scholarly journals Influence of weather situation on non-CO<sub>2</sub> aviation climate effects: the REACT4C climate change functions

2021 ◽  
Vol 21 (11) ◽  
pp. 9151-9172
Author(s):  
Christine Frömming ◽  
Volker Grewe ◽  
Sabine Brinkop ◽  
Patrick Jöckel ◽  
Amund S. Haslerud ◽  
...  

Abstract. Emissions of aviation include CO2, H2O, NOx, sulfur oxides, and soot. Many studies have investigated the annual mean climate impact of aviation emissions. While CO2 has a long atmospheric residence time and is almost uniformly distributed in the atmosphere, non-CO2 gases and particles and their products have short atmospheric residence times and are heterogeneously distributed. The climate impact of non-CO2 aviation emissions is known to vary with different meteorological background situations. The aim of this study is to systematically investigate the influence of characteristic weather situations on aviation climate effects over the North Atlantic region, to identify the most sensitive areas, and to potentially detect systematic weather-related similarities. If aircraft were re-routed to avoid climate-sensitive regions, the overall aviation climate impact might be reduced. Hence, the sensitivity of the atmosphere to local emissions provides a basis for the assessment of weather-related, climate-optimized flight trajectory planning. To determine the climate change contribution of an individual emission as a function of location, time, and weather situation, the radiative impact of local emissions of NOx and H2O to changes in O3, CH4, H2O and contrail cirrus was computed by means of the ECHAM5/MESSy Atmospheric Chemistry model. From this, 4-dimensional climate change functions (CCFs) were derived. Typical weather situations in the North Atlantic region were considered for winter and summer. Weather-related differences in O3, CH4, H2O, and contrail cirrus CCFs were investigated. The following characteristics were identified: enhanced climate impact of contrail cirrus was detected for emissions in areas with large-scale lifting, whereas low climate impact of contrail cirrus was found in the area of the jet stream. Northwards of 60∘ N, contrails usually cause climate warming in winter, independent of the weather situation. NOx emissions cause a high positive climate impact if released in the area of the jet stream or in high-pressure ridges, which induces a south- and downward transport of the emitted species, whereas NOx emissions at, or transported towards, high latitudes cause low or even negative climate impact. Independent of the weather situation, total NOx effects show a minimum at ∼250 hPa, increasing towards higher and lower altitudes, with generally higher positive impact in summer than in winter. H2O emissions induce a high climate impact when released in regions with lower tropopause height, whereas low climate impact occurs for emissions in areas with higher tropopause height. H2O CCFs generally increase with height and are larger in winter than in summer. The CCFs of all individual species can be combined, facilitating the assessment of total climate impact of aircraft trajectories considering CO2 and spatially and temporally varying non-CO2 effects. Furthermore, they allow for the optimization of aircraft trajectories with reduced overall climate impact. This also facilitates a fair evaluation of trade-offs between individual species. In most regions, NOx and contrail cirrus dominate the sensitivity to local aviation emissions. The findings of this study recommend considering weather-related differences for flight trajectory optimization in favour of reducing total climate impact.

2020 ◽  
Author(s):  
Christine Frömming ◽  
Volker Grewe ◽  
Sabine Brinkop ◽  
Patrick Jöckel ◽  
Amund S. Haslerud ◽  
...  

Abstract. Emissions of aviation include CO2, H2O, NOx, sulfur oxides and soot. Many studies have investigated the annual mean climate impact of aviation emissions. While CO2 has a long atmospheric residence time and is almost uniformly distributed in the atmosphere, non-CO2 gases, particles and their products have short atmospheric residence times and are heterogeneously distributed. The climate impact of non-CO2 aviation emissions is known to vary with different meteorological background situations. The aim of this study is to systematically investigate the influence of different weather situations on aviation climate effects over the North Atlantic region, to identify the most sensitive areas and potentially detect systematic weather related similarities. If aircraft were re-routed to avoid climate-sensitive regions, the overall aviation climate Impact might be reduced. Hence, the sensitivity of the atmosphere to local emissions provides a basis for the assessment of weather related, climate optimized flight trajectory planning. To determine the climate change contribution of an individual Emission as function of location, time and weather situation, the radiative impact of local emissions of NOx and H2O to changes in O3, CH4, H2O and contrail-cirrus was computed by means of the ECHAM5/MESSy Atmospheric Chemistry model. 4-dimensional climate change functions (CCFs) were derived thereof. Typical weather situations in the North Atlantic region were considered for winter and summer. Weather related differences in O3-, CH4-, H2O-, and contrail-cirrus-CCFs were investigated. The following characteristics were identified: Enhanced climate impact of contrail-cirrus was detected for emissions in areas with large scale lifting, whereas low climate impact of contrail-cirrus was found in the area of the jet stream. Northwards of 60° N contrails usually cause climate warming in winter, independent of the weather situation. NOx emissions cause a high positive climate impact if released in the area of the jet stream or in high pressure ridges, which induces a south- and downward transport of the emitted species. Whereas NOx emissions at, or transported towards high latitudes, cause low or even negative climate impact. Independent of the weather situation, total NOx effects show a minimum at ∼250 hPa, increasing towards higher and lower altitudes, with generally higher positive impact in summer than in winter. H2O emissions induce a high climate Impact when released in regions with lower tropopause height, whereas low climate impact occurs for emissions in areas with higher tropopause height. H2O-CCFs generally increase with height, and are larger in winter than in summer. The CCFs of all individual species can be combined, facilitating the assessment of total climate impact of aircraft trajectories considering CO2 and spatially and temporally varying non-CO2 effetcs. Furthermore they allow the optimization of aircraft trajectories with reduced overall climate impact. In most regions NOx and contrail-cirrus dominate the sensitivity to local aviation emissions. The findings of this study recommend, to consider weather related differences for flight trajectory optimization in favour of reducing total climate impact.


2018 ◽  
Vol 14 (8) ◽  
pp. 1253-1273 ◽  
Author(s):  
Kees Nooren ◽  
Wim Z. Hoek ◽  
Brian J. Dermody ◽  
Didier Galop ◽  
Sarah Metcalfe ◽  
...  

Abstract. The impact of climate change on the development and disintegration of Maya civilisation has long been debated. The lack of agreement among existing palaeoclimatic records from the region has prevented a detailed understanding of regional-scale climatic variability, its climatic forcing mechanisms and its impact on the ancient Maya. We present two new palaeo-precipitation records for the central Maya lowlands, spanning the Pre-Classic period (1800 BCE–250 CE), a key epoch in the development of Maya civilisation. A beach ridge elevation record from world's largest late Holocene beach ridge plain provides a regional picture, while Lake Tuspan's diatom record is indicative of precipitation changes at a local scale. We identify centennial-scale variability in palaeo-precipitation that significantly correlates with the North Atlantic δ14C atmospheric record, with a comparable periodicity of approximately 500 years, indicating an important role of North Atlantic atmospheric–oceanic forcing on precipitation in the central Maya lowlands. Our results show that the Early Pre-Classic period was characterised by relatively dry conditions, shifting to wetter conditions during the Middle Pre-Classic period, around the well-known 850 BCE (2.8 ka) event. We propose that this wet period may have been unfavourable for agricultural intensification in the central Maya lowlands, explaining the relatively delayed development of Maya civilisation in this area. A return to relatively drier conditions during the Late Pre-Classic period coincides with rapid agricultural intensification in the region and the establishment of major cities.


Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 525
Author(s):  
Keliang Zhang ◽  
Lanping Sun ◽  
Jun Tao

Analyzing the effects of climate change on forest ecosystems and individual species is of great significance for incorporating management responses to conservation policy development. Euscaphis japonica (Staphyleaceae), a small tree or deciduous shrub, is distributed among the open forests or mountainous valleys of Vietnam, Korea, Japan, and southern China. Meanwhile, it is also used as a medicinal and ornamental plant. Nonetheless, the extents of E. japonica forest have gradually shrunk as a result of deforestation, together with the regional influence of climate change. The present study employed two methods for modeling species distribution, Maxent and Genetic Algorithm for Rule-set Prediction (GARP), to model the potential distribution of this species and the effects of climate change on it. Our results suggest that both models performed favorably, but GARP outperformed Maxent for all performance metrics. The temperate and subtropical regions of eastern China where the species had been recorded was very suitable for E. japonica growth. Temperature and precipitation were two primary environmental factors affecting the distribution of E. japonica. Under climate change scenarios, the range of suitable habitats for E. japonica will expand geographically toward the north. Our findings may be used in several ways such as identifying currently undocumented locations of E. japonica, sites where it may occur in the future, or potential locations where the species could be introduced and so contribute to the conservation and management of this species.


2013 ◽  
Vol 26 (16) ◽  
pp. 6046-6066 ◽  
Author(s):  
Yalin Fan ◽  
Isaac M. Held ◽  
Shian-Jiann Lin ◽  
Xiaolan L. Wang

Abstract Surface wind (U10) and significant wave height (Hs) response to global warming are investigated using a coupled atmosphere–wave model by perturbing the sea surface temperatures (SSTs) with anomalies generated by the Working Group on Coupled Modeling (WGCM) phase 3 of the Coupled Model Intercomparison Project (CMIP3) coupled models that use the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4)/Special Report on Emissions Scenarios A1B (SRES A1B) scenario late in the twenty-first century. Several consistent changes were observed across all four realizations for the seasonal means: robust increase of U10 and Hs in the Southern Ocean for both the austral summer and winter due to the poleward shift of the jet stream; a dipole pattern of the U10 and Hs with increases in the northeast sector and decreases at the midlatitude during boreal winter in the North Atlantic due to the more frequent occurrence of the positive phases of the North Atlantic Oscillation (NAO); and strong decrease of U10 and Hs in the tropical western Pacific Ocean during austral summer, which might be caused by the joint effect of the weakening of the Walker circulation and the large hurricane frequency decrease in the South Pacific. Changes of the 99th percentile U10 and Hs are twice as strong as changes in the seasonal means, and the maximum changes are mainly dominated by the changes in hurricanes. Robust strong decreases of U10 and Hs in the South Pacific are obtained because of the large hurricane frequency decrease, while the results in the Northern Hemisphere basins differ among the models. An additional sensitivity experiment suggests that the qualitative response of U10 and Hs is not affected by using SST anomalies only and maintaining the radiative forcing unchanged (using 1980 values), as in this study.


2016 ◽  
Vol 113 (11) ◽  
pp. 2964-2969 ◽  
Author(s):  
Andrew D. Barton ◽  
Andrew J. Irwin ◽  
Zoe V. Finkel ◽  
Charles A. Stock

Anthropogenic climate change has shifted the biogeography and phenology of many terrestrial and marine species. Marine phytoplankton communities appear sensitive to climate change, yet understanding of how individual species may respond to anthropogenic climate change remains limited. Here, using historical environmental and phytoplankton observations, we characterize the realized ecological niches for 87 North Atlantic diatom and dinoflagellate taxa and project changes in species biogeography between mean historical (1951–2000) and future (2051–2100) ocean conditions. We find that the central positions of the core range of 74% of taxa shift poleward at a median rate of 12.9 km per decade (km⋅dec−1), and 90% of taxa shift eastward at a median rate of 42.7 km⋅dec−1. The poleward shift is faster than previously reported for marine taxa, and the predominance of longitudinal shifts is driven by dynamic changes in multiple environmental drivers, rather than a strictly poleward, temperature-driven redistribution of ocean habitats. A century of climate change significantly shuffles community composition by a basin-wide median value of 16%, compared with seasonal variations of 46%. The North Atlantic phytoplankton community appears poised for marked shift and shuffle, which may have broad effects on food webs and biogeochemical cycles.


2020 ◽  
Author(s):  
Majed Khadem ◽  
Richard Dawson ◽  
Claire Walsh

&lt;p&gt;Uneven distribution of water resources in the face of climate change and population growth is imposing increasing threats to communities as well as challenging decision-makers. Inter-basin water transfer (IBT) schemes have been appreciated as one of the common approaches to tackle this issue. This work presents a framework for climate impact assessment and feasibility study for IBTs. The framework investigates negative impacts of IBTs on the donor and receiving bodies. This is done by calculating hydrological drought risk and environmental risks to freshwater habitats under 1200 future climatic scenarios and two different transfer scenarios. 2.2 Km resolution time-series from UK&amp;#8217;s Met Office most recent climate projection (UKCP18) is used as the input scenario and a water resources model developed at Newcastle University is implemented to determine allocation and calculate the above risk factors. This work considers transferring raw water from England&amp;#8217;s water-rich North East to its water-stressed South East as the case study. This case was chosen because England, with no major IBT scheme, is experiencing challenges from more frequent climate change and increasing demand for water in London. Additionally, organisations such as National Infrastructure Commission (NIC) and Environment Agency (EA) have encouraged England&amp;#8217;s water companies to consider IBT as one of the options to improve water supply resilience. In this study, we assess schemes to transfer water using the existing infrastructures of water companies located from North East to South East of England to minimise costs and environmental impacts. Results suggest that, under a wide range of future scenarios, meeting London&amp;#8217;s annual water shortage through transfers from the North East during wet season of each year not only increases London&amp;#8217;s water supply resilience but also boosts flood resilience in the North East donor basin while still meeting environmental requirements.&lt;/p&gt;


2018 ◽  
Vol 52 (1-2) ◽  
pp. 417-438 ◽  
Author(s):  
Ralf Hand ◽  
Noel S. Keenlyside ◽  
Nour-Eddine Omrani ◽  
Jürgen Bader ◽  
Richard J. Greatbatch

2011 ◽  
Vol 24 (23) ◽  
pp. 6054-6076 ◽  
Author(s):  
Haiyan Teng ◽  
Grant Branstator ◽  
Gerald A. Meehl

Abstract Predictability of the Atlantic meridional overturning circulation (AMOC) and associated oceanic and atmospheric fields on decadal time scales in the Community Climate System Model, version 3 (CCSM3) at T42 resolution is quantified with a 700-yr control run and two 40-member “perfect model” climate change experiments. After taking into account both the mean and spread about the mean of the forecast distributions and allowing for the possibility of time-evolving modes, the natural variability of the AMOC is found to be predictable for about a decade; beyond that range the forced predictability resulting from greenhouse gas forcing becomes dominant. The upper 500-m temperature in the North Atlantic is even more predictable than the AMOC by several years. This predictability is associated with subsurface and sea surface temperature (SST) anomalies that propagate in an anticlockwise direction along the subpolar gyre and tend to be prominent during the 10 yr following peaks in the amplitude of AMOC anomalies. Predictability in the North Atlantic SST mainly resides in the ensemble mean signals after three to four forecast years. Analysis suggests that in the CCSM3 the subpolar gyre SST anomalies associated with the AMOC variability can influence the atmosphere and produce surface climate predictability that goes beyond the ENSO time scale. However, the resulting initial-value predictability in the atmosphere is very weak.


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