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Major power outages have risen over the last two decades, largely due to more extreme weather conditions. However, there is a lack of knowledge on the distribution of power outages and its relationship to social vulnerability and co-occurring hazards. We examined the associations between localized outages and social vulnerability factors (demographic characteristics), controlling for environmental factors (weather), in Washington State between 2018–2021. We additionally analyzed the validity of PowerOutage.us data compared to federal datasets. The population included 27 counties served by 14 electric utilities. We developed a continuous measure of daily outage burden using PowerOutage.us data and operationalized social vulnerability using four factors: poverty level, unemployment, disability, and limited English proficiency. We applied zero-altered lognormal generalized additive mixed-effects models to characterize the relationship between social vulnerability and daily power outage burden, controlling for daily minimum temperature, maximum wind speed, and precipitation, from 2018 to 2021 in Washington State. We found that social vulnerability factors have non-linear relationships with outages. Wind and precipitation are consistent drivers of outage occurrence and duration. There are seasonal effects that vary by county-utility area. Both PowerOutage.us and federal datasets have missing and inaccurate outage data. This is the first study evaluating differential exposure to localized outages as related to social vulnerability that has accounted for weather and temporal correlation. There is a lack of transparency into power outage distribution for those most vulnerable to climate impacts, despite known contributions by electric utilities to climate change. For effective public health surveillance of power outages and transparency, outage data should be made available at finer spatial resolution and temporal scales and/or utilities should be required to report differential exposure to power outages for socially vulnerable populations. [ABSTRACT FROM AUTHOR]

As managers of agricultural and natural resources are confronted with uncertainties in global change impacts, the complexities associated with the interconnected cycling of nitrogen, carbon, and water present daunting management challenges. Existing models provide detailed information on specific sub-systems (e.g., land, air, water, and economics). An increasing awareness of the unintended consequences of management decisions resulting from interconnectedness of these sub-systems, however, necessitates coupled regional earth system models (EaSMs). Decision makers’ needs and priorities can be integrated into the model design and development processes to enhance decision-making relevance and “usability” of EaSMs. BioEarth is a research initiative currently under development with a focus on the U.S. Pacific Northwest region that explores the coupling of multiple stand-alone EaSMs to generate usable information for resource decision-making. Direct engagement between model developers and non-academic stakeholders involved in resource and environmental management decisions throughout the model development process is a critical component of this effort. BioEarth utilizes a bottom-up approach for its land surface model that preserves fine spatial-scale sensitivities and lateral hydrologic connectivity, which makes it unique among many regional EaSMs. This paper describes the BioEarth initiative and highlights opportunities and challenges associated with coupling multiple stand-alone models to generate usable information for agricultural and natural resource decision-making.

Effectively communicating scientific research has taken on greater importance as climate change impacts the world we live in. It is increasingly incumbent upon the science and education communities to produce and deliver curriculum that is timely, accessible, and scientifically accurate. In the summer of 2012, scientists and educators worked together to develop and conduct the "Adventure Learning @ Greenland" (AL@GL) project, which explored the capacity of hands-on and web-based climate science education experiences that occurred in Greenland and the US. The Adventure Learning approach and associated framework was used to design the learning experience during AL@GL activities. Participating students were from Greenland, Denmark, and the US; these students included participants who were diverse, rural, and traditionally underrepresented. Participating students worked closely with educators and scientists to learn about an atmospheric observatory at Summit Station, located on the Greenland Ice Sheet. The purpose of this article is to inform readers in how they may use Adventure Learning and the newly developed curriculum model called "Content, Transition, Inquiry, and Synthesis" for the education and outreach of research projects.

Atmospheric emission in the [v.sub.2] band of water vapor by the foreign-broadened continuum (1300-2000 [cm.sup.-1]) is important for retrievals of upper tropospheric water vapor. Previous work reported continuum coefficients retrieved from two downwelling emission measurements made with the Polar Atmospheric Emitted Radiance Interferometer (PAERI) at temperatures characteristic of the upper troposphere (below -25[degrees]C) at Dome C, Antarctica. These results are improved upon here using 19 different measurements. Improvements have been made to the PAERI radiance calibration, the radiance simulations, and the error analysis. Compared to the Mlawer, Tobin, Clough, Kneizys, Davies continuum, the retrieved continuum is found to be 20% to 50% lower from 1350 to 1490 [cm.sup.-1] and 0% to 20% higher from 1850 to 1980 [cm.sup.-1]. OCIS codes: 010.1280, 280.4991, 300.6340.

When retrieving geophysical parameters, it is advantageous to have an estimate of prior information that is based on observations with associated uncertainties, but this is often not possible. Long-term ground-based remote sensing measurements and the ozonesonde program at Summit Station, Greenland, provide an opportunity to create a unique framework to retrieve atmospheric ozone using observationally based prior information in the Arctic. This study investigates the potential of using the ground-based polar atmospheric emitted radiance interferometer (P-AERI) to estimate ozone below 10 km. Downlooking or limb-viewing sensors, such as those from satellites, have limited sensitivity to the lower atmosphere; however, uplooking, ground-based instruments provide complementary information to satellite observations to improve trace gas estimates at lower atmospheric levels. Modern-Era Retrospective Analysis for Research and Application, version 2 (MERRA-2) is a reanalysis product that integrates satellite information but also inherits their higher uncertainties at lower atmospheric levels. An observation-based climatology of the uncertainty in the MERRA-2 ozone dataset is estimated using ozonesondes launched at Summit Station. MERRA-2 shows high accuracy in the middle stratosphere but larger uncertainties below 10 km. Retrievals that use spectral radiance measurements from the P-AERI improve the estimates of ozone concentrations in the troposphere and lower stratosphere by using prior information from MERRA-2 and our climatology of MERRA-2 uncertainties as the covariance of the prior. Using ozonesonde observations from 2012 to 2017 at Summit Station, Greenland, the quality of the retrieved results is assessed. Comparisons show that retrieved partial columns reduce the bias of MERRA-2 ozone estimation below 10 km, and the average tropospheric ozone concentration is improved significantly. [ABSTRACT FROM AUTHOR]

To accurately estimate near-surface (2 m) air temperatures in a mountainous region for hydrologic prediction models and other investigations of environmental processes, the authors evaluated daily and seasonal variations (with the consideration of different weather types) of surface air temperature lapse rates at a spatial scale of 10 000 [km.sup.2] in south-central Idaho. Near-surface air temperature data ([T.sub.max], [T.sub.min], and [T.sub.avg]) from 14 meteorological stations were used to compute daily lapse rates from January 1989 to December 2004 for a medium-elevation study area in south-central Idaho. Daily lapse rates were grouped by month, synoptic weather type, and a combination of both (seasonal synoptic). Daily air temperature lapse rates show high variability at both daily and seasonal time scales. Daily [T.sub.max] lapse rates show a distinct seasonal trend, with steeper lapse rates (greater decrease in temperature with height) occurring in summer and shallower rates (lesser decrease in temperature with height) occurring in winter. Daily [T.sub.min] and [T.sub.avg] lapse rates are more variable and tend to be steepest in spring and shallowest in midsummer. Different synoptic weather types also influence lapse rates, although differences are tenuous. In general, warmer air masses tend to be associated with steeper lapse rates for maximum temperature, and drier air masses have shallower lapse rates for minimum temperature. The largest diurnal range is produced by dry tropical conditions (clear skies, high solar input). Cross-validation results indicate that the commonly used environmental lapse rate [typically assumed to be -0.65[degrees]C [(100 m).sup.-1]] 11 is solely applicable to maximum temperature and often grossly overestimates [T.sub.min] and [T.sub.avg] lapse rates. Regional lapse rates perform better than the environmental lapse rate for [T.sub.min] and [T.sub.avg], although for some months rates can be predicted more accurately by using monthly lapse rates. Lapse rates computed for different months, synoptic types, and seasonal-synoptic categories all perform similarly. Therefore, the use of monthly lapse rates is recommended as a practical combination of effective performance and ease of implementation.

The foreign-broadened continuum of water vapor in the [v.sub.2] band (5-7.7 [micro]m, 1300-2000 [cm.sup.-1]) is important for satellite-based retrievals of water vapor in the upper troposphere, where temperatures are below -25 [degrees]C. Continuum coefficients have previously been measured mostly at or above +23 [degrees]C. We present continuum coefficients in the [v.sub.2] band retrieved from measurements made in Antarctica at temperatures near -30 [degrees]C: atmospheric transmission at South Pole Station and atmospheric emission at Dome C. The continuum coefficients derived from these measurements are generally in agreement with the widely used Mlawer, Tobin--Clough, Kneizys, Davies continuum. Differences are at most 30%, corresponding to a 6% relative error in retrieved upper-tropospheric humidity. OCIS codes: 010.1320, 010.1280, 120.0280, 300.6340.

Stratospheric circulation is a critical part of the Arctic ozone cycle. Sudden stratospheric warming events (SSWs) manifest the strongest alteration of stratospheric dynamics. Changes in planetary wave propagation vigorously influence zonal mean zonal wind, temperature, and tracer concentrations in the stratosphere over the high latitudes. In this study, we examine six major SSWs from 2004 to 2020 using the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2). Using the unique density of observations around the Greenland sector at high latitudes, we perform comprehensive comparisons of high latitude observations with the MERRA-2 ozone dataset during the six major SSWs. Our results show that MERRA-2 captures the high variability of mid stratospheric ozone fluctuations during SSWs over high latitudes. However, larger uncertainties are observed in the lower stratosphere and troposphere. The zonally averaged stratospheric ozone shows a dramatic increase of 9-29% in total column ozone (TCO) near the time of each SSW, which lasts up to two months. The SSWs exhibit a more significant impact on ozone over high northern latitudes when the polar vortex is mostly elongated as seen in 2009 and 2018 compared to the events in which the polar vortex is displaced towards Europe. The regional impact of SSWs over Greenland has a similar structure as the zona1 l average, however, exhibits more intense ozone anomalies which is reflected by 15-37% increase in TCO. The influence of SSW on mid stratospheric ozone levels persists longer than their impact on temperature. This paper is focused on the increased (suppressed) wave activity before (after) the SSWs and their impact on ozone variability at high latitudes. This includes an investigation of the different terms of tracer continuity using MERRA-2 parameters, which emphasizes the key role of vertical advection on mid-stratospheric ozone during the SSWs. [ABSTRACT FROM AUTHOR]

This study presents the first full annual cycle (2019-2020) of ambient surface aerosol number concentration (condensation nuclei > 20 nm, N20) measurements collected at Summit Station, in the centre of the Greenland Ice Sheet (72.58° N, -38.45° E, 3250 m asl). The mean surface N20 concentration in 2019 was 129 cm-3, with the 6 h mean ranging between 1 cm-3 and 1441 cm-3. The highest monthly mean concentrations occurred during the late spring and summer, with the minimum concentrations occurring in February (mean: 18 cm-3), demonstrating an opposite seasonal cycle in aerosol concentrations compared to low altitude Arctic stations (with latitudes > 66°N). High aerosol concentration events are linked to anomalous anticyclonic circulation over Greenland and the descent of free tropospheric aerosol down to the surface, whereas low aerosol concentration events are linked to cyclonic circulation over south-east Greenland that drives upslope flow and enhances precipitation en-route to Summit. Fog strongly effects N[sub 20] concentrations, on average reducing N20 by 20% during the first three hours of fog formation. Extremely low N20 concentrations (< 10 cm-3) occur in all seasons, and we suggest that fog, and potentially cloud formation, can be limited by low aerosol concentrations over central Greenland. [ABSTRACT FROM AUTHOR]

Improvements to climate model results in polar regions require improved knowledge of cloud microphysical properties. Surface-based infrared radiance spectrometers have been used to retrieve cloud microphysical properties in polar regions, but measurements are sparse. Reductions in cost and power requirements to allow more widespread measurements could be aided by reducing instrument resolution. Here we explore the effect of errors and instrument resolution on cloud microphysical property retrievals from downwelling infrared radiances for resolutions of 0.1 to 8 cm−1. Retrievals are tested on 331 radiance simulations characteristic of the Arctic, including mixed-phase, vertically inhomogeneous, and liquid-topped clouds and a variety of ice habits. Results indicate that measurement biases lead to biases in retrieved properties that are not represented by the retrieval error covariance matrix. Retrieval errors are high if mixed-phase is assumed throughout liquid-topped ice clouds. Errors due to assuming ice habit is spherical are progressively larger for solid columns, plates, and hollow bullet rosettes. Using retrieved cloud heights, particularly when errors are imposed, increases retrieval errors but decreases sensitivity to incorrect ice habits and vertical variation. Results indicate that retrieval accuracy is unaffected by resolution from 0.1 to 2 cm−1, after which it decreases only slightly. At a resolution of 4 cm−1, for typical errors expected in temperature (0.2 K) and water vapour (3 %), and assuming radiation bias and noise of 0.2 mW/(m2 sr cm−1), using retrieved cloud heights, error estimates are 0.1 ± 0.6 for optical depth, 0.0 ± 0.3 for ice fraction, 0 ±l 2 μm for effective radius of liquid, and 2 ± 2 μm for effective radius of ice. These results indicate that a moderately low resolution, portable, surface-based infrared spectrometer could provide microphysical properties to help constrain climate models. [ABSTRACT FROM AUTHOR]

Radiation fogs at Summit, Greenland (72.58° N, 38.48° W, 3210 masl) are frequently reported by observers. The fogs are often accompanied by fogbows, indicating the particles are composed of liquid and because of the low temperatures at Summit, this liquid is super-cooled. Here we analyse the formation of these fogs as well as their physical and radiative properties. In situ observations of particle size and droplet number concentration were made using scattering spectrometers near 2 m and 10 m height from 2012 to 2014. These data are complemented by co-located observations of meteorology, turbulent and radiative fluxes, and remote sensing. We find that liquid fogs occur in all seasons with the highest frequency in September and a minimum in April. Due to the characteristics of the boundary-layer meteorology, the fogs are elevated, forming between 2 m and 10 m and the particles then fall toward the surface. The diameter of mature particles is typically 20-25 µm in summer. Number concentrations are higher at warmer temperatures and, thus, higher in summer compared to winter. The fogs form at temperatures as warm as warm as -5 °C, while the coldest form at temperatures approaching -40 °C. Facilitated by the elevated condensation, in winter 2/3 of fogs occurred within a relatively warm layer above the surface when the near-surface air is below -40 °C, as cold as -57 °C, which is well below that which can support liquid water. This implies that fog particles settling through this layer of cold air freeze in the air column before contacting the surface, thereby accumulating at the surface as ice without riming. Liquid fogs under otherwise clear skies impart annually 1.5 W m-2 of cloud radiative forcing (CRF). While this is a relatively small contribution to the surface radiation climatology, individual events are influential. The mean CRF during liquid fog events is 26 W m-2, but can sometimes be much higher. An extreme case study was observed to radiatively force 5 °C of surface warming during the coldest part of the day, effectively damping the diurnal cycle. At lower elevations of the ice sheet where melting is more common, such damping could signal a role for fogs in preconditioning the surface for melting later in the day. [ABSTRACT FROM AUTHOR]