scholarly journals Wave-resonance fingerprint in the 2010 summer: a modelling experiment

2020 ◽  
Author(s):  
Giorgia Di Capua ◽  
Kai Kornhuber ◽  
Eftychia Rousi ◽  
Sarah Sparrow ◽  
David Wallom ◽  
...  
Keyword(s):  
High Latitude ◽  
Circulation Pattern ◽  
Temperature Profiles ◽  
Emission Scenarios ◽  
Wave Resonance ◽  
Surface Weather ◽  
Meridional Winds ◽  
Future Emission ◽  
Modelling Experiment ◽  
Upper Level

<p>Summer 2010 was characterized by two contemporaneous extreme events: the Russian heat wave and the Pakistan flood. Several studies have shown a link between the two events, and Quasi-Resonant Amplification (QRA) has been suggested as an atmosphere-dynamic mechanism leading to the anomalous wavy circulation pattern which connected both extremes. Here, we aim at reproducing the 2010 circulation conditions in the Northern Hemisphere by obtaining a large ensemble of simulations from the Weather@home project within climateprediction.net (CPDN). We identify those ensemble members exhibiting a specific latitudinal temperature profile characterised by amplified high-latitude land warming (QRA - fingerprint) and investigate their surface temperature and upper level circulation properties. We show that when the QRA - fingerprint is present, the mid-latitude circulation bears similar characteristics to those observed in the 2010 summer: hot temperatures over European Russia and a wavy pattern in the upper-tropospheric meridional winds. As temperature profiles are projected to become increasingly similar to the QRA-fingerprint under future emission scenarios, these results provide further evidence that high latitude warming might favour persistent surface weather in the mid-latitudes.</p>

scholarly journals Regional climate change scenarios for Greece: future temperature and precipitation projections form ensembles of RCMs

2013 ◽  
Vol 14 (4) ◽  
pp. 407-421 ◽  
Keyword(s):  
Regional Climate ◽  
Regional Climate Change ◽  
Summer Temperature ◽  
Climate Change Scenarios ◽  
Emission Scenarios ◽  
Temperature And Precipitation ◽  
The Future ◽  
Future Emission ◽  
Spatial Grid ◽  
Of Greece

The potential regional future changes in seasonal (winter and summer) temperature and precipitation are assessed for the greater area of Greece over the 21st century, under A2, A1B and B2 future emission scenarios of IPCC. Totally twenty-two simulations from various regional climate models (RCMs) were assessed; fourteen of them with a spatial grid resolution of 50km for the period 2071-2100 under A2 (9 simulations) and B2 (5 simulations) scenarios and eight of them with an even finer resolution of 25km under A1B scenario for both 2021-2050 and 2071-2100 time periods. The future changes in temperature and precipitation were calculated with respect to the control period (1961-1990). All the models estimated warmer and dryer conditions over the study area. The warming is more intense during the summer months, with the changes being larger in the continental than in the marine area of Greece. In terms of precipitation, the simulations of the RCMs estimate a decrease up to -60% (A2 scenario). Finally it is shown that the changes in the atmospheric circulation over Europe play a key role in the changes of the future precipitation and temperature characteristics over the domain of study in a consistent way for the different emission scenarios.

Present and Future Land Suitability Analysis for Almond and Pistachio Crops in the Beira Baixa Region Using Spatial Multicriteria Decision Systems

2022 ◽  
pp. 249-265
Author(s):  
Luís Quinta-Nova ◽  
Dora Ferreira
Keyword(s):  
Decision Making ◽  
Pairwise Comparison ◽  
Fruit Tree ◽  
Emission Scenarios ◽  
Suitability Analysis ◽  
Almond Tree ◽  
Decision Systems ◽  
Hierarchical Levels ◽  
The Face ◽  
Future Emission

The objective of this study is to determine the suitability for the cultivation of emerging fruit crops in the Beira Baixa region. The suitability was examined for the present time and in the face of two future emission scenarios (RCP 4.5 and 8.5). For this purpose, the biophysical criteria determining the cultivation of pistachio tree and almond tree were processed using a G. The analysis was performed by the AHP. After dividing the problem into hierarchical levels of decision making, a pairwise comparison of criteria was performed to evaluate the weights of these criteria, based on a scale of importance. In the present conditions, about 16.4% of the study area is classified as highly suitable for almond tree and 15.9% to pistachio tree. For the future scenarios, the area with high suitability will increase both for almond tree and pistachio tree. The AHP was adequate in the evaluation of the emerging fruit tree species suitability, since it allowed the integration of the several criteria studied, being a useful tool, which allows the decision making and the resolution of problems.

scholarly journals Current and future levels of mercury atmospheric pollution on global scale

2016 ◽  
Author(s):  
Jozef M. Pacyna ◽  
Oleg Travnikov ◽  
Francesco De Simone ◽  
Ian M. Hedgecock ◽  
Kyrre Sundseth ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Global Scale ◽  
Anthropogenic Sources ◽  
Anthropogenic Emissions ◽  
Emission Scenarios ◽  
Case Scenario ◽  
Mercury Emissions ◽  
Future Emission ◽  
The Eu ◽  
Air Concentrations

Abstract. An assessment of current and future emissions, air concentrations and atmospheric deposition of mercury world-wide are presented on the basis of results obtained during the performance of the EU GMOS (Global Mercury Observation System) project. Emission estimates for mercury were prepared with the main goal of applying them in models to assess current (2013) and future (2035) air concentrations and atmospheric deposition of this contaminant. The artisanal and small- scale gold mining, as well as combustion of fossil fuels (mainly coal) for energy and heat production in power plants and in industrial and residential boilers are the major anthropogenic sources of Hg emissions to the atmosphere at present. These sources account for about 37 % and 25 % of the total anthropogenic Hg emissions globally, estimated to be about 2000 tonnes. The emissions in Asian countries, particularly in China and India dominate the total emissions of Hg. The current estimate of mercury emissions from natural processes (primary mercury emissions and re-emissions), including mercury depletion events, were estimated to be 5207 tonnes per year which represent nearly 70 % of the global mercury emission budget. Oceans are the most important sources (36 %) followed by biomass burning (9 %). A comparison of the 2035 anthropogenic emissions estimated for 3 different scenarios with current anthriopogenic emissions indicates a reduction of these emissions in 2035 up to 85 % for the best case scenario. Two global chemical transport models (GLEMOS and ECHMERIT) have been used for the evaluation of future Hg pollution levels considering future emission scenarios. Projections of future changes in Hg deposition on a global scale simulated by these models for three anthropogenic emissions scenarios of 2035 indicate a decrease of up to 50 % deposition in the Northern Hemisphere and up to 35 % in Southern Hemisphere for the best case scenario. The EU GMOS project has proved to be a very important research instrument for supporting, first the scientific justification for the Minamata Convention, and then monitoring of the implementation of targets of this Convention, as well as, the EU Mercury Strategy. This project provided the state-of-the art with regard to the development of the latest emission inventories for mercury, future emission scenarios, dispersion modelling of atmospheric Hg on global and regional scale, and source – receptor techniques for Hg emission apportionment on a global scale.

Potential ozone production following convective transport based on future emission scenarios

1996 ◽  
Vol 30 (4) ◽  
pp. 667-672 ◽  
Author(s):  
W.G. Ellis ◽  
A.M. Thompson ◽  
S. Kondragunta ◽  
K.E. Pickering ◽  
G. Stenchikov ◽  
...  
Keyword(s):  
Convective Transport ◽  
Ozone Production ◽  
Emission Scenarios ◽  
Future Emission

scholarly journals Processes for Occurrence of Strong Cold Events over Eastern China

2017 ◽  
Vol 30 (22) ◽  
pp. 9247-9266 ◽  
Author(s):  
Lei Song ◽  
Renguang Wu
Keyword(s):  
North Atlantic ◽  
High Latitude ◽  
Wave Train ◽  
East Asian ◽  
Eastern China ◽  
Cold Air ◽  
East Asian Trough ◽  
Siberian High ◽  
Cold Events ◽  
Upper Level

A strong cold event hit eastern China around 24 January 2016 with surface air temperature reaching more than 10°C below the climatological mean in most regions of eastern China south of 40°N. A total of 37 strong cold events similar to the January 2016 event with temperature anomalies over eastern China exceeding −5°C have been identified during the winters from 1979/80 to 2015/16. A comparative analysis of events with surface temperature anomalies of the same intensity but limited to north of 40°N indicates that the southward invasion of cold air to eastern China south of 40°N is related to two factors. One is the latitudinal location of the upper-level wave train, the surface Siberian high, and the midtropospheric East Asian trough over the mid- to high-latitude Eurasian continent. The other is a subtropical upper-level wave train emanating from the midlatitude North Atlantic. The emergence of the subtropical wave train is related to the positive phase of the North Atlantic Oscillation (NAO). When the mid- to high-latitude wave train is located too far northward and the subtropical wave train induces an anomalous midtropospheric high over southern China, the East Asian trough does not extend southwestward and the Siberian high does not expand southeastward. In such a case, the cold air mainly affects northeastern China and northern Japan.

Extratropical–Tropical Interaction during Onset of the Australian Monsoon: Reanalysis Diagnostics and Idealized Dry Simulations

2007 ◽  
Vol 64 (10) ◽  
pp. 3475-3498 ◽  
Author(s):  
Noel E. Davidson ◽  
Kevin J. Tory ◽  
Michael J. Reeder ◽  
Wasyl L. Drosdowsky
Keyword(s):  
Wave Propagation ◽  
High Latitude ◽  
Monsoon Trough ◽  
Background Flow ◽  
Australian Monsoon ◽  
Subtropical Jet ◽  
Westerly Winds ◽  
Rossby Wave Propagation ◽  
Upper Level ◽  
The Tropics

Abstract The onset of the Australian monsoon is examined using (i) reanalysis data for seasons when enhanced observational networks were available and (ii) a 15-yr onset composite. Similar to previous findings, onset is characterized by a sudden strengthening and deepening in tropical westerly winds, which are overlain with upper-tropospheric easterlies. All onsets are preceded by up to a 7-day preconditioning period of enhanced vertical motion and moistening. During the transition season, the 6 weeks prior to onset, a number of moist westerly events occur. Generally they are only sustained for short periods and overlain by upper-level westerly winds, suggesting an association with midlatitude troughs, which protrude into the deep Tropics. For individual years and for a 15-yr composite, monsoon onset is associated with major cyclogenesis events over the southwest Indian Ocean in the presence of a subtropical jet over the eastern Indian Ocean. The proposed mechanism for extratropical–tropical interaction is northeastward Rossby wave propagation from the cyclogenesis region toward the Tropics at upper levels. At these levels, westerly winds extend to nearly 10°S and provide a favorable background flow for such propagation. The process eventually results in the amplification of an equatorward-extending midlatitude upper trough and tropical ridge, which appears to trigger the development of the underlying monsoon trough. To test the hypothesis, the influence of high-latitude cyclogenesis on the tropical circulation is investigated with the aid of an idealized, dry, three-dimensional, baroclinic wave channel model. The initial state consists of (i) a zonally constant baroclinic region centered on 40°S, from which the high-latitude cyclogenesis develops, (ii) a weak monsoon trough at 15°S, and (iii) a subtropical jet at 25°S. The major findings from the simulations are as follows: 1) There is evidence of northeastward Rossby wave propagation from the cyclogenesis region toward low latitudes. 2) Consistent with theoretical studies, the subtropical jet plays a key role by providing a favorable westerly background flow for group propagation into the Tropics. 3) High-latitude cyclogenesis in the presence of a subtropical jet can influence the meridional location, zonal structure, vorticity, and divergence in the monsoon trough. 4) Vorticity and divergence changes are consistent with enhancement of the monsoon trough (increases in low-level cyclonic vorticity) and the potential for triggering a large-scale convective outbreak (changes in upper-level divergence).

scholarly journals Current and future levels of mercury atmospheric pollution on a global scale

2016 ◽  
Vol 16 (19) ◽  
pp. 12495-12511 ◽  
Author(s):  
Jozef M. Pacyna ◽  
Oleg Travnikov ◽  
Francesco De Simone ◽  
Ian M. Hedgecock ◽  
Kyrre Sundseth ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Global Scale ◽  
Anthropogenic Emissions ◽  
Emission Scenarios ◽  
Case Scenario ◽  
Mercury Emission ◽  
Mercury Emissions ◽  
Future Emission ◽  
The Eu ◽  
Air Concentrations

Abstract. An assessment of current and future emissions, air concentrations, and atmospheric deposition of mercury worldwide is presented on the basis of results obtained during the performance of the EU GMOS (Global Mercury Observation System) project. Emission estimates for mercury were prepared with the main goal of applying them in models to assess current (2013) and future (2035) air concentrations and atmospheric deposition of this contaminant. The combustion of fossil fuels (mainly coal) for energy and heat production in power plants and in industrial and residential boilers, as well as artisanal and small-scale gold mining, is one of the major anthropogenic sources of Hg emissions to the atmosphere at present. These sources account for about 37 and 25 % of the total anthropogenic Hg emissions globally, estimated to be about 2000 t. Emissions in Asian countries, particularly in China and India, dominate the total emissions of Hg. The current estimates of mercury emissions from natural processes (primary mercury emissions and re-emissions), including mercury depletion events, were estimated to be 5207 t year−1, which represents nearly 70 % of the global mercury emission budget. Oceans are the most important sources (36 %), followed by biomass burning (9 %). A comparison of the 2035 anthropogenic emissions estimated for three different scenarios with current anthropogenic emissions indicates a reduction of these emissions in 2035 up to 85 % for the best-case scenario. Two global chemical transport models (GLEMOS and ECHMERIT) have been used for the evaluation of future mercury pollution levels considering future emission scenarios. Projections of future changes in mercury deposition on a global scale simulated by these models for three anthropogenic emissions scenarios of 2035 indicate a decrease in up to 50 % deposition in the Northern Hemisphere and up to 35 % in Southern Hemisphere for the best-case scenario. The EU GMOS project has proved to be a very important research instrument for supporting the scientific justification for the Minamata Convention and monitoring of the implementation of targets of this convention, as well as the EU Mercury Strategy. This project provided the state of the art with regard to the development of the latest emission inventories for mercury, future emission scenarios, dispersion modelling of atmospheric mercury on a global and regional scale, and source–receptor techniques for mercury emission apportionment on a global scale.

scholarly journals Multidecadal Climate Variability and the “Warming Hole” in North America: Results from CMIP5 Twentieth- and Twenty-First-Century Climate Simulations*

2013 ◽  
Vol 26 (11) ◽  
pp. 3511-3527 ◽  
Author(s):  
Sanjiv Kumar ◽  
James Kinter ◽  
Paul A. Dirmeyer ◽  
Zaitao Pan ◽  
Jennifer Adams
Keyword(s):  
North Atlantic ◽  
Climate Models ◽  
First Century ◽  
Emission Scenarios ◽  
The North ◽  
Cmip5 Climate Models ◽  
Climate Simulations ◽  
Future Emission ◽  
The North Atlantic ◽  
Twenty First Century

Abstract The ability of phase 5 of the Coupled Model Intercomparison Project (CMIP5) climate models to simulate the twentieth-century “warming hole” over North America is explored, along with the warming hole’s relationship with natural climate variability. Twenty-first-century warming hole projections are also examined for two future emission scenarios, the 8.5 and 4.5 W m−2 representative concentration pathways (RCP8.5 and RCP4.5). Simulations from 22 CMIP5 climate models were analyzed, including all their ensemble members, for a total of 192 climate realizations. A nonparametric trend detection method was employed, and an alternative perspective emphasizing trend variability. Observations show multidecadal variability in the sign and magnitude of the trend, where the twentieth-century temperature trend over the eastern United States appears to be associated with low-frequency (multidecadal) variability in the North Atlantic temperatures. Most CMIP5 climate models simulate significantly lower “relative power” in the North Atlantic multidecadal oscillations than observed. Models that have relatively higher skill in simulating the North Atlantic multidecadal oscillation also are more likely to reproduce the warming hole. It was also found that the trend variability envelope simulated by multiple CMIP5 climate models brackets the observed warming hole. Based on the multimodel analysis, it is found that in the twenty-first-century climate simulations the presence or absence of the warming hole depends on future emission scenarios; the RCP8.5 scenario indicates a disappearance of the warming hole, whereas the RCP4.5 scenario shows some chance (10%–20%) of the warming hole’s reappearance in the latter half of the twenty-first century, consistent with CO2 stabilization.

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