雰囲気

US7204894 (Annealing of hot rolled steel coils with clam shell furnace)
"In this type of high temperature annealing, the use of a normal air atmosphere（通常の空気（大気？）雰囲気）during the annealing promotes decarburization of the steel coil. The combination of high heat and a normal air atmosphere initially depletes a layer of carbon on the surface of the steel coil and decarburization results."

US4079156 (Conductive metal pigments)
"Conductive metal pigments which may be used in electrical devices are prepared by forming an alloy of a non-noble conductive metal and at least one oxidizable material, mixing the resulting alloy with a vitreous frit and an organic vehicle to form an ink, screening said ink onto a substrate, firing the alloy in an air atmosphere（空気雰囲気）at a temperature in excess of about 500° C. and cooling the ink to produce a conductive pigment."

US7368409 (Regeneration method of heterogeneous catalysts and adsorbents)
"This operation of regeneration has often to be preceded of stripping step consisting of heating step, either under air or inert atmosphere（空気または不活性雰囲気）(nitrogen or lean gas) in order to eliminate some free hydrocarbons contained in the catalyst porosity, just by promoting a phenomenon of evaporation."

「大気雰囲気」はan atmospheric atmosphere? the atmosphere? an air atmosphere?

atmospheric atmosphereとの記載はググってもネイティブの英語ではほとんど見つからない。
追記11FEB2016
WO 2013161969 A1 ゴム成形体の製造方法（ニチアス株式会社）
「大気雰囲気下とは、酸素を含有する大気雰囲気下を示すこととする。すなわち、従来架橋剤として用いられている過酸化物に由来するＣＯＯラジカル（ＣＯＯ・）が失活する大気雰囲気下を示すこととする。例えば、本発明における大気雰囲気下は、空気雰囲気下であることとしてもよいし、窒素約８０ｖｏｌ％、酸素約２０ｖｏｌ％を含有する大気雰囲気下であることとしてもよいし、酸素の体積含有率が１０ｖｏｌ％以上、３ｖｏｌ％以上、あるいは１ｖｏｌ％以上の大気雰囲気下であることとしてもよい。」（段落0091）

US2015/0137408 (上記の対応ＵＳ出願；日本語からの翻訳）
"[0088] In addition, the atmospheric atmosphere in the present invention refers to an atmospheric atmosphere containing oxygen. That is, the atmospheric atmosphere refers to an atmospheric atmosphere in which a COO radical (COO.) derived from a peroxide, which has heretofore been used as a crosslinking agent, is deactivated. For example, the atmospheric atmosphere in the present invention may be an air atmosphere, may be an atmospheric atmosphere containing about 80 vol % of nitrogen and about 20 vol % of oxygen, or may be an atmospheric atmosphere having an oxygen volume content of 10 vol % or more, 3 vol % or more, or 1 vol % or more."

数少ないネイティブ英語の例：
US4717798 (Low voltage vacuum circuit interrupter)
"4. The vacuum circuit interrupter of claim 3 wherein said enclosed space is at least partially evacuated for returning said metal diaphragm and said contact to said first position by difference in pressure between atmospheric atmosphere and reduced pressure within said enclosed space when said control signal is removed from said spaced wires."

US3460818 (Apparatus for treatment of particulate material on moving support)
"The downdraft gas flow through the grate and balls in the induration zone arises from a super-atmospheric atmosphere, such as about 10 inches of water, maintained above the layer of balls by conduit 74, and from a suitable subatmospheric pressure maintained below the layer of balls in the indurating zone by suction of fans 79."

空気雰囲気（上にあるが）も少ないような気がする。
US5086016 (Reservoir feed method of making ceramic composite structures and structures made thereby)
"EXAMPLE 3

A permeable preform of the shape of preform 56 in FIG. 5 was prepared by the technique of Table A, steps (B) and (C), using the same sedimentation casting composition except that only 5 parts by weight of the silicon metal powder was used. The preform was coated on its outer surface with two thin layers of air-permeable plaster of paris barrier material and the same aluminum alloy as in Table C was provided as the parent metal in a vessel (58 in FIG. 5). The lay-up was heated in an air atmosphere for 68 hours at 1000° C."

US20040009359 A1 (Alpha Al2O3 and Ti2O3 protective coatings on aluminide substrates)
"The process includes creating a dry air atmosphere with a concentration of water vapor below about 750 ppm at a temperature above about 550° C."