scholarly journals The Role of Tropical, Midlatitude, and Polar Cloud-Radiative Changes for the Midlatitude Circulation Response to Global Warming

2020 ◽  
Vol 33 (18) ◽  
pp. 7927-7943 ◽  
Author(s):  
Nicole Albern ◽  
Aiko Voigt ◽  
David W. J. Thompson ◽  
Joaquim G. Pinto
Keyword(s):  
Global Warming ◽  
Storm Track ◽  
Radiative Heating ◽  
Sea Surface ◽  
Relative Importance ◽  
Upper Troposphere ◽  
The Mean ◽  
The Impact ◽  
Circulation Changes

AbstractPrevious studies showed that global cloud-radiative changes contribute half or more to the midlatitude atmospheric circulation response to global warming. Here, we investigate the relative importance of tropical, midlatitude, and polar cloud-radiative changes for the annual-mean, wintertime, and summertime circulation response across regions in AMIP-like simulations. To this end, we study global warming simulations from the ICON model run with the cloud-locking method and prescribed sea surface temperatures, which isolate the impact of changes in atmospheric cloud-radiative heating. Tropical cloud changes dominate the global cloud impact on the 850 hPa zonal wind, jet strength, and storm track responses across most seasons and regions. For the jet shift, a more diverse picture is found. In the annual mean and DJF, tropical and midlatitude cloud changes contribute substantially to the poleward jet shift in all regions. The poleward jet shift is further supported by polar cloud changes across the Northern Hemisphere but not in the Southern Hemisphere. In JJA, the impact of regional cloud changes on the jet position is small, consistent with an overall small jet shift during this season. The jet shift can be largely understood via the anomalous atmospheric cloud-radiative heating in the tropical and midlatitude upper troposphere. The circulation changes are broadly consistent with the influence of cloud-radiative changes on upper-tropospheric baroclinicity and thus the mean potential energy available for conversion into eddy kinetic energy. Our results help to explain the jet response to global warming and highlight the importance of tropical and midlatitude cloud-radiative changes for this response.

Drivers of biases in the extratropical storm tracks in CMIP6

2020 ◽  
Author(s):  
Matthew Priestley ◽  
Duncan Ackerley ◽  
Jennifer Catto ◽  
Kevin Hodges ◽  
Ruth McDonald ◽  
...  
Keyword(s):  
Large Scale ◽  
Climate Models ◽  
Storm Track ◽  
Storm Tracks ◽  
Extratropical Cyclones ◽  
Ocean Coupling ◽  
Coupled Climate Models ◽  
The Mean ◽  
The Impact

<p>Extratropical cyclones are the leading driver of the day-to-day weather variability and wintertime losses for Europe. In the latest generation of coupled climate models, CMIP6, it is hoped that with improved modelling capabilities come improvements in the structure of the storm track and the associated cyclones. Using an objective cyclone identification and tracking algorithm the mean state of the storm tracks in the CMIP6 models is assessed as well as the representation of explosively deepening cyclones. Any developments and improvements since the previous generation of models in CMIP5 are discussed, with focus on the impact of model resolution on storm track representation. Furthermore, large-scale drivers of any biases are investigated, with particular focus on the role of atmosphere-ocean coupling via associated AMIP simulations and also the influence of large-scale dynamical and thermodynamical features.</p>

scholarly journals Cirrus, Transport, and Mixing in the Tropical Upper Troposphere

2014 ◽  
Vol 71 (4) ◽  
pp. 1339-1352 ◽  
Author(s):  
Tra Dinh ◽  
Stephan Fueglistaler
Keyword(s):  
Radiative Heating ◽  
Transport Time ◽  
Adequate Model ◽  
Upper Troposphere ◽  
Advection Diffusion Equation ◽  
Free Region ◽  
The Mean ◽  
The Individual ◽  
The Impact ◽  
Tropical Upper Troposphere

Abstract The impact of cloud radiative heating on transport time scales from the tropical upper troposphere to the stratosphere is studied in two-dimensional numerical simulations. Clouds are idealized as sources of radiative heating and are stochastically distributed in space and time. A spatial probability function constrains clouds to occur in only part of the domain to depict heterogeneously distributed clouds in the atmosphere. The transport time from the lower to upper boundaries (age of air) is evaluated with trajectories. The spectra of age of air obtained in the simulations are bimodal, with the first mode composed of trajectories that remain in the cloudy part of the domain during their passages from the lower to upper boundaries, and the second mode composed of the remaining trajectories that visit the cloud-free regions. For the first group of trajectories only, the mean age scales inversely with the time-mean radiative heating in cloudy air, and the one-dimensional advection–diffusion equation provides an adequate model for transport. However, the exchange between the cloudy and cloud-free regions renders the mean age over all trajectories (including those that visit the cloud-free region) much longer than the time expected if all air parcels remain in cloudy air. In addition, the overall mean age is not inversely proportional to the time-mean heating rate in cloudy air. Sensitivity calculations further show that the sizes, durations, and amplitudes of the individual clouds are also important to the transport time. The results show that the frequently used decomposition of radiative heating into clear-sky and cloud radiative heating may give incorrect interpretations regarding the time scale of transport into the stratosphere.

A nonlinear multi-scale theory of atmospheric blocking: Structure and evolution of blocking linked to meridional and vertical structures of storm tracks

2021 ◽  
Author(s):  
Dehai Luo ◽  
Wenqi Zhang
Keyword(s):  
Storm Track ◽  
Interaction Model ◽  
Maximum Amplitude ◽  
Transient Eddy ◽  
Baroclinic Mode ◽  
Upper Troposphere ◽  
Multi Scale ◽  
The North ◽  
Baroclinic Modes ◽  
The Impact

AbstractThis paper examines the impact of the meridional and vertical structures of a preexisting upstream storm track (PUST) organized by preexisting synoptic-scale eddies on eddy-driven blocking in a nonlinear multi-scale interaction model. In this model, the blocking is assumed, based on observations, to be comprised of barotropic and first baroclinic modes, whereas the PUST consists of barotropic, first baroclinic and second baroclinic modes. It is found that the nonlinearity (dispersion) of blocking is intensified (weakened) with increasing amplitude of the first baroclinic mode of the blocking itself. The blocking tends to be long-lived in this case. The lifetime and strength of blocking are significantly influenced by the amplitude of the first baroclinic mode of blocking for given basic westerly winds (BWWs), whereas its spatial pattern and evolution are also affected by the meridional and vertical structures of the PUST.It is shown that the blocking mainly results from the transient eddy forcing induced by the barotropic and first baroclinic modes of PUST, whereas its second baroclinic mode contributes little to the transient eddy forcing. When the PUST shifts northward, eddy-driven blocking shows an asymmetric dipole structure with a strong anticyclone/weak cyclone in a uniform BWW, which induces northward-intensified westerly jet and storm track anomalies mainly on the north side of blocking. However, when the PUST has no meridional shift and is mainly located in the upper troposphere, a north-south anti-symmetric dipole blocking and an intensified split jet with maximum amplitude in the upper troposphere form easily for vertically varying BWWs without meridional shear.

scholarly journals PRE- and POST-STORM LiDAR SURVEYS FOR ASSESSMENT OF IMPACT ON COASTAL EROSION

2019 ◽  
Vol XLII-3/W8 ◽  
pp. 261-266
Author(s):  
A.-L. Montreuil ◽  
M. Chen ◽  
A. Esquerré ◽  
R. Houthuys ◽  
R. Moelans ◽  
...  
Keyword(s):  
Management Practices ◽  
Morphological Changes ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Airborne Lidar ◽  
Coastline Change ◽  
The Mean ◽  
The Impact

<p><strong>Abstract.</strong> Sustainable management of the coastal resources requires a better understanding of the processes that drive coastline change. The coastline is a highly dynamic sea-terrestrial interface. It is affected by forcing factors such as water levels, waves, winds, and the highest and most severe changes occur during storm surges. Extreme storms are drivers responsible for rapid and sometimes dramatic changes of the coastline. The consequences of the impacts from these events entail a broad range of social, economic and natural resource considerations from threats to humans, infrastructure and habitats. This study investigates the impact of a severe storm on coastline response on a sandy multi-barred beach at the Belgian coast. Airborne LiDAR surveys acquired pre- and post-storm covering an area larger than 1 km<sup>2</sup> were analyzed and reproducible monitoring solutions adapted to assess beach morphological changes were applied. Results indicated that the coast retreated by a maximum of 14.7 m where the embryo dunes in front of the fixed dunes were vanished and the foredune undercut. Storm surge and wave attacks were probably the most energetic there. However, the response of the coastline proxies associated with the mean high water line (MHW) and dunetoe (DuneT) was spatially variable. Based on the extracted beach features, good correlations (r>0.73) were found between coastline, berm and inner intertidal bar morphology, while it was weak with the most seaward bars covered in the surveys. This highlights the role of the upper features on the beach to protect the coastline from storm erosion by reducing wave energy. The findings are of critical importance in improving our knowledge and forecasting of coastline response to storms, and also in its translation into management practices.</p>

scholarly journals THE LUCK IN “TALENT VERSUS LUCK” MODELING

2020 ◽  
Vol 23 (03) ◽  
pp. 2050007
Author(s):  
SEAN ELVIDGE
Keyword(s):  
Mean Value ◽  
Maximum Amount ◽  
Random Numbers ◽  
Individual Parameter ◽  
Input Parameters ◽  
The Mean ◽  
Model Variability ◽  
The Impact ◽  
The Relationship

This paper further investigates the Talent versus Luck (TvL) model described by [Pluchino et al. Talent versus luck: The role of randomness in success and failure, Adv. Complex Syst. 21 (2018) 1850014] which models the relationship between ‘talent’ and ‘luck’ on the impact of an individuals career. It is shown that the model is very sensitive to both random sampling and the choice of value for the input parameters. Running the model repeatedly with the same set of input parameters gives a range of output values of over 50% of the mean value. The sensitivity of the inputs of the model is analyzed using a variance-based approach based upon generating Sobol sequences of quasi-random numbers. When using the model to look at the talent associated with an individual who has the maximum capital over a model run it has been shown that the choice for the standard deviation of the talent distribution contributes to 67% of the model variability. When investigating the maximum amount of capital returned by the model the probability of a lucky event at any given epoch has the largest impact on the model, almost three times more than any other individual parameter. Consequently, during the analysis of the model results one must keep in mind the impact that only small changes in the input parameters can have on the model output.

scholarly journals THE IMPACT OF GLOBAL WARMING ON THE PUBLIC HEALTH INCREASING THE BACTERIAL CAUSING INFECTIOUS DISEASES PERFORMED BY EXPERIMENT: VECTOR-BORNE DISEASES INSECTS, TAIF, KSA

2017 ◽  
Vol 5 (5) ◽  
pp. 42-53
Author(s):  
Sherifa Mostafa M. Sabra ◽  
Samar Ahamed
Keyword(s):  
Public Health ◽  
Global Warming ◽  
Infectious Diseases ◽  
Vector Borne Diseases ◽  
The Public ◽  
Colony Forming Unit ◽  
Tapinoma Sessile ◽  
Vector Borne ◽  
The Mean ◽  
The Impact

The search conducted on "The impact of global warming (GW) on the public health (PH) increasing the bacterial causing infectious diseases (IDs) performed by experiment: Vector-borne diseases (VBDs) insects, Taif, KSA", the experiment used ants (Taif Tapinoma sessile), prepared, arranged appropriate nests and adjusted the temperature at (20, 25, 30, 35, 40 and 45°C), for a week of each zone. It revealed the behaviour as (normal, semi-normal and ab-normal), the mean of mortality rates were between (0-53.3%). The bacterial contents measured by the turbidity indicated the presence of multiplication, were between (0.109-0.328). The bacterial growth degrees by sings were between (+ - +++++) and percent between (12-100%). Colony Forming Unit/ml (CFU/ml) confined between (1.8X102-15.0X102)/mL. Through this experiment it turned out the GW had a significant role on the PH, helped the proliferation of bacterial pathogens that caused IDS. The conclusion wiped from the experiment that the extent degrees of GW disadvantages on the PH. The PH workers must take the "Preventive Health Prophylaxis Measures" (PHPMs) to protect the individuals from IDs by eliminating the VBDs of various types, monitoring the immunological situation of individuals, provided the vaccinations of IDs and preparing for complete PHPMs against any changes in the PH.

scholarly journals Global to USA County Scale Analysis of Weather, Urban Density, Mobility, Homestay, and Mask Use on COVID-19

2020 ◽  
Vol 17 (21) ◽  
pp. 7847
Author(s):  
Sajad Jamshidi ◽  
Maryam Baniasad ◽  
Dev Niyogi
Keyword(s):  
Transmission Rate ◽  
Climate Impact ◽  
Relative Importance ◽  
Urban Density ◽  
Spatial And Temporal Scales ◽  
Urban Dynamics ◽  
Causal Processes ◽  
The Impact ◽  
The Relationship

Prior evaluations of the relationship between COVID-19 and weather indicate an inconsistent role of meteorology (weather) in the transmission rate. While some effects due to weather may exist, we found possible misconceptions and biases in the analysis that only consider the impact of meteorological variables alone without considering the urban metabolism and environment. This study highlights that COVID-19 assessments can notably benefit by incorporating factors that account for urban dynamics and environmental exposure. We evaluated the role of weather (considering equivalent temperature that combines the effect of humidity and air temperature) with particular consideration of urban density, mobility, homestay, demographic information, and mask use within communities. Our findings highlighted the importance of considering spatial and temporal scales for interpreting the weather/climate impact on the COVID-19 spread and spatiotemporal lags between the causal processes and effects. On global to regional scales, we found contradictory relationships between weather and the transmission rate, confounded by decentralized policies, weather variability, and the onset of screening for COVID-19, highlighting an unlikely impact of weather alone. At a finer spatial scale, the mobility index (with the relative importance of 34.32%) was found to be the highest contributing factor to the COVID-19 pandemic growth, followed by homestay (26.14%), population (23.86%), and urban density (13.03%). The weather by itself was identified as a noninfluential factor (relative importance < 3%). The findings highlight that the relation between COVID-19 and meteorology needs to consider scale, urban density and mobility areas to improve predictions.

Cardiovascular Risk After Sepsis: Understanding the Role of Statin Indications and the Impact of Clinical Inertia on Prescribing Patterns

2020 ◽  
Vol 25 (6) ◽  
pp. 541-547
Author(s):  
Vedant A. Gupta ◽  
Talal S. Alnabelsi ◽  
Sandipan Shringi ◽  
Steve W. Leung ◽  
Vincent L. Sorrell
Keyword(s):  
Cohort Analysis ◽  
Prescribing Patterns ◽  
Clinical Inertia ◽  
Major Adverse Cardiovascular Events ◽  
Prescribing Practices ◽  
Retrospective Cohort Analysis ◽  
The Mean ◽  
The Impact ◽  
Statin Use

Introduction: Patients with sepsis have high rates of major adverse cardiovascular events (MACE) in the literature, but the stratification of those at risk has been limited. Statin indicated groups provides clear criteria for therapy, but the risk of MACE after sepsis based on these groups has never been assessed. Materials and Methods: This was a retrospective cohort analysis conducted on adult patients admitted from January 1, 2013, to December 31, 2013, with suspected or confirmed sepsis and data available on statin use. Patients’ past medical history; statin use prior, during, or at time of discharge; and occurrence of MACE were recorded from electronic health records. Result: A total of 321 patients were screened and 265 were found to have data available on statin use. The mean age of the patients was 59 ± 15 years and 47% were female. Overall, 9% were observed to have a MACE at 1 year, with significantly higher rates in those in a statin indicated group (12.2%). On admission, 174 patients were not taking a statin out of whom 52% were in a statin indicated group. Among those in a statin indicated group who survived to hospital discharge, only 10% not on a statin on admission received a statin on discharge, whereas 89% on a statin on admission received a statin on discharge. Conclusion: There is a high risk of MACE after sepsis especially among those in statin indicated groups with significant clinical inertia in prescribing practices.

HOW IMPORTANT IS THE SIZE OF A REPRINT ORDER?

2003 ◽  
Vol 19 (4) ◽  
pp. 711-714 ◽  
Author(s):  
Sally Hopewell ◽  
Mike Clarke
Keyword(s):  
Randomized Trials ◽  
Citation Index ◽  
Control Group ◽  
Relative Importance ◽  
The Mean ◽  
Control Set ◽  
Number Of Citations ◽  
The Impact ◽  
Very High ◽  
Subsequent Literature

Objectives: This study aims to assess the impact of articles with very high reprint orders (“high-reprint articles”) by measuring their citation in the subsequent literature as compared with a control group of articles.Methods: The twenty-one articles (published in the Lancet in 1998) with reprint orders of over 10,000 were matched with a control set of twenty-one articles with smaller reprint orders. The Science Citation Index was used to obtain the number of citations for each of the forty-two articles.Results: The twenty-one high-reprint articles were cited 2,548 times; the mean number of citations was 121 (range, 3 to 499 citations per article). Five of the twenty-one high-reprint articles had more than 200 citations, but seven (33%) were cited twenty-five times or fewer. The twenty-one control articles were cited 986 times; the mean number of citations was forty-seven (range, 1 to 165). Fifteen (71%) of the twenty-one control articles were cited twenty-five times or fewer. Thirteen of the high-reprint articles were reports of randomized trials with a mean of 163 citations. In the control articles, six were reports of randomized trials with a mean of eighty-eight citations.Conclusions: Articles with a high-reprint order were cited more frequently than other articles. However, some high-reprint articles were cited infrequently. If the size of a reprint order is related to the importance of an article, those articles with very high reprint orders may, therefore, be perceived as more important. Further research is needed to explore other aspects of the relative importance and impact of high-reprint articles.

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