NASA’s 20-year global satellite data are categorized by their range, duration, and Severity of extreme drought and the flood rising with global warminga new study reveals.
Study co-author Matthew Rodell, a scientist at NASA’s Goddard Space Flight Center, said the study looked at the timing of such events and where they are occurring around the world.
The study, published in Nature Water, Strong correlations between extreme wet and dry events and rising temperatures.
More extreme events have occurred more frequently, louder, and more severely since 2015, ranking among the 10 warmest on record, Rodel said.
The study supports growing evidence to suggest that droughts and floods could become more frequent, widespread and severe as warming continues.
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weather phenomena are changing
We find that warmer temperatures lead to these more intense events and that they occur more frequently. Very likely.”
Warm air causes more evaporation during drought, increasing the amount of water available during wet weather thunderstorms and other precipitation.
2021 USA TODAY Survey showed an increase in extreme precipitation Droughts were becoming more frequent and more severe in the eastern half of the United States.
investigation:A summer of extreme weather has brought about astonishing changes in rainfall in the United States.
Years of research predicted that this might be the case, but as with surveys, most academic studies use rainfall data.
Rodell and Bailing Lee, who work at the Space Flight Center at the University of Maryland, used information from NASA satellites.More accurate data could help explain the underestimation that occurs in extreme precipitation data, Rodell said. On the uncertainty of rain and snow measurements at high altitudes.
what did the scientists do?
- Observed: Changes in land-based water storage measured by remote sensing satellites, including groundwater, soil moisture, snow and ice, and surface water worldwide.
- found: From 2002 to 2021, there will be 505 wet weather events and 551 extreme dry events, with an average duration of 5-6 months.
- analysis: Compare monthly temperature records with monthly total intensity of all wet and dry events.
what did they find?
One of the key findings is the decrease in frequency of precipitation events and the increase in frequency of dry events in the United States, such as the series of droughts in the Southwest since 2012.
again:
- A “highly correlated” relationship between global average temperature and the intensity of extreme wet and dry events – a combination of range, duration and severity.
- A stronger link to temperature than to El Niño and other cyclical patterns.
- Transition from wetter to drier events in southeastern Brazil and within “a vast stretch from southern Europe across the Middle East and Arabian Peninsula to southwest China and Bangladesh”.
- The first half of the decade saw drier events in sub-Saharan Africa and central-western South America, while the second half saw wetter events.
- A major flood event that covered much of Central Africa, beginning in 2019 and continuing through the end of 2021, was three times as large as the next largest wet or dry event across the 20-year span.
US rainfall change:See how the community has changed
Satellite data and precipitation data
“People intuitively know that extreme events are happening more often, but it’s hard to say for sure.”Satellite data gives us new perspectives, which gives us considerable confidence that it is already happening. “
“We’re not always good at measuring extreme precipitation,” he said. Also, rain and snow measurements cannot account for evaporation and runoff and do not give a ‘big picture’ of the total amount of water gained or lost.
Rodell and Li used a satellite known as the GRACE satellite. For gravity recovery and climate experimentsThe satellites measure reflected light, monitor each other’s orbits, account for gravitational forces that affect the data collected, and measure orbits “incredibly accurately.”
Similar to how the US Drought Monitor routinely monitors drought conditions within the country, “the approach presented by Rodel and Li could routinely monitor abnormal wet and dry events globally. ” writes Melissa Rohde. March.
“Recognizing droughts and floods before they intensify can help water managers respond accordingly and mitigate negative impacts,” she said. Goddard’s scientist’s approach “helps communicate the urgency of addressing climate change.”
Digging deeper:
Recent videos of drought around the world:
Dinah Voyles Pulver covers climate and environmental issues for USA TODAY. You can contact her at dpulver@gannett.com or @dinahvp on her Twitter.
