scholarly journals The slowdown tends to be greater for stronger tropical cyclones

2021 ◽  
pp. 1-43
Author(s):  
Yuan Sun ◽  
Zhong Zhong ◽  
Tim Li ◽  
Lan Yi ◽  
Yixuan Shen
Keyword(s):  
Tropical Cyclones ◽  
Tropical Circulation ◽  
Translation Speed ◽  
Steering Flow ◽  
Global Trend ◽  
Latitudinal Shift ◽  
Upper Level ◽  
The Impact ◽  
The Relationship ◽  
As Effects

AbstractUnderstanding the impact of climate change on tropical cyclones (TCs) has become a hot topic. The slowdown of TC translation speed contributes greatly to the locally accumulated TC damage. While the recent observational evidence shows that TC translation speed has decreased globally by 10% since the mid-twentieth century, the robustness of the trend is questioned by other studies as effects of changes in observational capability can strongly affect the global trend. Moreover, none of the published studies considered dependence of TC slowdown on TC intensity. This is the caveat of these analyses as the effect of TC slowdown is closely related to TC intensity. Here, we investigate the relationship between TC translation speed trend and TC intensity, and reveal possible reasons for the trend. We show that the global slowing trend without weak TC moments (≤ 17 m s-1) is about double of that with weak TC moments in a recent study. This is because the slowing trend is dominated by strong TCs’ trend. Stronger (weaker) TCs tend to be controlled more by upper-level (lower-level) steering flow, and the calculated trend of upper-level steering flow is much larger than that of lower-level steering flow. This may be an important reason for the large difference between the slowing trend without weak TC moments and that with weak TC moments. Furthermore, the changes of TC tracks (including inter-basin trend and latitudinal shift), which are partly attributed to data inhomogeneity, make a much larger contribution to the slowing trend, compared with the weakening of tropical circulation, which is related to anthropogenic warming.

A Study of Proactive Personality, LMX Quality and Employee Creativity in Delhi and NCR Organisations

2017 ◽  
Vol 9 (2) ◽  
pp. 77
Author(s):  
Nishita Gupta ◽  
N. K. Chadha
Keyword(s):  
Conceptual Model ◽  
Proactive Personality ◽  
Employee Creativity ◽  
Upper Level ◽  
The Impact ◽  
The Relationship

This study investigated the impact of LMX quality and proactive personality on employee creativity as assessed by their supervisors. On the basis of theoretical linkages among the constructs, a conceptual model and hypotheses were established. The sample was drawn from nine Indian firms in Delhi and NCR. The results suggested that proactive personality and LMX quality contributed to employee creativity. Compared with LMX Quality, however, proactive personality had higher impact on employee creativity. Three of six hypotheses were supported. The relationship between proactive personality, LMX quality and Employee creativity at lower and upper level of management turned out to be non-significant.

scholarly journals On the Impact of Tropical Cyclones on Rossby Wave Packets: A Climatological Perspective

2016 ◽  
Vol 144 (5) ◽  
pp. 2021-2048 ◽  
Author(s):  
Julian F. Quinting ◽  
Sarah C. Jones
Keyword(s):  
Tropical Cyclones ◽  
Rossby Wave ◽  
North Atlantic ◽  
South Indian Ocean ◽  
Wave Amplification ◽  
Divergent Flow ◽  
South Indian ◽  
Flow Interactions ◽  
Upper Level ◽  
The Impact

Many studies have highlighted the importance of recurving tropical cyclones (TCs) in triggering Rossby waves. This study investigates the impact of western North Pacific (WNP), south Indian Ocean, and North Atlantic recurving TCs on the amplitude and frequency of synoptic-scale Rossby wave packets (RWPs) over a 30-yr period. The results indicate a significant increase of RWP frequency downstream of WNP and south Indian Ocean TCs. A statistically significant RWP amplitude anomaly downstream of these TCs suggests that RWPs, which are associated with TCs, are stronger than those that generally occur in midlatitudes. North Atlantic TCs do not seem to be associated with a statistically significant increase in RWP frequency and amplitude downstream. Processes that contribute to Rossby wave amplification are identified by creating composites for WNP TCs with and without downstream development. Potential vorticity, eddy kinetic energy, and quasigeostrophic forcing diagnostics highlight dynamical mechanisms that contribute to the synergistic interaction between the TC and the midlatitude flow. The existence of an upstream Rossby wave favors a downstream development. Diabatically enhanced upper-level divergent flow that can be attributed to the nonlinear interaction between the TC and the midlatitude flow impedes the eastward propagation of the upstream trough, amplifies the downstream ridge, and intensifies the jet. The amplified midlatitude flow provides upper-level forcing, which helps to maintain the predominantly diabatically driven divergent flow. Forecast uncertainties that are related to these complex TC–midlatitude flow interactions may spread into downstream regions. A climatological analysis of ensemble reforecast data emphasizes the importance of TC–midlatitude flow interactions and Rossby wave amplification on downstream predictability.

scholarly journals Satellite-based monitoring and prediction of tropical cyclone intensity and movement

MAUSAM ◽  
2021 ◽  
Vol 48 (2) ◽  
pp. 157-168
Author(s):  
R. R. KELKAR
Keyword(s):  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Tropical Cyclone Intensity ◽  
Intensity Estimation ◽  
Cyclone Intensity ◽  
Estimation Scheme ◽  
Water Vapour Absorption ◽  
Upper Level ◽  
Absorption Channel ◽  
The Impact

    ABSTRACT. Capabilities of meteorological satellites have gone a long way in meeting requirements of synoptic analysis and forecasting of tropical cyclones. This paper shows the impact made by the satellite data in the intensity estimation and track prediction of tropical cyclones in the Indian Seas and also reviews the universally applied Dvorak algorithm for performing tropical cyclone intensity analysis. Extensive use of Dvorak's intensity estimation scheme has revealed many of its limitations and elements of subjectivity in the analysis of tropical cyclones over the Arabian Sea and the Bay of Bengal, which, like cyclones in other ocean basins, also exhibit wide structural variability as seen in the satellite imagery. Satellite-based cyclone tracking techniques include: (i) use of satellite-derived mean wind flow,             (ii) animation of sequence of satellite images and extrapolation of the apparent motion of the cloud system and (iii) monitoring changes in the upper level moisture patterns in the water vapour absorption channel imagery. Satellite-based techniques on tropical cyclone intensity estimation and track prediction have led to very significant improvement in disaster warning and consequent saving of life and property.    

Toward Environmental Democracy? Procedural Environmental Rights and Environmental Justice

2018 ◽  
Vol 18 (1) ◽  
pp. 99-121 ◽  
Author(s):  
Joshua C. Gellers ◽  
Chris Jeffords
Keyword(s):  
Environmental Justice ◽  
Positive Development ◽  
Access To Information ◽  
Environmental Rights ◽  
Legal Provisions ◽  
Global Trend ◽  
Fertile Ground ◽  
The Impact ◽  
The Relationship ◽  
Environmental Democracy

The global trend toward adopting environmental rights within national constitutions has been largely regarded as a positive development for both human rights and the natural environment. The impact of constitutional environmental rights, however, has yet to be systematically assessed using empirical data. In particular, expanding procedural environmental rights—legal provisions relating to access to information, participation, and justice in environmental matters—provides fertile ground for analyzing how environmental rights directly interface with conditions necessary for a functioning democracy. To understand the extent to which these provisions deliver on their lofty aspirations, we conducted a quantitative analysis to assess the relationship between procedural environmental rights and environmental justice, while also controlling for the extent of democracy within a country. The results suggest that states with procedural environmental rights are more likely than nonadopting states to facilitate attaining environmental justice, especially as it relates to access to information.

The role of using fair value on relevance and representation faithfulness of accounting information in accordance with the Common Conceptual Framework (FASB-IASB)

2019 ◽  
Vol 118 (12) ◽  
pp. 142-165
Author(s):  
Dr. Nada Kaki Bira ◽  
Layla Naji Majeed Al Fatlawi
Keyword(s):  
Conceptual Framework ◽  
Accounting Information ◽  
Fair Value ◽  
Fair Value Accounting ◽  
Global Trend ◽  
The Common ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

The global trend towards the use of fair value accounting is increasing, so the current study aimed to maximize the impact of fair value application on achieving relevance and representation faithfulness of accounting information in accordance with the common conceptual framework. To achieve the objective of this study, the researcher has determined in the theoretical framework the relationship of fair value with the characteristics of relevance and representation faithfulness of accounting information and the extent of achieving these characteristics, as well as conducting a field study by preparing a questionnaire distributed to a sample of academics (50) and auditors (50) with a total number of selected participants (100) of academics and auditors.

Observational Evidence for Oceanic Controls on Hurricane Intensity

2011 ◽  
Vol 24 (4) ◽  
pp. 1138-1153 ◽  
Author(s):  
Ian D. Lloyd ◽  
Gabriel A. Vecchi
Keyword(s):  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
North Atlantic ◽  
Translation Speed ◽  
Ocean Stratification ◽  
Cyclone Intensity ◽  
The North ◽  
Sst Cooling ◽  
The North Atlantic ◽  
The Impact

Abstract The influence of oceanic changes on tropical cyclone activity is investigated using observational estimates of sea surface temperature (SST), air–sea fluxes, and ocean subsurface thermal structure during the period 1998–2007. SST conditions are examined before, during, and after the passage of tropical cyclones, through Lagrangian composites along cyclone tracks across all ocean basins, with particular focus on the North Atlantic. The influence of translation speed is explored by separating tropical cyclones according to the translation speed divided by the Coriolis parameter. On average for tropical cyclones up to category 2, SST cooling becomes larger as cyclone intensity increases, peaking at 1.8 K in the North Atlantic. Beyond category 2 hurricanes, however, the cooling no longer follows an increasing monotonic relationship with intensity. In the North Atlantic, the cooling for stronger hurricanes decreases, while in other ocean basins the cyclone-induced cooling does not significantly differ from category 2 to category 5 tropical cyclones, with the exception of the South Pacific. Since the SST response is nonmonotonic, with stronger cyclones producing more cooling up to category 2, but producing less or approximately equal cooling for categories 3–5, the observations indicate that oceanic feedbacks can inhibit intensification of cyclones. This result implies that large-scale oceanic conditions are a control on tropical cyclone intensity, since they control oceanic sensitivity to atmospheric forcing. Ocean subsurface thermal data provide additional support for this dependence, showing weaker upper-ocean stratification for stronger tropical cyclones. Intensification is suppressed by strong ocean stratification since it favors large SST cooling, but the ability of tropical cyclones to intensify is less inhibited when stratification is weak and cyclone-induced SST cooling is small. Thus, after accounting for tropical cyclone translation speeds and latitudes, it is argued that reduced cooling under extreme tropical cyclones is the manifestation of the impact of oceanic conditions on the ability of tropical cyclones to intensify.

scholarly journals Surface processes in the 7 November 2014 medicane from air–sea coupled high-resolution numerical modelling

2019 ◽  
Author(s):  
Marie-Noëlle Bouin ◽  
Cindy Lebeaupin Brossier
Keyword(s):  
Tropical Cyclones ◽  
Surface Processes ◽  
Convective Precipitation ◽  
Surface Cooling ◽  
Air Masses ◽  
Low Level ◽  
Cold Pools ◽  
Ocean Atmosphere ◽  
Upper Level ◽  
The Impact

Abstract. A medicane, or Mediterranean cyclone with characteristics similar to tropical cyclones, is simulated using a kilometre-scale ocean–atmosphere coupled modelling platform. A first baroclinic phase of the cyclone leads to strong convective precipitation, with high potential vorticity anomalies aloft due to an upper-level trough. The deepening and tropicalization of the cyclone is due first to the crossing of the upper-level jet, then to low-level convergence and uplift of conditionally unstable air masses by cold pools, resulting either from rain evaporation or from advection of continental air masses from North Africa. Backtrajectories show that air–sea heat exchanges warm and moisten the low-level inflow feeding the latent heat release during the mature phase of the medicane. However, the impact of ocean–atmosphere coupling on the cyclone track, intensity and lifecycle is very weak, due to a surface cooling one order of magnitude weaker than for tropical cyclones, even on the area of strong enthalpy fluxes. Isolating the influence of the surface parameters on the surface fluxes at sea during the different phases of the cyclone confirms the impact of the cold pools on the surface processes. The evaporation is controlled mainly by the sea surface temperature and wind, with a significant additional impact of the humidity and temperature at first level during the development phase. The sensible heat flux is influenced mainly by the temperature at first level throughout the whole medicane lifetime. This study shows that the tropical transition, in this case, is dependent on processes widespread in the Mediterranean Basin, like advection of continental air, rain evaporation, and dry air intrusion.

scholarly journals The Outflow–Rainband Relationship Induced by Environmental Flow around Tropical Cyclones

2019 ◽  
Vol 76 (7) ◽  
pp. 1845-1863 ◽  
Author(s):  
Yi Dai ◽  
Sharanya J. Majumdar ◽  
David S. Nolan
Keyword(s):  
Numerical Simulation ◽  
Tropical Cyclones ◽  
Large Scale ◽  
Inner Core ◽  
Vertical Wind Shear ◽  
Environmental Flow ◽  
Asymmetric Structure ◽  
Upper Level ◽  
The Relationship

Abstract This study investigates the role of the asymmetric interaction between the tropical cyclone (TC) and the environmental flow in governing the TC inner-core asymmetric structure. Motivated by the limitations of bulk measures of vertical wind shear in representing the complete environmental flow, the TC outflow is used as a focus for the asymmetric interaction. By analyzing an idealized numerical simulation, it is demonstrated that parcels can go directly from the asymmetric rainband to the upper-level outflow. The relatively large vertical mass flux in the rainband region also suggests that the asymmetric rainband is an important source of the outflow. In a simulation that suppresses convection by reducing the water vapor within the rainband region, the upper-level outflow is weakened, further supporting the hypothesis that the rainband and outflow are directly connected. Finally, it is demonstrated that the asymmetric outflow and the outer rainband are coupled through the descending inflow below the outflow. Some of the main characteristics of the outflow–rainband relationship are also supported by a real-case numerical simulation of Hurricane Bill (2009). The relationship is potentially useful for understanding and predicting the evolution of the TC inner-core structure during the interaction with the large-scale environmental flow.

scholarly journals Influence of Environmental Vertical Wind Shear on the Intensity of Hurricane-Strength Tropical Cyclones in the Australian Region

2005 ◽  
Vol 133 (12) ◽  
pp. 3644-3660 ◽  
Author(s):  
Linda A. Paterson ◽  
Barry N. Hanstrum ◽  
Noel E. Davidson ◽  
Harry C. Weber
Keyword(s):  
Tropical Cyclones ◽  
Wind Shear ◽  
Time Lag ◽  
Vertical Wind Shear ◽  
Vertical Wind ◽  
Intensity Change ◽  
Negative Effects ◽  
Australian Region ◽  
Upper Level ◽  
The Impact

Abstract NCEP–NCAR reanalyses have been used to investigate the impact of environmental wind shear on the intensity change of hurricane-strength tropical cyclones in the Australian region. A method of removing a symmetric vortex from objective analyses is used to isolate the environmental flow. A relationship between wind shear and intensity change is documented. Correlations between wind shear and intensity change to 36 h are of the order of 0.4. Typically a critical wind shear value of ∼10 m s−1 represents a change from intensification to dissipation. Wind shear values of less than ∼10 m s−1 favor intensification, with values between ∼2 and 4 m s−1 favoring rapid intensification. Shear values greater than ∼10 m s−1 are associated with weakening, with values greater than 12 m s−1 favoring rapid weakening. There appears to be a time lag between the onset of increased vertical wind shear and the onset of weakening, typically between 12 and 36 h. A review of synoptic patterns during intensification-weakening cycles revealed the juxtaposition of a low-level anticyclone on the poleward side of the storm and an approaching 200-hPa trough to the west. In most cases, intensification commences under weak shear with the approach of the trough, but just prior to the onset of high shear. Further, based on described cases when wind shear was weak but no intensification occurred, it is suggested that weak shear is a necessary but not a sufficient condition for intensification. It is illustrated here that the remote dynamical influence of upper-level potential vorticity anomalies may offset the negative effects of environmental shear.

Accent Policy and Accent Modification Enterprises as Potential Indicators of Intercultural Power Relations: A Call for an Updated Research Agenda

2013 ◽  
Vol 3 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Brynne D. Ovalle ◽  
Rahul Chakraborty
Keyword(s):  
International Relations ◽  
Identity Construction ◽  
Social Theory ◽  
Power Relations ◽  
Linguistic Diversity ◽  
Cultural Organization ◽  
Using Data ◽  
The Individual ◽  
The Impact ◽  
The Relationship

This article has two purposes: (a) to examine the relationship between intercultural power relations and the widespread practice of accent discrimination and (b) to underscore the ramifications of accent discrimination both for the individual and for global society as a whole. First, authors review social theory regarding language and group identity construction, and then go on to integrate more current studies linking accent bias to sociocultural variables. Authors discuss three examples of intercultural accent discrimination in order to illustrate how this link manifests itself in the broader context of international relations (i.e., how accent discrimination is generated in situations of unequal power) and, using a review of current research, assess the consequences of accent discrimination for the individual. Finally, the article highlights the impact that linguistic discrimination is having on linguistic diversity globally, partially using data from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and partially by offering a potential context for interpreting the emergence of practices that seek to reduce or modify speaker accents.

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