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Thomas Paine : Britain, America, and France in the Age of Enlightenment and revolution
\"Thomas Paine (1737-1809) was England's greatest revolutionary: no other reformer was as actively involved in events of the scale of the American and French Revolutions, and none wrote such best-selling texts with the impact of Common Sense and Rights of Man. No one else combined the roles of activist and theorist, or did so in the 'age of revolutions', fundamental as it was to the emergence of the 'modern world'. But his fame meant that he was taken up and reinterpreted for current use by successive later commentators and politicians, so that the 'historic Paine' was too often obscured by the 'usable Paine'.\"--Page 4 of cover.
Book
Polarized Gamma-Ray Emission from the Crab
Pulsar systems accelerate particles to immense energies. The detailed functioning of these engines is still poorly understood, but polarization measurements of high-energy radiation may allow us to locate where the particles are accelerated. We have detected polarized gamma rays from the vicinity of the Crab pulsar using data from the spectrometer on the International Gamma-Ray Astrophysics Laboratory satellite. Our results show polarization with an electric vector aligned with the spin axis of the neutron star, demonstrating that a substantial fraction of the high-energy electrons responsible for the polarized photons are produced in a highly ordered structure close to the pulsar.
Journal Article
Ground-based Ku-band microwave observations of ozone in the polar middle atmosphere
Ground-based observations of 11.072 GHz atmospheric ozone (O3) emission have been made using the Ny-Ålesund Ozone in the Mesosphere Instrument (NAOMI) at the UK Arctic Research Station (latitude 78∘55′0′′ N, longitude 11∘55′59′′ E), Spitsbergen. Seasonally averaged O3 vertical profiles in the Arctic polar mesosphere–lower thermosphere region for night-time and twilight conditions in the period 15 August 2017 to 15 March 2020 have been retrieved over the altitude range 62–98 km. NAOMI measurements are compared with corresponding, overlapping observations by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite instrument. The NAOMI and SABER version 2.0 data are binned according to the SABER instrument 60 d yaw cycles into nominal 3-month “winter” (15 December–15 March), “autumn” (15 August–15 November), and “summer” (15 April–15 July) periods. The NAOMI observations show the same year-to-year and seasonal variabilities as the SABER 9.6 µm O3 data. The winter night-time (solar zenith angle, SZA ≥ 110∘) and twilight (75∘ ≤ SZA ≤ 110∘) NAOMI and SABER 9.6 µm O3 volume mixing ratio (VMR) profiles agree to within the measurement uncertainties. However, for autumn twilight conditions the SABER 9.6 µm O3 secondary maximum VMR values are higher than NAOMI over altitudes 88–97 km by 47 % and 59 %, respectively in 2017 and 2018. Comparing the two SABER channels which measure O3 at different wavelengths and use different processing schemes, the 9.6 µm O3 autumn twilight VMR data for the three years 2017–2019 are higher than the corresponding 1.27 µm measurements with the largest difference (58 %) in the 65–95 km altitude range similar to the NAOMI observation. The SABER 9.6 µm O3 summer daytime (SZA < 75∘) mesospheric O3 VMR is also consistently higher than the 1.27 µm measurement, confirming previously reported differences between the SABER 9.6 µm channel and measurements of mesospheric O3 by other satellite instruments.
Journal Article
Assessment of satellite-derived rainfall and its use in the ACRU agro-hydrological model
Unfortunately, for various reasons, in-situ rain gauge networks are diminishing, especially in southern Africa, resulting in sparse networks whose records give a poor representation of rainfall occurrence, patterns and magnitudes. Hydrological models are used to inform decision making; however, model performance is directly linked to the quality of input data, such as rainfall. Therefore, the use of satellite-derived rainfall is being increasingly advocated as a viable alternative or supplement. The aim of this study was to evaluate the representativeness of satellite-derived rainfall and its utility in the ACRU agro-hydrological model to simulate streamflow magnitudes, distributions and patterns. The satellite-derived rainfall products selected for use in this study were TRMM3B42, FEWSARC2.0, FEWSRFE2.0, TAMSAT 3.0 and GPM-IMERG4. The satellite rainfall products were validated against available historical observed records and then were used to drive simulations using the ACRU agro-hydrological model in the upper uMngeni, upper uThukela and upper and central Breede catchments in South Africa. At the daily timescale, satellite-derived and observed rainfall were poorly correlated and variable among locations. However, monthly, seasonal and yearly rainfall totals and simulated streamflow volumes were in closer agreement with historical observations than the daily correlations; more so in the upper uMngeni and uThukela than in the upper and central Breede (e.g. FEWSARC2.0 and FEWSRFE2.0, producing relative volume errors of 3.18%, 4.63%, −5.07% and 2.54%, 9.54%, −1.67%, respectively, at Gauges V2E002, 0268883 and 02396985). Therefore, the satellite-derived rainfall shows promise for use in applications operating at coarser temporal scales than at finer daily ones. Complex topographical rainfall generation and varying weather systems, e.g. frontal rainfall, afected the accuracy of satellite-derived product estimates. This study focused on utilising the wealth of available raw satellite data; however, it is clear that the raw satellite data need to be corrected for bias and/or downscaled to provide more accurate results.
Journal Article
Carbon and Nitrogen Accumulation in Post-Agricultural Forest Soils of Western New England
The agricultural history of New England is reflected in the species composition, biomass, and productivity of the second-growth forests of the region. There are also effects of agricultural use on soil morphology, soil organic C (SOC) and N content, erosion status, and C stability, which can be specific to site-level characteristics or prior agricultural use. We conducted a survey of SOC amounts in chronosequences comprising 25 post-agricultural second-growth forests. Time since abandonment was estimated from tree ages, and the chronosequences were bounded by sites currently in agricultural use (n = 6) and minimally disturbed old forest (n = 4). At sites currently used for pasture, hay, or row crops, the median amount of SOC (to a depth of 55 cm) was 6.5 kg C m−2 compared with 10.3 kg C m−2 in the soils of the oldest forest stands. The chronosequences indicated that nearly all of the SOC accumulation occurred in the first century of afforestation. There were significant trends of SOC accumulation in the forest floor, upper mineral horizons (0–10 or 10–20 cm), and B horizons (20–55 cm) of soils that had been used for pasture, hay, or row crops but not for former woodlots. Multivariate analysis showed that years since agricultural abandonment and growing season degree days were the most important variables related to SOC content (68% sum of squares explained). There was a significant trend of N accumulation (1.3 g N m−2 yr−1) in soils (to a depth of 55 cm) formerly used for cultivated crops but not for other former uses. Farms in this region were an important C sink during the last 150 yr; however, the capacity of former agricultural soils to gain SOC in the future is probably limited.
Journal Article
Soil Organic Matter Quality in Chronosequences Of Secondary Northern Hardwood Forests In Western New England
We developed chronosequences in western New England northern hardwood forests for abandoned cultivated land (n = 10) and fields used as pasture or hay (n = 10). The top 20 cm of mineral soil was excavated using quantitative soil pits to examine particulate and potentially mineralizable organic matter as indicators of changes in soil organic matter (SOM) quality. The chronosequences were bound by land currently in agricultural use (n = 6) and native forest stands at least 250 yr in age with a history of minimal disturbance (n = 4). A 62-d incubation showed that a greater proportion of bulk soil C was potentially mineralizable in modern agricultural soils (108 g CO2–C kg−1 soil C) than at forested sites (63 g CO2–C kg−1 soil C), regardless of former use. Physical fractionation of SOM revealed that a greater proportion of bulk soil C was contained in the particulate organic matter (POM) fractions in plowed (86%) and pastured–hayed fields (49%) compared with regrowing forests 40 yr after abandonment (33–41%). Mineral-associated organic matter increased at a rate of 0.04 Mg ha−1 yr−1. While C/N ratios increased with forest age across the chronosequences for the bulk soil, they did not change with time for physical SOM fractions except for a weak but significant trend for the mineral-associated fraction of plowed soils (r2 = 0.26, P < 0.01). Multivariate regression trees showed that differences in soil texture accounted for a significant portion of the variability in the mineral (<53 mm) and sand (53–250 mm) associated fractions, while coarse POM C (>250 mm) was better related to climatic variables. These results suggest that the stability of SOM increases when native forests are allowed to invade abandoned agricultural fields.
Journal Article