Spatiotemporal Gap Research Articles

OVERCOMING EMPTINESS IN THE TRANSLATION OF DUBRAVKA UGREŠIĆ

The theme of this paper concerns the main aspects of translating a linguistically and culturally hybrid text, using the example of two Dubravka Ugrešić’s books (1949–2023), Karaoke culture and Europe in Sepia. The author addresses contemporary themes in a globalised and increasingly virtual world, while constantly revisiting the Soviet and Yugoslav communist past through her personal experiences. Existing between languages and interpreting such a diverse literary world requires a profound understanding of historical, linguistic, and cultural contexts, as well as translation strategies aimed at bridging the inevitable spatiotemporal gap that arises between the two versions of the text. The main research questions are: what are the criteria for including or excluding different elements of heterolinguism/ plurilingualism in a translated text? By what linguistic means is it domesticated in a culturally and linguistically hybrid text?

Dual Ratiometric Fluorescence Monitoring of Mechanical Polymer Chain Stretching and Subsequent Strain-Induced Crystallization.

Tracking the behavior of mechanochromic molecules provides valuable insights into force transmission and associated microstructural changes in soft materials under load. Herein, we report a dual ratiometric fluorescence (FL) analysis for monitoring both mechanical polymer chain stretching and strain-induced crystallization (SIC) of polymers. SIC has recently attracted renewed attention as an effective mechanism for improving the mechanical properties of polymers. A polyurethane (PU) film incorporating a trace of a dual-emissive flapping force probe (N-FLAP, 0.008 wt %) exhibited a blue-to-green FL spectral change in a low-stress region (<20 MPa), resulting from conformational planarization of the probe in mechanically stretched polymer chains. More importantly, at higher probe concentrations (∼0.65 wt %), the PU film showed a second spectral change from green to yellow during the SIC growth (20-65 MPa) due to self-absorption of scattered FL in a short wavelength region. The reversibility of these spectral changes was demonstrated by load-unload cycles. With these results in hand, the degrees of the polymer chain stretching and the SIC were quantitatively mapped and monitored by dual ratiometric imaging based on different FL ratios (I525/I470 and I525/I600). Simultaneous analysis of these two mappings revealed a spatiotemporal gap in the distribution of the polymer chain stretching and the SIC. The combinational use of the dual-emissive force probe and the ratiometric FL imaging is a universal approach for the development of soft matter physics.

S wave Splitting in Central Apennines (Italy): anisotropic parameters in the crust during seismic sequences

In this work, we reviewed the main anisotropic results obtained in the last two decades along the Central Apennines. Moreover, we improved this database, with new results coming from the seismicity that occurred in the Montereale area, between 2009 and 2017, which corresponds to a spatio-temporal gap in the previously analyzed datasets. The examined papers concerned both seismic sequences (as Colfiorito in 1997, Pietralunga in 2010, L’Aquila in 2009, Amatrice in 2016) and background seismicity (as the 2000-2001 Città di Castello experiment). The whole of the collected results shows a general NW-SE fast shear wave direction consistent with both the orientation of the extensional active Quaternary and inherited compressive fault systems, focal mechanisms and local stress field. Also, we observed a more intense anisotropy strength (normalized delay time &gt; 0.006 s/km) nearby the strongest events (M &gt; 5), all concentrated in the hanging-wall of the activated fault systems. In fact, this area is deeply affected by the surrounding rock volume perturbations that, in turn, have altered both the local stress field and crustal fracturing network. The most common anisotropic interpretative models that could explain our results are 1) the stress-induced anisotropy according to the Extensive-Dilatancy Anisotropy (EDA) model where the anisotropic pattern is related to the local stress variation and most of the variability is visible in time; 2) the tectonic-controlled anisotropy according to the Structural-Induced Anisotropy (SIA) model where the anisotropic pattern is related to the major structural features and most of the variability is visible only in space. As reported by the examined studies in Central Apennines the possibility to discriminate between stress and structural anisotropy is quite complex in a region where the directions of the extensional regime, the in situ horizontal maximum stress, the strike of major faults, both active and inherited coincide. Generally, in this review, we noted an overlap and mixture of the two aforementioned mechanisms and, just through a temporal analysis, made in the Montereale area, we supposed a predominant stressinduced anisotropy only in rock volumes where anisotropic parameter variations have been detected.

Resolving molecular diffusion and aggregation of antibody proteins with megahertz X-ray free-electron laser pulses

X-ray free-electron lasers (XFELs) with megahertz repetition rate can provide novel insights into structural dynamics of biological macromolecule solutions. However, very high dose rates can lead to beam-induced dynamics and structural changes due to radiation damage. Here, we probe the dynamics of dense antibody protein (Ig-PEG) solutions using megahertz X-ray photon correlation spectroscopy (MHz-XPCS) at the European XFEL. By varying the total dose and dose rate, we identify a regime for measuring the motion of proteins in their first coordination shell, quantify XFEL-induced effects such as driven motion, and map out the extent of agglomeration dynamics. The results indicate that for average dose rates below 1.06 kGy μs−1 in a time window up to 10 μs, it is possible to capture the protein dynamics before the onset of beam induced aggregation. We refer to this approach as correlation before aggregation and demonstrate that MHz-XPCS bridges an important spatio-temporal gap in measurement techniques for biological samples.

A partial tyrannosauroid femur from the mid-Cretaceous Wayan Formation of eastern Idaho, USA

AbstractThe diversity of mid-Cretaceous tyrannosauroids is poorly understood. We describe a partial tyrannosauroid femur from the Albian–Cenomanian Wayan Formation of eastern Idaho that helps to fill in an important spatiotemporal gap in the North American record of tyrannosaurs. This specimen, consisting of the proximal half of the bone, is morphologically similar to the femur of Moros intrepidus, a small-bodied tyrannosauroid from the Cenomanian Mussentuchit Member of the Cedar Mountain Formation of Utah, but not referable to this taxon. The Wayan femur lacks an autapomorphy diagnostic for Moros intrepidus, indicating the presence of a previously unrecognized tyrannosauroid taxon in the early Late Cretaceous of Laramidia. Histological results indicate that, at the time of death, this individual was at least five years old, skeletally immature, and undergoing growth at a moderate rate. The addition of this tyrannosauroid to the Wayan-Vaughn Assemblage provides additional evidence for the widespread distribution of various tyrannosauroid taxa in Laramidia during the early Late Cretaceous.

Staging Frank Lloyd Wright’s Imperial Hotel

ABSTRACT In recent years, a small but growing number of buildings designed by American architect Frank Lloyd Wright have been collected, moved and reconstructed by museums for exhibition. While those involved have done their best to mitigate the physical impact of relocation, the remaking of these buildings in new sites also brings an inevitable conceptual shift: a spatio-temporal gap between the ‘original' building and its new life as an ostensible stage set on display. Nowhere is this staging more palpable than at Wright's reconstructed Imperial Hotel. Opened in 1923, the Imperial Hotel maintains an almost mythical presence in Wright's oeuvre, having famously survived the Great Kanto earthquake that decimated Tokyo. Yet, despite its fame, the hotel succumbed to the pressures of redevelopment and was demolished in 1968. Nearly a decade later, a reconstruction of the hotel's lobby and reflecting pool was opened at the Meiji-mura architecture museum as a much-diminished relic combining original salvage with extensive new construction. Through a formal examination of the exhibit, this article examines those questions of authenticity and staging that plague architectural reconstructions in museums. While such exhibits are often perceived as second-rate substitutes for the real thing, the set-like presentation of the reincarnated Imperial Hotel is argued here to instead highlight the inherent theatricality of Wright’s design, which is arguably more apparent in the reconstruction than it ever was in the original.

The first Middle Ordovician and Gondwanan record of the cincinnaticrinid crinoidOhiocrinus byeongseonin. sp. from South Korea: biostratigraphy, paleobiogeography, and taphonomy

AbstractOhiocrinus byeongseonin. sp. from the Middle Ordovician (Darriwilian) Jigunsan Formation of South Korea in the Sino-Korean (North China) block is the oldest species ofOhiocrinusof the Cincinnaticrinidae and the first record outside Laurentia.O.byeongseoniis characterized by a loosely clockwise-coiled anal sac, isotomous branching throughout arms, long, slender xenomorphic column, and small lichenocrinid-type holdfast. The new species occurs in association with a deep-water siliciclastic environment, unlike the Laurentian species with a shallow-water carbonate environment. The monospecific crinoid assemblage is interpreted as parautochthonous, considering that the crinoids were reworked by relatively weak down-current probably caused by storm but preserved within the environment where they lived. The occurrence ofO.byeongseonipresents a considerable spatiotemporal gap and ecologic disparity in evolution ofOhiocrinusand the Cincinnaticrinidae.UUID:http://zoobank.org/240417a4-8d33-4f45-aedb-afcc07f1ecbb

Effective method for filling gaps in time series of environmental remote sensing data: An example on evapotranspiration and land surface temperature images

Phenomena such as cloudiness, atmospheric aerosol or sensor failure cause missing data (gaps) in remote sensing images and damage spatial and temporal continuity. Dealing with this deficiency is of importance for continuous spatio-temporal modeling and environmental studies. Simplicity, efficiency and accuracy are dominant factors in practicality of gap filling algorithms especially in dealing with large gaps and long time series. In this study, an effective and efficient spatio-temporal gap filling algorithm is proposed, implemented and tested. The method was applied to MODIS 8-day Land Surface Temperature (LST) and Evapotranspiration (ET) datasets with a 1 km spatial resolution. To assess the performance of the proposed methods, artificial gaps were introduced and filled. Then estimated and real values were compared. The results showed that our method can predict the missing values very accurately (based on RMSE) even in gaps with heterogeneous surface for both variables. Our proposed method has no limitation on the shape and size of the gaps. The proposed algorithm is flexible regarding parameterization. It can handle large volumes of datasets due to its parallelizable structure. More importantly, the method run-time is extremely low even in large gaps.

Genome-wide analyses of human noroviruses provide insights on evolutionary dynamics and evidence of coexisting viral populations evolving under recombination constraints.

Norovirus is a major cause of acute gastroenteritis worldwide. Over 30 different genotypes, mostly from genogroup I (GI) and II (GII), have been shown to infect humans. Despite three decades of genome sequencing, our understanding of the role of genomic diversification across continents and time is incomplete. To close the spatiotemporal gap of genomic information of human noroviruses, we conducted a large-scale genome-wide analyses that included the nearly full-length sequencing of 281 archival viruses circulating since the 1970s in over 10 countries from four continents, with a major emphasis on norovirus genotypes that are currently underrepresented in public genome databases. We provided new genome information for 24 distinct genotypes, including the oldest genome information from 12 norovirus genotypes. Analyses of this new genomic information, together with those publicly available, showed that (i) noroviruses evolve at similar rates across genomic regions and genotypes; (ii) emerging viruses evolved from transiently-circulating intermediate viruses; (iii) diversifying selection on the VP1 protein was recorded in genotypes with multiple variants; (iv) non-structural proteins showed a similar branching on their phylogenetic trees; and (v) contrary to the current understanding, there are restrictions on the ability to recombine different genomic regions, which results in co-circulating populations of viruses evolving independently in human communities. This study provides a comprehensive genetic analysis of diverse norovirus genotypes and the role of non-structural proteins on viral diversification, shedding new light on the mechanisms of norovirus evolution and transmission.

Plio‐Pleistocene Continental Hydroclimate and Indian Ocean Sea Surface Temperatures at the Southeast African Margin

AbstractEfforts to understand long‐term Indian Ocean dynamics and land‐sea linkages in southeast Africa during periods of significant global and regional climate change have been inhibited by a lack of high‐resolution climate records, particularly during the Plio‐Pleistocene. Here we present new biomarker and pollen records from International Ocean Discovery Program (IODP) Site U1478, located at the Upper Agulhas Confluence near the Limpopo River mouth, to establish environmental conditions at the southeast African margin between 4 and 1.8 Ma and address this spatiotemporal gap. Compound‐specific hydrogen isotopes of terrestrial leaf waxes (δDwax) and TEX86, using marine archaeal lipids, document hydroclimate variability and sea surface temperature (SST), respectively, permitting an onshore‐offshore climate comparison. The U1478 records establish the Limpopo catchment response to the switch in Indonesian Throughflow source waters, the mid‐Pliocene Warm Period, and intensification of Northern Hemisphere glaciations at ∼2.7 Ma. Broad coherence between the δDwax and SST records supports a linkage between Indian Ocean temperatures and southeast African hydroclimate. We hypothesize that additional mechanisms including Indian Ocean cross‐basin SST gradients (ΔSST) and high latitude glaciation acted as hydroclimate controls during the Plio‐Pleistocene. We use ΔSST to evaluate ocean‐atmosphere patterns similar to the Indian Ocean Dipole (IOD) and establish generally wetter conditions in the region associated with positive IOD‐like phases. Additionally, an obliquity signal evident in the δDwax record indicates that glacial‐interglacial variability likely influenced the tropical rain belt position and also controlled rainfall. Hydroclimate and environmental conditions across the Plio‐Pleistocene in southeast Africa may have important implications for regional hominin evolution.

On the empirical coherence and the spatiotemporal gap problem in quantum gravity: and why functionalism does not (have to) help

The empirical coherence problem of quantum gravity is the worry that a theory which does not fundamentally contain local beables located in space and time—such as is arguably the case for certain approaches to quantum gravity—cannot be connected to measurements (which are actually carried out in space and time) and thus has its prospects of being empirically adequate undermined. Spacetime functionalism à la Lam and Wüthrich (Stud Hist Philos Mod Phys 64:39–51, 2018) is said to solve this empirical coherence problem as well as bridging a (putatively) severe conceptual gap between spatiotemporal structures of classical spacetime theories on the one hand, and the (so-called) non-spatiotemporal structures in quantum gravity approaches on the other hand (call this the spatiotemporal gap problem). The aim of this essay is to offer a deflationary account of both the empirical coherence problem and the spatiotemporal gap problem as they are claimed to arise at least prima facie for current theories of quantum gravity by Huggett and Wüthrich (Stud Hist Philos Mod Phys 44(3):276–285, 2013), Lam and Wüthrich (2018) and Le Bihan (Synthese 2019. https://doi.org/10.1007/s11229-019-02449-6). I defend the view that (1) spacetime functionalism is set up to address a problem (the empirical coherence problem) which can usually be solved without it; and that (2) it is wrongly claimed to (dis)solve another problem which for any actual account of quantum gravity is in fact currently non-existent anyway (the spatiotemporal gap problem).

Comprehensive evaluation of a spatio-temporal gap filling algorithm: Using remotely sensed precipitation, LST and ET data

Temporal and spatial continuity of remote sensing data is flawed due to cloudiness, sensor malfunction or atmospheric pollution. Different methods have been presented to estimate missing values in remote sensing data. In this study, we evaluate the performance of a spatio-temporal gap filling algorithm developed by Weiss et al. (2014). This algorithm is interesting and worthy for further evaluation because it achieves high accuracy while maintaining the computational complexity considerably low. To conduct a comprehensive evaluation, we applied the algorithm to MODIS (Land Surface Temperature (LST) and evapotranspiration (ET)) and TRMM (precipitation) time series and investigate the effects of several factors including seasonality, variable type, gap size and surface characteristics through simulation scenarios. The performances were discussed using qualitative and quantitative assessments based on different simulation scenarios. A crucial finding of this study is a subtle structural deficiency of the algorithm. In particular, the algorithm outputs highly erroneous estimations when dealing with pixels with values mostly between zero and one. Such unexpected errors were observed in the seasonal assessment of land surface temperature estimations. In addition, according to the results of this study, the algorithm was sensitive to the variable type; however there was no correlation between the studied gap sizes and the error values. Among the three studied variables, LST and ET missing values were restored very accurately while estimations of precipitation missing values were more erroneous. The results also exhibit that in heterogeneous areas with complex topography, the errors of estimations were higher than homogeneous regions and areas with less complex topography. Based on the results, the algorithm should be used with caution in the discrete parameters like precipitation and area with abrupt variations. Furthermore, the design of the method may be refined for such datasets which include values with range between zero and one.

Absence, silence, and the shades of Takemitsu’s Ma in Venice

I propose to set up a dialogue between absence and silence; in particular, between my own interpretations of absence through layered images, and silence as it features in the musical works by Tōru Takemitsu. My layered images seek to re-present experiences of absence, as they appear to the senses in the built environment, responding to its capacity to evoke multiple, uncertain and distant presences that seem to be away from our grasp. In Takemitsu’s multi-layered and unstructured pieces, silence plays a key role in bringing about “ma” – a meaningful spatio-temporal gap or in-between condition with metaphysic connotations, of great significance in Japanese culture. Following a hint by composer Philip Dawson, and largely driven by intuition, I explore the –albeit distant– resonances of my visual work in the acclaimed Japanese composer’s music. In this way, I expand the interpretative possibilities of absence and layering in representing the vanishing atmospheres of Venice, an example of fragile existence and aggregated formation.

Evaluation analysis of NASA SMAP L3 and L4 and SPoRT-LIS soil moisture data in the United States

Soil moisture has a critical role in the development, frequency and persistence of climatic and hydrologic extremes such as drought, heat wave and flooding events. In situ soil moisture data are uneven and sparse in time and space. This highlights the need to utilize other soil moisture sources to fill this spatiotemporal gap. The goal of this study is to validate one satellite-based and two model-based soil moisture datasets with in situ data across the United States. Soil moisture information from the Soil Moisture Active Passive (SMAP) enhanced level 3 (L3) (SMAP L3) and modeled level 4 (L4) (SMAP L4) data at 9-km resolution and Short-term Prediction Research and Transition-Land Information System (SPoRT-LIS) modeled at 3-km resolution were selected for evaluation. SPoRT-LIS is a near real-time, high resolution operational land analysis data. Ground-based data were obtained from the North American Soil Moisture Database (NASMD) for 362 stations. Seven statistical indicators including anomaly, Spearman, and Pearson correlation coefficients, the systematic error (Bias), root mean square error (RMSE), unbiased root mean square error (ubRMSE), and normalized standard deviation (SDV) were used to evaluate the satellite- and model-derived soil moisture data. In addition, the triple collocation (TC) error model was used to measure the error among SMAP L4, SPoRT-LIS and ground-based data. This study assesses which satellite or modeled dataset is most appropriate for specific times and locations to use as a surrogate for in situ observations. Temporal and spatial analysis demonstrated that, overall, SMAP L4 performed better than SMAP L3 and SPoRT-LIS. Strong agreement was observed between SMAP L4 and in situ observations (ρ = 0.53, Bias = −0.006) in all seasons and most regions with various land covers, especially in winter and in the central regions of the United States. For croplands, SMAP L4 presented the best agreement with in situ data, analyzing all period (ρ = 0.60) and non-winter period (ρ = 0.61) separately.

The Concept of Intermediate Existence in the Early Buddhist Theory of rebirth

ABSTRACTThis article investigates the concept of intermediate existence in the early Buddhist theory of rebirth. The main sources investigated for this article are the Pāli canonical and commentarial literature. My main thesis is that early Buddhist discourses contain instances that suggest a spatial-temporal gap between death and rebirth known as ‘intermediate existence’ (antarābhava), in contrast to the idea of Theravāda Buddhist theory that rebirth takes place immediately without a spatial-temporal gap. In order to prove this, I argue that the ‘one who liberates in interval’ (anarāparinibbāyī) attains Nibbāna in the intermediate existence and the concept of gandhabbā in early Buddhist discourses refers to a being in intermediate existence, not to a dying consciousness (cuti-viññāna), and there are indirect inferences to an spatiotemporal gap between death and rebirth in the early Buddhist discourses.

‘Telepathic’ phenomena and separation anxiety

By discussing a treatment characterized by its difficult ending, the author strives to show the dynamic impact of separation on phenomena that can be seen as ‘telepathic’. Led to develop some inalienable attachment to her analyst in the primary transference, the analysand found herself caught up in the contradiction of her visceral dread of dependency, which compelled her to interrupt the work in progress. She then began to work out her analyst's comings and goings and to run into him in public places, as if to be assured of his immovability. This phenomenon arose with high frequency as the effect of some idealization of the maternal object aiming to deny the spatiotemporal gap. The chance that the experience of rejection via indifference may be repeated also entailed the transferential unfurling of a fantasy involving a double, undifferentiation counterbalancing the lived experience of separation. Furthermore, a ‘telepathic’ dream occurred as confirmation of this twin relationship which illustrates the analysand's refusal to renounce her narcissistic object. Projective identifications, agglutinated ego nuclei along with primitive cross‐identifications could, among other concepts, account for such phenomena which are projective in nature yet real all the same. Such mechanisms could have the power to relay thoughts the moment undifferentiated parts of the ego – if not unborn parts of the self – were activated in a potentially symbiotic zone. Marked by a feeling of dispossession, the analyst's countertransference not only seemed to underscore this hypothesis, it also gave a partial explanation for it. Until the analyst could recognize his own nostalgia for a symbiotic relationship, he had to encourage the occurrence of those unexpected meetings which stemmed from a convergence between the transference and the countertransference.

Integrated Object-Based Spatiotemporal Characterization of Forest Change from an Annual Time Series of Landsat Image Composites

Identifying and mapping the location, extent, severity, and causal agent of forest change events is necessary for obtaining a wide range of information. Using 6 ecologically representative test sites (each ∼ 800 km2) in the province of Saskatchewan, Canada, for the period 1998–2012, our objective was to prototype an object-based approach for identifying spectral change features, filling data gaps in Landsat reflectance annual best-available-pixel (BAP) composites, and attributing change processes to the derived stand-like spatial objects. The tasseled cap angle (TCA), which combines information from the visible, near-infrared, and midinfrared, enabled the description of landscape condition and its temporal derivative, the process indicator (PI), relates the rate and directionality of change at the landscape level. Data gaps, as well as anomalous values identified using time-series similarity analysis with dynamic time warping and cross-correlation measures, were replaced by spatiotemporal interpolation, resulting in annual proxy composites with no missing values. An assessment of proxy values against surface reflectance values indicated high agreement for reflectance bands (R = 0.79–0.96, RMSE = 0.005–0.021) and for TCA (R = 0.93, RMSE = 0.005), and a decrease in reliability of the proxy value as the size of the spatiotemporal gap increased, with longer temporal gaps having a greater impact on infill reliability than larger spatial gaps. Distinctive change dynamics of the sample sites were captured, demonstrating a capacity to simultaneously identify low and high magnitude changes as well as positive (e.g., growth) and negative (e.g., wildfire) trajectories using the PI. The approach presented herein provides a robust option for monitoring forest change by simultaneously describing state and ongoing change processes.

Fast phasic release properties of dopamine studied with a channel biosensor.

Few other neurotransmitters are of as intense interest to neuropsychiatry and neurology as dopamine, yet existing techniques to monitor dopamine release leave an important spatiotemporal gap in our understanding. Electrochemistry and fluorescence imaging tools have been developed to fill the gap, but these methods have important limitations. We circumvent these limitations by introducing a dopamine-gated chloride channel into rat dorsal striatal medium spiny neurons, targets of strong dopamine innervation, thereby transforming dopamine from a slow transmitter into a fast transmitter and revealing new opportunities for studying moment-to-moment regulation of dopamine release. We demonstrate pharmacological and biophysical properties of the channel that make it suitable for fast, local dopamine measurements, and we demonstrate for the first time spontaneous and evoked responses to vesicular dopamine release in the dorsal striatum. Evoked dopamine currents were separated into a fast, monosynaptic component and a slower-rising and decaying disynaptic component mediated by nicotinic receptor activation. In summary, LGC-53 represents a dopamine biosensor with properties suitable for temporal separation of distinct dopamine signals in targets of dopamine innervation.

Evidence for insect-mediated skeletonization on an extant fern family from the Upper Triassic of China

Leaf skeletonization represents a distinctive form of insect feeding behavior. It commonly occurs in angiosperm leaves after their initial appearance during the Early Cretaceous. This type of feeding behavior rarely has been documented in pre-Mesozoic fossils. We describe the earliest evidence of insect-skeletonized leaves of Dictyophyllum nathorstii Zeiller, affi li- ated with the extant fern family Dipteridaceae in the Late Triassic Yipinglang fl ora from southwestern China. The skeletonization generally is located adjacent to the pinna rachilla of the distal free portion of the leaf. In the skeletonized area, the interveinal tissue is com- pletely removed, exposing the pinna rachilla, pinnule midveins, and lateral veins. Most non- vascular tissue has been removed between the vascular bundles, the latter forming polygo- nal meshes of varying size. Our report of insect-mediated skeletonization of fern leaves from southwestern China fi lls a spatiotemporal gap in the published data on the paleogeographi- cal distribution and stratigraphic occurrence of plant-arthropod associations, and indicates an antagonistic relationship between a fern host and its insect herbivore.

Assimilation of Circumpolar Wind Vectors Derived from Highly Elliptical Orbit Imagery: Impact Assessment Based on Observing System Simulation Experiments

AbstractThere is a well-recognized spatiotemporal meteorological observation gap at latitudes higher than 55°, especially in the region 55°–70°. A possible solution to address this issue is a constellation of four satellites in a highly elliptical orbit (HEO), that is, two satellites for each polar region. An important satellite product to support weather prediction is atmospheric motion wind vectors (AMVs). This study uses observing system simulation experiments (OSSEs) to evaluate the benefit to forecasts resulting from the assimilation of HEO AMVs covering one or both polar regions. The OSSE employs the operational global data assimilation system of the Canadian Meteorological Center. HEO AMVs are assimilated north of 50°N and south of 50°S. From 2-month assimilation cycles, the study examines the following three issues: 1) the impact of AMV assimilation in the real system, and how this compares to the impact seen in the simulated system, 2) the added value of HEO AMVs in the Arctic on top of what is currently available, and 3) the relative impact of HEO AMVs in the Arctic and Antarctic in comparison with no AMVs. Although the simulated impact of currently available AMVs is somewhat higher than the real impact, a firm conclusion is that the added value of Arctic HEO AMVs is substantial, improving predictability at days 3–5 by a few hours in terms of 500-hPa geopotential height. The impact of HEO AMVs is relatively stronger in the Southern Hemisphere. Forecast validation of atmospheric profiles against the simulated “true” state and against analyses generated within the assimilation cycles yields very similar results beyond 48 h.