A Framework for Parameterizing Eddy Potential Vorticity Fluxes

A framework for parameterizing eddy potential vorticity fluxes is developed that is consistent with conservation of energy and momentum while retaining the symmetries of the original eddy flux. The framework involves rewriting the residual-mean eddy force, or equivalently the eddy potential vorticity flux, as the divergence of an eddy stress tensor. A norm of this tensor is bounded by the eddy energy, allowing the components of the stress tensor to be rewritten in terms of the eddy energy and nondimensional parameters describing the mean shape and orientation of the eddies. If a prognostic equation is solved for the eddy energy, the remaining unknowns are nondimensional and bounded in magnitude by unity. Moreover, these nondimensional geometric parameters have strong connections with classical stability theory. When applied to the Eady problem, it is shown that the new framework preserves the functional form of the Eady growth rate for linear instability. Moreover, in the limit in which Reynolds stresses are neglected, the framework reduces to a Gent and McWilliams type of eddy closure where the eddy diffusivity can be interpreted as the form proposed by Visbeck et al. Simulations of three-layer wind-driven gyres are used to diagnose the eddy shape and orientations in fully developed geostrophic turbulence. These fields are found to have large-scale structure that appears related to the structure of the mean flow. The eddy energy sets the magnitude of the eddy stress tensor and hence the eddy potential vorticity fluxes. Possible extensions of the framework to ensure potential vorticity is mixed on average are discussed. © 2012 American Meteorological Society

Extant! Living Bembidion palosverdes Kavanaugh and Erwin (Coleoptera: Carabidae) Found on Santa Catalina Island, California Full Access

Kavanaugh and Erwin (1992) described Bembidion palosverdes from seven specimens from two localities on the Palos Verdes Peninsula, Los Angeles Co., CA (Pt. Vicente, ∼33.741°N, 118.411°W, and Pt. Fermin, ∼33.705°N, 118.294°W), collected in June 1964 by Derham Giuliani. The species\u27 authors spent two days searching for specimens at the two known localities, but found no additional specimens. They suggested that the species may have become extinct prior to its formal description, citing a major 1969 oil spill as a potential factor

An unexpected clade of South American ground beetles (Coleoptera, Carabidae, Bembidion)

Phylogenetic relationships of the Antiperyphanes Complex of the genus Bembidion are inferred using DNA sequences from seven genes (two nuclear ribosomal, four nuclear protein coding, and one mitochondrial protein coding). Redefined subgenera within the complex are each well-supported as monophyletic. Most striking was the discovery that a small set of morphologically and ecologically heterogeneous species formed a clade, here called subgenus Nothonepha. This unexpected result was corroborated by the discovery of deep pits in the lateral body wall (in the mesepisternum) of all Nothonepha, a trait unique within Bembidion. These pits are filled with a waxy substance in ethanol-preserved specimens. In one newly discovered species (Bembidion tetrapholeon sp. n., described here), these pits are so deep that their projections into the body cavity from the two sides touch each other internally. These structures in Bembidion (Nothonepha) are compared to very similar mesepisternal pits which have convergently evolved in two other groups of carabid beetles. The function of these thoracic pits is unknown. Most members of subgenus Nothonepha have in addition similar but smaller pits in the abdomen. A revised classification is proposed for the Antiperyphanes Complex.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Pensoft Publishers. The published article can be found at: http://www.pensoft.net/journals/zookeys. Supplementary files for the article can be found at: http://www.pensoft.net/journals/zookeys/article/7706/supp.Keywords: Carabidae, Ground beetles, Phylogeny, Systematics, Bembidiini, DNA, South America, Bembidio

Acute sensitivity of global ocean circulation and heat content to eddy energy dissipation time-scale

The global ocean overturning circulation, critically dependent on the global density stratification, plays a central role in regulating climate evolution. While it is well-known that the global stratification profile exhibits a strong dependence to Southern Ocean dynamics and in particular to wind and buoyancy forcing, we demonstrate here that the stratification is also acutely sensitive to the mesoscale eddy energy dissipation time-scale. Within the context of a global ocean circulation model with an energy constrained mesoscale eddy parameterization, it is shown that modest variations in the eddy energy dissipation time-scale lead to significant variations in key metrics relating to ocean circulation, namely the Antarctic Circumpolar Current transport, Atlantic Meridional Overturning Circulation strength, and global ocean heat content, over long time-scales. The results highlight a need to constrain uncertainties associated with eddy energy dissipation for climate model projections over centennial time-scales, but also for paleoclimate simulations over millennial time-scales.Comment: 13 pages, 4 figures; preprint version; accepted by Geophysical Research Letters, post-print version to be made available at a later poin

Evaluating nuclear proteincoding genes for phylogenetic utility in beetles.

a b s t r a c t Although nuclear protein-coding genes have proven broadly useful for phylogenetic inference, relatively few such genes are regularly employed in studies of Coleoptera, the most diverse insect order. We increase the number of loci available for beetle systematics by developing protocols for three genes previously unused in beetles (alpha-spectrin, RNA polymerase II and topoisomerase I) and by refining protocols for five genes already in use (arginine kinase, CAD, enolase, PEPCK and wingless). We evaluate the phylogenetic performance of each gene in a Bayesian framework against a presumably known test phylogeny. The test phylogeny covers 31 beetle specimens and two outgroup taxa of varying age, including three of the four extant beetle suborders and a denser sampling in Adephaga and in the carabid genus Bembidion. All eight genes perform well for Cenozoic divergences and accurately separate closely related species within Bembidion, but individual genes differ markedly in accuracy over the older Mesozoic and Permian divergences. The concatenated data reconstruct the test phylogeny with high support in both Bayesian and parsimony analyses, indicating that combining data from multiple nuclear loci will be a fruitful approach for assembling the beetle tree of life

A new species of Bembidion (Ecuadion) from Ecuador (Coleoptera, Carabidae, Bembidiini), with a key to members of the georgeballi species group

A new species of ground beetle, Bembidion ricei, is described from the Andes mountains of Ecuador east of Quito. It belongs to the georgeballi species group of subgenus Ecuadion, and is most similar to Bembidion georgeballi. A key to the species of the group is provided.Keywords: Systematics, Morphology, DNA, Bembidiini, Bembidion, Trechinae, Taxonom

Photographic Assessment of Change in Trichotillomania: Psychometric Properties and Variables Influencing Interpretation

Although photographic assessment has been found to be reliable in assessing hair loss in Trichotillomania, the validity of this method is unclear, particularly for gauging progress in treatment. The current study evaluated the psychometric properties of photographic assessment of change in Trichotillomania. Photographs showing hair loss of adults with Trichotillomania were taken before and after participating in a clinical trial for the condition. Undergraduate college students (N = 211) rated treatment response according to the photos, and additional archival data on hair pulling severity and psychosocial health were retrieved from the clinical trial. Photographic assessment of change was found to possess fair reliability (ICC = 0.53), acceptable criterion validity (r = 0.51), good concurrent validity (r = 0.30–0.36), and excellent incremental validity (ΔR2 = 8.67, p \u3c 0.01). In addition, photographic measures were significantly correlated with change in quality of life (r = 0.42), and thus could be considered an index of the social validity of Trichotillomania treatment. Gender of the photo rater and pulling topography affected the criterion validity of photographic assessment (partial η2 = 0.05–0.11). Recommendations for improving photographic assessment and future directions for hair pulling research are discussed

checkpoint_schedules: schedules for incremental checkpointing of adjoint simulations

checkpoint_schedules provides schedules for step-based incremental checkpointing of the adjoints to computer models. The schedules contain instructions indicating the sequence of forward and adjoint steps to be executed, and the data storage and retrieval to be performed.These instructions are independent of the model implementation, which enables the model authors to switch between checkpointing algorithms without recoding. Conversely, checkpointing_schedules provides developers of checkpointing algorithms a direct mechanism to convey their work to model authors. checkpointing_schedules has been integrated into tlm_adjoint (James R. Maddison et al., 2019), a Python library designed for the automated derivationof higher-order tangent-linear and adjoint models and work is ongoing to integrate it with pyadjoint (Mitusch et al., 2019). This package can be incorporated into other gradient solvers based on adjoint methods, regardless of the specific approach taken to generate the adjoint model

Scale-awareness in an eddy energy constrained mesoscale eddy parameterization

There is an increasing interest in mesoscale eddy parameterizations that are scale-aware, normally interpreted to mean that a parameterization does not require re-tuning of parameters as the model resolution changes. Here we examine whether Gent--McWilliams (GM) based version of GEOMETRIC, a mesoscale eddy parameterization that is constrained by a parameterized eddy energy budget, is scale-aware in its energetics. It is generally known that GM-based schemes severely damp out explicit eddies, so the parameterized component would be expected to dominate across resolutions, and we might expect a negative answer to the question of energetic scale-awareness. A consideration of why GM-based schemes damp out explicit eddies leads a suggestion for what we term a splitting procedure: a definition of a `large-scale' field is sought, and the eddy-induced velocity from the GM-scheme is computed from and acts only on the large-scale field, allowing explicit and parameterized components to co-exist. Within the context of an idealized re-entrant channel model of the Southern Ocean, evidence is provided that the GM-based version of GEOMETRIC is scale-aware in the energetics as long as we employ a splitting procedure. The splitting procedure also leads to an improved representation of mean states without detrimental effects on the variability.Comment: 26 pages, 8 figures, 1 table. Previous version has data generated from a bugged NEMO implementation of GEOMETRIC, and the results from the previous version could be regarded as a case where GEOMETRIC is used ***without*** mean flow advection of parameterised eddy energy. This bug is fixed in the present version, with minor updates to the article to reflect the chang

Phylogeny of minute carabid beetles and their relatives based upon DNA sequence data (Coleoptera, Carabidae, Trechitae)

The phylogeny of ground beetles of supertribe Trechitae is inferred using DNA sequences of genes that code for 28S ribosomal RNA, 18S ribosomal RNA, and wingless. Within the outgroups, austral psydrines are inferred to be monophyletic, and separate from the three genera of true Psydrina (Psydrus, Nomius, Laccocenus); the austral psydrines are formally removed from Psydrini and are treated herein as their own tribe, Moriomorphini Sloane. All three genes place Gehringia with Psydrina. Trechitae is inferred to be monophyletic, and sister to Patrobini. Within trechites, evidence is presented that Tasmanitachoides is not a tachyine, but is instead a member of Trechini. Perileptus is a member of subtribe Trechodina. Against Erwin’s hypothesis of anillines as a polyphyletic lineage derived from the tachyine genus Paratachys, the anillines sampled are monophyletic, and not related to Paratachys. Zolini, Pogonini, Tachyina, and Xystosomina are all monophyletic, with the latter two being sister groups. The relationships of the subtribe Bembidiina were studied in greater detail. Phrypeus is only distantly related to Bembidion, and there is no evidence from sequence data that it belongs within Bembidiina. Three groups that have been recently considered to be outside of the large genus Bembidion are shown to be derived members of Bembidion, related to subgroups: Cillenus is related to the Ocydromus complex of Bembidion, Zecillenus is related to the New Zealand subgenus Zeplataphus, and Hydrium is close to subgenus Metallina. The relationships among major lineages of Trechitae are not, however, resolved with these data.Keywords: Trechinae, DNA, Trechitae, Carabidae, Bembidiini, Molecular phylogeny, Ground beetle