Tectonic tremors occurring on subducting plate boundaries are known to migrate at various timescales and migration speeds. Spatiotemporal patterns of tremor migration are key to investigating the rupture growth of slow earthquakes. However, spatiotemporal patterns are not sufficiently simple to visually define tremor migrations. This study developed a space-time Hough transform to objectively extract tremor migrations. The space-time Hough transform enables the extraction of multiple tremor migrations with various durations, migration directions, and migration speeds. We applied this method to a catalog of tremors for the period from 2012 to 2014, which was determined from the data analysis of a dense seismic array deployed in the Kii Peninsula, Southwest Japan. We successfully extracted 1,010 tremor migrations with durations ranging from 10 min to 24 h. Along-strike migrations propagating southwestward were predominant in the northeastern part of the Kii Peninsula, whereas those propagating northeastward were principal in the southwestern part. Regarding the along-dip direction, tremor migrations propagating in the up-dip directions were predominant in the deep part, and those propagating in the down-dip directions were principal in the shallow part. The patterns of along-strike migrations were related to the distribution of tremor energies, suggesting that tremor migrations may be controlled by heterogeneous structures of frictional properties on the plate interface. We further found that the migration speed is proportional to the inverse of the square root of the duration. This relation implies that a diffusion process controls the growth of fault ruptures behind tremor migrations.

Maize (Zea mays L.) is a crop of major economic and food security importance globally. The fall armyworm (FAW), Spodoptera frugiperda, can devastate entire maize crops, especially in countries or markets that do not allow the use of transgenic crops. Host-plant insect resistance is an economical and environmentally benign way to control FAW, and this study sought to identify maize lines, genes, and pathways that contribute to resistance to FAW. Of 289 maize lines phenotyped for FAW damage in artificially infested, replicated field trials over three years, 31 were identified with good levels of resistance that could donate FAW resistance into elite but susceptible hybrid parents. The 289 lines were genotyped by sequencing to provide SNP markers for a genome-wide association study (GWAS), followed by a metabolic pathway analysis using the Pathway Association Study Tool (PAST). GWAS identified 15 SNPs linked to 7 genes, and PAST identified multiple pathways, associated with FAW damage. Top pathways, and thus useful resistance mechanisms for further study, include hormone signaling pathways and the biosynthesis of carotenoids (particularly zeaxanthin), chlorophyll compounds, cuticular wax, known antibiosis agents, and 1,4-dihydroxy-2-naphthoate. Targeted metabolite analysis confirmed that maize genotypes with lower levels of FAW damage tend to have higher levels of chlorophyll a than genotypes with high FAW damage, which also tend to have lower levels of pheophytin, lutein, chlorophyll b and β-carotene. The list of resistant genotypes, and the results from the genetic, pathway, and metabolic study, can all contribute to efficient creation of FAW resistant cultivars.

Quaternary convergence at rates of ~10 mm/yr between the Arabian and Eurasian plates is largely accommodated by the Kura fold-thrust belt at the longitude of the Greater Caucasus Mountains in Azerbaijan and eastern Georgia. Here we present the results of the first paleoseismic study of the Kura fold-thrust belt in Azerbaijan. A single paleoseismic trench was excavated across a 2-m-high fault scarp near Agsu revealing evidence of two recent surface rupturing earthquakes. Radiocarbon dating of the faulted sediments places limits of earthquake timing of AD 1713-1895 and AD 1872-2003 for the two events. Allowing for uncertainties in radiocarbon dating, the two events likely correspond to historical destructive M~7 earthquakes near Shamakhi, Azerbaijan in AD 1668 and 1902. Holocene shortening and dip-slip rates for the Kura fold-thrust belt are 8 and 8.5 mm/yr, respectively, based on the depositional age of an abandoned uplifted strath terrace in a water gap to the west of Agsu. These rates should be treated as maxima, as they are ~100% of the previously determined structurally and geodetically measured shortening across the belt, and were measured from only one of two primary structures in this part of the belt. The lack of reported historical ruptures from the past 8 centuries to the west of Agsu, in contrast with the numerous recorded destructive earthquakes of the Shamakhi region, suggests that the central and western parts of the Kura fold-thrust belt produce less frequent, but more destructive earthquakes, and may have accumulated sufficient strain to produce a M>8 earthquake.

We exploit nonlinear elastodynamic properties of fractured rock to probe the micro-scale mechanics of fractures and understand the relation between fluid transport and fracture aperture and area, stiffness proxy, under dynamic stressing. Experiments are conducted on rough, tensile-fractured Westerly granite specimen subject to triaxial stresses. Fracture permeability is measured from steady-state fluid flow with deionized water. Pore pressure oscillations are applied at amplitudes ranging from 0.2 to 1~MPa at 1~Hz frequency. During dynamic stressing we transmit acoustic signals through the fracture using an array of piezoelectric transducers (PZTs) to monitor the evolution of fracture interface properties. We examine the influence of fracture aperture and contact area by conducting measurements at effective normal stresses of 10, 12.5, 15, 17.5, and 20~MPa. Additionally, the evolution of contact area with stress is characterized using pressure sensitive film. These experiments are conducted separately with the same fracture and they map contact area at stresses from 9 to 21~MPa. The resulting ‘true’ area of contact measurements made for the entire fracture surface and within the calculated PZT sensor footprints, numerical modeling of Fresnel zone. We compare the elastodynamic response of the the fracture using the stress-induced changes ultrasonic wave velocities for a range of transmitter-receiver pairs to image spatial variations in contact properties, which is informed by fracture contact area measurements. These measurements of the nonlinear elasticity are related to the fluid-flow, permeability, in response to dynamic stressing and similar comparisons are made for the slow-dynamics, recovery, of the fracture interface following the stress perturbations.

Heat related illnesses are one of the leading causes of weather-related mortality in the United States, and heat extremes continue to increase in frequency and duration. Public health interventions include population mobility, including travel to central cooling centers or wellness checks on vulnerable populations. Using anonymized cellphone data from Safegraph’s neighborhood patterns dataset and gridded temperature data from gridMET, we explored the mobility-temperature relationship in the San Francisco Bay Area at fine spatial and temporal scale. We leveraged spatial variability in median income and temporal variability in COVID-19 related policies across two summers (2020-2021) to analyze their influence on the mobility-temperature relationship. We completed quantile regressions for a dataset stratified by income and year. We found that mobility increased at a higher rate with higher temperatures in 2020 than 2021. However, in 2021, the relationship reversed for several wealthier income groups, where mobility decreased with higher temperatures. We then augmented the analysis and calculated a panel regression with fixed effects to characterize the mobility-temperature relationship while controlling for temporal and spatial variability. This analysis suggested that all areas exhibited lower mobility with higher summer temperatures. However, similar to the results of the quantile regression, the rate of decrease in mobility in response to high temperature was significantly greater among the wealthiest census block groups compared with the least wealthy. Given the fundamental difference in the mobility response to temperature across income groups, our results are relevant for heat mitigation efforts in highly populated regions in current and future climate conditions.

Sequencing-based genotyping of heterozygous diploids requires sufficient depth to accurately call heterozygous genotypes. In interspecific hybrids, alignment of reads to both parental genomes simultaneously can generate haploid data, potentially eliminating the problem of heterozygosity. Two populations of interspecific hybrid rootstocks of walnut (Juglans) and pistachio (Pistacia) were genotyped using alignment to the maternal genome, paternal genome, and dual alignment to both genomes simultaneously. Downsampling was used to examine concordance of imputed genotype calls as a function of sequencing depth. Dual alignment resulted in datasets essentially free of heterozygous genotypes, simplifying the identification and removal of cross-contaminated samples. Concordance between full and downsampled genotype calls was always highest after dual alignment. Nearly all SNPs in dual alignment datasets were shared with the corresponding single-parent datasets, but 60-90% of single-parent SNPs were private to that dataset. Private SNPs in single-parent datasets had higher rates of heterozygosity, lower levels of concordance, and were enriched in fixed differences between parental genomes (“homeo-SNPs”) compared to shared SNPs in the same dataset. In multi-parental walnut hybrids, the paternal-aligned dataset was ineffective at resolving population structure in the maternal parent. Overall, the dual alignment strategy effectively produced phased, haploid data, increasing data quality and reducing cost.

In 2021, the World Health Organization (WHO) ranked Nigeria among the most polluted nations in the world, an indication of a deteriorating air quality, especially in the major urban areas of the country, which might pose adverse human health impacts. In this study, the Integrated Source Apportionment Method (ISAM) tool in the Community Multiscale Air Quality (CMAQ) model (CMAQ-ISAM) was employed to quantify the contributions of eight emissions sectors to fine particulate matter (PM2.5) and its major components in Lagos during a prolonged severe atmospheric pollution episode (APE) in January 2021. The influence of meteorological conditions on the formation and dispersion of PM2.5 during the APE was also elucidated. Spatially, elevated PM2.5 concentrations were found in the northwestern region of Lagos, an urban area with larger anthropogenic emissions. Residential and industry were the two major sources of PM2.5. Residential contributed the most to total PM2.5 (~40 μg/m3), followed by industry (~20 μg/m3). High concentrations of secondary inorganic aerosols (SIA) at the northwest and upper northern areas of Lagos were majorly attributed to residential and industry sectors. In addition, sulfate accounted for the largest fraction of PM2.5, with residential, industry, and energy being its major sources. Residential, industry, and on-road sectors dominated the contributions to nitrate, while residential and industry were the major contributors to ammonium. Furthermore, the elevated PM2.5 concentrations during the APE were greatly enhanced by unfavorable meteorological conditions. This study provides insights for designing effective emissions control strategies to mitigate future severe PM2.5 pollution episode in Lagos.

The wetting properties of pore walls have a strong effect on multiphase flow through porous media. However, the fluid flow behaviour in porous materials with both complex pore structures and non-uniform wettability are still unclear. Here, we performed unsteady-state quasi-static oil- and waterflooding experiments to study multiphase flow in two sister heterogeneous sandstones with variable wettability conditions (i.e. one natively water-wet and one chemically treated to be mixed-wet). The pore-scale fluid distributions during this process were imaged by laboratory-based X-ray micro-computed tomography (micro-CT). In the mixed-wet case, we observed pore filling events where the fluid interface appeared to be at quasi-equilibrium at every position along the pore body (13% by volume), in contrast to capillary instabilities typically associated with slow drainage or imbibition. These events corresponded to slow displacements previously observed in unsteady-state experiments, explaining the wide range of displacement time scales in mixed-wet samples. Our new data allowed us to quantify the fluid saturations below the image resolution, indicating that slow events were caused by the presence of microporosity and the wetting heterogeneity. Finally, we investigated the sensitivity of the multi-phase flow properties to the slow filling events using a state-of-the-art multi-scale pore network model. This indicated that pores where such events took place contributed up to 19% of the sample’s total absolute permeability, but that the impact on the relative permeability may be smaller. Our study sheds new light on poorly understood multiphase fluid dynamics in complex rocks, of interest to e.g. groundwater remediation and subsurface CO2 storage.

The Arctic is marked by deep intrusions of warm, moist air, alternating with outbreaks of cold air down to lower latitudes. The typical vertical structure of clouds and precipitation during these two synoptic weather extremes is examined at a coastal site at 69°N in Norway. The Norwegian Sea is a corridor for warm-air intrusions (WAIs) and frequently witnesses cold-air outbreaks (CAOs). This study uses data from profiling radar, lidar, and microwave radiometer, radiosondes and other probes that were collected during the Cold air Outbreaks in the Marine Boundary Layer Experiment (COMBLE) between 1 December 2019 and 31 May 2020. Marine CAOs are defined in terms of thermal instability relative to the sea surface temperature, and warm-air intrusions in terms of stratification of moist static energy between the surface and 850 hPa. Cloud structures in CAOs are convective, driven by strong surface heat fluxes over a long fetch of open water, with cloud tops between 2-4 km. The mostly open-cellular convection may contain substantial ice and produce intermittent moderate precipitation at the observational site, notwithstanding the low precipitable water vapor. In contrast, WAIs are marked by high values of precipitable water vapor and integrated vapor transport. WAI clouds are stratiform, with cloud tops often exceeding 6 km, sometimes layered, and generally producing persistent precipitation that can be heavier than in CAOs.

Numerical wave models have been developed to reproduce the evolution of waves generated in all directions and over a wide range of wavelengths. The amount of wave energy in the different directions and wavelength is the result of a number of physical processes that are not well understood and that may not be represented in parameterizations. Models have generally been tuned to reproduce dominant wave properties: significant wave height, mean direction, dominant wavelengths. A recent update in wave dissipation parameterizations has shown that it can produce realistic energy levels and directional distribution for shorter waves too. Here we show that this new formulation of the wave energy sink can reproduce the variability of measured infrasound power below a frequency of 2 Hz, associated with a large energy level of waves propagating perpendicular to the wind, for waves with frequencies up to at least 1 Hz. The details are sensitive to the balance between the non-linear transfer of energy away from the wind direction, and the influence of dominant and relatively long waves on the dissipation of shorter waves in other directions.

The use of heavy machinery is increasing in agricultural industries in particular cotton farming systems, which induces an increased risk of soil compaction and yield reduction. Hence, there is a need for a technical solution to use available tools to measure projected soil compaction due to farm machinery traffics. The aim of this work was to compare the effects of static and dynamic loads on soil compaction. In this study, three vertosols (common soil for cotton production) were selected to examine soil compaction under a range of static and dynamic loads using uniaxial compression equipment and a modified proctor test, respectively. In general, soils behaved similarly under static and dynamic loads with no significant difference between bulk density values for all moisture contents with a high index of agreement (d=0.96, RMSE= 0.056). The results further indicate better agreement between soil compaction for static and dynamic loads Uniaxial compression test (static loads) produced higher compaction compared to the modified proctor test (dynamic loads) in particular at moisture contents lower than the plastic limit condition. The variation in soil compaction for static and loads was often evident for loads ≥600 kPa, with the highest soil compaction induced under loads ≥1200 kPa. The findings of this study confirm the suitability of a modified proctor method to assess soil compaction as an alternative tool under a range of moisture contents and machinery loads for vertosols.

Marine Isotope Stage (MIS) 5e (130-116 ka) represents a ‘process analogue’ for future anthropogenic warming. Climate model simulations for MIS 5e have previously failed to produce Southern Ocean sea-surface temperatures (SST) and sea-ice extent reconstructed from marine sediment core proxy records. Here we compare state of the art HadGEM3 and HadCM3 simulations of Peak MIS 5e Southern Ocean summer SST and September sea-ice concentrations with the latest marine sediment core proxy data. The model outputs and proxy records show the least consistency in the regions located near the present-day Southern Ocean gyre boundaries, implying that model simulations are currently unable to fully realise changes in gyre extent and position during MIS 5e. Including Heinrich 11 meltwater forcing in Peak MIS 5e climate simulations improves the likeness to proxy data but it is clear that longer (3-4 ka) run times are required to fully test the consistency between models and data.

The Tropical cyclone (TC) forecast skill of the eight global medium-range forecast models which are participating in the DIMOSIC (DIfferent Models, Same Initial Conditions) project is investigated in this study. Each model was used to generate 10-day forecasts from the same initial conditions provided by the European Centre for Medium-Range Weather Forecasts. There are a total of 123 initial dates spanning in one year from June 2018 to June 2019 with a 3-day interval. The TC track and intensity forecasts are evaluated against the best track dataset. TC-related precipitation and tropical cyclogenesis forecasts are also compared to explore the differences and similarities of TC forecasts across the models. This comparison of TC forecasts allows model developers in different centers to benchmark their model against other models, with the impact of the initial condition quality removed. The verifications reveal that most models show slow-moving and right-of-track biases in their TC track forecasts. Also, a common dry bias in TC-related precipitation indicates a general deficiency in TC intensity and convection in the models which should be related to insufficient model resolution. These findings provide important references for future model developments.

Growing media constituents have heterogeneous particle size and shape, and their physical properties are partly related to them. Particle size distribution is usually analyzed through sieving process, segregating the particles by their width. However, sieving techniques are best describing more granular shapes and are not as reliable for materials exhibiting large varieties of shapes, like growing media constituents. A dynamic image analysis has been conducted for a multidimensional characterization of particle size distribution of several growing media constituents (white and black peats, pine bark, coir, wood fiber, and perlite), from particles that were segregated and dispersed in water. Diameters describing individual particle width and length were analyzed, then compared to particle size distribution obtained by sieving DM and HM methods. This work suggests the relevance of two parameters, Feret MAX and Chord MIN diameters for assessing particle length and width, respectively. They largely varied among the growing media constituents, confirming their non-spherical (i.e. elongated) shapes, demonstrating the advantages in using dynamic image analysis tools over traditional sieving methods. Furthermore, large differences in particle size distribution were also observed between dynamic image analysis and sieving procedures, with a finer distribution for dynamic image analysis. The discrepancies observed between methodologies were discussed (particle segregation, distribution weighing, etc.), while describing in details methodological limitations of dynamic image analysis.

The Indian plate underthrusting the Himalaya is considered to be segmented along the collision belt arc and seismic images of the Indian mantle lithosphere (IML) suggest along-arc variations in the angle of underthrusting and its northern limit beneath Tibet. The pre-existing transverse tectonic structures of the Indian plate mapped in the Ganga foreland basin have been related to these segmentation boundaries. These segmentations imply changes in mechanical properties of adjoining blocks which should manifest in the form of spatial variations in topography build-up. We have analysed a geomorphic index, normalized channel steepness (ksn), along the Himalayan arc using the ALOS elevation dataset to test whether there is any correlation between the and these segmentation boundaries. Our results bring out spatial variability in the along the arc. Based on these results, the arc can be segmented into five blocks, similar to the ones delineated based on correlation between the width of the Ganga foreland basin and the disposition of major Himalayan thrusts from the foothills. Thus, the ksn can be used as a proxy to demarcate different tectonic blocks along the Himalayan arc. Further, we have found a good correlation between the basin width and the northern limit of the IML for all block except the Uttarakhand block. We infer that transverse crustal heterogeneities in this block due to the continuation of different litho-units of the Aravalli-Delhi Fold Belt could be a plausible cause for this anti-correlation.

A more vital soil science future 11Acceptance speech at the Presidential Award ceremony of the 2022 Soil Science Society of America (SSSA) meeting in BaltimoreAlfred E. HarteminkUniversity of Wisconsin-Madison, Department of Soil Science, FD Hole Soils Lab, 1525 Observatory Drive, Madison Wi 53711, USA. E-mail [email protected] some measures, soil science is doing fine. We have gained a battery of aspiring young scientists, and became more gender-balanced although still not as diverse as we should be (Carter et al., 2021). The number of soil scientific papers and books are growing at an almost exponential rate reflecting increased research and funding and, hopefully, an expanding knowledge base. An enormous amount of soil information is available, and increasingly peer-reviewed publications are freely accessible. Soon there will be no barrier for humanity between what is known and what information can be retrieved about soil.Soil awareness has grown among policy makers and the general public, following enduring campaigns by national and international soil organizations. It is not uncommon to hear podcasts, talks on the tv, or read articles about soil health, regenerative agriculture, or the relationships between soil management, greenhouse gases and the changing climate. Scientific disciplines ranging from medical geology to urban planning recognize the relevance of soils and have embarked on soil research.Countless technological advances enable us to observe, measure, model and monitor soil attributes at accelerating speed (Wadoux and McBratney, 2021). The private sector and industry have entered the soil carbon market, discovered the commercial value of the soil microbiome, and continues to develop technologies to optimize soil water use. But as soil science is rapidly evolving with a particular focus to solve the grand environmental challenges, it is vital that the science is done efficiently and impactful, and that it stays well-ahead of the technology.Some soil research approaches are holding us back. First, a lot of soil science is conducted at the fringe of traditional soil science centers and departments by a community that has not had the benefit of primary schooling in soil science. Our discipline has always been enriched by approaches and theory from other scientific disciplines but, at the same time, a lot of fundamental knowledge about our soils, knowledge that was learned the hard way, is ignored (Hartemink, 2015; Schimel and Chadwick, 2013). This particularly refers to the lack of viewing soils as a four-dimensional system that cannot be reduced to measuring a limited set of attributes in one or a few timesteps and from shallow soil depth.Quite a lot of research purports to investigate systems and aims to derive knowledge from differences among the systems. For example, soils under different vegetation or cropping systems are sampled for certain fractions, say, soil organic carbon, and the differences are attributed to land use and management. Too often, samples are collected only from the uppermost 20 cm (Yost and Hartemink, 2020) and, in many studies, diverse vegetation or a ‘range of agricultural soils’ are sampled across the continent so as to maximize variation. No wonder that differences are unearthed, but such studies rarely progress beyond the description of loosely connected phenomena that are hard to extrapolate, or interpolate.With research framed within one or other grand environmental challenge (Wortman and Lovell, 2013), it remains unclear how the results translate or contribute to solving those challenges. Studying and understanding soils is noy easy. The best studies are those that investigate a multitude of soils and their attributes across a range of spatial and timescales using a wide range of tools and, above all are based on a solid framework and sound theory. We need to speculate more and think deeper and longer, and require more explorations that combine measurements with modelling and predictions across time and space.Next, there is soil anxiety – that might be described as the hidden apprehension of doing something new and novel. This seems to occur, for example, at the research proposal stage whereby new ideas are met with: ‘Why?’ instead of a firm: ‘Why not!’. This goes along with the lack of study whether the research has already been done: it is easier to repeat than to formulate and invent. Part of the soil anxiety is the strictly regional approach that can be summed up as: ‘We have done in North Dakota. Now we do it in South Dakota.’ Science needs verification but there is quite a limit to progress in this direction. Progress comes from tirelessly chasing of new ideas, quite often with only partial success, but the lack of ideas - equivalent to maintaining a status quo - is regressive. It is not: ‘Go big or go home’ but: ‘Do something new or go home. Dare to fail - and dare to publish it.’And, finally, a lot more effort is needed to develop sound theory. Sound theory is the bedrock of all the soil science subdisciplines. This could be the last chapter of every PhD thesis. It is not the same thing as hypothesis formulation and testing. Research considered ‘high impact-high risk’ is no guarantee of novelty or an overture for theory development if that is not the overarching aim. Funding bodies might hesitate to support foundational soil science research but it is good to see that methodology development is advancing in most soil science subdisciplines. It seems to go hand in hand with increased technological availability.So, soil science is thriving, but it can do better. As much of our research findings are available, we have all the more responsibility to deliver the best. The future directions of our science are by no means solely determined by funding or the environmental challenges but, in particular, by the community, its education and willingness to strive for excellence. There is surely a role for the soil science journals to weed out problematic research approaches, but it is the task of the community, research centers and universities to guarantee that the research approaches are solid, reproducible, and innovative. Innovation should be the foundation of our research and not a special program defined as ‘high risk’ or ‘quick impact’. Concerted efforts should be made to force breakthroughs, for the growth of soil science theory and frameworks, and to think about the vitality of our discipline – now and in the future. And in all that, there is no need to think outside the box. There is no box.

Floating communities exist throughout the world. Many live on water with a high pathogen load due to difficulties associated with sewage management. In Claverito, an informal floating community in Iquitos, Peru, we conducted a controlled experiment to test the ability of water hyacinth (Eichhornia crassipes) to remove Escherichia coli from water. When river E. coli concentrations were at or below ~1500 CFU 100 mL-1, water hyacinth reduced shallow concentrations (8-cm depth) down to levels deemed safe by U.S. EPA for recreational use. Above this threshold, plants were able to reduce E. coli levels within shallow water, but not down to “safe” levels. At deeper depths (>25 cm), there was evidence that plants increased E. coli concentrations. Water hyacinth removed E. coli from shallow water by providing a surface (i.e., submerged roots) onto which pathogens sorbed and by protecting organisms that consume E. coli. Unfortunately, because of root association, the total E. coli load within the water column was greater with water hyacinth present, and results hinted that the plants’ protective environment also harbored parasites. The use of water hyacinth to keep surface water around floating communities low in E. coli could be beneficial as this is the water layer with which people most likely interact. Aquatic vegetation naturally proliferates in and around Claverito. While this study was based on curating aquatic plants in order to achieve a water-quality outcome, it nonetheless supports concrete actions for Claverito residents under non-curated conditions, which are outlined at the end of the manuscript.

Attention is increasingly being turned towards an investigation of extreme hydrometeorological events within the context of land-atmosphere coupling in the wider hydrological cycle, particularly with respect to the identification of compound and seesaw events. To examine these events, accurate soil moisture data are essential. Here, soil moisture from three reanalysis products (ERA5-Land, BARRA and ERA5) are compared to station observations from 12 sites across New Zealand for an average timespan of 18 years. Soil moisture data from all three reanalyses were subsequently used to investigate land-atmosphere coupling with gridded (observational) precipitation and temperature. Finally, compound (co-occurrence of hot and dry) and seesaw (transitions from dry to wet) periods were identified and examined. No best performing reanalysis dataset for soil moisture is evident (min r = 0.78, max r = 0.80). All datasets successfully capture the seasonal and residual component of soil moisture, but not the observed soil moisture trends at each location. Strong coupling between soil moisture and temperature occurs across the predominately energy-limited regions of the lower North Island and entire South Island. Consequently, these regions reveal a high frequency of compound period occurrence and potential shifts in land states to a water limited phase during compound months. A series of seesaw events are also detected for the first time in New Zealand (terminating an average of 17% of droughts), with particularly high frequency of seesaw event occurrence detected in previously identified areas of atmospheric river (AR) activity, indicating the likely wider significance of ARs for drought termination.