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<p>While camphene is one of the dominant monoterpenes measured in biogenic and pyrogenic emission samples, oxidation of camphene has not been well-studied in environmental chambers and very little is known about its potential to form secondary organic aerosol (SOA). The lack of chamber-derived SOA data for camphene may lead to significant uncertainties in predictions of SOA from oxidation of monoterpenes using existing parameterizations when camphene is a significant contributor to total monoterpenes. Therefore, to advance the understanding of camphene oxidation and SOA formation and to improve representation of camphene in air quality models, a series of experiments was performed in the University of California Riverside environmental chamber to explore camphene SOA mass yields and properties across a range of chemical conditions at atmospherically relevant OH concentrations. The experimental results were compared with modeling simulations obtained using two chemically detailed box models: Statewide Air Pollution Research Center (SAPRC) and Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A). SOA parameterizations were derived from the chamber data using both the two-product and volatility basis set (VBS) approaches. Experiments performed with added nitrogen oxides (NO<span class="inline-formula">_<i>x</i></span>) resulted in higher SOA mass yields (up to 64 %) than experiments performed without added NO<span class="inline-formula">_<i>x</i></span> (up to 28 %). In addition, camphene SOA mass yields increased with SOA mass (<span class="inline-formula"><i>M</i>_o</span>) at lower mass loadings, but a threshold was reached at higher mass loadings in which the SOA mass yields no longer increased with <span class="inline-formula"><i>M</i>_o</span>. SAPRC modeling of the chamber studies suggested that the higher SOA mass yields at higher initial NO<span class="inline-formula">_<i>x</i></span> levels were primarily due to higher production of peroxy radicals (RO<span class="inline-formula">₂</span>) and the generation of highly oxygenated organic molecules (HOMs) formed through unimolecular RO<span class="inline-formula">₂</span> reactions. SAPRC predicted that in the presence of NO<span class="inline-formula">_<i>x</i></span>, camphene RO<span class="inline-formula">₂</span> reacts with NO and the resultant RO<span class="inline-formula">₂</span> undergoes hydrogen (H)-shift isomerization reactions; as has been documented previously, such reactions rapidly add oxygen and lead to products with very low volatility (i.e., HOMs). The end products formed in the presence of NO<span class="inline-formula">_<i>x</i></span> have significantly lower volatilities, and higher O : C ratios, than those formed by initial camphene RO<span class="inline-formula">₂</span> reacting with hydroperoxyl radicals (HO<span class="inline-formula">₂</span>) or other RO<span class="inline-formula">₂</span>. Further analysis reveals the existence of an extreme NO<span class="inline-formula">_<i>x</i></span> regime, wherein the SOA mass yield can be suppressed again due to high NO <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M16" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="c6f00d13d95b9183e3e2526db4298e27"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-3131-2022-ie00001.svg" width="8pt" height="14pt" src="acp-22-3131-2022-ie00001.png"/></svg:svg></span></span> HO<span class="inline-formula">₂</span> ratios. Moreover, particle densities were found to decrease from 1.47 to 1.30 g cm<span class="inline-formula">⁻³</span> as [HC]<span class="inline-formula">₀</span> <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M20" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="78c74280a32911099c6aadbec3864e34"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-3131-2022-ie00002.svg" width="8pt" height="14pt" src="acp-22-3131-2022-ie00002.png"/></svg:svg></span></span> [NO<span class="inline-formula">_<i>x</i></span>]<span class="inline-formula">₀</span> increased and O : C decreased. The observed differences in SOA mass yields were largely explained by the gas-phase RO<span class="inline-formula">₂</span> chemistry and the competition between RO<span class="inline-formula">₂+</span> HO<span class="inline-formula">₂</span>, RO<span class="inline-formula">₂+</span> NO, RO<span class="inline-formula">₂+</span> RO<span class="inline-formula">₂</span>, and RO<span class="inline-formula">₂</span> autoxidation reactions.</p>