Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (705 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
The mixture of gases present in the earth's atmosphere consisting of oxygen, nitrogen, carbon dioxide, and small amounts of other gases.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Where it fits in the MeSH classification
- Broader topics
- Atmosphere
- Narrower topics
- Compressed Air; Air Ionization; Air Movements
Research landscape
PubMed indexes 29,123 records tagged with the MeSH heading “Air” (counts retrieved 2026-10-31). 3,124 of them (10.7%) were published from 2020 onward, and the busiest period so far is through 1999 with 9,682 records.
Reviews account for 1,168 records (4.0%) and meta-analyses for 82. Randomized controlled trials number 556 (1.9%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 9,682 |
| 2000-2009 | 7,498 |
| 2010-2019 | 8,819 |
| 2020 onward | 3,124 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 1,168 | 4.0% |
| Meta-analyses | 82 | 0.3% |
| Randomized controlled trials | 556 | 1.9% |
Method: PubMed query "Air"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in public health and nutrition
Population and nutrition studies mostly observe what people eat, breathe or are exposed to and then look for links with health, which shows association and not proof of cause. Self-reported diet is imprecise, people who eat or live differently also differ in other ways, and effects measured across a population may not apply to one person. Check the study design, how exposure was measured, what else was accounted for and the size of the effect, not only whether it was statistically significant.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Atmospheric dryness reduces photosynthesis along a large range of soil water deficits | 2022 | Research article Design not recorded in structured metadata | 80 | cc by PMID 35190562 · DOI · PMC8861027 |
| Neural circuit mechanisms for transforming learned olfactory valences into wind-oriented movement | 2023 | Research article Design not recorded in structured metadata | 24 | cc by PMID 37721371 · DOI · PMC10588983 |
| U.S. winter wheat yield loss attributed to compound hot-dry-windy events | 2022 | Research article Design not recorded in structured metadata | 23 | cc by PMID 36433980 · DOI · PMC9700680 |
| Aerodynamic limits of gliding flight in grey-headed albatrosses under variable wind conditions | 2026 | Research article Design not recorded in structured metadata | 0 | cc by PMID 42548238 · DOI · PMC13602366 |
Atmospheric dryness reduces photosynthesis along a large range of soil water deficits [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Both low soil water content (SWC) and high atmospheric dryness (vapor pressure deficit, VPD) can negatively affect terrestrial gross primary production (GPP).
- Closing excerpt
- Earth System Models underestimate the negative effect of VPD and the positive effect of SWC on GPP such that they should underestimate the GPP reduction due to increasing VPD in future climates.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (169 words)
Both low soil water content (SWC) and high atmospheric dryness (vapor pressure deficit, VPD) can negatively affect terrestrial gross primary production (GPP). The sensitivity of GPP to soil versus atmospheric dryness is difficult to disentangle, however, because of their covariation. Using global eddy-covariance observations, here we show that a decrease in SWC is not universally associated with GPP reduction. GPP increases in response to decreasing SWC when SWC is high and decreases only when SWC is below a threshold. By contrast, the sensitivity of GPP to an increase of VPD is always negative across the full SWC range. We further find canopy conductance decreases with increasing VPD (irrespective of SWC), and with decreasing SWC on drier soils. Maximum photosynthetic assimilation rate has negative sensitivity to VPD, and a positive sensitivity to decreasing SWC when SWC is high. Earth System Models underestimate the negative effect of VPD and the positive effect of SWC on GPP such that they should underestimate the GPP reduction due to increasing VPD in future climates.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 35190562 · DOI · PMC8861027
Neural circuit mechanisms for transforming learned olfactory valences into wind-oriented movement [2]
Abstract reading summary — source excerpts
- Opening excerpt
- How memories are used by the brain to guide future action is poorly understood.
- Closing excerpt
- Thus, our results provide insight into how learned abstract valences are gradually transformed into concrete memory-driven actions through divergent and convergent networks, a neuronal architecture that is commonly found in the vertebrate and invertebrate brains.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (196 words)
How memories are used by the brain to guide future action is poorly understood. In olfactory associative learning in Drosophila, multiple compartments of the mushroom body act in parallel to assign a valence to a stimulus. Here, we show that appetitive memories stored in different compartments induce different levels of upwind locomotion. Using a photoactivation screen of a new collection of split-GAL4 drivers and EM connectomics, we identified a cluster of neurons postsynaptic to the mushroom body output neurons (MBONs) that can trigger robust upwind steering. These UpWind Neurons (UpWiNs) integrate inhibitory and excitatory synaptic inputs from MBONs of appetitive and aversive memory compartments, respectively. After formation of appetitive memory, UpWiNs acquire enhanced response to reward-predicting odors as the response of the inhibitory presynaptic MBON undergoes depression. Blocking UpWiNs impaired appetitive memory and reduced upwind locomotion during retrieval. Photoactivation of UpWiNs also increased the chance of returning to a location where activation was terminated, suggesting an additional role in olfactory navigation. Thus, our results provide insight into how learned abstract valences are gradually transformed into concrete memory-driven actions through divergent and convergent networks, a neuronal architecture that is commonly found in the vertebrate and invertebrate brains.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 37721371 · DOI · PMC10588983
U.S. winter wheat yield loss attributed to compound hot-dry-windy events [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Climate extremes cause significant winter wheat yield loss and can cause much greater impacts than single extremes in isolation when multiple extremes occur simultaneously.
- Closing excerpt
- winter wheat production and beyond.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (147 words)
Climate extremes cause significant winter wheat yield loss and can cause much greater impacts than single extremes in isolation when multiple extremes occur simultaneously. Here we show that compound hot-dry-windy events (HDW) significantly increased in the U.S. Great Plains from 1982 to 2020. These HDW events were the most impactful drivers for wheat yield loss, accounting for a 4% yield reduction per 10 h of HDW during heading to maturity. Current HDW trends are associated with yield reduction rates of up to 0.09 t ha-1 per decade and HDW variations are atmospheric-bridged with the Pacific Decadal Oscillation. We quantify the "yield shock", which is spatially distributed, with the losses in severely HDW-affected areas, presumably the same areas affected by the Dust Bowl of the 1930s. Our findings indicate that compound HDW, which traditional risk assessments overlooked, have significant implications for the U.S. winter wheat production and beyond.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 36433980 · DOI · PMC9700680
Aerodynamic limits of gliding flight in grey-headed albatrosses under variable wind conditions [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Adult grey-headed albatrosses breeding on Marion Island, South Africa, experience highly variable near-ground wind vectors that can result in crash landings, some of which are fatal.
- Closing excerpt
- Given that albatrosses preferentially exploit crosswinds at the meso-scale, transient gusts combining crosswind and downdraft components may force birds into the ground, particularly during low-altitude nest departure, increasing the likelihood of fatal crash landings.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (193 words)
Adult grey-headed albatrosses breeding on Marion Island, South Africa, experience highly variable near-ground wind vectors that can result in crash landings, some of which are fatal. This study quantifies the combinations of airspeed and wind direction that can lead to loss of lift or the generation of downforce sufficient to cause such crashes. Using previously developed three-dimensional grey-headed albatross body geometry, we conducted numerical simulations of this rigid geometry across a wide range of flight conditions defined by airspeed, angle of attack, and sideslip angle. Lift and aerodynamic efficiency (lift-to-drag ratio) were then evaluated to identify the conditions under which insufficient lift was produced. Simulations show that for airspeeds below 10 m s-1, the generated lift was lower than the average weight of an adult grey-headed albatross, with peak aerodynamic efficiency occurring at an angle of attack of approximately 5°. While the geometry generates lift effectively under either strong crosswinds or downdrafts alone, their combination can produce substantial downforce. Given that albatrosses preferentially exploit crosswinds at the meso-scale, transient gusts combining crosswind and downdraft components may force birds into the ground, particularly during low-altitude nest departure, increasing the likelihood of fatal crash landings.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42548238 · DOI · PMC13602366
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article What have we learned from 15 years of free-air CO2 enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO2 [5]
- Research article Elevated CO2 effects on plant carbon, nitrogen, and water relations: six important lessons from FACE [6]
- Research article Direct Capture of CO2 from Ambient Air [7]
- Research article Navigational strategies used by insects to find distant, wind-borne sources of odor [8]
- Research article Resuscitation of newborn infants with 100% oxygen or air: a systematic review and meta-analysis [9]
- Research article Practical aerobic oxidations of alcohols and amines with homogeneous copper/TEMPO and related catalyst systems [10]
References
- Fu Z, Ciais P, Prentice IC, Gentine P, Makowski D, Bastos A, et al.. Atmospheric dryness reduces photosynthesis along a large range of soil water deficits. . 2022. PMID 35190562 · DOI · PMC8861027
- Aso Y, Yamada D, Bushey D, Hibbard KL, Sammons M, Otsuna H, et al.. Neural circuit mechanisms for transforming learned olfactory valences into wind-oriented movement. . 2023. PMID 37721371 · DOI · PMC10588983
- Zhao H, Zhang L, Kirkham MB, Welch SM, Nielsen-Gammon JW, Bai G, et al.. U.S. winter wheat yield loss attributed to compound hot-dry-windy events. . 2022. PMID 36433980 · DOI · PMC9700680
- Schoombie J, Craig KJ, Smith L. Aerodynamic limits of gliding flight in grey-headed albatrosses under variable wind conditions. . 2026. PMID 42548238 · DOI · PMC13602366
- Ainsworth EA, Long SP. What have we learned from 15 years of free-air CO2 enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO2. New Phytol. 2005. PMID 15720649 · DOI
- Leakey AD, Ainsworth EA, Bernacchi CJ, Rogers A, Long SP, Ort DR. Elevated CO2 effects on plant carbon, nitrogen, and water relations: six important lessons from FACE. J Exp Bot. 2009. PMID 19401412 · DOI
- Sanz-Pérez ES, Murdock CR, Didas SA, Jones CW. Direct Capture of CO2 from Ambient Air. Chem Rev. 2016. PMID 27560307 · DOI
- Cardé RT, Willis MA. Navigational strategies used by insects to find distant, wind-borne sources of odor. J Chem Ecol. 2008. PMID 18581182 · DOI
- Davis PG, Tan A, O'Donnell CP, Schulze A. Resuscitation of newborn infants with 100% oxygen or air: a systematic review and meta-analysis. Lancet. 2004. PMID 15474135 · DOI
- Ryland BL, Stahl SS. Practical aerobic oxidations of alcohols and amines with homogeneous copper/TEMPO and related catalyst systems. Angew Chem Int Ed Engl. 2014. PMID 25044821 · DOI · PMC4165639
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-11-04; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-11-04.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.