisition, analysis, or interpretation of data: Feyman, Griffith.

Drafting of the manuscript: All authors.

Critical revision of the manuscript for important intellectual content: Feyman, Griffith.

Statistical analysis: Feyman, Griffith.

Obtained funding: Griffith.

Administrative, technical, or material support: Fener.

Supervision: Griffith.

Conflict of Interest Disclosures: None reported.

Funding/Support: This study was supported by grant K12 HS026395 (Dr Griffith) from the Agency for Healthcare Research and Quality.

Role of the Funder/Sponsor: The Agency for Healthcare Research and Quality had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

References

1.

Barnes  MW.  Gender differentiation in paid and unpaid work during the transition to parenthood.   Sociol Compass. 2015;9(5):348-364. doi:10.1111/soc4.12263Google ScholarCrossref

2.

Meraviglia  C, Dudka  A.  The gendered division of unpaid labor during the COVID-19 crisis: did anything change? evidence from Italy.   Int J Sociol. 2020;0(0):1-12. doi:10.1080/00207659.2020.1832346Google Scholar

3.

Johns Hopkins Coronavirus Resource Center. Home page. Accessed September 15, 2020. https://coronavirus.jhu.edu/

4.

Raifman  J, Nocka  K, Jones  D,  et al. COVID-19 US state policy database. Published April 10, 2020. Accessed April 23, 2020. https://docs.google.com/spreadsheets/d/1zu9qEWI8PsOI_i8nI_S29HDGHlIp2lfVMsGxpQ5tvAQ/edit?usp=sharing&usp=embed_facebook

5.

Christnacht  C, Sullivan  B. About two-thirds of the 23.5 million working women with children under 18 worked full-time in 2018. US Census Bureau. Published May 8, 2020. Accessed January 23, 2021. https://www.census.gov/library/stories/2020/05/the-choices-working-mothers-make.html

6.

Russell  L, Sun  C. The effect of mandatory child care center closures on women’s labor market outcomes during the COVID-19 pandemic.  COVID Economics. 2020;(62):124-154.

 21st CENTURY ALCHEMISTS

Curtin research finds 'fool's gold' not so foolish after all

Curtin University research has found tiny amounts of gold can be trapped inside pyrite, commonly known as 'fool's gold,' which would make it much more valuable than its name suggests

CURTIN UNIVERSITY

Research News 

Curtin University research has found tiny amounts of gold can be trapped inside pyrite, commonly known as 'fool's gold', which would make it much more valuable than its name suggests.

This study, published in the journal Geology in collaboration with the University of Western Australia and the China University of Geoscience, provides an in-depth analysis to better understand the mineralogical location of the trapped gold in pyrite, which may lead to more environmentally friendly gold extraction methods.

Lead researcher Dr Denis Fougerouse from Curtin's School of Earth and Planetary Sciences said this new type of "invisible" gold has not previously been recognised and is only observable using a scientific instrument called an atom probe.

"The discovery rate of new gold deposits is in decline worldwide with the quality of ore degrading, parallel to the value of precious metal increasing," Dr Fougerouse said.

"Previously gold extractors have been able to find gold in pyrite either as nanoparticles or as a pyrite-gold alloy, but what we have discovered is that gold can also be hosted in nanoscale crystal defects, representing a new kind of "invisible" gold.

"The more deformed the crystal is, the more gold there is locked up in defects. The gold is hosted in nanoscale defects called dislocations - one hundred thousand times smaller than the width of a human hair - so a special technique called atom probe tomography is needed to observe it."

Dr Fougerouse said the team also explored gold extraction methods and possible ways to obtain the trapped gold with less adverse impacts on the environment.

"Generally, gold is extracted using pressure oxidizing techniques (similar to cooking), but this process is energy hungry. We wanted to look into an eco-friendlier way of extraction," Dr Fougerouse said.

"We looked into an extraction process called selective leaching, using a fluid to selectively dissolve the gold from the pyrite. Not only do the dislocations trap the gold, but they also behave as fluid pathways that enable the gold to be "leached" without affecting the entire pyrite."

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The study is supported by the Australian Research Council and the Science and Industry Endowment Fund. Dr Fougerouse is affiliated with The Institute for Geoscience Research (TIGeR), Curtin's flagship Earth Sciences research institute.

The full paper 'A new kind of invisible gold in pyrite hosted in deformation-related dislocations' is available online here: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G49028.1/604581/A-new-kind-of-invisible-gold-in-pyrite-hosted-in

RUSSIAN ALKEMY

NUST MISIS scientists create unique alloy for air, rail transports

NATIONAL UNIVERSITY OF SCIENCE AND TECHNOLOGY MISIS

Research News

 

IMAGE: TORGOM AKOPYAN, SENIOR RESEARCHER AT NUST MISIS DEPARTMENT OF METAL FORMING view more 

CREDIT: SERGEY GNUSKOV, NUST MISIS

Scientists from the National University of Science and Technology "MISIS" (NUST MISIS) in cooperation with their colleagues from the Siberian Federal University and the Research and Production Centre of Magnetic Hydrodynamics (Krasnoyarsk) have developed a technology for producing a unique heat-resistant aluminium alloy with improved durability.

According to the researchers, this new alloy could replace more expensive and heavier copper conductors in aircraft and high-speed rail transport. The study results were published in an interdisciplinary, peer-reviewed journal, the Materials Letters. (https://www.sciencedirect.com/science/article/abs/pii/S0167577X2100896X)

Researchers have created a method for producing a unique heat-resistant, high-strength wire. The wire is made from an aluminium alloy, initially cast as a long billet, about 10 mm in diameter, in an electromagnetic crystalliser. The authors have succeeded in obtaining a thermally stable structure (up to and including 4000°C), which is considerably superior to known aluminium alloys with thermal stability, retaining their properties up to 250-3000°C.

"Before, alloys with such a structure were attempted to be produced using complicated and expensive technology involving ultrafast melt crystallisation, pellet production and subsequent methods of powder metallurgy", Nikolay Belov, Chief Scientist and Professor of Materials Science and Light Alloys at National University of Science and Technology "MISiS", explained.

The researchers have conducted direct deformation of a long billet - rolling and drawing - without using the traditional operations of homogenization and hardening for aluminium alloys. The key feature of their proposed technology lies in the casting and annealing regimes which produce a structure of thermally stable nanoparticles containing copper (Cu), manganese (Mn) and zirconium (Zr).

"We have been able to produce a high-strength heat-resistant wire from this alloy. We are now determining its physical and mechanical properties, and the first results are already very impressive. We are planning to patent the method of producing this type of wire", Torgom Akopyan, senior researcher at NUST MISIS Department of Metal Forming, noted.

Heat-resistant, high-strength conductivity conductors could find use in aircraft and high-speed rail transport instead of the significantly more expensive and heavier copper ones. According to the authors, the unique and cheap technology could interest producers of wrought aluminium alloy semi-finished products.

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The main results of the study were supported by the Russian Science Foundation (RSF) Grant No. 20-19-00249.

 

Smart transfer rules can strengthen EU climate policy

POTSDAM INSTITUTE FOR CLIMATE IMPACT RESEARCH (PIK)

Research News

 

"Fit for 55": under this heading, the EU Commission will specify the implementation of the European Green Deal on 14 July. This refers to the more ambitious climate policy announced, with 55 instead of 40 percent emission reduction by 2030 (relative to 1990), and net-zero emissions in 2050. Coordination between the 27 EU states is expected to be difficult since unanimity is usually required here for sweeping changes. An economic model study by the Berlin-based climate research institute MCC (Mercator Research Institute on Global Commons and Climate Change) and the Potsdam Institute for Climate Impact Research (PIK) examines how to achieve good results under such conditions. The study has just been published in the renowned Journal of Environmental Economics and Management.

In a model based on so-called game theory, the researchers mathematically depict the main features of such negotiations. This includes a coexistence of climate policy at the federal and state levels, the need for coordination between rich and poor as well as large and small countries and, as an anchor point, the assumption that there is zero idealism involved in the tug-of-war over climate protection. Focusing on maximising national welfare, governments veto any action they perceive as excessive at the federal level, generating more costs than benefits.

"We expand the economic theory on fiscal federalism to include climate policy and consensus-building," explains Christina Roolfs, researcher in the joint MCC-PIK Future Lab on Public Economics and Climate Finance and lead author of the study. "We were interested in how we could achieve as much climate protection as possible under such circumstances. It is about smart policy design that should set the right incentives, so that common plus national policy together render climate emissions as costly as appropriately, and accordingly cause them to decline."

The decisive factor is how the revenues from joint emissions pricing are being distributed within the states. Up to a certain point, rich countries accept the role of net donor, making transfers to poorer countries to support climate policy. Given their prosperity, the effect of climate damage on their economy is likely to be large, and countermeasures are therefore particularly worthwhile. Only when the transfers become too high will they switch from being the driver to putting on the brakes. The researchers model the behaviour of individual governments under different forms of revenue distribution, and for different decision processes: if the countries anticipate that they will benefit from the revenues generated from federal emissions pricing, they will agree to a higher common price. The key finding of the study is that the revenues from emissions pricing should be distributed between countries not according to population, and not according to current emissions, but according to historical emissions before the start of the pricing system. This principal will provide the greatest leeway for a consensual ambitious climate policy.

"This is of practical importance for the European Green Deal," emphasises Ottmar Edenhofer, Director of MCC and PIK and one of the study's co-authors." Money from the EU Emissions Trading System in the energy and industry sectors is already distributed primarily according to historical emissions. But the revenue base is currently riddled with holes because about half of the emission rights are allocated for free. There is a need for a harmonised and consistent design. This also applies to the intended expansion of pricing to the transport and heat sectors." According to Edenhofer, the study is relevant to international cooperation in general: "The theoretical analysis shows that large differences in size and wealth are obstacles. That is why, for example, linking carbon pricing systems might initially be a sensible thing to undertake between similarly strong partners, for example between the EU and the USA."

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Article:
Roolfs, C., Gaitan, B., Edenhofer, O. (2021): Make or brake - Rich states in voluntary federal emission pricing. Journal of Environmental Economics and Management

Emissions cause delay in rainfall

Human activity inflicts four-day rain delay, hampers hydrological cycle

DOE/PACIFIC NORTHWEST NATIONAL LABORATORY

Research News

 

RICHLAND, Wash.--Earth bears many signs of human influence, from warming that exceeds pre-industrial temperatures to a rising sea. Add to that list, now, the human influence on the timing of Earth's water cycle, revealed by a new study led by researchers at the U.S. Department of Energy's Pacific Northwest National Laboratory.

The research, published this week in the journal Nature Climate Change, peels back layers of climatological noise to uncover a clear signal: from 1979 to 2019, increases in greenhouse gases and reductions in human-generated aerosols triggered an approximate four-day delay in seasonal rainfall over tropical land and the Sahel. The lag could mean delayed crop production, exacerbated heat waves, and worsened wildfires, among other consequences.

"The global warming we've seen has already been attributed to human activities with high confidence," said atmospheric scientist Ruby Leung, who coauthored the study. "But, historically, we have not been very successful in pinpointing the footprint of human activity in the hydrological cycle. This study shows that, yes, the later onset of monsoon rainfall, paired with future warming projected by climate models, has already emerged."

More moisture

Ironically, the rain delay is caused by an increasingly moist atmosphere. As greenhouse gases warm Earth's surface, more water vapor makes its way into the atmosphere. This added moisture boosts the amount of energy needed to heat the atmosphere as spring transitions to summer, which can shift the timing of rainy seasons.

"When there is more water vapor in the atmosphere, it becomes more ocean-like," said Earth scientist and first author Fengfei Song. "And we know the ocean takes longer to warm up than the atmosphere. More moisture means it will take longer for the atmosphere to absorb energy and produce rainfall."

Human-generated aerosols, like the particulates produced from burning fossil fuels, tend to reflect sunlight. These cool the atmosphere and undercut the warming trend caused by greenhouse gases.

But, as aerosol concentrations continue to decline from efforts to improve air quality, some of that cooling effect is lost, which escalates both warming and the delay of monsoon rainfall in recent decades, according to the study.

If aerosol concentrations continue to decline and greenhouse gas concentrations continue to rise, the delay will extend in the future, said Leung. The study's authors project that, by the end of the century, the rainy season could be further delayed by more than five days over northern tropical land and more than eight days over the Sahel.

"For monsoon regions, like India, with an agrarian economy," said Leung, "a delayed onset of summer rainfall could devastate crop production and jeopardize the livelihood of large populations, unless farmers recognize and adapt to the long-term changes amidst the highly variable monsoon onset date."

What is the hydrological cycle?

Most of Earth's water lies within the ocean. Sunlight heats the sea, and some of that water rises from the surface as vapor. That water vapor, along with water transpired from plants and water evaporated from soil, can condense and produce clouds and rainfall when it encounters rising air.

Rising air currents are strongest in the tropics, where solar radiation is strongest. Gaze upon our planet from space and you'd see the product of these strong, moisture-rich air currents: Earth's signature rain band, vigorous with storms and showers, encircling the planet about its middle.

As seasons shift and the Sun migrates between hemispheres, the rain band moves. When the band reaches land, it marks the onset of the monsoon season, delivering ample water supply for both tropical forests and the large populations that live within and near them.

In a world made warmer by human activity, a more moisture-laden atmosphere stores more energy, delaying the movement of the rain band and the onset of monsoon rainfall.

A signal among noise

Researchers first projected the rain delay through climate modeling roughly a decade ago. Being able to point to the delay within the observational record, however, proved challenging. One does not simply measure global precipitation; the difficulty, said Leung, is twofold.

First, disentangling human-caused influence from the day-to-day or year-to-year variability in Earth's climate is arduous work. Think of trying to pinpoint a single voice's signature audio wave in a recording filled with background chatter.

"Temperature and precipitation aren't the same each year," said Leung. "There's a huge amount of variability."

The second challenge stems from data collection. Where the historical record of global temperature is long-standing, data-rich, and directly measured, the record of global precipitation is relatively short and saddled by uncertainty.

Satellites measure global precipitation indirectly by detecting energy reflected by clouds and raindrops, which imbues a degree of uncertainty. Widespread satellite use began in the late 1970s, leaving a record of only several decades.

Uncovering the delay signal buried in the noise of climatic variability came as global precipitation data became increasingly available and climate models grew more robust. By using eight observational data sets paired with 243 simulations made through multiple models, the study's authors were finally able to show that rainfall had indeed delayed in spring in the northern hemisphere.

Much of the seasonal shift came as a result of post-World War II economic development that brought increased greenhouse gas emissions and, subsequently, a reduction of aerosol emissions beginning in the 1980s, according to the study. Human activity was not the only driver behind the delay, however. Decadal sea surface temperature variability, among other factors, may have also contributed to the seasonal shift.

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This research was funded by the U.S. Department of Energy Office of Science Biological and Environmental Research as part of the Regional and Global Modeling and Analysis program area, which is part of the Earth and Environmental Systems Modeling Program.

Pacific Northwest National Laboratory draws on its distinguishing strengths in chemistry, Earth sciences, biology and data science to advance scientific knowledge and address challenges in sustainable energy and national security. Founded in 1965, PNNL is operated by Battelle for the U.S. Department of Energy's Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States. DOE's Office of Science is working to address some of the most pressing challenges of our time. For more information, visit PNNL's News Center. Follow us on Twitter, Facebook, LinkedIn and Instagram.

Scientists use NASA satellite data to track ocean microplastics from space

NASA/GODDARD SPACE FLIGHT CENTER

Research News

 

IMAGE: AN ASSORTMENT OF MICROPLASTIC FRAGMENTS, FILAMENTS, AND FIBERS FROM THE NORTH ATLANTIC SUBTROPICAL GYRE DISPLAYED IN A DISPOSABLE WATER BOTTLE. view more 

CREDIT: COURTESY OF NICOLE TRENHOLM / OCEAN RESEARCH PROJECT

Scientists from the University of Michigan have developed an innovative way to use NASA satellite data to track the movement of tiny pieces of plastic in the ocean.

Microplastics form when plastic trash in the ocean breaks down from the sun's rays and the motion of ocean waves. These small flecks of plastic are harmful to marine organisms and ecosystems. Microplastics can be carried hundreds or thousands of miles away from the source by ocean currents, making it difficult to track and remove them. Currently, the main source of information about the location of microplastics comes from fisher boat trawlers that use nets to catch plankton - and, unintentionally, microplastics.

The new technique relies on data from NASA's Cyclone Global Navigation Satellite System (CYGNSS), a constellation of eight small satellites that measures wind speeds above Earth's oceans and provides information about the strength of hurricanes. CYGNSS also uses radar to measure ocean roughness, which is affected by several factors including wind speed and debris floating in the water.

Working backward, the team looked for places where the ocean was smoother than expected given the wind speed, which they thought could indicate the presence of microplastics. Then they compared those areas to observations and model predictions of where microplastics congregate in the ocean. The scientists found that microplastics tended to be present in smoother waters, demonstrating that CYGNSS data can be used as a tool to track ocean microplastic from space.

The results were published online on June 9, 2021 in IEEE Transactions of Geoscience and Remote Sensing. The work was done by Chris Ruf, professor at the University of Michigan and principal investigator for CYGNSS, and undergraduate student Madeline C. Evans.

CAPTION

Assortment of microplastics that were sifted from the ocean.

CREDIT

NASA