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We combine methods to identify substorms and geomagnetic storms into a single, novel method that identifies four categories: quiet times, storm only, substorm only, substorms in storms. We employ Birkeland current density data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) between 2010–2017 and use our new combined identification method to sort data in this range into one of the four categories. We then subsample such that each category comprises the same number of data, in order that each category behaves statistically similarly. We then examine the large global behaviour of each category for the first time. We find that the mean current density is larger during substorms and its standard deviation is larger during geomagnetic storms. We assess the kurtosis and variance of the underlying distributions, and determine that the kurtosis is far higher during geomagnetic storms than during substorms. We use the survival function to quantify the probability of current densities above set thresholds and find that current densities which are above a low threshold are more likely during substorms, but that extreme currents are far more likely during geomagnetic storms. We shift the data into an adaptive coordinate system defined by the boundary between Regions 1 and 2 Birkeland current and demonstrate that extreme currents are most likely to flow within Region 2 current during geomagnetic storms. This is consistent with the literature on geomagnetic storms driving extreme behaviour, but unexpected in a paradigm of the current systems in which Region 1 current is generally larger.

Lunar Vertex is a mission at the intersection of multiple science communities, from planetary geology to space plasma physics. As the first Payloads and Research Investigations on the Surface of the Moon (PRISM1) investigation, scheduled for delivery to the Reiner Gamma (RG) magnetic anomaly in 2024 aboard a commercial lunar lander, Lunar Vertex will unravel the nature of the RG anomaly, the connection to and origin of the associated lunar swirl surface feature, and the structure and impact of the “mini-magnetosphere” in this region. Lunar Vertex includes a suite of magnetometers (Vector Magnetometer – Lander; VML), a fixed-mounted set of cameras (Vertex Camera Array; VCA), and a low-energy ion and electron plasma analyzer (Magnetic Anomaly Plasma Spectrometer; MAPS) on the lander. In addition, a second suite of commercial fluxgate magnetometers (Vector Magnetometer – Rover; VMR) and a multispectral imager (Rover Multispectral Microscope; RMM) are mounted on a dedicated rover that will traverse a distance of at least 500 m from the lander, providing additional multi-point measurements. The combination of magnetic field measurements taken during cruise and descent by VML and during surface operations by both VML and VMR will characterize the surface magnetic field within a strong lunar magnetic anomaly. The combined magnetic field and plasma measurements from VML and MAPS will provide direct observations of plasma populations reaching the lunar surface and the associated local magnetic field configuration. Furthermore, the lunar regolith within the RG magnetic anomaly and over different regions of the associated lunar swirl will be characterized by RMM and VCA to reveal the surface texture, composition, and particle distribution around both the lander and rover locations and the correspondence to potential surface weathering processes.

We track the progression of height-integrated conductances over the course of an average substorm in a narrow local time sector of the nightside polar cap. These conductances are calculated from the mean energy flux and energy flux of precipitation, as estimated from a ratio of auroral emissions of the Lyman-Birge-Hopfield long and short band obtained by multiple polar region crossings of the Defence Meteorological Satellite Program F16, F17, and F18 spacecraft. Contributing auroral emission data span 1 January 2005 to 31 December 2017. Both Pedersen and Hall conductances are considered, as well as the influence of the magnetic latitude of substorm onset. Substorm onset times and magnitudes are provided by the SuperMAG network and SOPHIE substorm lists. We compare superimposed epoch ordered conductances with similarly averaged field aligned currents from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). Shortly before onset, conductances increase in a low latitude region, before an increase in conductance seen at all latitudes at the time of onset. The energy flux is shown to peak quickly after substorm onset, followed by mean energy. The conductances, energy flux, and mean energy are ordered by magnetic latitude of substorm onset, so that the lowest onset latitudes correspond to the highest value of any given parameter. Conductances recover quicker to pre-substorm levels for those substorms with higher onset magnetic latitudes.

Subauroral polarization streams (SAPS) typically refer to an enhanced westward plasma flow channel in the duskside subauroral ionosphere. SAPS overlap with the low-latitude part of downward Region-2 field-aligned currents (FACs). The relatively low subauroral conductance in this region requires a strong electric field for current closure, which drives the fast sunward plasma flow. Observations have shown dynamic variability of SAPS under various solar wind and interplanetary magnetic field (IMF) conditions, which are related to the variability of FACs and auroral precipitation, as well as their source regions in the ring current and plasmasheet. In this study, we use satellite observations and numerical simulations with the state-of-the-art Multiscale Atmosphere Geospace Environment (MAGE) model to investigate: 1) The role of diffuse electron precipitation in the formation of SAPS; 2) SAPS variability under IMF BY; and 3) Dawnside (as opposed to the more conventional duskside) SAPS as a unique feature of major geomagnetic storms. With data-model comparison, we will demonstrate that SAPS result from the different behaviors of ring current ions and plasma sheet electrons, and the corresponding self-consistent response of the ionosphere-thermosphere system via electrodynamic and particle coupling with the magnetosphere. We conclude that SAPS distribution and variability represent a fundamental feature of the geospace response to solar disturbances during storm time.

Glaciers in every region on Earth have lost mass over the past two decades as global temperature has risen 0.5C. Retreating glaciers symbolize climate change and present societal challenges across the globe. To better quantify the consequences of climate change, previous studies have established methods to calculate the anthropogenic component of extreme weather and climate events. Previously, we established a framework using existing event attribution methods together with glacier mass balance modeling to determine the increase in probability of extreme annual mass loss of New Zealand glaciers occurring with climate change. Here, we look to expand our developed attribution framework to calculate the change in probability and amount of extreme annual mass loss for glaciers around the world. To do this, we simulate glacier mass balance using a degree-day model, driven with general circulation model (GCM) output from available CMIP6 models and ensemble members. Historical natural simulations define climate without anthropogenic forcing, and SSP5 8.5 simulations define climate with anthropogenic forcing. We use the two different climate forcings to produce scenarios of glacier mass change with and without climate change. The differences in these scenarios are compared with measurements from the highest annual glacier mass loss years. We develop the attribution method though application to several glaciers around the world, including South Cascade Glacier (USA), Gries Glacier (Switzerland), and Brewster Glacier (New Zealand). Our initial results show large increases in probability and amount of annual glacier mass loss occurring due to climate change for all three glaciers. Difficulties in applying the attribution framework to glaciers globally include accessing modern glacier outlines and reconciling differences between glaciological and geodetic measurements of glacier mass change.

We quantify the contributions of different convection states to the magnetic flux through-put of the magnetosphere during 2010. To do this we provide a continuous classification of convection state for the duration of 2010 based upon observations of the solar wind and interplanetary magnetic field, geomagnetic indices, and field-aligned currents measured by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). Convection states are defined as 1) quiet and 2) weak activity, substorm 3) growth, 4) expansion, and 5) recovery phases, 6) substorm driven phase (when relatively steady magnetospheric convection occurs), 7) recovery bays (when recovery phase is accompanied by a negative excursion of the AL electrojet index), and 8) periods of multiple intensifications (storm-time periods when continuous short-period AL activity occur). The magnetosphere is quiet for 46% of the time, when very little convection takes place. The majority of convection occurs during growth and driven phases (21% and 38%, respectively, of open magnetic flux accumulation by dayside reconnection). We discuss these results in the context of the expanding/contracting polar cap model of convection, and describe a framework within which isolated substorms and disturbances during periods of more continuous solar wind-magnetosphere driving can be understood.

The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) has revolutionized the way in which we can study the electrical current systems present over the poles of Earth. With high cadence measurements taken in both hemispheres, the data has proven invaluable in developing our understanding of the current systems that couple the magnetosphere and ionosphere and how they change in response to space weather. By employing the AMPERE data set, we aim to offer new insights into the complex and dynamic region 1 and region 2 current systems as they respond to the impact of solar wind disturbances on the magnetosphere and the driving of geomagnetic storms.We investigate the relationship between the hemispherically-integrated current flowing into or out of each pole and upstream solar wind parameters to understand how these currents are driven. As expected, current magnitude increases with increasing interplanetary magnetic field strength and solar wind speed. A key aim of the analysis is to determine if current magnitude saturates under strongly driven conditions, in the same way that the cross-polar cap potential is known to saturate. We present preliminary results, indicating a variety of behaviours at high driving, and discuss these in terms of theories of solar wind-magnetosphere coupling.

Glacier mass loss is recognized as a significant contributor to current sea-level rise. However, large uncertainties remain in projections of glacier mass loss on global and regional scales. We present an ensemble of 279 global-scale glacier mass and area change projections for the 21st century based on eleven glacier models using up to ten General Circulation Models (GCMs) and four Representative Concentration Pathways (RCPs) as boundary conditions. We partition the total uncertainty into the individual contributions caused by glacier models, GCMs, RCPs, and natural variability. We find that emission scenario uncertainty is growing throughout the 21st century, and is the largest source of uncertainty by 2100. The relative importance of glacier model uncertainty decreases over time, but it is the greatest source of uncertainty until the middle of this century. The projection uncertainty associated with natural variability is small on the global scale but has strong effects on small regional scales. The projected global mass loss by 2100 relative to 2015 (75±64 mm sea-level equivalent (SLE) for RCP2.6, 165±98 mm SLE for RCP8.5) is lower than, but within the uncertainty range of previous projections.

Quantitative palaeoclimate reconstructions provide data for evaluating the mechanisms of past, natural climate variability. Geometries of former mountain glaciers, constrained by moraine mapping, afford the opportunity to reconstruct palaeoclimate, due to the close relationship between ice extent and local climate. In this study, we present results from a series of experiments using a 2-D coupled energy balance–ice flow model that investigate the palaeoclimate significance of Last Glacial Maximum moraines within nine catchments in the central North Island, New Zealand. We find that the former ice limits can be simulated when present-day temperatures are reduced by between 4 and 7 °C, if precipitation remains unchanged from present. The spread in the results between the nine catchments is likely to represent the combination of chronological and model uncertainties. The majority of catchments targeted require temperature decreases of 5.1 to 6.3 °C to simulate the former glaciers, which represents our best estimate of the temperature anomaly in the central North Island, New Zealand, during the Last Glacial Maximum. A decrease in precipitation of up to 25 % from present, as suggested by proxy evidence and climate models, increases the magnitude of the required temperature changes by up to 0.8 °C. Glacier model experiments using reconstructed topographies that exclude the volume of post-glacial (