Recent land use changes associated with climatic suitability loss in some Coffea arabica growing regions in Guatemala have promoted an accelerated assessment of ecosystem services provided by shade coffee plantations. Yet, the different management schemes operating this heterogeneous landscape limit our ability to extrapolate these findings. In addition to climate suitability loss, economical constrains and pests and infestations have promoted an overall loss of ecosystem services associated to these agroforestry systems, some of which have not yet been accounted for. Among these ecosystem services, carbon stored in shade coffee plantations has not been estimated for most of the coffee growing regions in Guatemala at a site-specific level nor have specific allometric equations being developed to include the stumps left behind after coffee has been pruned, resulting in an underestimation of carbon content in these systems. In this study, we estimated carbon content in living biomass above and below-ground in 36 different coffee farms along the Sierra Madre of Guatemala. We developed allometric equations for each dominant shade tree species and one for coffee plants (Coffea arabica). Remaining plant biomass and carbon stock was estimated using previously published equations. On average, the agroforestry plots contained 80.5 ± 5.2 t C / ha. In these plots, shade trees accounted for most of the carbon content (45%) followed by soil (40%). Coffee plants represented 9% of the carbon in the system, indicating that a coffee system with little or no shade has very low potential for carbon allocation. Coffee farms under a sustainability certification scheme were not statistically different than the non-certified farms. However, the effect of certification on the carbon content should continue to be explored in future research.

Water resources decisions are often presented as bonds for public vote, but water resources management is an esoteric topic for which improved public understanding is crucial. An art-science museum exhibit was developed to visualize aquatic habitats and species, communicate management tools, tradeoffs, and alternatives that guide water resources decision-making, and empower the public to make informed decision about water resources. Drone-based river habitat data was collected to identify vegetation, measure water surface temperature, represent topography, and show visible light. An artist composited all data into single large-format images to visualize river habitat. Another artist painted native fish, including Bonneville Cutthroat Trout and Bluehead Sucker that are managed for conservation, to capture the transcendent experience of encountering wild fish. 3D maps with video projections told stories of past water development choices, those we face in the future, and described water management models to balance river preservation with human water supply. Visitor surveys were conducted with willing participants to understand how art affected their experience and behavior. Preliminary results suggested that 41% of visitors thought integrating art and science greatly added to the exhibit experience, 22% thought art helped them to understand water management problems and opportunities, and 26% responded that art drew them into the exhibit. After visiting the exhibit, 15% of respondents said they were likely to write letters to government officials about water concerns, 25% said they were likely to attend a public meeting, 50% said they were likely to watch a presentation with proposed actions about water management, 59% said they were likely to talk to friends and family about water resources, and 62% said they were likely to visit a local river. This exhibit is estimated to reach about 130,000 visitors, despite capacity restrictions due to COVID-19 social distancing.

We report our cross-validation of equatorial plasma bubble (EPB) observations based on 2-D ΔTEC data maps over the South American sector, against equatorial spread-F (ESF) observations based on digisonde measurements at several locations. The 2-D ΔTEC data maps were derived using a GPS TEC data detrending procedure [Pradipta et al., 2015] that is inherently capable of distinguishing between wavelike fluctuations associated with traveling ionospheric disturbances (TIDs) and deep depletions associated with EPBs. The data detrending was performed for TEC signals along individual ionospheric piercing point (IPP) trajectories from individual stations, before spatially interpolating the ΔTEC values into a fine 0.2 deg x 0.2 deg geographic latitude/longitude grid. We validated the EPB/depletion observations from these 2-D ΔTEC data maps against digisonde observations of ESF occurrences at Jicamarca (JI91J), Cachoeira Paulista (CAJ2M), and Fortaleza (FZA0M) using data recorded in 2011. A general agreement was found between the EPB and ESF occurrences. Over Jicamarca: 55.1% fall within the EPB=YES & ESF=YES category, 20.6% fall within the EPB=NO & EPB=NO category, 24.4% fall within the EPB=NO & ESF=YES category, and 0% fall within the EPB=YES & ESF=NO category. Over Cachoeira Paulista: 48.5% fall within the EPB=YES & ESF=YES category, 37.4% fall within the EPB=NO & EPB=NO category, 13.2% fall within the EPB=NO & ESF=YES category, and 0.8% fall within the EPB=YES & ESF=NO category. Over Fortaleza: 68.8% fall within the EPB=YES & ESF=YES category, 10.4% fall within the EPB=NO & EPB=NO category, 20.2% fall within the EPB=NO & ESF=YES category, and 0.6% fall within the EPB=YES & ESF=NO category. The classification process of EPB/ESF occurrences (+’s) and no-occurrences (-’s) in this validation work also points at the possibility of performing combinatoric pattern analyses on EPB/ESF occurrence likelihood. This type of analysis may be useful in assessing the fundamental limit of EPB/ESF occurrence predictability that can be theoretically achieved.

Habitable regions of Europa may include a subsurface ocean and transient liquid environments within its icy shell. Ocean-surface communication may occur on 1–2 million-year (My) timescales or even more rapidly in chaos regions. Any ice-entombed organisms could remain viable at near-surface depths (10–100 cm) over 1–10 ky. The proposed Europa Lander will target samples at depths >10 cm, potentially enabling recovery of viable organisms if sampling conditions are ideal. Any life there would likely represent a separate genesis event from Earth life. Life detection approaches should therefore not only target life as we know it (contamination, common physicochemistry), but also as we don’t know it, to lower the risk of false negatives. We propose to target prebiotic, ancient, or extant life using a novel fully-electronic single-molecule detection strategy. Now in early development (PICASSO), the Electronic Life-detection Instrument for Enceladus/Europa (ELIE) instrument will utilize quantum electron tunneling between nanogap electrodes to interrogate the electronic structure of single molecules. Nanogaps are formed by breaking a gold nanowire embedded on a silicon chip. Bending is then used to control the gap size in the sub-nanometer regime. A molecule can be identified by its characteristic conductance and interaction time as a function of gap size. This technology can detect and distinguish among amino acids, and detect RNA and DNA bases and short base sequences. The extrapolated limit of detection for single amino acids is ~200 ppt after 5 min of sampling (~1 pMol/g). Integrating upfront separation methods will enhance specificity and sensitivity. Our lab-bench prototype integrates a nanogap chip, low-noise amplifier, and a laptop for data processing. We target a ~1 kg flight instrument mass. ELIE will be able to measure two key biosignatures: the amino acid complexity distribution, and charged informational polymers, through to be universal for aqueous based life.

Glacial acceleration is the largest source of uncertainty in sea-level-rise assessment, according to the Intergovernmental Panel on Climate Change. Of the different types of glacial acceleration, surging is the least understood. In this paper, we demonstrate how a combination of automated algorithms dedicated to analysis of two entirely different observation types - satellite altimetry from NASA’s ICESat-2 and satellite imagery from Planet SkySat - can aid in advancing glaciology, utilizing state-of-the art remote sensing /Earth observation technology. NASA’s Ice, Cloud and land Elevation Satellite ICESat-2, launched 15~September~2018, carries the first space-borne multi-beam micro-pulse photon counting laser altimeter system, the Advanced Topographic Laser Altimeter System (ATLAS). ATLAS observations are collected in three pairs of weak and strong beams with 0.7m nominal along-track spacing (under clear-sky conditions). The recording of the observations as a photon-point cloud requires a dedicated algorithm for identification of signal photons and determination of surface heights. As a solution, we developed the density-dimension algorithm for ice surfaces, the DDA-ice. ATLAS data analyzed with the DDA-ice allow determination of heights over heavily crevassed ice surfaces, which are characteristics of accelerating glaciers. The study presented here builds on a special multi-component data set, obtained through synoptic observations of an Arctic glacier system during surge (Negribreen, Svalbard): Airborne altimeter and image data collected during our ICESat-2 validation campaign, and SkySat image data from a special acquisition collected as part of NASA’s Commercial Smallsat Data Acquisitions Pilot program. These are complemented by WorldView (Maxar) and ESA Sentinel-1 data. With a spatial resolution of 0.7-0.86m, SkySat data and WorldView lend themselves to automated classification of crevasse types. Altogether, we obtain a characterization in 3 dimensions that allows discrimination of ice-surface types from surging glaciers (Negribreen) and continuously fast-moving and accelerating glaciers (Jakobshavn Isbrae) based on morphological characteristics.

How dire are the security implications of climate change? Research findings on the relationship between climate and conflict are diverse and contested, leaving policymakers of various types uncertain about productive ways to integrate climate into risk assessments and action plans. This talk reflects on the benefits of inclusive, rather than confrontational, approaches to reconciling scholarly and scientific disagreements. Using a recent expert elicitation-based, consensus-building exercise as a positive case study (Mach et al. 2019), this talk demonstrates how academic communities can make their work both more legible and representative when engaging with policy practitioners.

State-of-the-art astrogeodetic measurement systems—Digital Zenith Camera Systems (DZCSs) and the tachymeter-based QDaedalus systems—are currently used to obtain astrogeodetic deflection of the vertical (DoV) components. In this study, we use the CODIAC DZCS (accuracy ~0.05″) and two QDaedalus systems (accuracy ~0.20″) developed by ETH Zurich to collect DoV data in the Surses Region (Canton of Grisons), Switzerland. Based on these data, we assess the quality of the DoV predicted by the Global Gravity Model GGMplus and the Swiss Geoid model CHGeo2004. DoV data previously observed with the QDaedalus system in coastal (Istanbul) and smooth (Munich region) terrain areas were compared with GGMplus to determine the accuracy of the model for both types of terrain. The Surses Region was chosen for these observations because of its mountainous nature to examine the quality of the GGMplus model in mountainous terrain, as well as the GGMplus’ quality with the CHGeo2004. Astrogeodetic observations were conducted at 15 benchmarks in the astrogeodetic profile, at elevations ranging from 1185-1800 m and a station spacing of ~1.5 km. At one benchmark (BM12), observations were done with all three systems (eccentric BMs), while at 13 benchmarks, observations were only completed with the QDaedalus systems. Observations at the final benchmark were completed only with the CODIAC (0⁰ zenith angle) due to line of sight obstacles. The standard deviations of the QDaedalus data for each session are 0.04″-0.22″ and 0.01″-0.20″ for the N-S and E-W components, respectively. These high-quality data were compared to DoV data derived from GGMplus and CHGeo2004. The residuals from GGMplus are: The N-S component exhibit large residuals ranging from -2.31″ to 1.75″, while the E-W component residuals are -0.27″ to 1.80″. The residuals from CHGeo2004 range from -0.60 to 1.21 for the N-S components, and -1.01 to 0.32 for the E-W components. The results show that the predicted DoV data from CHGeo2004 are closer to the observed DoV, and more accurate than GGMplus. We conclude from these results that GGMplus is of significantly lower quality in mountainous terrain than in the smooth terrain of the Munich region (~0.2″, and reaching a maximum of 0.3″ and 0.4″ for the N-S and E-W components).

Volume II of the Fourth National Climate Assessment (NCA4) - Impacts, Risks, and Adaptation in the United States - evaluates the risks American society faces as a result of climate change and highlights actions underway across the country to address those risks. NCA4 Vol. II communicates what climate change means for communities across the country, focusing on impacts and risks affecting the things and places we value. The report also elevates the visibility of successful adaptation actions throughout the ten NCA4 regions (including, for the first time, the U.S. Caribbean), with the hope that communities elsewhere in the country can learn from these experiences. This poster will: (1) present the Summary Findings for NCA4 Vol. II and (2) highlight key aspects of the report Overview, which includes core sections on Economy & Infrastructure, Natural Environment & Ecosystem Services, and Human Health & Well-Being that synthesize findings from the underlying report. The Summary Findings and Overview were developed by an author team composed of the NCA4 Director, Federal Steering Committee members, and U.S. Global Change Research Program staff and member agency experts. They were developed in parallel with the underlying report chapters and went through the same rigorous review process.

Absorption of sunlight forms a diurnal warm layer (DWL) in the afternoon at the surface and upper meters of the ocean when wind is weak. Analyses using models and remote sensing data disagree on the frequency of DWLs stronger than 1 °C. In situ time series in the central Indian Ocean showed the DWL exceeded 1 °C for 24% of days in October-December 2011 during the Dynamics of the Madden Julian Oscillation (DYNAMO) experiment. For 4 days with mean wind of 1.4 m/s, the DWL was 1.5-2.5 °C. We observed atmospheric turbulence over the DWL using Doppler lidar. Mixed layer turbulence is convective, generated mostly by surface buoyancy flux. The turbulent kinetic energy dissipation of the convective marine atmospheric mixed layer scales with surface buoyancy flux like diurnal convective boundary layers over land and convective mixed layers in the ocean and lakes. This convection in the afternoon is out of phase with buoyancy flux from nocturnal atmospheric net radiative cooling. The afternoon atmospheric convective turbulence over the tropical ocean mixes heat and humidity from the ocean to the lifted condensation level of clouds.

Precipitation is an essential climate and forcing variable for modeling the global water cycle. Particularly, the Integrated Multi-satellitE Retrievals for GPM (IMERG) product retrospectively provides unprecedented two-decades of high-resolution satellite precipitation estimates (0.1-deg, 30-min) globally. The primary goal of this study is to examine the similarities and differences between the two latest and also arguably most popular GPM IMERG Early and Final Run (ER and FR) products systematically over the globe. The results reveal that: (1) ER systematically estimates 13.0% higher annual rainfall than FR, particularly over land (13.8%); (2) ER and FR show less difference with instantaneous rates (Root Mean Squared Difference: RMSD=2.38 mm/h and normalized RMSD: RMSD_norm=1.10), especially in Europe (RMSD=2.16 mm/h) and cold areas (RMSD_norm=0.87); and (3) with similar detectability of extreme events and timely data delivery, ER is favored for use in hydrometeorological applications, especially in early warning of flooding. Throughout this study, large discrepancies between ER and FR are found in inland water bodies, (semi) arid regions, and complex terrains, possibly owing to morphing differences and gauge corrections while magnified by surface emissivity and precipitation dynamics. The exploration of their similarities and differences provides a first-order global assessment of various hydrological utilities: FR is designed to be more suitable for retrospective hydroclimatology and water resource management, while the earliest available ER product, though not bias-corrected by ground gauges, shows suitable applicability in operational modeling setting for early rainfall-triggered hazard alerts.

The most widely-studied mechanism of mass loss from extrasolar planets is photoevaporation via XUV ionization, primarily in the context of highly irradiated planets. However, the EUV dissociation of hydrogen molecules can also theoretically drive atmospheric evaporation on low-mass planets. For temperate planets such as the early Earth, impact erosion is expected to dominate in the traditional planetesimal accretion model, but it would be greatly reduced in pebble accretion scenarios, allowing other mass loss processes to be major contributors. We apply the same prescription for photoionization to this photodissociation mechanism and compare it to an analysis of other possible sources of mass loss in pebble accretion scenarios. We find that there is not a clear path to evaporating the primordial atmosphere accreted by an early Earth analog in a pebble accretion scenario. Impact erosion could remove ~2,300 bars of hydrogen if 1% of the planet’s mass is accr eted as planetesimals, while the combined photoevaporation processes could evaporate ~750 bars of hydrogen. Photodissociation is likely a subdominant, but significant component of mass loss. Similar results apply to super-Earths and mini-Neptunes. This mechanism could also preferentially remove hydrogen from a planet’s primordial atmosphere, thereby leaving a larger abundance of primordial water compared to standard dry formation models. We discuss the implications of these results for models of rocky planet formation including Earth’s formation and the possible application of this analysis to mass loss from observed exoplanets.

The recent high spatial/spectral resolution observations have enabled constraining formation mechanisms of giant planets, especially at the final stages. The current interpretation of such observations is that these planets undergo magnetospheric accretion, suggesting the importance of planetary magnetic fields. We explore the properties of accreting, magnetized giant planets surrounded by their circumplanetary disks, using the physical parameters inferred for PDS 70 b/c. We compute the magnetic field strength and the resulting spin rate of giant planets, and find that these planets may possess magnetic dipole fields of either a few 10 G or a few 100 G; the former is the natural outcome of planetary growth and radius evolution, while the resulting spin rate cannot reproduce the observations. For the latter, a consistent picture can be drawn, where strong magnetic fields induced by hot planetary interiors, lead both to magnetospheric accretion and to spin-down due to disk locking. We also compute the properties of circumplanetary disks in the vicinity of these planets, taking into account planetary magnetic fields. The resulting surface density lies between the predictions of two empirically derived models of circumplanetary disks:the minimum mass subnebula model and the gas-starved model. Our model predicts a positive gradient of the surface density, which invokes the traps for both satellite migration and radially drifting dust particles. This work thus concludes that the final formation stages of giant planets are similar to those of low-mass stars such as brown dwarfs, as suggested by recent studies.

The eccentricity of the planet’s orbit and the inclination of the orbital plane carry important information about its formation and history. However, exoplanets detected via direct-imaging are often only observed for a very small fraction of their period, making it challenging to reliably estimate their orbits. The aim of this project is to investigate biases in the estimation of orbital parameters of directly-imaged exoplanets, particularly their eccentricities, and to define general guidelines to perform better estimations. For this, we constructed various orbits, and generated mock data for each spanning around 0.5% of their orbital period. We the Orbits For The Impatient (OFTI) algorithms to get orbit posteriors, and compared those to the true orbital parameters. We found that the inclination of the orbital plane is the parameter that most affects our estimations of eccentricity, with orbits that appear near-edge-on producing highly biased eccentricity posteriors. We also found a degeneracy between eccentricity and inclination that makes it ifficult to distinguish circular, edge-on orbits from eccentric, face-on orbits. For the exoplanet-imaging community, we propose practical recommendations, guidelines and warnings relevant to orbit-fitting.

Traditionally, astronomers have separated giant planets from brown dwarfs based on the object’s mass. Objects more massive than 13 Jupiter masses but less massive than 80 Jupiter masses are considered to be brown dwarfs. However, in detail, the lower mass threshold is 11 to 16 Jupiter masses depending on the metallicity of the object. This betrays how arbitrary a purely mass-based distinction between planets and brown dwarfs is. Instead, we take a critical look at the population of brown dwarfs for which we have the most fundamental information: transiting brown dwarfs. Transiting brown dwarfs provide us their mass, radius, and sometimes age, which makes them useful for directly testing substellar evolutionary models. Through a better understanding of how well these models describe the population of transiting brown dwarfs, we will develop a better definition of what makes a brown dwarf different than a giant planet: its formation mechanism. It is certainly true that in the mass range spanning between giant planets and low-mass stars that the dominant formation mechanism must change in a significant way. If we can determine which mass or distribution of masses that this change occurs at, then we will have a more physical way to distinguish planets from brown dwarfs. This poster provides an overview of the substellar mass-radius diagram and highlights several of the recent discoveries facilitated by the TESS mission.

Land cover changes (LCC) show biophysical effect on regional climate because they modify the land surface albedo, evapotranspiration, and surface roughness. Many previous studies focused on the effects of individual land cover transitions, such as idealized large-scale scenarios of deforestation/afforestation or historical forest clearance, but the combined effects from the detected recent historical land cover changes in Europe have not been explored. In this study, we use a combination of a regional climate model (the Weather Research and Forecasting model, WRF, v3.9.1) with a high resolution land cover data to explore the effects on surface temperature of land cover changes between 1992 and 2015. Previous studies use one unrealistic large-scale simulation for each LCC to estimate its climate effects which present large variations especially in mid-latitudes. Our analysis introduces a new method simultaneously considering the effects of the mix of historical land cover changes in Europe and the individual one contribution. This approach, based on a ridge statistical regression, does not require an explicit consideration of the different components of the surface energy budget, and directly shows the temperature changes from each land transition. Around 70 Mha of land transitions occurred in Europe from 1992 to 2015. Approximately 25 Mha of agricultural land was left abandoned, which was only partially compensated by cropland expansion (about 20 Mha). Declines in agricultural land mostly occurred in favor of forests (15 Mha) and urban settlements (8 Mha). Compared to 1992, we find that the land covers of 2015 are associated with an average temperature cooling of -0.12±0.20 °C, with seasonal and spatial variations. At a continental level, the mean cooling is mainly driven by agriculture abandonment (cropland-to-forest transitions). Idealized simulations where cropland transitions to other land classes are excluded result in a mean warming of +0.10±0.19 °C, especially during summer. Conversions to urban land always resulted in warming effects, whereas the local temperature response to forest gains and losses shows opposite signs from the western and central part of the domain (where forests have cooling effects) to the eastern part (where forests are associated to warming). Gradients in soil moisture and local climate conditions are the main drivers of these differences. Our findings are a first attempt to quantify the regional climate response to historical LCC in Europe, and our method allows to unmix the temperature signal of a grid cell to the underlying LCCs (i.e., temperature impact per land transition). Further developing biophysical implications from LCCs for their ultimate consideration in land use planning can improve synergies for climate change adaptation and mitigation. Key words: land use/cover change; regional climate mode; biophysical climate; EURO-CORDEX

Heat has historically resulted in more mortality than any other severe weather-related phenomenon in the United States, with the U.S. Centers for Disease Control attributing more than six hundred deaths to extreme heat each year. Agricultural workers are particularly vulnerable to environmental heat exposure: mortality rates due to heat amongst crop workers are twenty times higher than in the general worker population. The vulnerability of this group of workers to heat is exacerbated by factors such as economic vulnerability, immigration status, language barriers, access to health care, and the absence of worker heat standards in all but three of the fifty United States. Climate change threatens to increase the risk of heat-related illness in agricultural workers, but so far there has been no nation-wide evaluation of the expected change in heat exposure in a warmer climate for this group of workers. Here, we estimate baseline and future exposure of agricultural workers in the main growing regions of the continental U.S. to extreme heat. Given the diverse health impacts of different types of heat events, we compare metrics for both single day extremes and multi-day heat waves, and calculate how these statistics will change at the county level with 2 and 4 degrees Celsius of global warming. Our findings serve as a guideline for determining regionally appropriate heat standards, and underscore the need for agencies in all agricultural states to make preparations for a warmer climate.

▪ Our attenuation inversion method is based on Liu et al. (2015) using linear triplet of stations ▪ Application to the dense 3C linear array crossing the San Jacinto Fault in Ramona, CA ▪ Clear fundamental mode Rayleigh and Love wave phases are extracted ▪ Attenuation tomography maps reveal new information in addition to velocity tomography ▪ Shear velocity radial anisotropy and possible shear attenuation anisotropy

Since 1973 micro-erosion meters (MEM) have been used at Kaikōura Peninsula to determine lowering rates on inter-tidal shore platforms. Rates measured over two, two year periods (1973-1975 and 1994-1996) and at decadal scales (20-30 years) demonstrate that platform surface lowering is on average 1.1 mm/yr. The 14 November 2016 Kaikōura magnitude 7.8 (Mw) earthquake caused an instantaneous uplift of 0.8-1.0 m of the peninsula. The uplift offers the rare opportunity to examine how such an event alters processes and rates of erosion on these shore platforms, since these are now partially marine terraces as the inner margins of some platforms are now above high tidal levels (but perhaps not storm surge). Since the earthquake, 42 MEM sites have been measured seven times at 3 monthly intervals. Most recently in September 2018. MEM sites show widely varying responses to the uplift. Erosion rates are at some MEM sites three times the previous annual rate while other sites show significant amounts of rock swelling (3-4 mm in 6 months), or aggradation as weathered rock fragments are no longer removed by wave action. The coseismic uplift has fundamentally changed the process regime operating on these platforms. Zones of maximum wetting and drying have migrated seaward causing previously slow eroding (< 1 mm/yr) MEM sites to accelerate to twice the pre-earthquake rates. Erosion rates demonstrate rapid adjustment of the platform surface to this disturbance and illustrate how uplifted marine terraces can be rapidly eroded despite being above sea level. The preservation of the new marine terrace is probably dependent on further uplift within the next 300-400 years, otherwise erosion by lowering and backwear will likely remove the new surface. This scenario has significant implications for marine terrace preservation and the recording of coseismic events in the landscape.