Synchronous Modes of Terrestrial and Marine Productivity in the North Pacific

The primary productivity of adjacent terrestrial and marine ecosystems can display synchronous responses to climate variability. Previous work has shown that this behavior emerges along the California coast where internal modes of climate variability, such as El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), alter jet stream dynamics that influence marine ecosystems through changes in upwelling and terrestrial ecosystems through changes in precipitation. This study assesses whether marine-terrestrial synchrony is a widespread phenomenon across the North Pacific by utilizing satellite-derived Solar-Induced Fluorescence (SIF) and chlorophyll-α as proxies for land and sea productivity, respectively. The results show that terrestrial and marine ecosystems are consistently synchronized across 1000's of kms of the North Pacific coastline. This synchrony emerges because both marine and terrestrial ecosystems respond to climate modes with a similar north-south dipole pattern that is mirrored across the coastal interface. The strength of synchrony is modulated by the relative states of the PDO and ENSO because the terrestrial north-south dipole is strongly controlled by the PDO while the marine pattern follows ENSO. The consequence is marine and terrestrial productivity anomalies that are opposite one another along adjacent regions of the coastline. If ENSO and the PDO have shared low-frequency variance, then synchrony would be the dominant state despite local topographic and trophic diversity along the coastlines. This result suggests that climate proxy stacks that include biologically sensitive marine and terrestrial proxies would have a selective sensitivity to modes such as PDO that drive synchrony. Lastly, the coupling of land and sea productivity may have the effect of generating amplified regional responses of the carbon budget to climate variability by simultaneously enhancing the terrestrial and marine carbon sinks

Everything in Its Right Place: Social Cooperation and Artist Compensation

The music industry\u27s crisis response to the Internet has been the primary driver of U.S. copyright policy for over a decade. The core institutional response has been to increase the scope of copyright and the use of litigation, prosecution, and technical control mechanisms for its enforcement. The assumption driving these efforts has been that without heavily-enforced copyright, artists will not be able to make a living from their art. Throughout this period artists have been experimenting with approaches that do not rely on technological or legal enforcement, but on constructing web-based business models that engage fans and rely on voluntary compliance and payment mechanisms. Anecdotal reports of such efforts have occasionally surfaced in the media. Here we present the first extensive sales-data evidence, gleaned from hundreds of thousands of online voluntary transactions, from three web-based efforts over a period of several years. This Article examines the effectiveness of these voluntary models as compared to the baseline-forcing system advocated by the industry and adopted and enforced by Congress and successive U.S. administrations over the past fifteen years. Platforms for artist-fan cooperation are complex and dynamic systems, sensitive to a variety of design factors that can either increase participation and prosocial behavior or dampen participation and enable anti-social behavior. In addition to providing substantial evidence for copyright policy, our study reports field observations of the design characteristics that support cooperation. A growing literature experimentally and theoretically explores prosocial behavior that significantly and systematically refutes the self-interest hypothesis characterizing most rational actor modeling. This literature has not yet been translated into a design approach aimed specifically at designing systems of cooperation. Building on experimental and theoretical literature in diverse fields of behavioral sciences, we synthesize a series of design levers that should improve the degree to which individuals cooperate. We then specify how these design levers might be translated into specific user interface features, describe the ways in which these design levers have been utilized in the sites under study, and present hypotheses about additional features that could improve cooperative outcomes. The Article contributes to the Internet copyright policy debates by offering empirical evidence showing that well-designed voluntary cooperation models compare favorably to more aggressive and widely criticized enforcement policies based on copyright law and the Digital Millennium Copyright Act. It provides an empirical foundation for challenging the guiding assumptions of those policies

Everything in Its Right Place: Social Cooperation and Artist Compensation

The music industry\u27s crisis response to the Internet has been the primary driver of U.S. copyright policy for over a decade. The core institutional response has been to increase the scope of copyright and the use of litigation, prosecution, and technical control mechanisms for its enforcement. The assumption driving these efforts has been that without heavily-enforced copyright, artists will not be able to make a living from their art. Throughout this period artists have been experimenting with approaches that do not rely on technological or legal enforcement, but on constructing web-based business models that engage fans and rely on voluntary compliance and payment mechanisms. Anecdotal reports of such efforts have occasionally surfaced in the media. Here we present the first extensive sales-data evidence, gleaned from hundreds of thousands of online voluntary transactions, from three web-based efforts over a period of several years. This Article examines the effectiveness of these voluntary models as compared to the baseline-forcing system advocated by the industry and adopted and enforced by Congress and successive U.S. administrations over the past fifteen years. Platforms for artist-fan cooperation are complex and dynamic systems, sensitive to a variety of design factors that can either increase participation and prosocial behavior or dampen participation and enable anti-social behavior. In addition to providing substantial evidence for copyright policy, our study reports field observations of the design characteristics that support cooperation. A growing literature experimentally and theoretically explores prosocial behavior that significantly and systematically refutes the self-interest hypothesis characterizing most rational actor modeling. This literature has not yet been translated into a design approach aimed specifically at designing systems of cooperation. Building on experimental and theoretical literature in diverse fields of behavioral sciences, we synthesize a series of design levers that should improve the degree to which individuals cooperate. We then specify how these design levers might be translated into specific user interface features, describe the ways in which these design levers have been utilized in the sites under study, and present hypotheses about additional features that could improve cooperative outcomes. The Article contributes to the Internet copyright policy debates by offering empirical evidence showing that well-designed voluntary cooperation models compare favorably to more aggressive and widely criticized enforcement policies based on copyright law and the Digital Millennium Copyright Act. It provides an empirical foundation for challenging the guiding assumptions of those policies

Everything in its Right Place: Social Cooperation and Artist Compensation

The music industry’s crisis response to the Internet has been the primary driver of U.S. copyright policy for over a decade. The core institutional response has been to increase the scope of copyright and the use of litigation, prosecution, and technical control mechanisms for its enforcement. The assumption driving these efforts has been that without heavily-enforced copyright, artists will not be able to make a living from their art. Throughout this period artists have been experimenting with approaches that do not rely on technological or legal enforcement, but on constructing web-based business models that engage fans and rely on voluntary compliance and payment mechanisms. Anecdotal reports of such efforts have occasionally surfaced in the media. Here we present the first extensive sales-data evidence, gleaned from hundreds of thousands of online voluntary transactions, from three web-based efforts over a period of several years. This Article examines the effectiveness of these voluntary models as compared to the baseline-forcing system advocated by the industry and adopted and enforced by Congress and successive U.S. administrations over the past fifteen years. Platforms for artist-fan cooperation are complex and dynamic systems, sensitive to a variety of design factors that can either increase participation and prosocial behavior or dampen participation and enable anti-social behavior. In addition to providing substantial evidence for copyright policy, our study reports field observations of the design characteristics that support cooperation. A growing literature experimentally and theoretically explores prosocial behavior that significantly and systematically refutes the self-interest hypothesis characterizing most rational actor modeling. This literature has not yet been translated into a design approach aimed specifically at designing systems of cooperation. Building on experimental and theoretical literature in diverse fields of behavioral sciences, we synthesize a series of design levers that should improve the degree to which individuals cooperate. We then specify how these design levers might be translated into specific user interface features, describe the ways in which these design levers have been utilized in the sites under study, and present hypotheses about additional features that could improve cooperative outcomes. The Article contributes to the Internet copyright policy debates by offering empirical evidence showing that well-designed voluntary cooperation models compare favorably to more aggressive and widely criticized enforcement policies based on copyright law and the Digital Millennium Copyright Act. It provides an empirical foundation for challenging the guiding assumptions of those policies

Trends and oscillations in the Indian summer monsoon rainfall over the last two millennia

Observations show that summer rainfall over large parts of South Asia has declined over the past five to six decades. It remains unclear, however, whether this trend is due to natural variability or increased anthropogenic aerosol loading over South Asia. Here we use stable oxygen isotopes in speleothems from northern India to reconstruct variations in Indian monsoon rainfall over the last two millennia. We find that within the long-term context of our record, the current drying trend is not outside the envelope of monsoon’s oscillatory variability, albeit at the lower edge of this variance. Furthermore, the magnitude of multi-decadal oscillatory variability in monsoon rainfall inferred from our proxy record is comparable to model estimates of anthropogenic-forced trends of mean monsoon rainfall in the 21st century under various emission scenarios. Our results suggest that anthropogenic forced changes in monsoon rainfall will remain difficult to detect against a backdrop of large natural variability

Assessing a New Clue to How Much Carbon Plants Take Up

Current climate models disagree on how much carbon dioxide land ecosystems take up for photosynthesis. Tracking the stronger carbonyl sulfide signal could help

Supercooled liquid fogs over the central Greenland Ice Sheet

Radiation fogs at Summit Station, Greenland (72.58∘&thinsp;N, 38.48∘&thinsp;W; 3210&thinsp;m&thinsp;a.s.l.), 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 supercooled. Here we analyze 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 and 10&thinsp;m height from 2012 to 2014. These data are complemented by colocated 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 and 10&thinsp;m, and the particles then fall toward the surface. The diameter of mature particles is typically 20&ndash;25&thinsp;&micro;m 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 &minus;5&thinsp;∘C, while the coldest form at temperatures approaching &minus;40&thinsp;∘C. Facilitated by the elevated condensation, in winter two-thirds of fogs occurred within a relatively warm layer above the surface when the near-surface air was below &minus;40&thinsp;∘C, as cold as &minus;57&thinsp;∘C, which is too cold to 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 observed under otherwise clear skies annually imparted 1.5&thinsp;W&thinsp;m&minus;2 of cloud radiative forcing (CRF). While this is a small contribution to the surface radiation climatology, individual events are influential. The mean CRF during liquid fog events was 26&thinsp;W&thinsp;m&minus;2, and was sometimes much higher. An extreme case study was observed to radiatively force 5&thinsp;∘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. </div

Marine Carbonyl Sulfide (OCS) and Carbon Disulfide (CS\u3csub\u3e2\u3c/sub\u3e): A Compilation of Measurements in Seawater and the Marine Boundary Layer

Carbonyl sulfide (OCS) and carbon disulfide (CS2) are volatile sulfur gases that are naturally formed in seawater and exchanged with the atmosphere. OCS is the most abundant sulfur gas in the atmosphere, and CS2 is its most important precursor. They have attracted increased interest due to their direct (OCS) or indirect (CS2 via oxidation to OCS) contribution to the stratospheric sulfate aerosol layer. Furthermore, OCS serves as a proxy to constrain terrestrial CO2uptake by vegetation. Oceanic emissions of both gases contribute a major part to their atmospheric concentration. Here we present a database of previously published and unpublished (mainly shipborne) measurements in seawater and the marine boundary layer for both gases, available at https://doi.org/10.1594/PANGAEA.905430 (Lennartz et al., 2019). The database contains original measurements as well as data digitalized from figures in publications from 42 measurement campaigns, i.e., cruises or time series stations, ranging from 1982 to 2019. OCS data cover all ocean basins except for the Arctic Ocean, as well as all months of the year, while the CS2 dataset shows large gaps in spatial and temporal coverage. Concentrations are consistent across different sampling and analysis techniques for OCS. The database is intended to support the identification of global spatial and temporal patterns and to facilitate the evaluation of model simulations

Correlations between components of the water balance and burned area reveal new insights for predicting forest fire area in the southwest United States

We related measurements of annual burned area in the southwest United States during 1984–2013 to records of climate variability. Within forests, annual burned area correlated at least as strongly with spring–summer vapour pressure deficit (VPD) as with 14 other drought-related metrics, including more complex metrics that explicitly represent fuel moisture. Particularly strong correlations with VPD arise partly because this term dictates the atmospheric moisture demand. Additionally, VPD responds to moisture supply, which is difficult to measure and model regionally due to complex micrometeorology, land cover and terrain. Thus, VPD appears to be a simple and holistic indicator of regional water balance. Coupled with the well-known positive influence of prior-year cold season precipitation on fuel availability and connectivity, VPD may be utilised for burned area forecasts and also to infer future trends, though these are subject to other complicating factors such as land cover change and management. Assuming an aggressive greenhouse gas emissions scenario, climate models predict mean spring–summer VPD will exceed the highest recorded values in the southwest in nearly 40% of years by the middle of this century. These results forewarn of continued increases in burned forest area in the southwest United States, and likely elsewhere, when fuels are not limiting

Causes and Implications of Extreme Atmospheric Moisture Demand during the Record-Breaking 2011 Wildfire Season in the Southwestern United States

In 2011, exceptionally low atmospheric moisture content combined with moderately high temperatures to produce a record-high vapor pressure deficit (VPD) in the southwestern United States (SW). These conditions combined with record-low cold-season precipitation to cause widespread drought and extreme wildfires. Although interannual VPD variability is generally dominated by temperature, high VPD in 2011 was also driven by a lack of atmospheric moisture. The May–July 2011 dewpoint in the SW was 4.5 standard deviations below the long-term mean. Lack of atmospheric moisture was promoted by already very dry soils and amplified by a strong ocean-to-continent sea level pressure gradient and upper-level convergence that drove dry northerly winds and subsidence upwind of and over the SW. Subsidence drove divergence of rapid and dry surface winds over the SW, suppressing southerly moisture imports and removing moisture from already dry soils. Model projections developed for the fifth phase of the Coupled Model Intercomparison Project (CMIP5) suggest that by the 2050s warming trends will cause mean warm-season VPD to be comparable to the record-high VPD observed in 2011. CMIP5 projections also suggest increased interannual variability of VPD, independent of trends in background mean levels, as a result of increased variability of dewpoint, temperature, vapor pressure, and saturation vapor pressure. Increased variability in VPD translates to increased probability of 2011-type VPD anomalies, which would be superimposed on ever-greater background VPD levels. Although temperature will continue to be the primary driver of interannual VPD variability, 2011 served as an important reminder that atmospheric moisture content can also drive impactful VPD anomalies