AMS-60s (Aerosol Mass Spectrometer) 1 Minute Data https://data.eol.ucar.edu/dataset/618.014 Summary AMS-60s (Aerosol Mass Spectrometer) 1 Minute Data, chemically speciated submicron (PM1.5 vacuum aerodynamic) non-refractory particulate mass (AMS-60s), analyzed in 60 s averages of the native AMS data (reported under the AMS data ID)collected on board the NSF/NCAR GV HIAPER during the TI3GER (Technological Innovation Into Iodine and GV Environmental Research) field project conducted on the NCAR G-V from 2through 28 April 2022. This data set is in ICARTT format. Please see the header portion of the data files for details on instruments, parameters, quality assurance, quality control, contact information, and data set comments. Identifiers * Local archive identifier: 618.014 Versions 0.1 1.0 Citation Example citation following ESIP guidelines (http://bit.ly/data_citation): Kim, D, Guo, H, Campuzano-Jost, P and Jimenez, JL. 2022. AMS-60s (Aerosol Mass Spectrometer) 1 Minute Data. Version 1.0. UCAR/NCAR - Earth Observing Laboratory. https://data.eol.ucar.edu/dataset/618.014 Accessed 22 Nov 2022. If you plan to cite this dataset in a publication, please email us at: datahelp@eol.ucar.edu We may be able to provide an updated citation that includes a DOI. Acknowledgement In addition to the citation reference and any other acknowledgements, please acknowledge NCAR/EOL in your publications with text such as: Data provided by NCAR/EOL under the sponsorship of the National Science Foundation. https://data.eol.ucar.edu/ Related projects * TI3GER: Technological Innovation Into Iodine and GV Environmental Research https://data.eol.ucar.edu/project/TI3GER Additional information * Spatial Type: point * Frequency: continuous * Language: English Categories * Aircraft * Chemistry Platforms * Aircraft, NSF/NCAR GV HIAPER Instruments * AMS - Aerosol Mass Spectrometer INSTRUMENT_INFO: AMS_Type=V; Ionization_type=EI; AMS_SamplingTime: 1 s (0.2 for flux legs); AMS_SamplingCycle: Fast Mode, 6 s closed and 46 s open (+4 s SD, reported under a different DataID), 1 min synchronization clock; for flux measurements, SD and backgrounds are suppressed during flux legs in order to obtain continuous MS-mode (total PM1.5 concentration) data coverage. AMS_LensType=PM2.5; AMS_LensPressure=3.81 Torr (actively controlled); AMS_FlowRate=Flowrate_AMS; AMS_PrsTempFlowCal: 273K, 1 atm; AMS_STPConversionFactor=StdtoVol_AMS; AMS_DAQType = ADQ_1600; AMS_CE: Calculated using the algorithm from Middlebrook et al 2012, AS&T 46, 258–271 [https://doi.org/10.1080/02786826.2011.620041] using 1 min data when total inorganic aerosol is below 15 ug sm-3 and 1 s data above 15 ug sm-3; AMS_PMCut(D50)= ~1.5 um vacuum aerodynamic, based on in-field and available upon request; AMS_Calibrations: AN single particle IE calibration (ET, 500 nm particles) including ammonium RIE after every flight; sulfate RIE as well a AN and PSL size calibration (75-900 nm), at regular intervals, MSA, perchlorate, iodine, chloride, bromine and seasalt calibrations; laboratory calibrations transmission curve pre and post-deployment; AMS_FilEmmCurr = 1.6 mA (actively controlled); AMS_InletRH=not actively controlled, reported as InletRH_AMS based on data from the VCSEL instrument; AMS_SquirrelVersion=1.66G; AMS_IEOverAB=7E-13; AMS_RIENH4=3.75; AMS_RIESO4=1.44; AMS_RIEChl=1.73; AMS_RIEClO4=0.52; (based on in-field calibrations), AMS_RIEBr=0.85, AMSRIEI=0.67, AMS_CFMSA=0.148, AMS_CFSeasalt=1/110, AMS_PieberCorr=1.22% (as discussed in Pieber et al 2016, ES&T 50 (19), 10494–10503 [https://doi.org/10.1021/acs.est.6b01035]; AMS_HuCorr=-0.02% (as discussed in Hu et al 2017, AS&T 51 [https://doi.org/DOI:10.1080/02786826.2017.1296104]) DATA_INFO: Only brief explanations are provided here. Please refer to http://tinyurl.com/FAQ-AMS-Data for additional topics and more detailed explanations, and contact the PIs if in doubt. Both that web page and this header are updated regularly in response to questions from data users and/or new information about the instrument and data interpretation. All concentration data are reported under STP (273 K & 1013 mb); use the provided conversion factor to calculate under ambient temperature and pressure. Note that several other definitions of standard conditions are in use by others in the community, and some groups and models report under ambient and not standard conditions--check carefully before comparing! Data was taken on a 1 min clock with 6 s background and 46 s ambient measurements, reported in 1 s (or faster) increments. The remaining time was either instrument overhead or was spent taking particle size-segregated (SD) data. Bulk analysis of the SD data is included in this data stream, while the size-segregated products are reported under a different dataID (AMSSD). Note that these SD data are NOT included in the 60s AMS averaged product. IMPORTANT: All reported data in the AMS-60s file is derived by analyzing the averaged raw spectra in 1 min intervals (up to 60 s of sampling, exact sampling times provided). It is NOT an arithmetic average of the data reported under the AMS Id for native resolution. Hence it has higher S/N than the simple average and should be preferentially used for longer timescales. When measuring aerosol fluxes, backgrounds and SD data are manually disabled to capture the full length of the flux leg uninterrupted. Time base is corrected for inlet lag (about 0.2 s in the BL, 0.5 s in the stratosphere). GPS latitude, longitude, and altitude are provided (inlet lag adjusted) from the instruments' own GPS data feed. The inlet transmission of the CU AMS is characterized routinely in the field and available upon request, and should always be taken into account when performing comparisons with other aerosol sensors (see Guo et al, 2021, AMT 14,3631–3655 [https://doi.org/10.5194/amt-14-3631-2021]). A new aircraft inlet interface recently extended the sampling range of the AMS to PM1.5 vacuum aerodynamic (see Kim et al, 2025, Aerosol Research Discuss. [https://doi.org/10.5194/ar-2025-6]); in practice this means a full characterization of the accumulation mode, hence the range in the variable names stays unchanged (“PM1”), however, care is advised when comparing coarse mode compounds such as seasalt across different missions. All reported data (including the individual f_x marker fractions) are derived from fitting individual HR ions using the PIKA software package, and NOT by using the unit mass resolution (UMR) signal (analyzed by the Squirrel software package). Unlike the aerosol species concentrations (extensive properties), all the variables (intensive properties) detailing the chemical composition of the organic fraction were thresholded for the organic detection limit (OA_DL_PM1.5_AMS) to avoid averaging artifacts; the thresholded data should be averaged to slower time resolutions with OA mass weighting. Reported aerosol density is estimated for non-refractory material assuming an internally mixed aerosol, following the method of Salcedo et al 2006, ACP 6, 925–946 [https://doi.org/doi:10.5194/acp-6-925-2006]; please note that this calculation does not include seasalt, which is typically externally mixed with the non-refractory aerosol. The density of the organic fraction is estimated with the expression provided in Kuwata et al 2012, ES&T 46, 787-794 [https://doi.org/10.1021/es202525q]. Only species above DL are included in the density calculation. Atomic O/C, H/C, and OA/OC ratios are reported using the updated calibration proposed by Canagaratna, Jimenez et al. 2015, ACP 15, 253-272 [https://doi.org/10.5194/acp-15-253-2015], which results in, on average, 28% higher O/C and 7% higher H/C ratios than using the Aiken et al 2008, ES&T 42, 4478–4485 [https://doi.org/10.1021/es703009q] method. The oxidation state of organic carbon (OSc) is provided according to the approximate formula of Kroll et al 2011, Nat. Chem. 3, 133-139, 2011 [https://doi.org/10.1038/nchem.948] using the updated calibration described in Canagaratna, Jimenez et al. 2015. The molar ion ratio of ammonium to the inorganic anions (“Ammonium Balance” also referred to as cation/anion ratio) is provided as a rough proxy for aerosol acidity, see Schueneman et al, AMT 2021, 14, 2237–2260 [https://doi.org/10.5194/amt-14-2237-2021]; we also provide a modeled pH product (reported as a separate DataID) that is in general more meaningful. A CloudFlag (based on AMS measurements of particulate water and zinc) is included to identify periods when artifacts due to cloud particle impaction on the inlet (not shared with the other aerosol instruments on the plane) were observed; in general, AMS data seems to be impacted to a much lesser extent by these artifacts than other instruments, but extra caution should be exercised when using data from these periods. An organic nitrate fraction is included, see Day et al 2022, AMT 15, 459–483 [https:// doi.org/10.5194/amt-15-459-2022] for details; organic nitrate fraction data is not reported during elevated dust or seasalt episodes that lead to significant interferences. In some cases, the measured nitrate might also include organic nitro compounds and nitrite, although the presence of nitrite in submicron aerosols is very unusual in our experience (see Guo et al. 2016, JGR 121, 10355-10376 [https://doi.org/10.1002/2016JD025311]). Note that the AMS measures total, not inorganic sulfate. The organic sulfate fraction is thought to be typically small (<5%), but it was up to 90% in some smoke plumes sampled in previous missions; an experimental product is under development (excluding methanesulfonic acid (MSA), discussed below). Five non-AMS standard aerosol species are being reported as part of this dataset, MSA, seasalt, perchlorate, bromine and iodine (all PM1.5). All of these data products have been calibrated with laboratory standards, and some of them further validated by comparison with the PALMS and SAGA instruments. For seasalt and MSA, where only a subset of the ion signal is used for quantification, a calibration factor (CF=1/(f(Marker)*RIE)) is provided instead of an RIE. MSA was quantified based on the CH3SO2+ AMS ion, which is specific to MSA and both f(CH3SO2+) and RIE_MSA were calibrated using laboratory standards and further confirmed by PMF analysis, see Hodshire et al, ACP19, 3137–3160, 2019 [https://doi.org/10.5194/acp-19-3137-2019]. Please note that MSA aerosol mass is currently included as well both in sulfate and OA mass, so MSA should NOT be included when calculating total mass, and 68% of MSA mass should be subtracted from sulfate prior to calculating MSA/SO4 ratios and similarly 71% of MSA from OA. Submicron seasalt is reported following the method from Ovadnevaite et al, JGR 2012, 117 (D16), 1–11 [https://doi.org/10.1029/2011JD017379] based on detection of the Na_35Cl+ marker ion. For this species, cloud artifacts are observed (unlike for all other species), and the data has hence been filtered by the AMS cloudflag variable. The calibration factor CF=1/f(Marker)*RIE) was determined by chamber calibrations with dry and wet NaCl, and does not include other seasalt components (seasalt sulfate, primary OA). Perchlorate is detected as the sum of ClOx ions, with a contribution from Cl and HCl that is determined from in-field calibrations. Note that the main perchlorate ions suffer from interferences of H_34SOx ions, hence no perchlorate is reported at high sulfate concentrations (>2 ug sm-3). Neither perchlorate nor seasalt are part of the AMS chloride species reported here, but this is often not the case for other AMS datasets, so be careful when comparing. Particulate bromine and iodine are reported based on RIE calibrations with Br-/I- and BrOx-/IOx- salts (Koenig et al 2020, PNAS 117, 1860-1866, [https://doi.org/0.1073/pnas.1916828117]). Note that only the pure halogen ions are used for quantification of the haloxides and the sensitivity is comparable regardless of oxidation state (an estimation of halogen oxidation state is available upon request, although it is not always possible to do this). For most flights, the AMS was run at times in so-called flux mode (higher acquisition rate, less-frequent backgrounds, no size-segregated measurements, no clock synchronization) to be able to sample the full flux leg without interruptions. Due to the larger intervals between backgrounds, the uncertainty on the quantification of low volatility compounds (highly oxidized OA, sulfate and sea salt) is larger than during regular acquisition. UNCERTAINTY: Accuracy estimate (2 stdev): Inorganics +/-34%, Organics +/-38%, dominated by uncertainty in particle collection efficiency due to particle bounce, and absolute and relative ionization efficiency, as estimated in Bahreini et al. 2009, JGR 114, D00F16 (Supp. Info.)[https://doi.org/10.1029/2008JD011493]. Precision error (1 stdev) for each species is provided as a separate variable. Continuous detection limits are estimated based on the method of Drewnick et al, AMT 2, 33-46, 2009 [https://doi.org/10.5194/amt-2-33-2009] and were corrected by comparison with frequent, periodic blanks (every 15 min for this mission) GCMD Science Keywords * EARTH SCIENCE > ATMOSPHERE > AEROSOLS > ORGANIC PARTICLES * EARTH SCIENCE > ATMOSPHERE > AEROSOLS > AEROSOL PARTICLE PROPERTIES * EARTH SCIENCE > ATMOSPHERE > AEROSOLS > NITRATE PARTICLES * EARTH SCIENCE > ATMOSPHERE > AEROSOLS > SULFATE PARTICLES * EARTH SCIENCE > ATMOSPHERE > AEROSOLS > PARTICULATE MATTER * EARTH SCIENCE> ATMOSPHERE > AEROSOLS> CHEMICAL COMPOSITION> NON-REFRACTORY AEROSOL ORGANIC MASS * EARTH SCIENCE> ATMOSPHERE > ATMOSPHERIC CHEMISTRY> HALOCARBONS AND HALOGENS * EARTH SCIENCE> ATMOSPHERE > ATMOSPHERIC CHEMISTRY> TRACE GASES/TRACE SPECIES * EARTH SCIENCE> ATMOSPHERE > AIR QUALITY> PARTICULATES Temporal coverage * Begin datetime: 2022-04-02 00:00:00 * End datetime: 2022-04-28 23:59:59 Spatial coverage * Maximum (North) Latitude: 61.00 * Minimum (South) Latitude: 3.00 * Minimum (West) Longitude: -160.00 * Maximum (East) Longitude: -101.00 Primary contact information * pointOfContact: EOL Data Support https://data.eol.ucar.edu/contact/show/1 Additional contact information * author: Jose Luis Jimenez https://data.eol.ucar.edu/contact/show/1364 Alternate metadata formats * DataCite: https://data.eol.ucar.edu/dataset/618.014?format=datacite * ISO/TC 211: https://data.eol.ucar.edu/dataset/618.014?format=isotc211