Observations of nucleation-mode particle events and characterization of organic atmospheric particulate matter at a rural New England site

Air quality of New England reflects air quality of the eastern United States and Canada because of transport from these areas to New England. Particle number (PN) concentration, size distribution, and composition were observed in the winter/spring period at a rural New England site (Thompson Farm). Thirteen PN events identified on the basis of increased PN above the site average were investigated, with the majority of events originating from clean northwestern air masses. Steady particle growth rates were observed for events ranging between 0.9 and 5.5 nm. The organic composition of bulk aerosols were also investigated over a year (August 2007 to August 2008), through measurements of organic carbon, elemental carbon, and water-soluble organic carbon (WSOC) from 24-hour samples. Annual means and seasonal trends are reported. 1H-NMR showed little variation among functional groups present in WSOC on a seasonal basis but showed significant variation on a daily basis

Modelling soil erosion and transport in the Burrishoole catchment, Newport, Co. Mayo, Ireland

The Burrishoole catchment is situated in County Mayo, on the northwest coast of the Republic of Ireland. Much of the catchment is covered by blanket peat that, in many areas, has become heavily eroded in recent years. This is thought to be due, primarily, to the adverse effects of forestry and agricultural activities in the area. Such activities include ploughing, drainage, the planting and harvesting of trees, and sheep farming, all of which are potentially damaging to such a sensitive landscape if not managed carefully. This article examines the sediment yield and hydrology of the Burrishoole catchment. Flow and sediment concentrations were measured at 8-hourly intervals from 5 February 2001 to 8 November 2001 with an automatic sampler and separate flow gauge, and hourly averages were recorded between 4 July 2002 and 6 September 2002 using an automatic river monitoring system [ARMS]. The authors describe the GIS-based model of soil erosion and transport that was applied to the Burrishoole catchment during this study. The results of these analyses were compared, in a qualitative manner, with the aerial photography available for the Burrishoole catchment to see whether areas that were predicted to contribute large proportions of eroded material to the drainage network corresponded with areas where peat erosion could be identified through photo-interpretation

Assessing research impact on poverty: the importance of farmers’ perspectives

P. Kristjanson and P.K. Thornton are ILRI authorsIn this paper we provide evidence to show that farmers' perspectives on poverty processes and outcomes are critical in the early stages of evaluating impact of agricultural research on poverty. We summarize lessons learned from farmer impact assessment workshops held in five African locations, covering three agro-ecological zones and five different agroforestry and livestock technologies arising from collaborative national–international agricultural research. Poverty alleviation is a process that needs to be understood before impact can be measured. Workshops such as those we describe can help researchers to identify farmers' different ways of managing and using a technology and likely effects, unanticipated impacts, major impacts to pursue in more quantitative studies, the primary links between agricultural technology and poverty, and key conditioning factors affecting adoption and impact that can be used to stratify samples in more formal analyses. Farmer workshops inform other qualitative and quantitative impact assessment methods. We discuss the linkage of farmer-derived information with GIS-based approaches that allow more complete specification of recommendation domains and broader-scale measurement of impact

Exploring opportunities around climate-smart breeding for future food and nutrition security

There is a 95% chance that warming will exceed 2°C by the end of the century (Raftery et al. 2017). Global crop productivity is projected to fall by 5-10 % per degree of warming (Challinor et al. 2014), with even greater losses likely for some crops in some areas. The challenge of meeting future food demand is increasing, and climate change is already diminishing our ability to adapt through crop breeding (Challinor et al. 2016; Aggarwal et al. 2019). Recent research is suggesting that increases in climate variability are already affecting the number of food-insecure people, and that increasing atmospheric CO2 concentrations may affect the nutrient content of some food staples, with serious implications for food and nutrition security (Smith and Myers 2018). New crop varieties will be needed that can deliver higher yields as well as possessing the ability to withstand heat and greater tolerances for the secondary effects of a warmer world, such as increased pressures from drought, water-logging, pests and diseases, and reduced nutritional quality due to higher levels of CO2. The systems for accelerated delivery of climate-resilient varieties into food producers’ hands need to be massively upgraded (Cramer 2018). Innovative holistic breeding strategies for multiple traits will be needed that embrace the full pipeline from trait discovery to varietal deployment and seed system development

Modelling soil erosion and transport in the Burrishoole catchment, Newport, Co. Mayo, Ireland

The Burrishoole catchment is situated in County Mayo, on the northwestcoast of the Republic of Ireland. Much of the catchment is covered byblanket peat that, in many areas, has become heavily eroded in recent years(Fig. 1). This is thought to be due, primarily, to the adverse effects offorestry and agricultural activities in the area. Such activities includeploughing, drainage, the planting and harvesting of trees, and sheepfarming, all of which are potentially damaging to such a sensitivelandscape if not managed carefully

Boreal fire records in Northern Hemisphere ice cores: a review

Here, we review different attempts made since the early 1990s to reconstruct past forest fire activity using chemical signals recorded in ice cores extracted from the Greenland ice sheet and a few mid-northern latitude, high-elevation glaciers. We first examined the quality of various inorganic (ammonium, nitrate, potassium) and organic (black carbon, various organic carbon compounds including levoglucosan and numerous carboxylic acids) species proposed as fire proxies in ice, particularly in Greenland. We discuss limitations in their use during recent vs. pre-industrial times, atmospheric lifetimes, and the relative importance of other non-biomass-burning sources. Different high-resolution records from several Greenland drill sites and covering various timescales, including the last century and Holocene, are discussed. We explore the extent to which atmospheric transport can modulate the record of boreal fires from Canada as recorded in Greenland ice. Ammonium, organic fractions (black and organic carbon), and specific organic compounds such as formate and vanillic acid are found to be good proxies for tracing past boreal fires in Greenland ice. We show that use of other species – potassium, nitrate, and carboxylates (except formate) – is complicated by either post-depositional effects or existence of large non-biomass-burning sources. The quality of levoglucosan with respect to other proxies is not addressed here because of a lack of high-resolution profiles for this species, preventing a fair comparison. Several Greenland ice records of ammonium consistently indicate changing fire activity in Canada in response to past climatic conditions that occurred during the last millennium and since the last large climatic transition. Based on this review, we make recommendations for further study to increase reliability of the reconstructed history of forest fires occurring in a given region

An improved estimate for the delta C-13 and delta O-18 signatures of carbon monoxide produced from atmospheric oxidation of volatile organic compounds

Atmospheric carbon monoxide (CO) is a key player in global atmospheric chemistry and a regulated pollutant in urban areas. Oxidation of volatile organic compounds (VOCs) is an important component of the global CO budget and has also been hypothesized to contribute substantially to the summertime urban CO budget. In principle, stable isotopic analysis of CO could constrain the magnitude of this source. However, the isotopic signature of VOC-produced CO has not been well quantified, especially for the oxygen isotopes. We performed measurements of CO stable isotopes on air samples from two sites around Indianapolis, US, over three summers to investigate the isotopic signature of VOC-produced CO. One of the sites is located upwind of the city, allowing us to quantitatively remove the background air signal and isolate the urban CO enhancements. as well as the isotopic signature of these enhancements. In addition, we use measurements of &Delta;14CO2 in combination with the CO:CO2 emission ratio from fossil fuels to constrain the fossil-fuel-derived CO and thereby isolate the VOC-derived component of the CO enhancement. Combining these measurements and analyses, we are able to determine the carbon and oxygen isotopic signatures of CO derived from VOC oxidation as &minus;32.8&permil;&plusmn;0.5&permil; and 3.6&thinsp;&permil;&plusmn;1.2&thinsp;&permil;, respectively. Additionally, we analyzed CO stable isotopes for 1 year at Beech Island, South Carolina, US, a site thought to have large VOC-derived contributions to the summertime CO budget. The Beech Island results are consistent with isotopic signatures of VOC-derived CO determined from the Indianapolis data. This study represents the first direct determination of the isotopic signatures of VOC-derived CO and will allow for improved use of isotopes in constraining the global and regional CO budgets.</p

Boreal fire records in Northern Hemisphere ice cores: a review

Here, we review different attempts made since the early 1990s to reconstruct past forest fire activity using chemical signals recorded in ice cores extracted from the Greenland ice sheet and a few mid-northern latitude, high-elevation glaciers. We first examined the quality of various inorganic (ammonium, nitrate, potassium) and organic (black carbon, various organic carbon compounds including levoglucosan and numerous carboxylic acids) species proposed as fire proxies in ice, particularly in Greenland. We discuss limitations in their use during recent vs. pre-industrial times, atmospheric lifetimes, and the relative importance of other non-biomass-burning sources. Different high-resolution records from several Greenland drill sites and covering various timescales, including the last century and Holocene, are discussed. We explore the extent to which atmospheric transport can modulate the record of boreal fires from Canada as recorded in Greenland ice. Ammonium, organic fractions (black and organic carbon), and specific organic compounds such as formate and vanillic acid are found to be good proxies for tracing past boreal fires in Greenland ice. We show that use of other species – potassium, nitrate, and carboxylates (except formate) – is complicated by either post-depositional effects or existence of large non-biomass-burning sources. The quality of levoglucosan with respect to other proxies is not addressed here because of a lack of high-resolution profiles for this species, preventing a fair comparison. Several Greenland ice records of ammonium consistently indicate changing fire activity in Canada in response to past climatic conditions that occurred during the last millennium and since the last large climatic transition. Based on this review, we make recommendations for further study to increase reliability of the reconstructed history of forest fires occurring in a given region

Science in neo-Victorian poetry

This article considers the work of three contemporary poets and their engagement, in verse, with Victorian science. Beginning with the outlandish ‘theories’ of Mick Imlah’s ‘The Zoologist’s Bath’ (1983), it moves on to two works of biografiction – Anthony Thwaite’s poem ‘At Marychurch’ (1980), which outlines Philip Henry Gosse’s doomed attempts to unite evolution and Christianity, and Ruth Padel’s Darwin: A Life in Poems (2009). Starting off with John Glendening’s idea that science in neo-Victorian fiction, if fully embraced, provides an opportunity for self-revelation to characters, this article explores the rather less happy resolutions of each of these poems, while in addition discussing the ways in which these poems perform the formal changes and mutability discussed within them

Using ice core measurements from Taylor Glacier, Antarctica, to calibrate in situ cosmogenic 14 C production rates by muons

Cosmic rays entering the Earth’s atmosphere produce showers of secondary particles such as protons, neutrons, and muons. The interaction of these particles with oxygen-16 (16O) in minerals such as ice and quartz can produce carbon-14 (14C). In glacial ice, 14C is also incorporated through trapping of 14C-containing atmospheric gases (14CO2, 14CO, and 14CH4). Understanding the production rates of in situ cosmogenic 14C is important to deconvolve the in situ cosmogenic and atmospheric 14C signals in ice, both of which contain valuable paleoenvironmental information. Unfortunately, the in situ 14C production rates by muons (which are the dominant production mechanism at depths of > 6m solid ice equivalent) are uncertain. In this study, we use measurements of in situ 14C in ancient ice (> 50 ka) from the Taylor Glacier, an ablation site in Antarctica, in combination with a 2D ice flow model to better constrain the compound-specific rates of 14C production by muons and the partitioning of in situ 14C between CO2, CO, and CH4. Our measurements show that 33.7% (11.4%; 95% confidence interval) of the produced cosmogenic 14C forms 14CO and 66.1% (11.5%; 95% confidence interval) of the produced cosmogenic 14C forms 14CO2. 14CH4 represents a very small fraction (< 0.3%) of the total. Assuming that the majority of in situ muogenic 14C in ice forms 14CO2, 14CO, and 14CH4, we also calculated muogenic 14C production rates that are lower by factors of 5.7 (3.6–13.9; 95% confidence interval) and 3.7 (2.0–11.9; 95% confidence interval) for negative muon capture and fast muon interactions, respectively, when compared to values determined in quartz from laboratory studies (Heisinger et al., 2002a, b) and in a natural setting (Lupker et al., 2015). This apparent discrepancy in muogenic 14C production rates in ice and quartz currently lacks a good explanation and requires further investigation