Two new satellites to be launched this year to track Earth’s rising oceans
Two new satellites will provide more detailed information about rising sea levels and other ocean changes on Earth.
Launching in November, the Sentinel-6/Jason Continuity of Service mission (Jason-CS) will be the longest-running Earth observation mission dedicated to studying the rising oceans. The spacecraft will provide the most sensitive water level measurements as it reveals details about rising oceans, helping to build nearly 40 years of sea level records, space.com reported.
A joint US-European satellite mission, S6 follows in the footsteps of a trio of missions (TOPEX/Poseidon and Jason-1, Ocean Surface Topography/Jason-2, and Jason-3) that have measured how sea levels have risen over the past 30 years. The preceding spacecraft revealed that Earth’s oceans rose by an average of 0.1 inch (3mm) in the 1990s, increasing to 0.13 inch (3.4mm) today.
S6 will use two identical satellites (Sentinel-6A and Sentinel-6B) to continue that work by studying changes in ocean circulation, climate variability such as El Niño and La Niña, and weather patterns, including hurricanes and storms, in addition to rising oceans.
“Global sea level is, in a way, the most complete measure of how humans are changing the climate,” Josh Willis, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement.
“If you think about it, global sea level rise means that 70 percent of the Earth’s surface is getting taller — 70 percent of the planet is changing its shape and growing. So it’s the whole planet changing. That’s what we’re really measuring,” Willis said.
Generations of change
Since the Industrial Revolution, widespread fossil fuel usage has dumped significant amounts of carbon dioxide and other greenhouse gases into Earth’s atmosphere. Together, these gases have heated the planet’s atmosphere to increasingly high levels.
As they cover the bulk of Earth’s surface, the oceans help to stabilize the climate by absorbing over 90 percent of the heat trapped on the planet by excess greenhouse gas. As the water heats, it expands, increasing the volume of water. Trapped atmospheric heat also melts ice sheets and glaciers, contributing to the rising sea levels. Over the last 25 years, the rate at which the ocean levels rise has continued to increase.
Sentinel-6/Jason-CS consists of two spacecraft, Sentinel-6A and Sentinel-6B, which will launch five years apart. Sentinel-6A will launch next year from Vandenberg Air Force Base in California aboard a SpaceX Falcon 9 rocket. Its sister craft will launch in 2025.
Hovering 800 miles above the planet, the spacecraft will send pulses to Earth’s surface and measure how long they take to return to the satellite, a process that will measure how much water vapor is present along the spacecraft’s path. At the same time, Sentinel-6/Jason-CS will use GPS and ground-based lasers to find its position, along with a special network known as the Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). Combined, the technology will measure the height of the ocean with an accuracy of about an
Sentinel-6/Jason-CS will gather global ocean data every 10 days, which will help it to provide insights into large ocean features like El Niño events. Unlike its predecessors, the spacecraft will also be able to provide insights into smaller ocean features such as complex currents that will benefit navigation and fishing communities.
“Global sea level rise is one of the most expensive and disruptive impacts of climate change that there is,” said Willis. “In our lifetimes, we’re not going to see global sea level fall by a meaningful amount. We’re literally charting how much sea level rise we’re going have to deal with for the next several
“Fossil fuel production and consumption began with coal — its first reported uses date as far back as 4000 B.C. in China where carving took place out of black lignite (one of the several forms of coal). However, large-scale combustion of coal is typically correlated with the period around the beginning of the Industrial Revolution.”
“Most of the emissions of human-caused (anthropogenic) greenhouse gases (GHG) come primarily from burning fossil fuels — coal, hydrocarbon gas liquids, natural gas, and petroleum — for energy use”
“In 2017, carbon dioxide (CO2) emissions from burning fossil fuels for energy were equal to about 76 percent of total US anthropogenic GHG emissions (based on global warming potential) and about 93 percent of total US anthropogenic CO2 emissions.”
Technology takes pressure off China’s Spring Festival travel rush
Millions of Chinese are traveling smarter, faster, more efficiently and more comfortably than ever before after one of the world’s largest human migrations got underway last Friday.
And the travel choices for the 2020 Spring Festival travel rush are also more diverse with a comprehensive transport system covering road, rail, water and air, Xinhua reported.
The travel rush, which sees families and friends reunite around the country for China’s most important traditional holiday, began 15 days ahead of the Spring Festival, or Chinese Lunar New Year, which falls on January 25 this year.
The high-speed rail link between Beijing and Zhangjiakou, cohost city of the Beijing 2022 Winter Olympics in north China’s Hebei Province, started operating on December 30 last year.
The travel time between the two cities has been greatly shortened, and Zhangjiakou is now with Beijing’s one-hour economic circle, said Li Shengwu, head of the Infrastructure Development Department of Zhangjiakou Development and Reform Commission.
A core part of the “eight verticals and eight horizontals” rail network, the Beijing-Zhangjiakou high-speed service connects with the Zhangjiakou-Hohhot and Datong-Zhangjiakou high-speed lines, helping to reduce the holiday travel pressure in Beijing, eastern Inner Mongolia, Shanxi Province and northern Hebei Province.
Travel is becoming more efficient for travelers this Spring Festival, who are expected to make 3.6 billion trips during the period.
Ticket sale is the first big test. Rapid technological development has accelerated online ticket sales and ticket checking.
In the 2020 holiday rush, the daily ticketing capacity of the official 12306 online booking service will increase from 15 million to 20 million.
Ticket checking is faster as e-tickets are quickly replacing paper tickets. The checking of e-tickets, a service now available at all high-speed railway stations, takes 30 percent less time compared with manual checking of paper tickets.
Facial recognition technology has also been used in some stations to speed up the ticket checking process.
Travel services are also becoming more intelligent with robot information services and intelligent storage facilities further improving travel efficiency.
In recent years, stations with heavy traffic such as the southern city of Guangzhou and the northwestern city of Xi’an have been using patrol robots for security. The robot can be on duty 24 hours a day in all weathers and check potential risks to prevent fire and other safety problems.
Artificial intelligence (AI) security monitoring is realizing real-time analysis and early warning of passenger flows, so authorities can effectively prevent stampedes and other safety issues during the travel rush.
The Beijing-Zhangjiakou railway is the first intelligent high-speed service with scientific and technological elements inside and out.
The carriages offer 5G signal, wireless charging, intelligent light adjustment, stepless color-changing windows, blind guidance and other functions. They also have adjustable seats and ski equipment cabinets, and can receive live broadcasts from the 2022 Winter Olympics.
The in-depth application of big data, AI and 5G technologies promises to usher in more new-generation intelligent vehicles such as self-driving vehicles, ultra-high-speed trains, unmanned aerial vehicles and intelligent ships.
Crater left by one of Earth’s biggest ever meteorite impacts finally found
About 800,000 years ago, a monster space rock struck the Earth hard and fast. The impact of the 1.2 mile-wide (1.9 kilometer-wide) meteorite flung debris across 10 percent of the planet’s surface.
Scientists have found this ancient debris, mostly in the form of glass blobs known as tektites, in Asia, Australia, and Antarctica. But until now, researchers had never found the site where the meteorite hit, Business Insider reported.
They’d been searching unsuccessfully for more than a century.
In a new study published in the journal Proceedings of the National Academy of Sciences, scientists describe the location where they think this massive rock crashed: A volcanic field in southeastern Laos.
“There have been many, many attempts to find the impact site and many suggestions, ranging from northern Cambodia, to central Laos, and even southern China, and from eastern Thailand to offshore Vietnam,” Kerry Sieh, the lead author of the study, told CNN.
Sieh’s team’s research offers strong evidence that the crater is buried underground — which explains why researchers couldn’t find it before.
Missing impact crater
When a meteorite hits, it super-heats rocks at the point of impact and catapults them into the sky. These liquefied rocks then cool into tektites. By examining where tektites are strewn, scientists can trace the origin of the meteorite that created them.
In the case of this strike, the tektites told scientists that a massive meteorite struck Earth’s surface 800,000 years ago, somewhere between the three continents where they found the glass bits.
The greatest density of tektites have been found in Indochina — the peninsula that consists of Cambodia, Laos, and Vietnam — making that the most logical place to search for the crater.
But a meteorite that big should have left a mile-wide scar on the Earth and plunged 300 feet (91.4 meters) into the ground, according to the study authors.
“That’s a very difficult size hole to make go away,” Aaron Cavosie, an Australian planetary scientist who was not involved in the study, told The New York Times.
Impact craters can, however, get buried under shifting tectonic plates or scraped away by erosion (though Indochina is a relatively stable part of our planet).
In his hunt for the crater, Sieh first looked at three ancient impact sites in Cambodia, central Laos, and southern China. But each crater was tens of millions of years older than the crash site has was searching for.
Then, in a region of southern Laos called the Bolaven Plateau, the researchers found lava flows that fit the age bracket: They were between 51,000 and 780,000 years old.
Eruptions on that 2,300-square-mile (6,000-square-kilometer) plateau had created a bed of layered lava 1,000 feet (300 meters) deep — a volcanic field big enough to hide a meteorite crater.
“This thick pile of volcanic rocks does indeed bury the site of the impact,” Sieh and his coauthors wrote.
All evidence points to Laos
To arrive at their conclusion, Sieh’s team compared the chemistry of the rocks in the volcanic field to that of the tektites. They matched.
Then they measured gravitational fields around the Bolaven Plateau. Sure enough, the researchers found an underground, elliptical area 300 feet (90 meters) thick, 11 miles (18 kilometers) long, and eight miles (13 kilometers) wide where gravity got weird.
Because craters are filled with less dense material than the surrounding rock, they have a slightly weaker gravitational pull. The gravity signals in the Laotian volcanic field indicated the presence of a subterranean crater.
What’s more, the lava on top of the potential impact crater was less than 800,000 years old.
The final piece of evidence sat 12 miles (19 kilometers) away from the summit of the volcanic field: A patch of sandstone looked to be battered with debris.
The sandstone outcrop contained fractured quartz grains, which the geologists think were proximal ejecta from the meteorite — the term for material that gets pushed out from an impact site into nearby rocks.
According to Cavosie, the new study does not determine unambiguously that the impact crater is buried in Laos, but he told The New York Times that “it’s a great lead on a new site worthy of investigation.”
Scientists will need to drill deeper into the lava bed — likely a few hundred meters down — to find the evidence they need to put this geological mystery to rest.
An alert signaling an incident at the Pickering Nuclear Generating Station near Toronto in Canada was sent in error to millions of residents, causing a scare and prompting calls for an investigation, AFP reported.