As part of a five-week exercise in the northernmost part of the Earth, the Groton-based USS Hartford (SSN 768) will practice operating in the Arctic, surface at the North Pole and work with the National Science Foundation and other organizations to collect data such as changes in the salinity and temperature of Arctic water and sea ice measurements. 

The Hartford, one of two Los Angeles-class attack submarines participating in Ice Exercise 2016, returned from a six-month deployment in the European theater just three months ago.  

The USS Hampton (SSN 767) based in San Diego, is also participating in the exercise, which is "designed to assess the operational readiness of the submarine force while also continuing to advance scientific research in the arctic region," according to a Navy news release.

"Being here is a somewhat limited opportunity," Hartford's Commanding Officer Cmdr. Thomas Aydt said, speaking by phone from the Arctic.

In Aydt's 27-year Navy career, including serving on six submarines, this crew is the best he's ever worked with, he said. He also acknowledged the "amazing family support network" back in Groton.

After returning from deployment, the crew worked hard to quickly turn the submarine around to get it ready for the exercise. As the crew progresses in their careers, Aydt said, they will have the unique experience and knowledge of operating in the Arctic.

While it's colder aboard the Hartford, operating underwater in the Arctic doesn't look much different with the exception of some ice on the submarine's sonar cameras.

Above the water is a different story. Outside the submarine, it's extremely quiet, very calm and very dry, Aydt said. Once the submarine surfaced in ice, some of the crew members were brave enough to toss around a football.

"If you closed your eyes you would almost think you were in a recording studio," Aydt said, describing the quietness.

Atmosphere control and the health of associated systems on the Hartford is one of the crew's primary jobs while in the Arctic.

Those systems are performing well and underwent a maintenance and certification process before the Hartford left for the Arctic, Aydt said.

During the 2011 Ice Exercise, the USS New Hampshire's oxygen generator broke, so the crew had to burn sodium chlorate candles, which produce oxygen, in a specially designed furnace.

To prepare for the exercise, Hartford's 140-member crew took a weeklong course, led by specialists with the Arctic Submarine Lab based in San Diego, that detailed the environmental conditions and weather patterns in the Arctic, and how the submarine's equipment would operate in the region.

The crew then practiced in trainers that simulate an under-ice environment before training in familiar waters in the Groton area.

The Hartford was certified for Arctic operations twice in the last year, according to Aydt. Once the crew completes the ice exercise, they'll feed what they learn back into the training process to improve it.

In looking at readiness in addition to operational and maintenance schedules, the Hartford emerged as the right choice to support the exercise, Cmdr. Tommy Crosby, spokesman for Submarine Force Atlantic, said. The exercise features one boat from each coast.

The U.S. submarine force has conducted under-ice operations in the Arctic for more than 50 years, including more than 26 iterations of the ice exercise, and will continue to do so for "many, many more years," Crosby said.

The Arctic region is becoming increasingly important to the Navy, U.S. Sen. Chris Murphy, D-Conn., said.

"You've got the increased pace of Russian activity throughout the Arctic, global warming on the verge of creating new navigable pathways, and increasing claims on territory by foreign governments including the Russians," Murphy said, adding that there have been more demands for U.S. submarines in the Arctic.

Navy officials have said the exercise isn't driven by concerns about Russian expansion.

On Saturday, Murphy will fly from Andrews Air Force Base in Maryland to Deadhorse, Alaska.

From there, he'll take a small plane to Ice Camp Sargo, a temporary station set up on top an ice floe for the exercise, and then a helicopter to spend a few days aboard either the Hartford or the Hampton.

He couldn't say which one.

It will be Murphy's second time riding on a submarine, but his first "authentic" trip. He was aboard the USS California as it returned to Groton in October from a monthlong operation.

But the Arctic trip will be his first time on a submarine while it's submerged.

"Anytime you get to spend a couple days in this job thinking and working only on one topic, it makes you exponentially smarter," Murphy said. "This job is all about spending 10 minutes on this topic and 30 minutes on the next topic."

After the Arctic trip, Murphy said he will be in a better position to advocate on behalf of submarine funding programs, a big decision for federal lawmakers.

Congress must figure out how to pay for the Navy's top funding priority, the Ohio-class replacement program, 12 next generation ballistic missile submarines to replace the current fleet of 14 "boomers" built in the 1980s and 1990s.

The Congressional Research Service estimated that the program will cost $95 billion.

But a more immediate challenge for Murphy is explaining to his kids why the Navy is patrolling near Santa Claus at the North Pole.

j.bergman@theday.com