I discuss the impact factor of Space Weather for 2021, its small decrease with respect to the number in 2020, and potential causes for this decrease. The limitations of the impact factor are emphasized as reported in past studies, in particular due to the large weight of highly cited papers. For Space Weather, over several years, the median number of citations received by a paper per year is close to the impact factor at the time of publication, with very few papers receiving no citations. I expect that, as the solar cycle ramps up, the impact factor will start to grow again. Key Point Space Weather has an impact factor of 4.29 in 2021, a 4% decrease as compared to 2020 but a 49% increase as compared to 2017.

In 2017 Ocean Networks Canada (ONC), a research infrastructure operator, sought to redefine its core reporting metrics. We asked, “which metrics should we hold as key, essential metrics to drive our organizational priorities and decision making?” This question helped us define a collection of eleven sets of yardsticks, some inward-looking, others squarely focused on societal outcomes. Here, we introduce the individual metrics adopted, insights they are helping us glean and some of their inherent challenges. ONC’s core funding agency, the Canada Foundation for Innovation (CFI), continues to emphasize scientific output as a primary criterion. We measure this by counting peer-reviewed presentations and publications resulting from use the facility and ONC’s data archives. But this seemingly clear-cut metric has been a thorny one to define, track and grow. Training and support for post-secondary students is another core reporting metric, however this measurement is also fraught with ambiguities. Some of the easier metrics to track are those specifically related to facility operations, such as reliability and user satisfaction. But we were perplexed by the question of how to measure “optimal use” of the facility, as mandated by CFI. Optimal use is hard to define for an underwater infrastructure design like ONC’s, which can be flexibly extended with no hard limits on hardware capacity, archive volume or data access. When it comes to societal benefit, our approach has been twofold. One set of metrics examines technology transfer, grants and contracts. Another set focuses on our engagements and active collaborations with governmental, indigenous and non-governmental organizations. However, some outcomes remain challenging to measure. While it is straightforward to count up our external interactions and collaborations, how can we quantify their current and future societal impact? These and related questions will be explored.

A number of insitu and passive microwave satellite sensors have observed Arctic sea ice and Greenland Ice Sheet (GrIS) mass loss trends over recent decades. Along with sea and land ice declines, above-freezing, near-surface air temperatures are observed earlier in boreal spring and later in autumn thus extending periods of melt beyond the core of summer (JJA). Little is known about whether lengthening periods of open ocean proximate to the ice sheet, for instance, demonstrably effect unseasonal GrIS melt events. Here, a new Baffin Bay sea ice advance dataset is utilized to determine dates of sea ice growth along Greenland’s west coast for the 2011-2015 period. Preceding, multi-scale ocean-atmospheric conditions, including at the Baffin-GrIS interface, are analyzed and linked to unseasonal melt events observed at a series of on-ice automatic weather stations (AWS) along the K-transect in southwest Greenland. The local marine versus synoptic influence on the above and below freezing surface air temperature events is assessed through analyses involving AWS winds, pressure, and humidity observations. These surface observations are further compared against Modele Atmospherique Regional (MAR), Regional Atmospheric Climate Model (RACMO), and ERA-Interim reanalysis fields to understand the airmass origins and (thermo)dynamic drivers of the melt events. Results suggest that the K-transect transition season melt events, primarily in the ablation zone, are strongly affected by ridging atmospheric circulation patterns that transport warm, moist air from lower latitude land-ocean areas toward west Greenland. While local conduction of oceanic surface heat appears to impact coastal air temperatures, consistent with previous studies, marine air incursions from Baffin waters onto the ice sheet are likely obstructed by barrier flows and the pressure gradient-driven katabatic regime off of central Greenland.

The morphodynamic response of the Dutch Wadden Islands to the effects of climate change (e.g. sea level rise) or human interventions (e.g. nourishments) is closely tied to the evolution of the ebb-tidal deltas between them. To understand the fate of these ebb-tidal deltas, we must quantify the behaviour and transport patterns of sediment as it moves across them. In September 2017, 2000 kg of dual signature (fluorescent and ferrimagnetic) sediment tracer was deployed on the seabed at Ameland ebb-tidal delta in the Netherlands. The tracer’s physical characteristics (d50= 285 μm, ρ = 2628 kg/m3) closely matched those of the native sediment to ensure that it was eroded, transported and deposited in a similar manner. The tracer study was complemented by simultaneous measurements of hydrodynamics and suspended sediment at four locations across the ebb-tidal delta. Over the subsequent 41 days, the tracer’s dispersal was monitored via the collection of seabed grab samples and determination of tracer content and particle size within each sample. In addition, high-field magnets mounted on mooring lines 1, 2, and 5 m above the seabed at strategic locations around the deployment site were used to sample tracer particles travelling in suspension. Tracer particles were recovered from over 60 of approximately 200 samples, despite the occurrence of two significant storm events (Hs > 4 m). Although hydrodynamic measurements suggest an eastward tidal residual flow, the spatial pattern of the recovered tracer indicates that transport is highly dispersive, likely due to the storms. Furthermore, the samples recovered from the suspended magnets show an upward fining trend in grain size through the water column. The active sediment tracing approach provides useful insight into sediment transport patterns and sorting processes in energetic coastal environments. The study also demonstrated the potential of dual signature sediment tracers to monitor sand nourishment effectiveness. In particular, the use of magnets proved highly effective at sampling tracer travelling in suspension, enabling both bed load and suspended load transport processes to be investigated. The data obtained through this study will serve as a basis for future numerical model calibration and validation.

The sub-auroral ion drift (SAID) denotes a latitudinally narrow channel of fast westward ion drift in the sub-auroral region. The recently recognized sub-auroral optical phenomenon, the Strong Thermal Emission Velocity Enhancement (STEVE), is intrinsically related to intense SAIDs. Recently, we had developed a 2D time-dependent model to study the self-consistent variations of the ionosphere under intense SAID. The present study further advances the model to a current generator scenario of SAID. By assuming magnetospheric field-aligned current (FAC) inputs based on existing knowledge and observations, we model the self-consistent variations of the ionosphere, with focus on the dynamic changes of the plasma density, the Pedersen conductance, and the electric field. We can reproduce the self-consistent evolution of an intense SAID and its associated ionospheric dynamics such as extreme heating and depletion. We illustrate that the ion Pedersen drifts can cause dynamic density variations in the lower ionosphere. Positive feedback is found to exist between the self-consistent variations of the electric field and the conductance: the ion Pedersen transport associated with the electric field leads to density depletion in the lower ionosphere, thus reducing the Pedersen conductance and further enhancing the electric field there. We conclude that such positive feedback is key to the formation of intense SAID’s in the ionosphere.

Continental and global-scale groundwater models have been proposed recently to complete and improve the simulation of the hydrologic cycle. This development is still impeded by the resolution of these models either due to data availability and/or computational demands. One of the major challenges is determining the location of surface water bodies on the global scale based on land surface elevation data, as surface water elevation directly influences the model results. Closely connected to this problem is the comparison of simulated model results to observations of depth to groundwater. The models calculate hydraulic head so depth to groundwater is heavily influenced by how the variation in topography is reflected in one computational cell. This presentation demonstrates by means of the newly developed global groundwater model G³M that depth to groundwater observations need to be contemplated in the context of the elevation of the surface water bodies to draw proper conclusions on the model performance. The impact of uncertainty in surface water body elevation is illustrated based on multiple grid size experiments (5 arcmin, 30 arcsec, and 3 arcsec resolution) for New Zealand.

Water availability depends on water quantity and quality. Geogenic contaminants, including non-metals, metals, and metalloids from geologic sources, are among the most prevalent contaminants limiting water availability in the U.S. and globally. Typical geologic materials have geogenic concentrations such that dissolution of very small fractions can cause concentrations exceeding drinking water, ecological, and other water use thresholds. Geogenic contaminants often occur in groundwater due to subsurface water-rock interactions, but their distribution and concentration can also be affected by human activities such as mining, energy production, irrigation, and pumping practices. Many hydrogeologic and biogeochemical factors contribute to causing geogenic contamination that limits water availability. However, sociodemographic features, including drinking water source and missing water quality information, are often overlooked when evaluating, determining, and ranking the merit and benefit of research. Sociodemographic features, data gaps resulting from historical data collection disparities, social vulnerability indices, socioeconomic status, and infrastructure condition/age are examples of environmental justice (EJ) factors. To avoid perpetuating knowledge gaps while setting research priorities, EJ factors can be considered when developing ranking schemes to prioritize water availability research activities. The U.S. Geological Survey (USGS) is working to quantitatively incorporate and prioritize EJ factors in ranking regional-scale, geogenic-related water availability research priorities. USGS ranking schemes incorporate typical physical and geochemical factors such as existing data, climate variables, and water use. Missing and sociodemographic information will also be incorporated to begin addressing EJ inequities. EJ factors include, for example, sparse information about water quality in lower income and minority areas, and unknowns about water quality in areas of substantial cultural or subsistence hunting, fishing, or gathering. By considering both EJ and hydrogeological/biogeochemical factors, decision makers will have a more diverse, interdisciplinary toolbox to increase equity and reduce bias in prioritizing future water availability studies.

A document by Natalya Evans. Click on the document to view its contents.

For various heliogeophysical conditions during solar terminator passages results of observations of amplitude variations of the partial reflection radar signals (the observatory Tumanny of the Polar Geophysical Institute, 69.0N, 35.7E) at the heights of the D-region of the ionosphere are given. Temporary variations of signal amplitudes which were reflected in the interval of the heights of 75-90 km and their spectra were analyzed. It was found that the components of the time spectrum of the variations which corresponding to resonant frequencies of the atmosphere (the acoustic cut-off and the Brunt-Väisälä ones) in certain cases were intensified. On the basis of the theory of acoustic-gravity waves and the empirical model of neutral structure and temperature of the atmosphere (NRLMSISE-00) identification of the experimental periods corresponding to the atmospheric resonances was executed and calculation of temperature of the neutral atmosphere and sound speed at mesospheric heights was carried out. The received results showed satisfactory consent with data of other independent observations.

Understanding how the terrestrial biomass will respond to perturbations is currently a large source of uncertainty within ESMs. Cohort-based demographic models have been a recent development of DGVMs that can improve the representation of size-dependent interactions between the environment and species normally seen in individual-based models while removing stochastic characteristics within global runs. RED partitions the population of a PFT into size classes, of an appropriate variable (biomass, basal diameter) across the physiological range. Using a biomass/basal-diameter spaced advection equation that accounts for size-dependent scaling of the structural growth and mortality across the classes, we are able to model how the population evolves over time. By assuming a power scaling size-growth relationship with constant mortality, RED derives a quasi-Weibull distribution for the forest steady state. When compared to forest inventory data the solution provides a realistic fit. By applying a boundary condition limiting seedlings to open space, RED can derive solutions for the total vegetation fraction, biomass, and other variables by only knowing two parameters - the background ratio of mortality and growth and the fraction of NPP going into seedling production. From this, we have shown that RED can obtain realistic global outputs for biomass densities and evaluatory metrics.The analytical solutions derived from the foundational equations and assumptions of RED suggests an inherent simplicity of the forest structure, with low competition between trees, strong competition for seedlings, and size-independent mortality. Divergence from the analytical solution could indicate a historic disturbance. As RED allows for the representation of asymmetrical mortality and growth, disturbances in which size is important can be dynamically simulated. The theory and model allows for potential insights into how ecosystems will respond to future increases in CO2 and disturbances.

The curious undular bore// Propagates onward to shore// The energy flies// From low freqs to high// Until the wavefront is no more

In our study, we contribute one another connection between geophysics and planetary science by investigating influence of Solar Dipole field (SDF) and frequency of Earthquake’s occurence. First, during period from solar maximum at 2000 to solar maximum at 2012, we compare variations of Number of World’s Earthqaukes (NEQKs) , Solar Dipole (SDF) with equatorial (E-SDF) and axial (A-SDF)components which contribute to of Interplanetary Magnetic Field (IMF). Then, to describe diverging of outer core leading to earthquake, we apply a model of spherical shell composed of co-axial circular areas of infinatisimal thickness. The largest of them surrounds equatorial plane. The shell contains bulk of outer core’s conductive liquid. According to our model, we focus on total contributions from forces applied by Axial and Equatorial Dipole Fields, of Earth (A-EDF and E-EDF) along the radial distance, to act on azimuthal elecrical flow and convectional elecrical flows, respectively. Influence of Coriolis force decreases whenever the force acting on the convectional flow is effective to push the outer core diverges toward mantle to trigger an earthquake . Plotting of Number of Geomagnetic Storms (N-GMS) per Year is considered, the variations in N-GMS, and the strengths of A-SDF and E-SDF, are seen to be connected with the variations in N-WEQKs, throughout the solar storms, for the period of interest. During rising phase from 2000 to 20003, as the strength of SDF with dominant components of west to east oriented (WE ) E-SDF , which contributes mainly to IMF, increases. As the strength of WE IMF, increases, number of solar storms increases. The increasing number of solar storms , which distort the EDF with components of EW E-EDF and northward (NW) Axial EDF (A-EDF), results in decsending N-WEQKs . During rising phase from 2003 to 2009, as the strength of SDF with dominant components of west to east oriented (WE) E-SDF , which contributes mainly to IMF , decreases, the strength of WE IMF and number of solar storms decrease and leads to increase in N-WEQKs . During rising phase from 2009 to 2011, as the strength of SDF with dominant components of southward (SW ) SADF , which contributes mainly to IMF, decreases. leads to more effective NW A-EDF which results in ascending N-WEQKs.D uring rising phase from 2011 to 2012, the strength of SDF with dominant east to west oriented (EW ) SEDF , which contributes mainly to IMF , increases. The increasing strength of EW IMF leads to less effective NW A-EDF. Hence, N-WEQKs is reduced. To conclude, our study shows that better modeling and forecasting of earthquakes could be done throughout the conditions in Earth-Sun system, instead of conditions just on Earth.

We present numerical simulations of elastic wave propagation, scattering and attenuation in two-dimensional fractured media. Natural fracture systems following a power law length scaling are modeled by the discrete fracture network approach for the geometrical representation of fracture distributions and the displacement discontinuity method for the mechanical computation of fracture-wave interactions. The model is validated against analytical solutions for wave reflection, transmission and scattering by single fractures, after which we apply it to solve the spatiotemporal wavefield evolution in various synthetic fracture networks. We find that the dimensionless angular frequency ῶ plays a crucial role in governing wave transport. When ῶ is smaller than the critical frequency ῶc (≈ 5), waves are in the extended mode, either propagating (for small ῶ) or diffusing by multiple scattering (for intermediate ῶ); as ῶ exceeds ῶc, the wave energy becomes trapped, entering either the Anderson localization regime (kl* ≈ 1) in well-connected fracture systems or the weak localization regime (kl* > 1) in poorly-connected fracture systems, where k is the incident wavenumber and l* is the mean free path length. Consequently, the inverse quality factor Q-1 scales with ῶ obeying a two-branch power law dependence, showing significant frequency dependence when ῶ < ῶc and almost frequency independence when ῶ > ῶc. In addition, when ῶ < ῶc, the wavefield exhibits a weak dependence on fracture network geometry, whereas when ῶ > ῶc, the fracture network connectivity has an important impact on the wave behavior such that strong attenuation occurs in well-connected fracture systems.

The Amundsen Sea Low (ASL) is a distinctive feature of the Southern Hemisphere (SH) high latitude atmospheric circulation, regulating regional Antarctic climate, meridional heat transport, ocean circulation, and sea-ice in the Amundsen-Bellingshausen Seas. Most previous research on the ASL has focused on its variability with only a few studies attempting to understand why the climatological ASL exists. These studies have proposed different hypotheses to explain the presence of ASL, however, a clear understanding of the mechanisms responsible for the generation of the ASL remains uncertain. Here we use an atmospheric general circulation model to show that the ASL is a consequence of the interaction between Antarctic topography and the westerly wind jet, with negligible influence from low-latitude teleconnections. A non-rotating fluid flow simulation further suggests that the ASL can be explained by flow separation resulting from the interaction of westerly winds with the topography of Antarctica.

Geoscience doctoral programs are among the least diverse among STEM fields, with no progress since 1973 on ethnic and racial diversity among U.S. citizens earning doctorates in the earth, atmosphere and ocean sciences [1]. In this contribution, we examine Asian American representation in U.S. geoscience doctoral programs (defined here as U.S. citizens and permanent residents) [2]. Temporal trends of geoscience Ph.D. recipients lead to four key findings. (1) Since 1973, Asian Americans make up 5.3% of geoscience doctorates, below the current U.S. citizenry. However, since 2001, the proportion of Asian American geoscience doctorates has declined to 4.4% since 2001, while degrees earned by temporary residents have greatly increased (>85% of all Asians since 2006). (2) Trends since 1973 are impacted by a short-lived spike in Asian American geoscience Ph.D. recipients in the mid-1990s. (3) Gender parity among Asian Americans has improved from 16% female in the 1970s to 51% since 2001. (4) Within the geoscience disciplines (earth, ocean, and atmospheric), the earth sciences have lagged in Asian American representation with only 3.7% of total graduates since 2001 concentrated in a few U.S. states. In sum, Asian Americans are similar to other minority groups in that gender parity has been reached, although proportional representation has not. Additionally, the high proportion of temporary residents may bias the perception of participation by Asian Americans. Despite these findings, participation gaps from Black, Hispanic/Latino, and Native American groups lag those of Asians significantly [1]. While not categorized as ‘underrepresented’ in 2016, Asian Americans are still a minority and therefore face similar challenges to other minority groups. Further, Asian Americans represent diverse racial and ethnic backgrounds not captured by current survey methods. The active inclusion of Asian American groups in the diversity conversation may increase engagement in the geosciences and potentially encourage Asian Americans to act as allies to other groups. Through this contribution we hope to place Asian representation in the context of minority participation in the geosciences and foster a network of Asian American geoscientists. 1. doi:10.1038/s41561-018-0116-6 2. https://www.nsf.gov/statistics/2018/nsf18304/

The Millennium Drought (Drought) from about 1997 to 2008 was one of if not the most severe drought in recorded Australian history. In 2006 River Murray inflows were 40% below the previous low. Nothing of this severity occurs without a cause, which must have the same time span, and the obvious challenge is to identify the culprit and explain how it caused the Drought. CAWCR Technical Report 26 discussed ENSO; the North West Shelf Sea Surface Temperature (SST); MSLP SE Australia; the SAM; and the Neighbouring Tasman Sea SST as possible causes and found that: local MSLP is the major influence; and ENSO’s influence is created by “large-scale circulation changes”. The literature and the Bureau of Meteorology (BoM) also link the positive phase of the Indian Ocean Dipole (IOD) to drought in Australia. Many researchers have tried to connect ENSO events to volcanic eruptions without success as their focus was on large eruptions which injected gases and tephra into the stratosphere. I include all eruptions in a restricted area, south east Asia (SE Asia), and show how they create ENSO events by reducing convection over the Maritime Continent and forcing the Trade Winds to relax. Simultaneously the volcanic plume moves the regional southern Hadley Cell south and creates the anomalous, persistent high pressure over south eastern Australia. Finally by intercepting the solar radiation by absorption and/or reflection, the volcanic plume cools the sea surface beneath it - the region where moisture which falls as rain in SE Australia evaporates - thereby reducing the available moisture in SE Australia and also creates IOD events. I show that SE Asian tectonic activity is highly variable and the level of volcanic tephra ejected during the Drought was treble the average for the 20th century and this was exacerbated by the anthropogenic aerosols in the same region which increased by 687% from 1979 to 2000 in September. Thus the Millennium Drought was caused by the increased levels of volcanic and anthropogenic aerosols over south east Asia which simultaneously: forced the circulation changes which created the anomalous high pressure over SE Australia; ENSO; and IOD events

Time series of piezometric head implicitly contain information about groundwater system. This information is reflected in the impulse response function of precipitation. In order to use these functions as a signature of the system, they must be determined with appropriate reliability. In order to investigate the effect of other influences on the determination of the precipitation response, piezometric data have been studied from a transect running from dunes along the Dutch North Sea coast with natural vegetation into a polder area with agricultural and urban land use. In the dune area, there are several drinking water abstractions with known abstraction rates or levels. Each time series of piezometric head has been modeled with precipitation, evaporation and up to 4 extractions as explanatory variables. The precipitation impulse response functions from these models have been evaluated per piezometer and compared to neighboring piezometers. Over-parametrization gives more problems for the determination of the precipitation impulse response than the presence of other influences as long as these are not too correlated with the precipitation. The reliability of the precipitation response can be assessed using spatial correlation with neighboring piezometers and the local hydrogeology. Reliable impulse response functions can be used for interpolation and prediction of heads and for characterisaton of the hydrogeological settings.

The hazard of wildfires in Chile is latent, especially in densely populated urban centers that are embedded in a Wildland-Urban Interface (WUI). As an example of that is Concepción which is the second most populated conurbation in Chile. This kind of hazard is strengthened by development models that end up conflicting as is the case of the Chilean Forest Model (MFC) and the Urban Development Model (MDU). Both models are based on liberalized economic principles and spatial growth that have been contributed to the construction of wildfire risk scenarios. In this work, the complexity of the wildfire hazard in the Metropolitan Area of Concepción is addressed. LANDSAT-8 and ASTER satellite images are used to evaluate the danger of wildfires. The anthropic factors (soil cover, road network, controlled burning points, camping), and natural factors (topography, flammability, insolation, altitude) that influence the hazard are analyzed. To corroborate the detected hazard zones and WUI according to satellite data, the foci of fires provided by the forestry management government agency (CONAF) are also spatialized. Finally, the main structural agents that can contribute to wildfire hazard in the area are discussed, specifically: the closeness between land cover associated with monocultives and the areas resulting from urban expansion; and the economic incentives given by the government that have increased the area of the plantations and the housing area.