In the Mail on Sunday article, Dr. Bates, who at one point was in charge of archiving climate data at the centers, accused Mr. Karl of having used “unverified” data. In a long blog post published Saturday, Dr. Bates went into extensive detail — the kind that only true data geeks could love — about how data sets are or are not archived and verified at NOAA.

But Dr. Bates also accused Mr. Karl of misusing the process. “We find Tom Karl’s thumb on the scale pushing for, and often insisting on, decisions that maximize warming and minimize documentation,” he wrote.

Republicans on the House committee and Mr. Smith, in particular, have long attacked Mr. Karl’s paper and have focused on it as part of a lingering investigation of what Mr. Smith has described as the Obama administration’s “suspect climate agenda.” The committee has demanded that NOAA researchers turn over emails related to the work; the scientists have refused to do so.

Do the claims have merit?

Climate scientists, some of whom had worked on the data sets, voiced support for the work of Mr. Karl and the other researchers. In a post on the blog of the Irish Climate Analysis and Research Units at Maynooth University, Peter Thorne, who worked on the data but left NOAA before work began on the paper itself, disputed much of what Dr. Bates said.

Dr. Bates, Dr. Thorne wrote, was not involved in the data work and had misrepresented “the processes that actually occurred.” Dr. Thorne also disputed the idea that Mr. Karl had his “thumb on the scale.” Mr. Karl only used the data — he was not personally involved in the refinements, Dr. Thorne wrote. “At no point was any pressure brought to bear to make any scientific or technical choices.”

In a post at Carbon Brief, a British website that covers climate science and policy, Zeke Hausfather, a climate scientist at the University of California, Berkeley, disputed the contention that the data sets used in Mr. Karl’s paper were unverified or that the data had been manipulated.

Dr. Hausfather was one of the authors of a review of the NOAA ocean data, which showed the most change. The paper, published in January, compared the old and new NOAA data with independent data from satellites, buoys and other sources and found that the new data matched the independent data more closely. The result, he wrote, “strongly suggests that NOAA got it right and that we have been underestimating ocean warming in recent years.”