Four North Atlantic Aerosol and Marine Ecosystems Study (NAAMES) field campaigns from winter 2015 through spring 2018 sampled an extensive set of oceanographic and atmospheric parameters during the ...annual phytoplankton bloom cycle. This unique dataset provides four seasons of open-ocean observations of wind speed, sea surface temperature (SST), seawater particle attenuation at 660 nm (c
p,660, a measure of ocean particulate organic carbon), bacterial production rates, and sea-spray aerosol size distributions and number concentrations (N
SSA). The NAAMES measurements show moderate to strong correlations (0.56 < R < 0.70) between N
SSA and local wind speeds in the marine boundary layer on hourly timescales, but this relationship weakens in the campaign averages that represent each season, in part because of the reduction in range of wind speed by multiday averaging. N
SSA correlates weakly with seawater cp,660 (R = 0.36, P << 0.01), but the correlation with cp,660, is improved (R = 0.51, P < 0.05) for periods of low wind speeds. In addition, NAAMES measurements provide observational dependence of SSA mode diameter (d
m) on SST, with d
m increasing to larger sizes at higher SST (R = 0.60, P << 0.01) on hourly timescales. These results imply that climate models using bimodal SSA parameterizations to wind speed rather than a single SSA mode that varies with SST may overestimate SSA number concentrations (hence cloud condensation nuclei) by a factor of 4 to 7 and may underestimate SSA scattering (hence direct radiative effects) by a factor of 2 to 5, in addition to overpredicting variability in SSA scattering from wind speed by a factor of 5.
Natural killer (NK) cells likely play an important role in immunity to malaria, but the effect of repeated malaria on NK cell responses remains unclear. Here, we comprehensively profiled the NK cell ...response in a cohort of 264 Ugandan children. Repeated malaria exposure was associated with expansion of an atypical, CD56
population of NK cells that differed transcriptionally, epigenetically, and phenotypically from CD56
NK cells, including decreased expression of PLZF and the Fc receptor γ-chain, increased histone methylation, and increased protein expression of LAG-3, KIR, and LILRB1. CD56
NK cells were highly functional and displayed greater antibody-dependent cellular cytotoxicity than CD56
NK cells. Higher frequencies of CD56
NK cells were associated with protection against symptomatic malaria and high parasite densities. After marked reductions in malaria transmission, frequencies of these cells rapidly declined, suggesting that continuous exposure to
is required to maintain this modified, adaptive-like NK cell subset.
Background: The Psychological Science Accelerator (PSA) recently completed a large-scale moral psychology study using translated versions of the Oxford Utilitarianism Scale (OUS). However, the ...translated versions have no validity evidence. Objective: The study investigated the structural validity evidence of the OUS across 15 translated versions and produced version-specific validity reports. Methods: We analyzed OUS data from the PSA, which was collected internationally on a centralized online questionnaire. We also collected qualitative feedback from experts for each translated version. Results: For each version, we produced version-specific psychometric reports which include the following: (1) descriptive item and demographics analyses, (2) factor structure evidence using confirmatory factor analyses, (3) measurement invariance testing across languages using multiple-group confirmatory factor analyses and alignment optimization, and (4) reliability analyses using coefficients α and ω.
Stratocumulus clouds over the Southern Ocean have fewer droplets and are more likely to exist in the predominately supercooled phase than clouds at similar temperatures over northern oceans. One ...likely reason is that this region has few continental and anthropogenic sources of cloud‐nucleating particles that can form droplets and ice. In this work, we present an overview of aerosol particle types over the Southern Ocean, including new measurements made below, in and above clouds in this region. These measurements and others indicate that biogenic sulfur‐based particles >0.1 μm diameter contribute the majority of cloud condensation nuclei number concentrations in summer. Ice nucleating particles tend to have more organic components, likely from sea‐spray. Both types of cloud nucleating particles may increase in a warming climate likely to have less sea ice, more phytoplankton activity, and stronger winds over the Southern Ocean near Antarctica. Taken together, clouds over the Southern Ocean may become more reflective and partially counter the region's expected albedo decrease due to diminishing sea ice. However, detailed modeling studies are needed to test this hypothesis due to the complexity of ocean‐cloud‐climate feedbacks in the region.
Plain Language Summary
Clouds over the Southern Ocean tend to have less droplets and ice crystals than similar clouds over northern oceans due to fewer sources of cloud‐nucleating aerosol particles in the region. In this work, we present an overview of aerosol particle types over the Southern Ocean, including new measurements made below, in and above clouds. These measurements indicate that while sea‐spray‐derived salts do provide cloud nuclei, the majority of aerosol particles that influence summertime clouds in this region are biogenic—that is, derived from ocean microorganisms, with the ocean region near Antarctica being a large summertime source. These cloud‐nucleating particles may increase in a warming climate likely to have less sea ice and more phytoplankton activity near Antarctica. These additional particles could make low clouds reflect more light and offset a portion of the warming expected due to diminishing sea ice in a future climate.
Key Points
Biogenic sulfate dominates the number concentration of 0.1–0.5 microns diameter particles and cloud condensation nuclei (CCN) over the summertime Southern Ocean
Biogenic organics are a key component of ice nucleating particles over the Southern Ocean
As Antarctic climate changes, increased biological activity could partially offset warming effects of sea‐ice loss via influences on CCN
The majority of the aerosol particle number (condensation nuclei or CN) in the marine boundary layer (MBL) consists of sulfate and organic compounds that have been shown to provide a large fraction ...of the cloud condensation nuclei (CCN). Here we use submicron non‐refractory Aerosol Mass Spectrometer (AMS) and filter measurements of organic and sulfate components of aerosol particles measured during four North Atlantic Aerosol and Marine Ecosystems Study (NAAMES) research cruises to assess the sources and contributions of submicron organic and sulfate components for CCN concentrations in the MBL during four different seasons. Submicron hydroxyl group organic mass (OM) correlated strongly to sodium concentrations during clean marine periods (R = 0.9), indicating that hydroxyl group OM can serve as a proxy for sea‐spray OM in ambient measurements. Sea‐spray OM contributed 45% of the sum of sea‐spray OM and sea salt during late spring (biomass climax phase) compared to <20% for other seasons, but the seasonal difference was not statistically significant. The contribution of non‐combustion sources during clean marine periods to submicron OM was 47 to 88% and to non‐sea‐salt sulfate 31 to 86%, with likely sources being marine and biogenic. The remaining submicron OM and sulfate were likely associated with ship or continental sources, including biomass burning, even during clean marine periods. The seasonal contribution from secondary sulfate and OM components to submicron aerosol mass was highest during late spring (60%), when biogenic emissions are expected to be highest, and lowest during winter (18%). Removing submicron sea‐spray OM decreased CCN concentrations by <10% because of competing effects from increased hygroscopicity and decreased particle size. During all seasons, adding biogenic secondary sulfate increased hygroscopicity, particle size, and CCN concentrations at 0.1–0.3% supersaturations by 5–66%. The largest change was during early spring when the fraction of hygroscopic sulfate components in the 0.1–0.2 μm size range was highest (80%). During continental periods, the increased contribution from low‐hygroscopicity organic components to 0.1–0.2 μm diameter particles reduces the CCN/CN by 20–100% for three seasons despite the increased CN and mass concentrations. These results illustrate the important role of the chemical composition of particles with diameters 0.1–0.2 μm for controlling CCN in the MBL.
Key Points
Ambient hydroxyl group mass correlated strongly to sodium, and their ratio for the limited samples available correlated to dissolved organic carbon normalized by salinity for generated sea spray aerosol
Non‐combustion, likely secondary biogenic, sources contribute 47–88% of submicron organic mass and 21–86% of submicron sulfate during marine periods
The fraction of particles in the 0.1–0.2 μm size range that were cloud condensation nuclei was highest during early spring due to a larger fraction of hygroscopic sulfate
Classic findings from psychology and the behavioural sciences are increasingly being revisited. Methodological and technological advances provide opportunities to replicate studies across a wide ...range of countries and settings to investigate whether these findings are universally applicable, limited to specific countries, or vary in magnitude depending on settings. Researchers from around the world connect to revisit such findings collaboratively, adapt the original design to the Zeitgeist, integrate new knowledge to improve statistical analyses, and broaden the scope by testing effects globally – or at least in as many countries, as budget and feasibility allow. We currently observe multiple international consortia conducting large-scale multi-country replications. How do such collaborations form and how do they approach these complex investigations? This paper brings together researchers from different initiatives that conduct replications on an international scale to outline approaches and summarises what we have learned in applying them: Junior Researcher Programme (JRP), Psychological Science Accelerator (PSA), ManyBabies, Collaborative Open-science REsearch (CORE), and International Study of Metanorms (ISMN). We describe different ways for study selection, methodological approaches, statistical analyses, ethical issues, and most importantly, how the different collaborations formed and how team communication worked. We look in detail at challenges of including typically underrepresented countries in psychological science, not only in terms of data collection but also in making it possible for local researchers to contribute. This paper provides a structured insight into how different collaborations work and issues to consider for anyone who seeks to conduct a multi-country replication in psychology, or looking for additional perspectives to their existing plan. We close the article with a checklist built as a helpful tool for colleagues putting together their study protocols for such efforts – and invite them to collaboratively expand it in the future.
Submicron atmospheric primary marine aerosol (aPMA) were collected during four North Atlantic Aerosol and Marine Ecosystem Study (NAAMES) research cruises between November 2015 and March 2018. The ...average organic functional group (OFG) composition of the aPMA samples was 72–85% hydroxyl group mass, 6–13% alkane group mass, and 5–8% amine group mass, which is similar to prior observations and to aerosol generated from Sea Sweep. The carboxylic acid group had seasonal averages that ranged from 1% for Winter, 8% for Late Spring, and 10% for Autumn. The carboxylic acid group mass concentration correlated with nitrate mass concentration and weakly with photosynthetically active radiation (PAR) above 100 W m
–2
, suggesting a substantial secondary organic aerosol contribution in sunnier months. The three sizes of aPMA aerosol particles (<0.18, <0.5, and <1 μm) had the same four organic functional groups (hydroxyl, alkane, amine, and carboxylic acid groups). The aPMA spectra of the three sizes showed more variability (higher standard deviations of cosine similarity) within each size than between the sizes. The ratio of organic mass (OM) to sodium (OM/Na) of submicron generated primary marine aerosol (gPMA) was larger for Autumn with project average of 0.93 ± 0.3 compared to 0.55 ± 0.27 for Winter, 0.47 ± 0.16 for Late Spring, and 0.53 ± 0.24 for Early Spring. When the gPMA samples were separated by latitude (47–60°N and 18–47°N), the median OM/Na concentration ratio for Autumn was higher than the other seasons by more than the project standard deviations for latitudes north of 47°N but not for those south of 47°N, indicating that the seasonal differences are stronger at higher latitudes. However, the high variability of day-to-day differences in aPMA and gPMA composition within each season meant that seasonal trends in organic composition were generally not statistically distinguishable.
The Oceano Dunes State Vehicular Recreation Area (ODSVRA) is a large natural source of wind-driven dust emissions that primarily consist of particulate matter (PM) for which most of the mass is ...greater than 1 μm. The San Luis Obispo County Air Pollution Control District (SLOAPCD) has targeted ODSVRA emissions to reduce exceedances of the state standard of 50 μg m−3 for PM smaller than 10 μm (PM10) at a coastal monitoring site located 1 mile downwind of the dune area. To evaluate the potential effectiveness of this abatement strategy, five sets of measurements were collected during the windy afternoons of high-wind months (May and October) from 2019 to 2021 to quantify the organic and elemental composition of PM10 and PM smaller than 2.5 μm (PM2.5) samples. The five-campaign average afternoon PM2.5 composition relative to Beta Attenuation Monitor (BAM) concentrations included 14 ± 12% dust, 9 ± 9% sea salt, 4 ± 5% non-sea salt sulfate, and 8 ± 8% organic components, with the difference between BAM and the measured components contributing the remaining 66 ± 16% unidentified components. The high afternoon unidentified contribution was partially attributable to water, consistent with the increasing relative humidity during warm afternoons, since there was a lower unidentified contribution for overnight samples. The remaining unidentified components are consistent with prior measurements of semivolatile contributions of ammonium nitrate and organic compounds constituting >40% of PM2.5 in central California. The organic functional group signature in Fourier Transform Infrared (FTIR) spectroscopy for PM2.5 was similar to previously reported ambient marine aerosol, consistent with a natural marine source for most of the organic mass concentration. For PM10, the dust fraction was 11 ± 8% of BAM PM10 concentration and increased to 14 ± 10% of BAM PM10 concentration during days in which hourly BAM PM10 concentration exceeded 140 μg m−3. There was no statistically significant difference (p»0.05) between dust, sea salt, sulfate, or organic PM2.5 fractions between weekend and weekday concentrations, similar to prior findings for the region. These results are consistent with national and state assessments of the good air quality of the region and suggest that semivolatile components may cause differences between BAM and gravimetric mass concentrations for sampling times shorter than 24 h. In addition, the results demonstrate that the regulated dust abatement implemented at ODSVRA is misapplied and unlikely to improve downwind air quality significantly, since ODSVRA and other nearby sandy areas contribute only 14% of BAM PM10 and have not been shown to include toxic components.
•Oceano Dunes mineral dust contributes an average of at most 14% of BAM PM10 measured downwind during windy afternoons.•Average afternoon PM2.5 included 14 ± 12% dust, 9 ± 9% sea salt, 4 ± 5% non-sea salt sulfate, and 8 ± 8% organic components.•Unidentified components are consistent with semivolatile contributions of ammonium nitrate and organic compounds.
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