NASA’s cryosphere mission to provide ‘exceptionally important’ data about our planet

A NASA mission to measure the cryosphere with powerful lasers promises to give us unprecedented insight into our changing planet.

GLOBAL scientists are about to get their most accurate and sober look at the rate of Earth’s melting ice sheets, glaciers and sea ice thanks to the launch of a NASA satellite boasting powerful new laser technology.

Earth’s frozen regions — collectively known as the cryosphere — are melting causing sea levels to rise, threatening Pacific Islands and major coastal cities around the world.

Over the weekend, NASA launched a new satellite that will help scientists monitor the rate of the planet’s melting ice in a mission described as “exceptionally important for science”.

The ICESat-2 mission (an acronym for Ice, Cloud and Land Elevation Satellite) launched from the Vandenberg Air Force Base in California on Saturday local time and carried a single instrument: the Advanced Topographic Laser Altimeter System, or ATLAS.

The device will be activated in about two weeks and is set to reveal unprecedented detail about the current thickness of ice at the vulnerable polar regions as the climate warms.

“With this mission we continue humankind’s exploration of the remote polar regions of our planet and advance our understanding of how ongoing changes of Earth’s ice cover at the poles and elsewhere will affect lives around the world, now and in the future,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate.

The United Launch Alliance (ULA) Delta II rocket with the NASA Ice, Cloud and land Elevation Satellite-2 (ICESat-2) on-board. Picture: Bill Ingalls

It has been nearly a decade since NASA had a tool in orbit to measure ice levels. Picture: Bill Ingalls/NASA

It has been nearly a decade since NASA had a tool in orbit to measure ice sheet surface elevation across the globe. The first iteration of this project launched in 2003 and operated until 2009.

But since then, NASA has been taking measurements from aeroplanes flying over Greenland and Antarctica as part of a program called Operation IceBridge.

The nearly $1.3 billion satellite is a much more powerful and precise instrument than its predecessor. On board the new satellite are powerful lasers that will fire 10,000 times a second as it measures the environment below.

The original ICESat fired 40 times a second. While the original ICESat device took measurements spaced at about 100 metres apart, the new equipment will takes measurements every metre.

NASA says it will be able to measure the change in elevation of the ice sheets in Antarctica and Greenland to less than a centimetre, or about the width of a pencil.

The ATLAS technology will also measure the heights of forests to determine the amount of vegetation in a region, as well as monitor other attributes of land surfaces, water and clouds.

By timing how long it takes laser beams to travel from the satellite to Earth and back, scientists can calculate the height of glaciers, sea ice, forests, lakes and more.

An artist concept from NASA’s Goddard Space Flight Center depicts ICESat-2, and how the spacecraft will use lasers and a very precise detection instrument to measure the elevation of Earth’s surface.

In this October 2014 image obtained from NASA, engineers and technicians check the fit of ICESat-2’s telescope to its sling, before moving it into place on the instrument’s optical bench. Picture: Debbie McCallum/NASA

The scientists behind the project say the launch will provide a much-needed boost to environmental data and couldn’t come at a more important time.

Richard Slonaker, ICESat-2 program executive at NASA called the mission “exceptionally important for science”.

Humanity’s constant reliance on fossil fuels for energy means planet-warming greenhouse gases are continuing to mount. Global average temperatures are climbing year after year, with four of the hottest years in modern times all taking place from 2014-2017.

ICESat-2 should help scientists understand just how much melting the ice sheets are contributing to sea level rise.

“We are going to be able to look at specifically how the ice is changing just over the course of a single year,” said Tom Wagner, cryosphere program scientist at NASA.

A Nature Geoscience paper published in 2010 concluded that, at their fronts, glaciers in western Greenland are melting as much as 100 times faster on their bottoms than on their tops. The higher rate of melting is driven by warming ocean waters.

NASA believes the mission will provide “a phenomenal picture” of changes in the environment and is keen to get the information available to the science community as quickly as possible, it said.

“One of the things that we are trying to do is, one, characterise the change that is taking place within the ice, and this is going to greatly improve our understanding of that, especially over areas where we don’t know how well it is changing right now,” Mr Wagner said, mentioning the deep interior of Antarctica as one such area of mystery.

The mission is meant to last three years but has enough fuel to continue for a full decade, if mission managers decide to extend its life.

— With AFP