Global warming causing more powerful hurricanes

The number of hurricanes are increasing and global warming is to blame, say scientists.

Hurricanes are getting stronger as the world gets warmer, according to a new analysis.

Studying how hurricanes have changed over decades is difficult. The technological tools scientists use to study them changes constantly, making comparisons from different time periods hard to correlate. While research has generally suggested that global warming would result in more powerful and erratic hurricanes, it has been difficult to document with any degree of scientific certainty. Until now, that is.

A new study of hurricanes published May 18, 2020 in the journal Proceedings of the National Academy of Sciences, covers a period of 39 years from 1979 to 2017. Looking at the entire four-decade span and normalizing the data, researchers found a clear trend: storms are getting stronger and major tropical cyclones are occurring more frequently.

The 39-year period of the study overlaps a period when climate change has dramatically accelerated, according to reports by the National Oceanic and Atmospheric Administration (NOAA). The earth’s temperature has increased each year in the past 39 years, including eight of the 10 warmest ever recorded. 2018 and 2019, too recent to be included in the study, were also the warmest on record.

“The main hurdle we have for finding trends is that the data are collected using the best technology at the time,” James Kossin, a NOAA scientist and University of Wisconsin-Madison professor, said in a statement. “Every year the data are a bit different than last year, each new satellite has new tools and captures data in different ways, so in the end we have a patchwork quilt of all the satellite data that have been woven together.”

To create a consistent record, researchers removed the edges from newer, sharper tropical cyclone images to fit an older standard: images where each pixel represents a 5 square mile area (8 sq/km), taken once every three hours. They also excluded newer satellite images of storms using angles not available in 1998. The remaining dataset includes roughly 225,000 similar-quality images of some 4,000 global tropical cyclones stretching back to the 1980s.

Using the images of tropical cyclones to estimate wind intensity, measured in kilotons, researchers found that the chances of a tropical cyclone becoming a hurricane (sustained winds of 74 mph/119 km/h or higher) have increased significantly over the past 40 years. In addition, the odds of major hurricanes (100-knot storms) have gone up by about 15%, with most of that increase occurring in the last 19 years of the 39-year study period.

Astronomers discover oldest disk galaxy hidden deep in the cosmos

New discovery of large disk galaxy hidden in shadows at the edge of the universe.

The Wolfe Disk is a massive rotating disk from the earliest days of the universe.

In a new study, published in the journal Nature on Wednesday, an international team of astronomers detected light from an ancient, huge disk-shaped galaxy in a far corner of the universe. The light took 12.5 billion years to reach Earth, meaning that the disk formed around 1.5 billion years after the Big Bang during the earliest days of the universe.

Using the Atacama Large Millimeter Array or ALMA, one of the world’s most powerful telescopes, a research team found the galaxy when it was studying light coming from a distant, huge black hole known as a quasar. Some of the light from the new galaxy was absorbed before heading toward earth, revealing the shape of the universe in dark space. Through ALMA and other data from the Hubble Telescope, the team was able to more clearly resolve some of its features.

“Previous studies hinted at the existence of these early rotating gas-rich disk galaxies,” said Marcel Neeleman, an astronomer at the Max Planck Institute for Astronomy and lead author on the study. “Thanks to ALMA we now have unambiguous evidence they occur as early as 1.5 billion years after the Big Bang.”

The newly discovered galaxy has been officially named DLA0817g, but the team nicknamed it the Wolfe Disk in honor of astronomer Arthur M. Wolfe.

Comparing observations with analytical models, the team determined that that the dark object was is a galaxy made of a dusty, gaseous disk spinning at approximately 169 miles (272 kilometers) per second, with an estimated mass 50 to 100 times more than the sun.

The research team also believes the Wolfe Disk galaxy is forming stars at an incredibly fast rate. According to Xavier Prochaska, astronomer at the University of California, Santa Cruz and a co-author on the study, DLA0817g “must be one of the most productive disk galaxies in the early universe.”

The discovery provides some clues about how galaxies are built and why we so often see the structures resembling huge disks, while in other cases they are not visible.