Margot Hanley, Jiunn-Tyng Yeh, Ryan Rodriguez
et al.
Brain foundation models bring the foundation model paradigm to the field of neuroscience. Like language and image foundation models, they are general-purpose AI systems pretrained on large-scale datasets that adapt readily to downstream tasks. Unlike text-and-image based models, however, they train on brain data: large-datasets of EEG, fMRI, and other neural data types historically collected within tightly governed clinical and research settings. This paper contends that training foundation models on neural data opens new normative territory. Neural data carry stronger expectations of, and claims to, protection than text or images, given their body-derived nature and historical governance within clinical and research settings. Yet the foundation model paradigm subjects them to practices of large-scale repurposing, cross-context stitching, and open-ended downstream application. Furthermore, these practices are now accessible to a much broader range of actors, including commercial developers, against a backdrop of fragmented and unclear governance. To map this territory, we first describe brain foundation models' technical foundations and training-data ecosystem. We then draw on AI ethics, neuroethics, and bioethics to organize concerns across privacy, consent, bias, benefit sharing, and governance. For each, we propose both agenda-setting questions and baseline safeguards as the field matures.
C. Arosio, V. Sofieva, A. Orfanoz-Cheuquelaf
et al.
<p>This paper presents an intercomparison between existing tropospheric ozone column (TrOC) datasets obtained using combined limb and nadir observations, i.e., exploiting collocated stratospheric profile and total column information retrieved from limb and nadir satellite observations, respectively. In particular, seven datasets have been considered, covering the past 2 decades and consisting of monthly-averaged time series with nearly global coverage. We perform a comparison in terms of climatology and seasonality, investigate the tropopause height used for the construction of each dataset and the related biases, and finally discuss long-term TrOC drifts and trends. The overall goal of the study is to assess the consistency between the datasets and explore possible strategies to reconcile the differences between them. Despite uncertainties associated with the limb–nadir residual methodology and large biases between the mean values of the considered datasets, we identify an overall agreement of TrOC distribution patterns. The different tropopause height definitions used to construct the datasets did not show a relevant role in explaining the biases between them. We demonstrate that a thorough investigation of the drifts with respect to ground-based observations is needed to evaluate TrOC trends from satellite data and that long-term trends in specific regions can be consistently detected, e.g., a positive trend of up to 1.5 DU per decade over China for the 2005–2021 period.</p>
We examine the implications of quantum foundations for AGI, focusing on how seminal results such as Bell's theorems (non-locality), the Kochen-Specker theorem (contextuality) and no-cloning theorem problematise practical implementation of AGI in quantum settings. We introduce a novel information-theoretic taxonomy distinguishing between classical AGI and quantum AGI and show how quantum mechanics affects fundamental features of agency. We show how quantum ontology may change AGI capabilities, both via affording computational advantages and via imposing novel constraints.
We develop foundations for a relational approach to quantum field theory (RQFT) based on the operational quantum reference frames (QRFs) framework considered in a relativistic setting. Unlike other efforts in combining QFT with QRFs, we use the latter to provide novel mathematical and conceptual foundations for the former. We focus on scalar fields in Minkowski spacetime and discuss the emergence of relational local (bounded) observables and (pointwise) fields from the consideration of Poincaré-covariant (quantum) frame observables defined over the space of (classical) inertial reference frames. We recover a relational notion of Poincaré covariance, with transformations on the system directly linked to the state preparations of the QRF. We introduce and analyse various causality conditions, and construct an explicit example of a covariant scalar relational quantum field which is causal relative to operationally meaningful preparations of a relativistic QRF. The theory makes direct contact with established foundational approaches to QFT: we demonstrate that the vacuum expectation values derived within our framework reproduce many of the essential properties of Wightman functions, carry out a detailed comparison of the proposed formalism with Wightman QFT with the frame smearing functions describing the QRF's localisation uncertainty playing the role of the Wightmanian test functions, and show how the properties of algebras generated by relational local observables suitably extend the core axioms of Algebraic QFT. We finish with an extensive outlook describing a number of further research directions. This work is an early step in revisiting the mathematical foundations of QFT from a relational and operational perspective.
A global representation is a compatible collection of representations of the outer automorphism groups of the groups belonging to some collection of finite groups $\mathscr{U}$. Global representations assemble into an abelian category $\mathsf{A}(\mathscr{U})$, simultaneously generalising classical representation theory and the category of VI-modules appearing in the representation theory of the general linear groups. In this paper we establish homological foundations of its derived category $\mathsf{D}(\mathscr{U})$. We prove that any complex of projective global representations is DG-projective, and hence conclude that the derived category admits an explicit model as the homotopy category of projective global representations. We show that from a tensor-triangular perspective it exhibits some unusual features: for example, there are very few dualizable objects and in general many more compact objects. Under more restrictive conditions on the family $\mathscr{U}$, we then construct torsion-free classes for global representations which encode certain growth properties in $\mathscr{U}$. This lays the foundations for a detailed study of the tensor-triangular geometry of derived global representations which we pursue in forthcoming work.
<p>Accurate and continuous estimates of the thermodynamic structure of the lower atmosphere are highly beneficial to meteorological process understanding and its applications, such as weather forecasting. In this study, the Tropospheric Remotely Observed Profiling via Optimal Estimation (TROPoe) physical retrieval is used to retrieve temperature and humidity profiles from various combinations of input data collected by passive and active remote sensing instruments, in situ surface platforms, and numerical weather prediction models. Among the employed instruments are microwave radiometers (MWRs), infrared spectrometers (IRSs), radio acoustic sounding systems (RASSs), ceilometers, and surface sensors. TROPoe uses brightness temperatures and/or radiances from MWRs and IRSs, as well as other observational inputs (virtual temperature from the RASS, cloud-base height from the ceilometer, pressure, temperature, and humidity from the surface sensors) in a physical iterative retrieval approach. This starts from a climatologically reasonable profile of temperature and water vapor, with the radiative transfer model iteratively adjusting the assumed temperature and humidity profiles until the derived brightness temperatures and radiances match those observed by the MWR and/or IRS instruments within a specified uncertainty, as well as within the uncertainties of the other observations, if used as input. In this study, due to the uniqueness of the dataset that includes all the abovementioned sensors, TROPoe is tested with different observational input combinations, some of which also include information higher than 4 km above ground level (a.g.l.) from the operational Rapid Refresh numerical weather prediction model. These temperature and humidity retrievals are assessed against independent collocated radiosonde profiles under non-cloudy conditions to assess the sensitivity of the TROPoe retrievals to different input combinations.</p>
<p>Current methods for detecting atmospheric plumes and inferring point-source rates from high-resolution satellite imagery are labor-intensive and not scalable with regard to the growing satellite dataset available for methane point sources. Here, we present a two-step algorithm called U-Plume for automated detection and quantification of point sources from satellite imagery. The first step delivers plume detection and delineation (masking) with a U-Net machine learning architecture for image segmentation. The second step quantifies the point-source rate from the masked plume using wind speed information and either a convolutional neural network (CNN) or a physics-based integrated mass enhancement (IME) method. The algorithm can process 62 images (each measuring 128 pixels <span class="inline-formula">×</span> 128 pixels) per second on a single 2.6 GHz Intel Core i7-9750H CPU. We train the algorithm using large-eddy simulations of methane plumes superimposed on noisy and variable methane background scenes from the GHGSat-C1 satellite instrument. We introduce the concept of point-source observability, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>O</mi><mtext>ps</mtext></msub><mo>=</mo><mi>Q</mi><mo>/</mo><mo>(</mo><mi>U</mi><mi>W</mi><mi mathvariant="normal">Δ</mi><mi>B</mi><mo>)</mo></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="88pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="4ce9e616e41414ff0022cfedbc0dcbb0"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-17-2625-2024-ie00001.svg" width="88pt" height="16pt" src="amt-17-2625-2024-ie00001.png"/></svg:svg></span></span>, as a single dimensionless number to predict plume detectability and source rate quantification error from an instrument as a function of source rate <span class="inline-formula"><i>Q</i></span>, wind speed <span class="inline-formula"><i>U</i></span>, instrument pixel size <span class="inline-formula"><i>W</i></span>, and instrument-dependent background noise <span class="inline-formula">Δ<i>B</i></span>. We show that <span class="inline-formula"><i>O</i><sub>ps</sub></span> can powerfully diagnose the ability of an imaging instrument to observe point sources of a certain magnitude under given conditions. U-Plume successfully detects and masks plumes from sources as small as 100 <span class="inline-formula">kg h<sup>−1</sup></span> in GHGSat-C1 images over surfaces with low background noise and successfully handles larger point sources over surfaces with substantial background noise. We find that the IME method for source quantification is unbiased over the full range of source rates, while the CNN method is biased towards the mean of its training range. The total error in source rate quantification is dominated by wind speed at low wind speeds and by the masking algorithm at high wind speeds. A wind speed of 2–4 <span class="inline-formula">m s<sup>−1</sup></span> is optimal for detection and quantification of point sources from satellite data.</p>
<p>An important transport process for particles and gases from the atmosphere to aquatic and terrestrial environments is through dry and wet deposition. An open-source, modular, off-grid, and affordable instrument that can automatically collect wet-deposition samples allows for more extensive deployment of deposition samplers in fieldwork and would enable more comprehensive monitoring of remote locations. Precipitation events selectively sampled using a conductivity sensor powered by a battery-based supply are central to off-grid capabilities. The prevalence of conductive precipitation – that which initially contains high solute levels and progresses through trace-level concentrations to ultrapure water in full atmospheric washout – depends on the sampling location but is ubiquitous. This property is exploited here to trigger an electric motor (via limit switches) to open and close a lid resting over a funnel opening. The motors are operated via a custom-built and modular digital logic control board, which has a low energy demand. All components, their design and rationale, and their assembly are provided for community use. The modularity of the control board allows the operation of up to six independent wet-deposition units, such that replicate measurements (e.g., canopy throughfall) or different collection materials for various targeted pollutants can be implemented as necessary.</p>
<p>We demonstrate that these platforms are capable of continuous operation off-grid for integrated monthly and bimonthly collections performed across the Newfoundland and Labrador Boreal Ecosystem Latitudinal Transect (47 to 53° N) during the growing seasons of 2015 and 2016. System performance was assessed through the measured power consumption from 115 V of alternating current (VAC; grid power) or 12 V of direct current from battery supplies during operation under both standby (40 or 230 mA, respectively) and in-use (78 or 300 mA, respectively) conditions. In the field, one set of triplicate samplers was deployed in the open to collect incident precipitation (open fall), while another set was deployed under the experimental forest canopy (throughfall). The proof-of-concept systems were validated with basic measurements of rainwater chemistry, which found (i) pH values ranging from 4.14 to 5.71 in incident open fall rainwater, (ii) conductivities ranging from 21 to 166 <span class="inline-formula">µ</span>S cm<span class="inline-formula"><sup>−1</sup></span>, and (iii) dissolved organic carbon concentrations in open fall and canopy throughfall of <span class="inline-formula">16±10</span> and <span class="inline-formula">22±12</span> mg L<span class="inline-formula"><sup>−1</sup></span>, respectively, with incident fluxes spanning 600 to 4200 mg C m<span class="inline-formula"><sup>−2</sup></span> a<span class="inline-formula"><sup>−1</sup></span> across the transect. Ultimately, this demonstrates that the customized precipitation sampling design of this new platform enables more universal accessibility of deposition samples for the atmospheric observation<span id="page3698"/> community – for example, those who have made community calls for targeting biogeochemical budgets and/or contaminants of emerging concern in sensitive and remote regions.</p>
Process science is a highly interdisciplinary field of research. Despite numerous proposals, process science lacks an adequate understanding of the core concepts of the field, including notions such as process, event, and system. A more systematic framework to cope with process science is mandatory. We suggest such a framework using an example. The framework itself addresses three aspects: architecture, statics, and dynamics. Corresponding formal concepts, based on established scientific theories, together provide an integrated framework for understanding processes in the world. We argue that our foundations have positive implications not only for theoretical research, but also for empirical research, e.g., because hypothesized relationships can be explicitly tested. It is now time to start a discussion about the foundations of our field.
The Minimalist Foundation, for short MF, was conceived by the first author with G. Sambin in 2005, and fully formalized in 2009, as a common core among the most relevant constructive and classical foundations for mathematics. To better accomplish its minimality, MF was designed as a two-level type theory, with an intensional level mTT, an extensional one emTT, and an interpretation of the latter into the first. Here, we first show that the two levels of MF are indeed equiconsistent by interpreting mTT into emTT. Then, we show that the classical extension emTT^c is equiconsistent with emTT by suitably extending the Gödel-Gentzen double-negation translation of classical logic in the intuitionistic one. As a consequence, MF turns out to be compatible with classical predicative mathematics à la Weyl, contrary to the most relevant foundations for constructive mathematics. Finally, we show that the chain of equiconsistency results for MF can be straightforwardly extended to its impredicative version to deduce that Coquand-Huet's Calculus of Constructions equipped with basic inductive types is equiconsistent with its extensional and classical versions too.
<p><span id="page3174"/>The version 10 (v10) Atmospheric Carbon Observations from Space (ACOS) Level 2 full-physics (L2FP) retrieval algorithm has been applied to multiyear records of observations from NASA's Orbiting Carbon Observatory 2 and 3 sensors (OCO-2 and OCO-3, respectively) to provide estimates of the carbon dioxide (CO<span class="inline-formula"><sub>2</sub></span>) column-averaged dry-air mole fraction (XCO<span class="inline-formula"><sub>2</sub></span>). In this study, a number of improvements to the ACOS v10 L2FP algorithm are described. The post-processing quality filtering and bias correction of the XCO<span class="inline-formula"><sub>2</sub></span> estimates against multiple truth proxies are also discussed. The OCO v10 data volumes and XCO<span class="inline-formula"><sub>2</sub></span> estimates from the two sensors for the time period of August 2019 through February 2022 are compared, highlighting differences in spatiotemporal sampling but demonstrating broad agreement between the two sensors where they overlap in time and space. A number of evaluation sources applied to both sensors suggest they are broadly similar in data and error characteristics. Mean OCO-3 differences relative to collocated OCO-2 data are approximately 0.2 and <span class="inline-formula">−</span>0.3 ppm for land and ocean observations, respectively. Comparison of XCO<span class="inline-formula"><sub>2</sub></span> estimates to collocated Total Carbon Column Observing Network (TCCON) measurements shows root mean squared errors (RMSEs) of approximately 0.8 and 0.9 ppm for OCO-2 and OCO-3, respectively. An evaluation against XCO<span class="inline-formula"><sub>2</sub></span> fields derived from atmospheric inversion systems that assimilated only near-surface CO<span class="inline-formula"><sub>2</sub></span> observations, i.e., did not assimilate satellite CO<span class="inline-formula"><sub>2</sub></span> measurements, yielded RMSEs of 1.0 and 1.1 ppm for OCO-2 and OCO-3, respectively. Evaluation of uncertainties in XCO<span class="inline-formula"><sub>2</sub></span> over small areas, as well as XCO<span class="inline-formula"><sub>2</sub></span> biases across land–ocean crossings, also indicates similar behavior in the error characteristics of both sensors. Taken together, these results demonstrate a broad consistency of OCO-2 and OCO-3 XCO<span class="inline-formula"><sub>2</sub></span> measurements, suggesting they may be used together for scientific analyses.</p>
<p>A new global O<span class="inline-formula"><sub>3</sub></span> data product retrieved from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) spectra with the IMK–IAA MIPAS data processor has been released.
These data are based on ESA version 8 recalibrated radiance spectra
with improved temporal stability. Changes in the level-2 processing with respect to previous data versions include the following:
(1) the retrievals use improved temperature data and thus suffer less from the propagation of related errors.
(2) The background continuum is now considered up to 58 km.
(3) A priori information is now used to constrain the retrieval of the
radiance offset. (4) Water vapour is fitted jointly with ozone to minimize
the impact of interfering water lines.
(5) A more adequate regularization has been chosen.
(6) Ozone absorption lines in the MIPAS A band (685–980 cm<span class="inline-formula"><sup>−1</sup></span>) are used almost exclusively because of inconsistencies in spectroscopic data in the MIPAS AB band (1010–1180 cm<span class="inline-formula"><sup>−1</sup></span>). Only at altitudes above 50 km, where A-band ozone lines do not provide sufficient information, are ozone lines in the MIPAS AB band used. (7) Temperature-adjusted climatologies of vibrational temperatures of O<span class="inline-formula"><sub>3</sub></span> and CO<span class="inline-formula"><sub>2</sub></span> are considered to account for non-local thermodynamic equilibrium radiation. Ozone errors are estimated to be less than 10 % in the altitude range 20–50 km.
The error budget is dominated by the spectroscopic errors, followed by
the uncertainty of the instrumental line shape function, the gain calibration error, and the spectral noise. The error contribution of interfering gases is almost negligible. The vertical resolution depends on altitude and atmospheric conditions. In 2002–2004 it varies between 2.5 km at the lowest altitudes and 6 km at 70 km, while in 2005–2012 it covers 2 to 5.5 km in the same altitude range. The horizontal smearing in terms of the full width at half maximum of the horizontal component of the two-dimensional averaging kernel matrix is smaller than, or approximately equal to, the distance between two subsequent limb scans at all altitudes.
This implies that the horizontal resolution is sampling-limited or optimal, respectively. An additional data version is made available that is free of the formal a priori information and thus more user-friendly for certain applications. Version 8 ozone results show a better consistency between the two MIPAS measurement periods.
They seem to be more realistic than preceding data versions in
terms of long-term stability, as at least a part of the drift is corrected.
Further, the representation of elevated stratopause situations is improved.</p>
The Olger Dyke is a large-scale linear earthwork in southern Jutland in Denmark which consists of a combination of earthwork and (in part) well-preserved timber palisades that can be traced for at least 12 km. The article provides a synthesis of the history of fieldwork of this monument, including detailed overviews of recent excavations, which have enabled new dating work to be carried out. This linear earthwork is unusual in that it has exceptional preservation of timber uprights in several palisade trenches, and recent dendrochronological dates combined with the application of new dating methods has enabled the construction sequence to be refined and accurately pinpointed to the early first century AD, lasting for around 100 years. The article presents the location, construction and function of the Olger Dyke together with an outline of the new dating evidence.
<p>An optimal estimation-based algorithm is developed to retrieve the number density of excited oxygen (O<span class="inline-formula"><sub>2</sub></span>) molecules that generate airglow emissions near 0.76 <span class="inline-formula">µ</span>m (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><msup><mi>b</mi><mn mathvariant="normal">1</mn></msup><msubsup><mi mathvariant="normal">Σ</mi><mi mathvariant="normal">g</mi><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="26pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="e23f4f729858696de5562ade75bd55ba"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-3721-2022-ie00001.svg" width="26pt" height="17pt" src="amt-15-3721-2022-ie00001.png"/></svg:svg></span></span> or <span class="inline-formula"><i>A</i></span> band) and 1.27 <span class="inline-formula">µ</span>m (<span class="inline-formula"><i>a</i><sup>1</sup>Δ<sub>g</sub></span> or <span class="inline-formula"><sup>1</sup>Δ</span> band) in the upper atmosphere. Both oxygen bands are important for the remote sensing of greenhouse gases. The algorithm is applied to the limb spectra observed by the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument in both the nominal (tangent heights below <span class="inline-formula">∼</span> 90 km) and mesosphere–lower thermosphere (MLT) modes (tangent heights spanning 50–150 km). The number densities of emitting O<span class="inline-formula"><sub>2</sub></span> in the <span class="inline-formula"><i>a</i><sup>1</sup>Δ<sub>g</sub></span> band are retrieved in an altitude range of 25–100 km near-daily in 2010, providing a climatology of O<span class="inline-formula"><sub>2</sub></span> <span class="inline-formula"><i>a</i><sup>1</sup>Δ<sub>g</sub></span>-band airglow emission. This climatology will help disentangle the airglow from backscattered light in nadir remote sensing of the <span class="inline-formula"><i>a</i><sup>1</sup>Δ<sub>g</sub></span> band. The global monthly distributions of the vertical column density of emitting O<span class="inline-formula"><sub>2</sub></span> in <span class="inline-formula"><i>a</i><sup>1</sup>Δ<sub>g</sub></span> state show mainly latitudinal dependence without other discernible geographical patterns. Temperature profiles are retrieved simultaneously from the spectral shapes of the <span class="inline-formula"><i>a</i><sup>1</sup>Δ<sub>g</sub></span>-band airglow emission in the nominal limb mode (valid altitude range of 40–100 km) and from both <span class="inline-formula"><i>a</i><sup>1</sup>Δ<sub>g</sub></span>- and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M18" display="inline" overflow="scroll" dspmath="mathml"><mrow><msup><mi>b</mi><mn mathvariant="normal">1</mn></msup><msubsup><mi mathvariant="normal">Σ</mi><mi mathvariant="normal">g</mi><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="26pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="11467d6e86e83b59d143f98a0818d72e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-3721-2022-ie00002.svg" width="26pt" height="17pt" src="amt-15-3721-2022-ie00002.png"/></svg:svg></span></span>-band airglow emissions in the MLT mode (valid range of 60–105 km). The temperature retrievals from both airglow bands are consistent internally and in agreement with independent observations from the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), with the absolute mean bias near or below 5 K and root mean squared error (RMSE) near or below 10 K. The retrieved emitting O<span class="inline-formula"><sub>2</sub></span> number density and temperature provide a unique dataset for the remote sensing of greenhouse gases and constraining the chemical and physical processes in the upper atmosphere.</p>
<p>Synthetic halogenated organic chlorofluorocarbons (CFCs) play an
important role in stratospheric ozone depletion and contribute significantly
to the greenhouse effect. In this work, the mid-infrared solar spectra
measured by ground-based high-resolution Fourier transform infrared
spectroscopy (FTIR) were used to retrieve atmospheric CFC-11 (CCl<span class="inline-formula"><sub>3</sub></span>F)
and CFC-12 (CCl<span class="inline-formula"><sub>2</sub></span>F<span class="inline-formula"><sub>2</sub></span>) at Hefei, China. The CFC-11 columns observed
from January 2017 to December 2020 and CFC-12 columns from September 2015 to
December 2020 show a similar annual decreasing trend and seasonal cycle,
with an annual rate of <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.47</mn><mo>±</mo><mn mathvariant="normal">0.06</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="a806b63420daa298ff93df3a88ef1a58"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-6739-2022-ie00001.svg" width="64pt" height="10pt" src="amt-15-6739-2022-ie00001.png"/></svg:svg></span></span> % yr<span class="inline-formula"><sup>−1</sup></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.68</mn><mo>±</mo><mn mathvariant="normal">0.03</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="05a558580ff3f283368b6ee9f0c86d63"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-6739-2022-ie00002.svg" width="64pt" height="10pt" src="amt-15-6739-2022-ie00002.png"/></svg:svg></span></span> % yr<span class="inline-formula"><sup>−1</sup></span>, respectively. So the decline rate of CFC-11 is
significantly lower than that of CFC-12. CFC-11 total columns were higher in
summer, and CFC-12 total columns were higher in summer and autumn. Both
CFC-11 and CFC-12 total columns reached the lowest in spring. Further, FTIR
data of NDACC (Network for the Detection of Atmospheric Composition Change)
candidate station Hefei were compared with the ACE-FTS (Atmospheric Chemistry Experiment Fourier transform spectrometer) satellite data, WACCM
(Whole Atmosphere Community Climate Model) data, and the data from other
NDACC-IRWG (InfraRed Working Group) stations (St. Petersburg, Jungfraujoch, and Réunion). The
mean relative difference between the vertical profiles observed by FTIR and
ACE-FTS is <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">5.6</mn><mo>±</mo><mn mathvariant="normal">3.3</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="a056c058674d3805ebe51300b5b3cb4c"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-6739-2022-ie00003.svg" width="52pt" height="10pt" src="amt-15-6739-2022-ie00003.png"/></svg:svg></span></span> % and <span class="inline-formula">4.8±0.9</span> % for CFC-11 and CFC-12 for an altitude of 5.5 to 17.5 km, respectively. The results demonstrate that our FTIR data agree relatively well with the ACE-FTS satellite data. The annual decreasing rate of CFC-11 measured from ACE-FTS and calculated by WACCM is <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M10" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">1.15</mn><mo>±</mo><mn mathvariant="normal">0.22</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="292a4f5bd3790f82523c868d6a58eb39"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-6739-2022-ie00004.svg" width="64pt" height="10pt" src="amt-15-6739-2022-ie00004.png"/></svg:svg></span></span> % yr<span class="inline-formula"><sup>−1</sup></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M12" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">1.68</mn><mo>±</mo><mn mathvariant="normal">0.18</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="fa5c9799570899d317ba42a3aa74e8e2"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-6739-2022-ie00005.svg" width="64pt" height="10pt" src="amt-15-6739-2022-ie00005.png"/></svg:svg></span></span> % yr<span class="inline-formula"><sup>−1</sup></span>, respectively. The interannual decreasing rates
of atmospheric CFC-11 obtained from ACE-FTS and WACCM data are higher than
that from FTIR observations. Also, the annual decreasing rate of CFC-12 from
ACE-FTS and WACCM is <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M14" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.85</mn><mo>±</mo><mn mathvariant="normal">0.15</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="2294670ac25a512326edc7e3d1cf5ace"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-6739-2022-ie00006.svg" width="64pt" height="10pt" src="amt-15-6739-2022-ie00006.png"/></svg:svg></span></span> % yr<span class="inline-formula"><sup>−1</sup></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M16" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.81</mn><mo>±</mo><mn mathvariant="normal">0.05</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="cc8aa34009771a0ee6ba2211bc2cb1d7"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-6739-2022-ie00007.svg" width="64pt" height="10pt" src="amt-15-6739-2022-ie00007.png"/></svg:svg></span></span> % yr<span class="inline-formula"><sup>−1</sup></span>, respectively, close to the corresponding values from the FTIR measurements. The total columns of CFC-11 and CFC-12 at the Hefei and St. Petersburg stations are significantly higher than those at the Jungfraujoch and Réunion (Maïdo) stations, and the two values reached the maximum in local summer or autumn and the minimum in local spring or winter at the four stations. The seasonal variability at the three stations in the Northern Hemisphere is higher than that at the station in the Southern Hemisphere.</p>
We scan Paul K. Feyerabend's work in philosophy of physics and of science more generally for insights that could be useful for the contemporary debate on the foundations of quantum mechanics. We take as our starting point what Feyerabend has actually written about quantum mechanics, but we extend our analysis to his general views on realism, objectivity, pluralism, and the relation between physics and philosophy, finding that these more general views could in fact offer many interesting insights for physicists and philosophers working on quantum foundations.
The gravitational equations were derived in general relativity (GR) using the assumption of their covariance relative to arbitrary transformations of coordinates. It has been repeatedly expressed an opinion over the past century that such equality of all coordinate systems may not correspond to reality. Nevertheless, no actual verification of the necessity of this assumption has been made to date. The paper proposes a theory of gravity with a constraint, the degenerate variants of which are general relativity (GR) and the unimodular theory of gravity. This constraint is interpreted from a physical point of view as a sufficient condition for the adiabaticity of the process of the evolution of the space–time metric. The original equations of the theory of gravity with the constraint are formulated. On this basis, a unified model of the evolution of the modern, early, and very early Universe is constructed that is consistent with the observational astronomical data but does not require the hypotheses of the existence of dark energy, dark matter or inflatons. It is claimed that: physical time is anisotropic, the gravitational field is the main source of energy of the Universe, the maximum global energy density in the Universe was 64 orders of magnitude smaller the Planckian one, and the entropy density is 18 orders of magnitude higher the value predicted by GR. The value of the relative density of neutrinos at the present time and the maximum temperature of matter in the early Universe are calculated. The wave equation of the gravitational field is formulated, its solution is found, and the nonstationary wave function of the very early Universe is constructed. It is shown that the birth of the Universe was random.
<p>Ozone (O<span class="inline-formula"><sub>3</sub></span>) plays a significant role in weather and
climate on regional to global spatial scales. Most studies on the
variability in the total column of O<span class="inline-formula"><sub>3</sub></span> (TCO) are typically carried out
using daytime data. Based on knowledge of the chemistry and transport of
O<span class="inline-formula"><sub>3</sub></span>, significant deviations between daytime and night-time O<span class="inline-formula"><sub>3</sub></span> are
only expected either in the planetary boundary layer (PBL) or high in the
stratosphere or mesosphere, with little effect on the TCO. Hence, we
expect the daytime and night-time TCO to be very similar. However, a detailed
evaluation of satellite measurements of daytime and night-time TCO is still
lacking, despite the existence of long-term records of both. Thus, comparing
daytime and night-time TCOs provides a novel approach to verifying the
retrieval algorithms of instruments such as the Atmospheric Infrared Sounder (AIRS)
and the Microwave Limb Sounder (MLS). In addition, such a comparison also
helps to assess the value of night-time TCO for scientific research.
Applying this verification on the AIRS and the MLS data, we identified
inconsistencies in observations of O<span class="inline-formula"><sub>3</sub></span> from both satellite
instruments. For AIRS, daytime–night-time differences were found over oceans
resembling cloud cover patterns and over land, mostly over dry land areas,
which is likely related to infrared surface emissivity. These differences point to
issues with the representation of both processes in the AIRS retrieval
algorithm. For MLS, a major issue was identified with the
“ascending–descending” orbit flag, used to discriminate night-time and
daytime MLS measurements. Disregarding this issue, MLS day–night differences
were significantly smaller than AIRS day–night differences, providing
additional support for the retrieval method origin of AIRS in stratospheric
column ozone (SCO) day–night differences. MLS day–night differences are
dominated by the upper-stratospheric and mesospheric diurnal O<span class="inline-formula"><sub>3</sub></span> cycle. These results provide useful information for improving infrared
O<span class="inline-formula"><sub>3</sub></span> products.</p>