This post has been updated

Scientists keep rallying behind Kathryn Sullivan, the federal official on one side of a two-month standoff with a senior House Republican over a groundbreaking climate change study.

On Monday, the chief of the National Oceanic and Atmospheric Administration received a letter signed by 587 individual scientists from chemists to biologists urging to hold her ground against House science committee Chairman Lamar Smith’s campaign to discredit NOAA scientists. It follows a letter last month signed by seven scientific organizations representing hundreds of thousands of researchers warning that his efforts are “establishing a practice of inquests”that will have a chilling effect.

The Texas Republican, through a subpoena and series of letters, is pressuring Sullivan and Commerce Secretary Penny Pritzker to turn over the internal deliberations of NOAA scientists who published a study in Science in June that refuted the notion of a global warming ‘pause.” Smith, a climate change skeptic, contends that the study was “rushed to publication” to advance President Obama’s climate agenda.

“We urge you to continue to stand firm against these bullying tactics in order to protect NOAA scientists’ ability to pursue research and publish data and results regardless of how contentious the issue may be,” wrote the scientists, members of the Science Network of the Union of Concerned Scientists , a nonprofit science advocacy group.

“Please continue to resist this dangerous abuse of congressional oversight power.”

Sullivan and Smith have been locked in a stalemate for two months. The chairman has demanded internal documents and emails from NOAA he says will prove that the scientists manipulated global temperature data. Sullivan has refused to turn them over, citing the scientists’ right to confidentiality in their deliberations. Smith then appealed to Pritzker, whose agency includes NOAA, and threatened to subpoena her.

Smith, in a statement, called the Union of Concerned Scientists a “left-wing environmental activist group” that “continues to misrepresent my efforts to hold federal government agencies accountable.”

“Whistleblowers have come forward with complaints that federal employees at NOAA rushed to submit a study that allegedly refutes the nearly two-decade plateau of global warming, which had been reported by numerous scientific studies,” he wrote. “Atmospheric satellite data, considered by many to be the most objective, has clearly showed no warming for 18 years. But NOAA ignored satellite data to reach the conclusions it wants.”

He said the study was “conveniently published right before the Obama administration announced its costly greenhouse gas regulations that will have no measurable impact on climate change. Who wouldn’t be suspicious of this timing?”

Sullivan hit her strongest punch yet in a letter to Smith last week, saying that she will not “allow anyone to manipulate the science or coerce the scientists who work for me.” She told Smith that if his committee doubts the integrity of the peer-reviewed study it should commission a competing one.

But Smith wrote Wednesday, “When a government employee’s salary is paid by taxpayers, they have an obligation to be open and honest…The American people have a right to see the data and know the motivations behind this study.”

He has since backed down on his demand for the scientists’ communications, but says he wants the emails of a range of other NOAA staff. NOAA spokeswoman Ciaran Clayton said the agency is reviewing his request.

Some of the scientists who signed Monday’s letter annotated their signatures.

“The Dark Ages seem to have returned,” wrote Kathryn Florio, a medical researcher in Sioux Falls, S.D. “Please remain strong; we’ve got your back.”

Also Monday, 23 former and retired NOAA scientists sent Sullivan a separate letter thanking her for “standing up for scientific integrity and independence” in research and urging her to “continue to resist any unwarranted congressional investigations” that would stifle the scientific process or intimidate agency scientists and their collaborators.

The letter, signed by scientists in a range of fields, most in senior roles at the agency, read:

“We know firsthand that scientists need intellectual space to debate new ideas and give each other confidential feedback without worrying that an individual comment will be subject to public scrutiny at a later date. Turning over scientists’ correspondence and other information to the committee would significantly damage NOAA’s ability to conduct science by putting NOAA’s scientific independence at risk, and making it more difficult for NOAA scientists to collaborate with peers in academia and the private sector.”