Relationships between surface and column aerosol radiative properties and air mass transport at a rural New England site

Chemical, physical, and radiative properties of surface and vertical column aerosols were measured at a rural site in southern New Hampshire from July 2000 to September 2001. The primary objective was to determine how intensive and extensive aerosol properties vary in air masses originating in different upwind regions. The data set also allows for an investigation of some of the relationships between surface and column aerosol properties at the site, and provides an estimate of direct radiative forcing by aerosols during the study period. Extensive properties (e.g., optical depth and chemical concentration) were at maximum values during times of south-southwest (S-SW) transport, while minimum values were seen during north-northeast (N-NE) transport. Certain intensive properties such as fine particle mass scattering efficiency did not vary significantly between times of transport from different source regions. Mean optical depth (wavelength = 500 nm) was 0.24 during S-SW transport, compared to 0.10 during N-NE transport. The study period average scattering efficiency for (NH4)2SO4 was 6.54 ± 0.26 m2 g−1 (± standard error) and 3.36 ± 0.49 m2 g−1 for organic carbon, while the absorption efficiency of elemental carbon was 12.85 ± 0.80 m2 g−1. Top of the atmosphere aerosol direct radiative forcing was −0.35 ± 0.83 Wm−2 (±1 standard deviation) in winter 2000–2001 and −9.06 ± 3.77 Wm−2 in summer 2001, differences that can be primarily attributed to seasonal changes in surface reflectance (high in winter, low in summer) and the relatively low values of single scatter albedo observed in winter. The annual average direct radiative forcing was −5.14 ± 4.32 Wm−2. We generally observed a moderate correlation between surface and column aerosol light extinction, suggesting that vertical column aerosol radiative properties measured by surface-based radiometers should be supplemented by boundary layer measurements of aerosol chemical, physical, and radiative properties to help understand the mechanisms contributing to global aerosol variability

Advances in delimiting the Hilbert-Schmidt separability probability of real two-qubit systems

We seek to derive the probability--expressed in terms of the Hilbert-Schmidt (Euclidean or flat) metric--that a generic (nine-dimensional) real two-qubit system is separable, by implementing the well-known Peres-Horodecki test on the partial transposes (PT's) of the associated 4 x 4 density matrices). But the full implementation of the test--requiring that the determinant of the PT be nonnegative for separability to hold--appears to be, at least presently, computationally intractable. So, we have previously implemented--using the auxiliary concept of a diagonal-entry-parameterized separability function (DESF)--the weaker implied test of nonnegativity of the six 2 x 2 principal minors of the PT. This yielded an exact upper bound on the separability probability of 1024/{135 pi^2} =0.76854$. Here, we piece together (reflection-symmetric) results obtained by requiring that each of the four 3 x 3 principal minors of the PT, in turn, be nonnegative, giving an improved/reduced upper bound of 22/35 = 0.628571. Then, we conclude that a still further improved upper bound of 1129/2100 = 0.537619 can be found by similarly piecing together the (reflection-symmetric) results of enforcing the simultaneous nonnegativity of certain pairs of the four 3 x 3 principal minors. In deriving our improved upper bounds, we rely repeatedly upon the use of certain integrals over cubes that arise. Finally, we apply an independence assumption to a pair of DESF's that comes close to reproducing our numerical estimate of the true separability function.Comment: 16 pages, 9 figures, a few inadvertent misstatements made near the end are correcte

Two-Qubit Separabilities as Piecewise Continuous Functions of Maximal Concurrence

The generic real (b=1) and complex (b=2) two-qubit states are 9-dimensional and 15-dimensional in nature, respectively. The total volumes of the spaces they occupy with respect to the Hilbert-Schmidt and Bures metrics are obtainable as special cases of formulas of Zyczkowski and Sommers. We claim that if one could determine certain metric-independent 3-dimensional "eigenvalue-parameterized separability functions" (EPSFs), then these formulas could be readily modified so as to yield the Hilbert-Schmidt and Bures volumes occupied by only the separable two-qubit states (and hence associated separability probabilities). Motivated by analogous earlier analyses of "diagonal-entry-parameterized separability functions", we further explore the possibility that such 3-dimensional EPSFs might, in turn, be expressible as univariate functions of some special relevant variable--which we hypothesize to be the maximal concurrence (0 < C <1) over spectral orbits. Extensive numerical results we obtain are rather closely supportive of this hypothesis. Both the real and complex estimated EPSFs exhibit clearly pronounced jumps of magnitude roughly 50% at C=1/2, as well as a number of additional matching discontinuities.Comment: 12 pages, 7 figures, new abstract, revised for J. Phys.

Questioning The Fidelity Of The Next Generation Science Standards For Astronomy And Space Sciences Education

Although the Next Generation Science Standards (NGSS) are not federally mandated national standards or performance expectations for K-12 schools in the United States, they stand poised to become a de facto national science and education policy, as state governments, publishers of curriculum materials, and assessment providers across the country consider adopting them. In order to facilitate national buy-in and adoptions, Achieve, Inc., the non-profit corporation awarded the contract for writing the NGSS, has repeatedly asserted the development of the Standards to be a state-driven and transparent process, in which the scientific content is taken "verbatim", from the 2011 NRC report, Frameworks for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas. This paper reports on an independently conducted fidelity check within the content domain of astronomy and the space sciences, conducted to determine the extent to which the NGSS science content is guided by the Frameworks, and the extent to which any changes have altered the scientific intent of that document. The side-by-side, two-document comparative analysis indicates that the science of the NGSS is significantly different from the Frameworks. Further, the alterations in the science represent a lack of fidelity, in that they have altered the parameters of the science and the instructional exposure (e.g., timing and emphasis). As a result the NGSS are now poised to interfere with widely desired science education reform and improvement. This unexpected finding affords scientists, educators, and professional societies with an opportunity, if not a professional obligation, to engage in positively impacting the quality of science education by conducting independent fidelity checks across other disciplines. This could provide a much needed formal support and guidance to schools, teachers, curriculum developers, and assessment providers

Does Your Article Need A Methods Or Methodology Sub-Section?

In the process of writing a discipline-based science education research article for the Journal of Astronomy &amp; Earth Sciences Education, authors are faced with the question of titling each of the article’s subjections. Some editors and authors advocate a METHODS section whereas others advocate for a METHODOLOGY(IES) section.&nbsp; What do we currently prefer in JAESE?&nbsp; The answer is an unsatisfying, “it depends.”&nbsp; The vast majority of papers in the JAESE Journal of Astronomy &amp; Earth Sciences Education use a traditional METHODS section because most—but certainly not all—papers to date describe studies in which the method of inquiry is based on a balance of pragmatism, cost, usefulness, and actionable information.&nbsp; This is in contrast to a METHODOLOGY section, which takes time to argue for why a particular approach will be most fruitful for the question at hand.&nbsp; A robust mix of both are vitally important across the broader discipline-based science education researcher community.&nbsp

Editors Note: Creating Engaging Abstracts For The Journal Of Astronomy & Earth Sciences Education

The crafting of journal article abstracts is a consistent weakness among authors across many disciplines. Far too many abstracts serve as brief “teasers” and fail to comprehensively provide a summary of the research.  Abstracts that result in the largest number of article citations are those that follow a simple writing formula that starts with a broad description of the field and highlights what is as yet unsatisfactorily examined in the existing literature.  The middle section provides the research question, a description of the study-participants, and the research methods used.  Finally, desirable, comprehensive abstracts that present a summary of the paper include illustrative results and a short statement of evidence-based conclusions

Improving Your Argument By Identifying A Literature Gap

More often than not, a peer-reviewed journal article’s literature review is a boring to read as it is to write.&nbsp; However, literature reviews do not need to be laborious for all involved.&nbsp; Instead, the best literature reviews offer a crisp view of a researcher’s landscape and succinctly provides a compelling case for critical research that needs to be done in order to move the field forward.&nbsp; In order to provide readers with a useful literature review, it is critical that authors avoid providing paragraph after paragraph describing a summative chronology of the topic in the literature, but instead provide a critical synthesis of what is known, and what is not known about a topic.&nbsp;In the end, if the reader is convinced of what will be known and advanced as a result of a researcher undertaking the considerable time and effort to conduct and publish a given study, the reader is much more likely to cite your paper downstream in their own work