Search

The carbon cycle plays a foundational role in the estimation of the remaining carbon budget. It is intrinsic for the determination of the transient climate response to cumulative CO2 emissions and the zero-emissions commitment. For the terrestrial carbon cycle, nutrient limitation is a core regulation on the amount of carbon fixed by terrestrial vegetation. Hence, the addition of nutrients such as nitrogen and phosphorus in land model structures in Earth system models is essential for an accurate representation of the carbon cycle feedback in future climate projections. Therefore, the estimation of the remaining carbon budget is impacted by the representation of nutrient limitation in modelled terrestrial ecosystems; however, it is rarely accounted for. Here, we estimate the carbon budget and remaining carbon budget of a nutrient-limited Earth system model, using nitrogen and phosphorus cycles to limit vegetation productivity and biomass. We use eight Shared Socioeconomic Pathways (hereafter SSP) scenarios and idealized experiments with three distinct model structures: (1) carbon cycle without nutrient limitation, (2) carbon cycle with terrestrial nitrogen limitation, and (3) carbon cycle with terrestrial nitrogen and phosphorus limitation. To capture the uncertainty in the remaining carbon budget, three different climate sensitives were tuned for each model version. Our results show that, overall, nutrient limitation reduced the remaining carbon budget for all simulations in comparison with the carbon cycle without nutrient limitation. Between nitrogen and nitrogen–phosphorus limitation, the latter had the lowest remaining carbon budget. The mean remaining carbon budgets obtained from the SSP scenario simulations for the 1.5 °C target in the non-nutrient-limited, nitrogen-limited, and nitrogen–phosphorus-limited models were 228, 185, and 175 Pg C, respectively, relative to the year 2020. For the 2 °C target, the mean remaining carbon budget values were 471, 373, and 351 Pg C for the non-nutrient-limited, nitrogen-limited, and nitrogen–phosphorus-limited models, respectively, relative to the year 2020. This represents a reduction of 19 % and 24 % for the 1.5 °C target and 21 % and 26 % for the 2 °C target for the respective nitrogen- and nitrogen–phosphorus-limited simulations compared with the non-nutrient-limited model. These results show that terrestrial nutrient limitation constitutes an important factor to be considered when estimating or interpreting remaining carbon budgets and that it is an essential uncertainty in the remaining carbon budgets from Earth system model simulations.

Campanian dialects such as Neapolitan feature a so-called ‘second form of the infinitive’ (SFI), a form consisting of the bare verbal stem, which can be used after functional verbs. This paper addresses the microvariation concerning the construction by analysing novel data from the Valle Caudina, located to the northeast of Naples. The SFI is frequently found specifically with the imperative va ‘go!’. In Neapolitan, the form has been reanalysed as an imperatival form in this context, yielding an asyndetic imperative. At a first glance, the use of the SFI in Valle Caudina looks very similar to its Neapolitan counterpart, but unlike Neapolitan, the SFI in these varieties has remained non-finite and has not been reanalysed as an imperative. These dialects can thus be considered a previous stage of the development described for Neapolitan by Ledgeway (1997, 2007, 2009). This claim finds support in the absence of metaphonetic forms - which have appeared in Neapolitan, as a consequence of the reanalysis - as well as the presence of clitic climbing. Finally, unlike Neapolitan, the SFI is becoming less productive in the varieties of the Valle Caudina.

Nitrogen (N) and phosphorus (P) biogeochemical dynamics are crucial for the regulation of the terrestrial carbon cycle. In Earth system models (ESMs) the implementation of nutrient limitations has been shown to improve the carbon cycle feedback representation and, hence, the fidelity of the response of land to simulated atmospheric CO2 rise. Here we aimed to implement a terrestrial N and P cycle in an Earth system model of intermediate complexity to improve projections of future CO2 fertilization feedbacks. The N cycle is an improved version of the Wania et al. (2012) N module, with enforcement of N mass conservation and the merger with a deep land-surface and wetland module that allows for the estimation of N2O and NO fluxes. The N cycle module estimates fluxes from three organic (litter, soil organic matter and vegetation) and two inorganic (NH4+ and NO3-) pools and accounts for inputs from biological N fixation and N deposition. The P cycle module contains the same organic pools with one inorganic P pool; it estimates influx of P from rock weathering and losses from leaching and occlusion. Two historical simulations are carried out for the different nutrient limitation setups of the model: carbon and nitrogen (CN), as well as carbon, nitrogen and phosphorus (CNP), with a baseline carbon-only simulation. The improved N cycle module now conserves mass, and the added fluxes (NO and N2O), along with the N and P pools, are within the range of other studies and literature. For the years 2001–2015 the nutrient limitation resulted in a reduction of gross primary productivity (GPP) from the carbon-only value of 143 to 130 Pg C yr−1 in the CN version and 127 Pg C yr−1 in the CNP version. This implies that the model efficiently represents a nutrient limitation over the CO2 fertilization effect. CNP simulation resulted in a reduction of 11 % of the mean GPP and a reduction of 23 % of the vegetation biomass compared to the baseline C simulation. These results are in better agreement with observations, particularly in tropical regions where P limitation is known to be important. In summary, the implementation of the N and P cycle has successfully enforced a nutrient limitation in the terrestrial system, which has now reduced the primary productivity and the capacity of land to take up atmospheric carbon, better matching observations.

The present paper introduces a corpus of Dutch Renaissance poetry which was automatically annotated by using neural networks. The analysis of the annotations provides a clear picture of the process of implementing the new poetic form into Dutch poetic tradition, and of its different stages. The development of iambic metre was a gradual process that required various attempts; this can be well observed when comparing Dutch poems from a 100 year time window. While syllabic instances can be observed among the first attempts, most of the earlier poems are not isosyllabic and have a rather varied syllable length. This study shows that isosyllabicity developed together with iambicity. Finally, automatic poetry annotation allows for testing and validating theoretical hypotheses and for investigating literary questions with the aid of large amount of data.

Nitrous Oxide (N _2 O) is a potent greenhouse gas with a centennial-scale lifetime that contributes significantly to global warming. It is emitted from natural and anthropogenic sources. In nature, N _2 O is released mainly from nitrification and denitrification from the ocean and terrestrial systems. The use of agricultural fertilizers has significantly increased the emission of N _2 O in the past century. Here we present, to our knowledge, the first coupled ocean and terrestrial N _2 O modules within an Earth System Model. The coupled modules were used to simulate the six Shared Socioeconomic Pathways (SSPs) scenarios with available nitrogen fertilizer inputs. Our results are compared to projections of atmospheric N _2 O concentrations used for SSPs scenario experiments. Additionally, an extra set of simulations were prescribed with emulated N _2 O concentrations available as input in Shared Socioeconomic Pathways scenarios. We report four main drivers for terrestrial N _2 O uncertainties: atmospheric temperature, agricultural fertilizer input, soil denitrification and agricultural model dynamics. We project an atmospheric N _2 O concentration range from 401 to 418 ppb in six SSPs simulations with a robust lack of sensitivity to equilibrium climate sensitivity. We found a large difference between our low emission scenarios N _2 O concentrations by 2100 compared to the concentration provided for SSPs experiments. This divergence is likely explained by strong mitigation assumptions that were not accounted for in this study, which would require a substantial decrease of agricultural N _2 O emissions. The coupled model and the simulations prescribed with N _2 O concentrations showed a difference between −0.02 and 0.09 ^∘ C by 2100. Our model simulation shows a lack of sensitivity to climate mitigation efforts projecting similar N _2 O concentration in low and high mitigation scenarios, that could indicate the need of further development of agricultural model dynamics. Further improvements in Earth system models should focus on the impact of oxygen decline on N _2 O dynamics in the ocean and the representation of anaerobic soils and agricultural dynamics on land, including mitigation methods on nitrogen fertilizers.

The carbon cycle plays a foundational role in the estimation of the remaining carbon budget. It is intrinsic for the determination of the transient climate response to cumulative CO2 emissions and the zero-emissions commitment. For the terrestrial carbon cycle, nutrient limitation is a core regulation on the amount of carbon fixed by terrestrial vegetation. Hence, the addition of nutrients such as nitrogen and phosphorus in land model structures in Earth system models is essential for an accurate representation of the carbon cycle feedback in future climate projections. Therefore, the estimation of the remaining carbon budget is impacted by the representation of nutrient limitation in modelled terrestrial ecosystems; however, it is rarely accounted for. Here, we estimate the carbon budget and remaining carbon budget of a nutrient-limited Earth system model, using nitrogen and phosphorus cycles to limit vegetation productivity and biomass. We use eight Shared Socioeconomic Pathways (hereafter SSP) scenarios and idealized experiments with three distinct model structures: (1) carbon cycle without nutrient limitation, (2) carbon cycle with terrestrial nitrogen limitation, and (3) carbon cycle with terrestrial nitrogen and phosphorus limitation. To capture the uncertainty in the remaining carbon budget, three different climate sensitives were tuned for each model version. Our results show that, overall, nutrient limitation reduced the remaining carbon budget for all simulations in comparison with the carbon cycle without nutrient limitation. Between nitrogen and nitrogen–phosphorus limitation, the latter had the lowest remaining carbon budget. The mean remaining carbon budgets obtained from the SSP scenario simulations for the 1.5 °C target in the non-nutrient-limited, nitrogen-limited, and nitrogen–phosphorus-limited models were 228, 185, and 175 PgC , respectively, relative to the year 2020. For the 2 °C target, the mean remaining carbon budget values were 471, 373, and 351 PgC for the non-nutrient-limited, nitrogen-limited, and nitrogen–phosphorus-limited models, respectively, relative to the year 2020. This represents a reduction of 19 % and 24 % for the 1.5 °C target and 21 % and 26 % for the 2 °C target for the respective nitrogen- and nitrogen–phosphorus-limited simulations compared with the non-nutrient-limited model. These results show that terrestrial nutrient limitation constitutes an important factor to be considered when estimating or interpreting remaining carbon budgets and that it is an essential uncertainty in the remaining carbon budgets from Earth system model simulations. [ABSTRACT FROM AUTHOR]

In southern Italian dialects, possessives have an enclitic variant typically associated with kinship nouns (Rohlfs 1967, Sotiri 2007, Ledgeway 2009, D’Alessandro & Migliori 2017) (e.g. [ˈfratə-mə] ˈbrother myˈ). The most common strategy to avoid violations of the three-syllable window is to avoid the enclitic form of the possessive, or stress shift, as in Lucanian (e.g. [ˌiennəˈru-mə] cf. [ˈiennərə], Lüdtke 1979:31). In the dialects of Airola and Boiano, a different strategy is attested: with proparoxytonic nouns (e.g. [ˈjennərə] ˈson-in-lawˈ in both varieties and [ˈsɔtʃəra]/[ˈswotʃəra] ˈmother/father-in-lawˈ in Boiano), the last unstressed syllable of the host is deleted (e.g. [ˈjennə-mə], [ˈsɔtʃə-mə], [ˈswotʃə-mə]). We claim that possessive enclitics in Airola and Boiano are internal clitics, that is, they amalgamate with the prosodic word that contains the host noun. We further propose that both proparoxytonic stress and the three-syllable-window derive from internally layered ternary feet (Martínez-Paricio 2013). These feet need to be aligned with the right edge of their containing prosodic word. When a possessive enclitic is incorporated, the most optimal strategy to comply with this alignment requirement is to build an internally layered ternary foot and delete the last syllable of the host noun, stress shift being excluded.