The South American Monsoon System (SAMS) is the dominant mode of hydroclimatic variability in South America and the associated dynamics have an important influence on atmospheric organization during pluvial and drought periods. Paleoclimate records from the monsoon domain have helped to describe the isotope hydrology of this region over the last millennium, but are insufficient to explain why the system has changed. Utilizing transient simulations of last millennium climate from isotope-enabled global climate models as well as experiments forced by isolated external forcings made available from the NCAR Community Earth System Model Last Millennium Ensemble (CESM-LME) project, we explore the dynamical drivers of variability documented in the isotopic record. We find that while models continue to underestimate the temporal variability of regional climate, they are able to reproduce documented spatial modes of variability. A Monte Carlo empirical orthogonal function (MCEOF) analysis is used to decompose major modes of isotope variability from both isotope proxy records and isotope-enabled global climate models over the last millennium (850 – 1850 CE). The principal component time series from the isotopic records show clear mean state departures during the early and late part of the record, corresponding to the Medieval Climate Anomaly and Little Ice Age periods. We explore the role of internal variability and different external forcings in driving these departures, and use the model space to describe changes to regional circulation patterns during these periods of extreme isotopic change. This enhanced understanding of the drivers of variability over the last millennium could provide a foundation upon which to interpret the sensitivity of this system to future changes due to external forcings, such as anthropogenic activity.

The Dragonfly Mercury Project (DMP) is a dynamic national scale program coupling scientific efforts to understand mercury pollution risks to protected areas with citizen engagement and education. We conducted a national-scale assessment of mercury (Hg) bioaccumulation in aquatic ecosystems using dragonfly larvae as biosentinels and implemented a carefully designed sampling methodology for citizen scientists to facilitate biological sampling. We assessed variation in dragonfly Hg concentrations across >450 sites spanning 100 US national parks and other protected places and examined intrinsic and extrinsic factors associated with variation in Hg concentrations. Mercury concentrations ranged between 10.4-1,411 ng/g across sites and varied among habitat types. Dragonfly Hg concentrations were up to 1.8-fold higher in lotic habitats than in lentic habitats, and 37% higher in waterbodies with abundant wetlands along their margins than those without wetlands. Mercury concentrations in dragonflies differed among families, but were correlated with each other, enabling adjustment to a consistent family to facilitate spatial comparisons among sampling units. Dragonfly THg concentrations were positively correlated with THg in both fish and amphibians from the same locations, indicating that dragonfly larvae are effective indicators of Hg bioavailability in aquatic food webs. Using the relationships between dragonfly and fish Hg concentrations we developed a series of integrated impairment indices that inform potential risk of Hg exposure to fish, wildlife, and human health. Most sample sites were in the moderate to low risk category, but 12% of sites were at high or severe risk for mercury, potentially causing harm to fish, wildlife, and people who eat those fish and wildlife. The scope and depth of this work stand it up as a potential landmark study on mercury in NPS lands and across the landscape, particularly in light of the citizen science framework under which it was implemented. More information on the Dragonfly Mercury Project can be found at https://wim.usgs.gov/geonarrative/dmp/ and https://www.nps.gov/articles/dragonfly-mercury-project.htm.

Rural communities in Colorado face different challenges than urban areas when responding to the impacts of climate change. While these communities may not have access to the financial resources and planning infrastructure that large cities do, close community ties and an entrepreneurial can-do attitude give these communities an advantage to create opportunities for meaningful classroom community engagement. HEART Force is a unique program for secondary students in rural Colorado formal learning settings that educates and empowers students to respond to climate change impacts in the face of increasing likelihood and severity of environmental hazards such as wildfires, floods and drought. The program supports youth partnership with community leaders and experts to build resilience through a three-pronged approach using a curriculum designed to support NGSS. Students begin the unit by learning about the science of environmental hazards and how these hazards will be affected by climate change through analysis of local data. Next, students learn how to manage and respond to hazards in their community in a scenario-based role-play game. The unit culminates in a community resilience expo, giving students the opportunity to address impacts from environmental hazards by developing, presenting, and implementing strategies to increase community resilience. We will share the program design, lessons learned from teacher professional development and support, and preliminary research findings on the program impacts on students and teachers.

Environmental hazards such as wildfire, flood, and drought impact communities throughout Colorado. As climate change ramps up, these environmental hazards are increasing in frequency and severity. These hazards and their impacts provide an excellent access point for students to explore earth science concepts and community well being. The Hazard Education Awareness and Resilience Task Force (HEART Force) is a program for secondary classrooms in rural Colorado designed to help teachers and students move beyond classroom instruction and empower them to lead local efforts to increase resilience to environmental hazards. Colorado has recently adapted and adopted NGSS which provide opportunities for students to engage in real world learning through exploring locally relevant phenomena, yet many classroom teachers are challenged to transition to a new style of teaching driven by student inquiry. With this transition, teachers are being asked to give up some control of the learning process and become facilitators rather than directors of learning. In order to successfully facilitate authentic student engagement, a network of community partners is essential to support students, as well as a supportive school administration and a high level of teacher comfort with risk and uncertainty. The HEART Force program is in the third year of implementation; here we share lessons learned and challenges in supporting teachers in this transition to student-led and community-based learning using resilience education.

Coronal mass ejections (CMEs), the large scale transient eruptions from the Sun, interact with the Earth’s magnetosphere while travelling into the heliosphere. The energetic interplanetary CME (ICME) at 1AU not only creates geomagnetic storms and disrupts the magnetic field structure around the Earth but also impacts the plasma environment, causes strong aurorae, and disturbs the radio and electrical transmission massively. We use 3D compressible magnetohydrodynamic simulation of a star-planet system and study the interesting magnetohydrodynamic processes like bow-shock, magnetopause, magnetotail, planet-bound current sheets, magnetic reconnections, atmospheric mass loss as well as particle injection, etc., when an ICME flux rope crosses the Earth at 1 AU. We use the uniformly twisted force-free flux rope model proposed by Gold and Hoyle in 1960 to initiate the ICME and vary the flux rope properties using actual observational data. We observe a change in magnetopause’s shape and the stand-off distance to the magnetopause. We notice twist helicity injection inside the magnetotail current system. We discover comparative increment in both the rates of atmospheric mass out-flow and solar wind in-flow in the vicinity of Earth during the geo-storm. Such studies will help us understand how energetic magnetic storms from a host star impact planetary magnetospheres and atmospheres with implications for planetary and exoplanetary habitability.

Communities across the Southwestern US are increasingly experiencing major disruptions from a changing climate and natural hazards, such as fire, flood, and drought. With this rise in hazardous events, there is a pressing need to support local education and community resilience efforts around climate change impacts. Teaching climate change can be challenging for educators, given the scientific complexity and the need to disentangle political dimensions surrounding the topic. Climate change and environmental hazards are tangible when their impacts are observed close to home. Grounding science learning in personal experiences provides an entry point for learners to the topic and makes learning relevant. In our experience, place-based learning has proven to be a powerful and transformative experience that unites learners through a shared place. Here we present results from three place-based educational programs that serve rural and tribal communities in the Southwestern US and highlight the common findings across these programs around changes in student beliefs and levels of transformation: 1) an after-school program in which students develop a short film about ways in which climate change impacts their community. The storytelling component of film making allows for culturally-sensitive engagement; 2) an in-class instructional unit focused on increasing community resilience in which students learn about local natural hazards through engaging with authentic data, scenario-based role play games and the development of their own community resilience strategy that students present to local community leaders; and 3) a library-based informal science learning program in the southwestern US where communities engage around water as a scarce and valuable resource and share their common stories around the relevance of water. All three programs share a deep grounding in shared place and culture and offer examples of effective engagement with rural communities.

The COVID-19 pandemic has caused concerns globally. However, there are some positive effects because of the outbreak such as cleaner air caused due to the lock-down. The pandemic and consequent lock-down (LD) has caused significant reduction in anthropogenic activities, which provided an unprecedented opportunity to study the contribution of manmade short-lived climate forcing agents from two distinct environmental locations; Bengaluru, a mega city and rural continental region, Challakere, in southern part of peninsular India. We have used continuous and simultaneous analytical measurements of the aerosol loading and optical properties of near-surface aerosols for this purpose. The near total shutdown of rail, road, and air traffic as well as total closure of most of the business establishments and IT industry, is found to dramatically reduce black carbon (BC) aerosol abundance. Within one week of the LD, urban Bengaluru has witnessed nearly 60% reduction in BC from fossil fuel (BCff) emissions, which is almost comparable to that at a rural region like Challakere, located about 230 km northwest to Bengaluru. BC concentration at Challakere did not show any major impact because of the lock-down. On other hand, BC from biomass burning (BCwb) from both the locations didn’t show any conspicuous impact. Consequently, the fraction of BCwb to total BC became more than double and spectral absorption coefficient increased from ~1.15 to ~1.4. The single scattering albedo increased from its prevailing mean value of ~0.66 before LD to 0.74 during LD1 and then gradually decreased with more relaxations. The measurements also have shown the manner in which the environment responded to the gradual relaxation in the subsequent phases of LD leading to gradual increase in emissions. The findings re-emphasize that the emissions from fossil fuel combustion in industrial and automobile sector are the major source of absorbing aerosols over urban and semi-urban environments.

Like most NSF-funded Research Experience for Undergraduates (REU) programs, the REU on Sustainable Land and Water Resources (REU SLAWR) had to choose between a virtual experience in summer 2020, or cancellation of the program due to the Covid19 pandemic. The REU SLAWR was restructured into a modular online program designed to meet the same program goals that have shaped the REU SLAWR over the past 11 years. Using program evaluations from 2011-2019, the authors will compare the results from 2020 to build knowledge on how the REU experience in 2020 was differently structured to meet the need for a virtual program, the impact this had on participant and mentor outcomes, and what can be learned for future REU programs. This provides valuable information for creating accessibility to the REU experience. The REU usually takes place at three locations (Salish Kootenai College, MT; at the Univ. of Minnesota in Mpls. and Duluth, MN). The program is centered on tribally-focused Community-based Participatory Research (CBPR), and is a place-based REU. The REU SLAWR has always incorporated a virtual experience designed to create cross-team socialization, community-building, and widen participants’ interest and knowledge about projects incorporating tribal CBPR. Summer 2020 immersed students, mentors, and tribal partners in a virtual learning environment. The PIs explored new methods for running an REU with virtual technology that will be incorporated in future programs for richer cross-team collaboration. A focus of the REU SLAWR has been to increase participants’ abilities to work on diverse teams. Collaborating virtually across distances is a skill all researchers need. Training in this can benefit next-generation researchers and STEM workers. One aspect of concern and interest is the impact of redesigning the research projects to make them possible to conduct in a virtual space. The projects were fundamentally different than previous years, with many focusing on using pre-existing data. While there were negative impacts in some aspects of building research skills (i.e., little exposure to field or lab work), other aspects (i.e., computational modeling, communicating science) showed gains. The authors explore both the limits and possibilities inherent in virtual collaboration in research for undergraduate students.

Cloud and shadow in satellite image are obstacles in the land cover classification. In addition, Landsat-7 Enhanced Thematic Mapper Plus (ETM+) image contains scan-gap (striping black areas) due to the failure of the Scan Line Corrector in May 2003. This is also the case with our land cover change analysis in Makassar, Maros, Sungguminasa, and Takalar (Mamminasata), Indonesia. The purpose of this study is to produce an accurate land cover classification map using the composite data of multi- temporal ETM+ data. Three scenes in April, July, and September 2011 were generated by filling the areas of clouds, shadows, and scan-gaps with other data observed in similar seasons. Land cover classification map was generated from 18 bands data by the Support Vector Machine classifier using local-government-produced land use map as training data. The effect of composite on the land cover classification and land cover classification accuracy will be evaluated in the presentation. The significance of this research is the improvements in classification by reducing the obstacles using a simple image composite method.

Fluctuations of the total water level in the U.S. East Coast depends on the complex interactions of freshwater flow, tide, storm surge and wave actions. In order to include all major forcings of water movement in this area, a coupled modeling system consisting of the National Water Model (NWM), the Advanced Circulation Ocean Model (ADCIRC), and the WAVEWATCH III model has been developed. In this system, a coupled inland hydrologic model is linked to an ocean hydrodynamic and wave model to compute total water levels in the coastal zones. In the freshwater component of the hydrodynamic model, 1D river components were included in the model to capture an accurate representation of tributaries to the 2D model of the estuary and oceans. The model domain included several states of the US East Coast starting from New Jersey to the St. Croix River at the US-Canada border. Model simulations were compared with 2012 superstorm Sandy measured tidal water levels and hurricane surge. Initial simulations reproduced satisfactory spatial and temporal variations of water levels due to riverine discharge and storm surge. The model predictions showed that using 1D component allowed better representations of the inland rivers and produced accurate river water levels. Simulations indicated that water levels in the inland areas depends on both river discharges and backwater effects of the ocean. These results showed the strengths of the coupled modeling system used in this research to compute total water levels during river flooding that coincides with extreme hurricane surge. Initial results showed that the coupled modeling framework used in this study is capable of total water estimation in the coastal zones and the accuracy of the water levels highly depends on the availability of reliable topographic, bathymetric, and bottom roughness data.

Calving is the process of blocks of ice detaching from an ice shelf of grounded calving cliff. Here, we focus on calving that occurs through the propagation of fractures through a floating ice shelf on sufficiently short time scales to allow ice rheology to be treated as elastic. We revisit the linear elastic fracture mechanics models of Weertman and van der Veen, which consider the propagation of cracks into slabs of ice, driven by an applied extensional stress and by water pressure inside the crack, due to sea water and surface melt entering the cracks. We extend their work by considering the interaction between multiple cracks and developing a method that allows us to compute crack propagation in arbitrary domain geometries. We show that the simple case of two aligned cracks, one extending from the ice surface and the other from the base, can be considered as a two-dimensional dynamical system. We are able to show that viable steady crack configurations (where the ice shelf is crevassed without calving) correspond to stable fixed points of that dynamical systems. Calving corresponds to the annihilation of steady states under a parameter change. That can either take the form a bifurcation that happens at specific combinations of forcing parameters, and leads to the abrupt, dynamic propagation of the crack across the remaining unbroken thickness of ice. Alternatively, calving can occur because the two crack tips gradually meet as forcing parameters change. We derive different forms of calving laws, depending on whether crack propagation to full calving is initiated from a previously un-cracked floating slab of ice, or from a previously cracked configuration. For the former, we show that calving laws take the form of a functional relationship between a water storage parameter, extensional stress, ice thickness and fracture toughness. For the latter, we obtain an history-dependent relationship in the form of a steady crack evolution problem that bears abstract similarity with plasticity models. We also discuss how these could be implemented in ice flow models.

Known as black bread mold, R. stolonifer is a fungus commonly found in contaminated food products such as meat, preserved, and/or baked goods. Potassium sorbate is a common food preservative used to prevent fungi, mold, and mycotoxin growth by damaging the cell membrane or altering proteins in the cell. Based on background research on potassium sorbate growth prevention, it was hypothesized that a 25% concentration of potassium sorbate will most efficiently prevent R. stolonifer growth compared to lower concentrations. R. stolonifer was grown on potato dextrose agar with eight levels of potassium sorbate concentrations. During a two week period, fungal growth was observed, photographed, and the height and width of each sample were recorded. At the end of two weeks, the fungi were stained using lactophenol cotton blue dye and observed under a microscope. Qualitative observation at the cellular level showed healthy R. stolonifer solely in the control group (see Figure 1). When comparing the fungi samples across the 5% and 30% concentration groups, large areas of dead mass dominated their cellular makeup. At the end of two weeks, the 1% concentration sample group had an observed increase of 1.383 cm2 in total area, a significant decrease compared to the control group. Between the 5% and 30% concentration sample groups, there were minor changes in total area with no change exceeding 0.125 cm2. Between the 1% and 5% experimental groups, there was a significant decrease in fungal area growth, and a similarly large decrease between the 10% and 15% concentration fungi samples. Thus, it can be concluded that it is unnecessary to exceed a 1% concentration of potassium sorbate to prevent fungal growth.

A common goal of next-generation Global Circulation Models (GCMs) is that they should be “scale-aware”, which typically implies that such models should not be excessively sensitive to grid spacings, and that they should in some sense converge monotonically towards a result as grid spacings decrease. While both horizontal and vertical resolution have been treated in this manner, time resolution is typically viewed differently. Specifically, a decrease in time step size is often viewed as a “necessary evil”, being decreased only in cases where spatial resolution is also decreased, requiring a change to the time resolution to satisfy a CFL condition. Our experiments with the E3SM Atmosphere Model suggest that cloud physics and precipitation in GCMs is in fact quite sensitive to process coupling time step size, and that the biases affected by time integration error are independent from (and of comparable size to) biases due to other common sources of error, such as grid spacing and choice of sub-grid-scale physics parameterizations. This suggests that process coupling frequency is a key feature that should be adjusted for future models.

The study of lunar plasma environment’s response to the extreme solar wind condition is the main subject of our investigation in this report. The computational model includes the self-consistent dynamics of the light (H_2+) and (He+), and heavy (Na^+}) pickup ions. The electrons are considered as a fluid. The lunar interior is considered as a weakly conducting body. The input parameters are taken from the ARTEMIS observations. The modeling demonstrates a formation of the various plasma structures near the Moon: (a) bow shock wave with split shock transition in case of extreme solar wind density and standard bulk velocity; (b) hyper-sonic/Alfvenic Mach cone in case of extreme solar wind bulk velocity and moderate solar wind density. The modeling shows a strong asymmetry in the solar wind ion VDF which connected with a plasma compression and ion reflection at the bow shock wave/Mach cone front.

The objective of the study is to assess the familiarity and the use of preprint servers by researchers to share their work. Data collection was conducted by Wiley through an online survey in May and June 2020. 44% of survey respondents (out of a total of 1,905) indicated they are not at all familiar with preprint servers. Most of the researchers surveyed indicated multiple reasons to upload their research on a preprint server. The most popular reasons were to get feedback on their work (46%) and for faster dissemination of their research (45%). 55% of respondents indicated that they have never uploaded any research outputs on preprint servers. This study and our key findings show that there is a need to share the benefits of preprints and to explain to researchers how servers work.

Climate change is impacting polar regions at an accelerated rate, causing rapid changes in land cover and biodiversity. One case is the “greening up” of the Western Antarctic Peninsula (WAP), the result of receding glacial fronts exposing substrate for plants and soil development, together with higher temperatures and potential increases in cloud-free conditions conducive to plant growth. The 2019/2020 austral summer was the warmest on record for the WAP, yet the controls on land surface temperature (LST) here are not well understood. We investigated the relationships between land cover type, solar radiation, and LST for several vegetated coastal outcrops (0.3 to 0.5 ha) distributed from 64 to 65°S along the WAP. Remote sensing data was collected in February/March 2020 using a consumer-grade unmanned aerial vehicle (UAV), additionally equipped with near-IR and thermal-IR sensors. Digital surface models produced from the UAV imagery were used to calculate surface solar radiation. NDVI was used to identify four land cover classes: healthy vegetation, unhealthy vegetation, loose substrate, bedrock. Thermal-IR data provided sub-decimeter LST mapping. LST ranges varied depending on atmospheric conditions. A site surveyed under cloud-free conditions and air temperature of 6.6°C showed a 37.2°C range in LST, while a nearby site surveyed the next day under overcast conditions and air temperature of 2°C showed a 10.4°C range in LST. Vegetation at these two sites reached maximum temperatures of 27°C and 11.6°C, respectively. We found little within-site difference in either mean or range of LST among the land cover classes. Using linear regression, solar radiation explained less than 50% of the observed LST. Healthy vegetation showed the strongest relationship between solar radiation and LST. It was determined that LST in the WAP was strongly affected by factors other than solar radiation, implying latent heat effects. As the abundance of healthy vegetation increases in these areas, LST may show a stronger relationship with solar radiation, thus effecting local feedbacks to warming. This study presents the first application of UAV-derived thermal-IR data for the analysis of LST controls in Antarctica, highlighting the capability of UAV as a data collection platform for use in remote and relatively data-poor environments.

Understanding the complex interplay between erosional and depositional processes, and their relative roles in shaping landscape morphology is a question at the heart of geomorphology. A unified framework for examining this question can be developed by simultaneously considering terrain elevation statistics over multiple scales. We show how a long-standing tool for landscape analysis, the elevation-area or hypsometry, can be complemented by an analysis of the elevation scalings to produce a more sensitive tool for studying the interplay between processes, and their impact on morphology. We then use this method, as well as well-known geomorphic techniques (slope-area scaling relations, the number of basins and basin size as a function of channel order) to demonstrate how the complexity of an experimental landscape evolves through time. Our primary result is that the complexity increases once a flux equilibrium is established as a consequence of the role of diffusive processes acting at intermediate elevations. We gauge landscape complexity by comparing results between the experimental landscape surfaces and those produced from a new algorithm that fixes in place the elevation scaling statistics, but randomizes the elevations with respect to these scalings. We constrain the degree of randomization systematically and use the amount of constraint as a measure of complexity. The starting point for the method is illustrated in the figure, which shows the original landscape (top-left) and three synthetic variants generated with no constraints to the randomization. The value quoted in these panels is the root-mean-squared difference in the elevation values for the synthetic cases relative to the original terrain. This value is greatest where the original ridge becomes a valley. All these landscapes contain the same elevation values (i.e. the same probability distribution functions), and the same elevation scalings at a point. The differences emerge because the elevations themselves are distributed randomly across the surface.

The Upper and Lower Quinn River subbasins (HUC-8 16040201,16040202) comprise one of the largest single drainages in northwest Nevada. The sub-basins cover approximately 1.7 million hectares. The Quinn river originates in the Montana Mountains and Santa Rosa Range and drains to the Black Rock Desert Playa. The elevational gradient ranges from 2000 m to 1100 m. Sagebrush and perennial grasses dominate the higher elevations, with the lowlands being dominated by greasewood, saltbrush, and desert scrub. This presentation examines the human habitation in the sub-basins over the past 13,000 years in context to the palaeoclimatic records from the sub-basins and adjoining areas. Over 1100 prehistoric sites exist in the study area, with 19 sites having been excavated and yielding 108 radiocarbon dates. Palaeoclimate proxies from the study area include the Mud Meadows and Summit Lake pollen cores, and the Jackson Mountain tree ring widths. While the radiocarbon record shows numerous gaps between 13 kBP and 5 kBP, the summed probability distribution of calibrated radiocarbon dates suggests continuous occupation from 5 kBP to 1 kBP with exponential growth. Based on the abundance of Chenopodiaceae pollen in the Summit Lake core, the study area is drier than today during the Late Holocene Drought (LHD, ca. 2.5 to 1.9kBP). During the LHD, sites south of 41N are abandoned or see no growth; northwards, sees site growth. Despite contrasting climatic conditions, the Late Antique Little Ice Age (LALIA) and the Medieval Climatic Anomaly (MCA) are both periods of site occupation and growth across the sub-basins. Occupied sites are found throughout the sub-basins during the LALIA, and during the MCA site occupation is focused at Trego hot springs and at higher elevations. As evidenced by the three palaeoclimate proxies from the sub-basins, the Little Ice Age is a period of cooler temperatures and increased moisture. Despite the ameliorated conditions, the number of dated sites significantly decreases. This may reflect a more dispersed settlement pattern with lower numbers of residents during the Terminal Prehistoric period.