Misinformation and instant access: inconsistent reporting during extreme climatic events, reflecting on Tropical Cyclone Idai

2021 ◽  
Keyword(s):  
Comparative Analysis ◽  
Wind Speed ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
News Reports ◽  
Extreme Climatic Events ◽  
Potential Source ◽  
Increased Risk ◽  
Official Sources

Abstract In an era of globalisation, the spread of misinformation is becoming increasingly problematic. The dissemination of inaccurate and conflicting news on events such as tropical cyclones, can result in people being placed at increased risk and negatively influence the amount of aid received by the region. This study scrutinises media articles, and with the use of comparative analysis, uncovers the potential cause of misinformation in disaster journalism. The results of the study found that 59% (n=80) of the articles reported on wind speed values while 80% (n=80) of the articles reported on the number of fatalities. Results indicate that 44% (n=80) of the articles used official sources, uncovering that the potential source of misinformation is not only what is provided to journalists from official sources, but how the various sources used lead to contradicting news articles. The variations in news reports can be attributed to factors such as, the influx of different reports and the changing conditions during a disaster, all of which make consistent reporting on a disaster a challenging process.

scholarly journals Tropical cyclone simulations over Bangladesh at convection permitting 4.4 km & 1.5 km resolution

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hamish Steptoe ◽  
Nicholas Henry Savage ◽  
Saeed Sadri ◽  
Kate Salmon ◽  
Zubair Maalick ◽  
...  
Keyword(s):  
Wind Speed ◽  
Tropical Cyclone ◽  
Sea Level ◽  
Tropical Cyclones ◽  
Weather Forecasting ◽  
Sea Level Pressure ◽  
Mean Sea Level ◽  
Level Pressure ◽  
Medium Range ◽  
Gust Speed

AbstractHigh resolution simulations at 4.4 km and 1.5 km resolution have been performed for 12 historical tropical cyclones impacting Bangladesh. We use the European Centre for Medium-Range Weather Forecasting 5th generation Re-Analysis (ERA5) to provide a 9-member ensemble of initial and boundary conditions for the regional configuration of the Met Office Unified Model. The simulations are compared to the original ERA5 data and the International Best Track Archive for Climate Stewardship (IBTrACS) tropical cyclone database for wind speed, gust speed and mean sea-level pressure. The 4.4 km simulations show a typical increase in peak gust speed of 41 to 118 knots relative to ERA5, and a deepening of minimum mean sea-level pressure of up to −27 hPa, relative to ERA5 and IBTrACS data. The downscaled simulations compare more favourably with IBTrACS data than the ERA5 data suggesting tropical cyclone hazards in the ERA5 deterministic output may be underestimated. The dataset is freely available from 10.5281/zenodo.3600201.

scholarly journals A New Compilation of North Atlantic Tropical Cyclones, 1851–98*

2014 ◽  
Vol 27 (23) ◽  
pp. 8674-8685 ◽  
Author(s):  
Michael Chenoweth
Keyword(s):  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
North Atlantic ◽  
The United States ◽  
Caribbean Region ◽  
News Reports ◽  
The North ◽  
Hurricane Wind ◽  
The Caribbean ◽  
First Time

Abstract A comprehensive new compilation of North Atlantic tropical cyclone activity for the years 1851–98 is presented and compared with the second-generation North Atlantic hurricane database (HURDAT2) for the same years. This new analysis is based on the retrieval of 9072 newspaper marine shipping news reports, 1260 original logbook records, 271 Maury abstract logs, 147 U.S. marine meteorological journals, and 34 Met Office (UKMO) logbooks. Records from throughout North America and the Caribbean region were used along with other primary and secondary references holding unique land and marine data. For the first time, North Atlantic daily weather maps for 1864/65, 1873, and 1881–98 were used in historical tropical cyclone research. Results for the years 1851–98 include the omission of 62 of the 361 HURDAT2 storms, and the further reduction resulting from the merging of storms to a total of 288 unique HURDAT2 tropical cyclones. The new compilation gave a total of 497 tropical cyclones in the 48-yr record, or an average of 10.4 storms per year compared to 6.0 per year in HURDAT2 less the author’s omissions. Of this total, 209 storms are completely new. A total of 90 hurricanes made landfall in the United States during this time. Seven new U.S. landfalling hurricanes are present in the new dataset but not in HURDAT2. Eight U.S. landfalling hurricanes in HURDAT2 are now considered to have only tropical storm impact or were actually extratropical at landfall. Across the North Atlantic, the number of category-4 hurricanes based on the Saffir–Simpson hurricane wind scale, compared with HURDAT2, increased from 11 to 25, 6 of which made U.S. landfall at category-4 level.

scholarly journals An Extended Model for the Potential Intensity of Tropical Cyclones

2012 ◽  
Vol 69 (2) ◽  
pp. 641-661 ◽  
Author(s):  
Thomas Frisius ◽  
Daria Schönemann
Keyword(s):  
Steady State ◽  
Wind Speed ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Convective Instability ◽  
Cloud Model ◽  
Convective Available Potential Energy ◽  
Extended Model ◽  
Flow Imbalance ◽  
Conditional Instability

Abstract Emanuel’s theory of hurricane potential intensity (E-PI) makes use of the assumption that slantwise convective instability vanishes in a steady-state vortex of a tropical cyclone. In the framework of an extended mathematical potential intensity model it is shown that relaxing this assumption and including an eye results in a larger maximum wind speed compared to that of the predictions made by E-PI. Previous studies by Bryan and Rotunno demonstrate that the effect of unbalanced flow considerably contributes to maximum winds in excess of E-PI (“superintensity”). The authors argue that the proposed mechanism induced by convective instability provides another possible explanation for simulated and observed tropical cyclones exceeding E-PI in addition to flow imbalance. Further evidence for the relevance of conditional instability in mature tropical cyclones to superintensity is given by the fact that convective available potential energy arises in numerical simulations of tropical cyclones. This is demonstrated by means of an axisymmetric cloud model that is in qualitative agreement with the analytical model. These simulations reveal a dependence of superintensity on the amount of CAPE outside the eyewall and also reproduce the decrease in superintensity with increased horizontal diffusion as found in previous studies.

Spatial variations of North Atlantic landfalling tropical cyclone wind speed decay over the continental United States

2021 ◽  
Author(s):  
Yi-Jie Zhu ◽  
Jennifer M. Collins ◽  
Philip J. Klotzbach
Keyword(s):  
United States ◽  
Wind Speed ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
East Coast ◽  
Gulf Coast ◽  
Spatial Variations ◽  
Decay Model ◽  
Weak Intensity ◽  
Landfalling Tropical Cyclones

AbstractUnderstanding tropical cyclone wind speed decay during the post-landfall stage is critical for inland hazard preparation. This paper examines the spatial variation of wind speed decay of tropical cyclones over the continental United States. We find that tropical cyclones making landfall over the Gulf Coast decay faster within the first 24 hours after landfall than those making landfall over the Atlantic East Coast. The variation of the decay rate over the Gulf Coast remains larger than that over the Atlantic East Coast for tropical cyclones that had made landfall more than 24 hours prior. Besides an average weaker tropical cyclone landfall intensity, the near-parallel trajectory and the proximity of storms to the coastline also help to explain the slower post-landfall wind speed decay for Atlantic East Coast landfalling tropical cyclones. Tropical cyclones crossing the Florida peninsula only slowly weaken after landfall, with an average of less than 20% post-landfall wind speed drop while transiting the state. The existence of these spatial variations also brings into question the utility of a uniform wind decay model. While weak intensity decay over the Florida peninsula is well estimated by the uniform wind decay model, the error from the uniform wind decay model increases with tropical cyclones making direct landfall more parallel to the Atlantic East Coast. The underestimation of inland wind speed by the uniform wind decay model found over the western Gulf Coast brings attention to the role of land-air interactions in the decay of inland tropical cyclones.

Estimating Tropical Cyclone Intensity from Infrared Image Data

2011 ◽  
Vol 26 (5) ◽  
pp. 690-698 ◽  
Author(s):  
Miguel F. Piñeros ◽  
Elizabeth A. Ritchie ◽  
J. Scott Tyo
Keyword(s):  
Wind Speed ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
North Atlantic Ocean ◽  
Infrared Image ◽  
Ocean Basin ◽  
Maximum Wind Speed ◽  
Tropical Cyclone Intensity ◽  
Cyclone Intensity ◽  
Maximum Wind

Abstract This paper describes results from a near-real-time objective technique for estimating the intensity of tropical cyclones from satellite infrared imagery in the North Atlantic Ocean basin. The technique quantifies the level of organization or axisymmetry of the infrared cloud signature of a tropical cyclone as an indirect measurement of its maximum wind speed. The final maximum wind speed calculated by the technique is an independent estimate of tropical cyclone intensity. Seventy-eight tropical cyclones from the 2004–09 seasons are used both to train and to test independently the intensity estimation technique. Two independent tests are performed to test the ability of the technique to estimate tropical cyclone intensity accurately. The best results from these tests have a root-mean-square intensity error of between 13 and 15 kt (where 1 kt ≈ 0.5 m s−1) for the two test sets.

Impacts of Air–Sea Flux Parameterizations on the Intensity and Structure of Tropical Cyclones

2013 ◽  
Vol 141 (7) ◽  
pp. 2308-2324 ◽  
Author(s):  
Benjamin W. Green ◽  
Fuqing Zhang
Keyword(s):  
Wind Speed ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Latent Heat ◽  
Weather Prediction ◽  
Surface Flux ◽  
Surface Fluxes ◽  
Sensible Heat ◽  
Near Surface ◽  
Flux Parameterization

Abstract Fluxes of momentum and moist enthalpy across the air–sea interface are believed to be one of the most important factors in determining tropical cyclone intensity. Because these surface fluxes cannot be directly resolved by numerical weather prediction models, their impacts on tropical cyclones must be accounted for through subgrid-scale parameterizations. There are several air–sea surface flux parameterization schemes available in the Weather Research and Forecasting (WRF) Model; these schemes differ from one another in their formulations of the wind speed–dependent exchange coefficients of momentum, sensible heat, and moisture (latent heat). The effects of surface fluxes on the intensity and structure of tropical cyclones are examined through convection-permitting WRF simulations of Hurricane Katrina (2005). It is found that the intensity (and, to a lesser extent, structure) of the simulated storms is sensitive to the choice of surface flux parameterization scheme. In agreement with recent studies, the drag coefficient CD is found to affect the pressure–wind relationship (between minimum sea level pressure and maximum 10-m wind speed) and to change the radius of maximum near-surface winds of the tropical cyclone. Fluxes of sensible and latent heat (i.e., moist enthalpy) affect intensity but do not significantly change the pressure–wind relationship. Additionally, when low-level winds are strong, the contribution of dissipative heating to calculations of sensible heat flux is not negligible. Expanding the sensitivity tests to several dozen cases from the 2008 to 2011 Atlantic hurricane seasons demonstrates the robustness of these findings.

scholarly journals Tropical cyclone exposure is associated with increased hospitalization rates in older adults

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Robbie M. Parks ◽  
G. Brooke Anderson ◽  
Rachel C. Nethery ◽  
Ana Navas-Acien ◽  
Francesca Dominici ◽  
...  
Keyword(s):  
Older Adults ◽  
Wind Speed ◽  
Tropical Cyclone ◽  
Confidence Interval ◽  
Tropical Cyclones ◽  
Respiratory Diseases ◽  
Poisson Model ◽  
Parasitic Diseases ◽  
Hospital Personnel ◽  
Hospitalization Rates

AbstractHurricanes and other tropical cyclones have devastating effects on society. Previous case studies have quantified their impact on some health outcomes for particular tropical cyclones, but a comprehensive assessment over longer periods is currently missing. Here, we used data on 70 million Medicare hospitalizations and tropical cyclone exposures over 16 years (1999–2014). We formulated a conditional quasi-Poisson model to examine how tropical cyclone exposure (days greater than Beaufort scale gale-force wind speed; ≥34 knots) affect hospitalizations for 13 mutually-exclusive, clinically-meaningful causes. We found that tropical cyclone exposure was associated with average increases in hospitalizations from several causes over the week following exposure, including respiratory diseases (14.2%; 95% confidence interval [CI]: 10.9–17.9%); infectious and parasitic diseases (4.3%; 95%CI: 1.2–8.1%); and injuries (8.7%; 95%CI: 6.0–11.8%). Average decadal tropical cyclone exposure in all impacted counties would be associated with an estimated 16,772 (95%CI: 8,265–25,278) additional hospitalizations. Our findings demonstrate the need for targeted preparedness strategies for hospital personnel before, during, and after tropical cyclones.

scholarly journals Comparative analysis of subjective/advanced objective technique of tropical cyclone intensity estimation

MAUSAM ◽  
2021 ◽  
Vol 57 (1) ◽  
pp. 159-164
Author(s):  
B. R. LOE ◽  
R. K. GIRI ◽  
B. L. VERMA ◽  
S. BALI ◽  
SOMA SEN ROY
Keyword(s):  
Comparative Analysis ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Tropical Cyclone Intensity ◽  
Intensity Estimation ◽  
Cyclone Intensity ◽  
Subjective Judgement ◽  
The World ◽  
Computer Based ◽  
Image Pattern

lkj & m".kdfVca/kh; pØokr dh rhozrk dk vkdyu djus ds fy, lewps fo’o esa O;kogkfjd :i ls mi;ksx dh tkus okyh M~oksjd rduhd esa mixzg ls izkIr fp=ksa dk mi;ksx fd;k tkrk gSA blesa O;ofLFkr laogu ds laca/k esa fo’ys"kd }kjk fd, x, foospu lfgr dqN izk;ksfxd ekunaMksa ds vk/kkj ij mixzg ls izkIr fp= ds iSVuZ dh igpku dh tkrh gSA fofHkUu fo’ys"k.k dsUnzksa }kjk fdlh ,d pØokr dk vkdyu djus esa gksus okyh fo"k;ijd foospu laca/kh folaxfr;k¡ daI;wVj ij vk/kkfjr ,yxksfjFe ds ek/;e ls de gqbZA bl la’kksf/kr rduhd dks fodflr fo"k;ijd M~oksjd rduhd ¼,- vks- Mh- Vh-½ dgk x;k vkSj ;g iw.kZ fodflr m".k dfVca/kh; pØokrksa ds fy, mi;qDr gSA bl 'kks/k&Ik= esa o"kZ 2004 esa vk, rhu m".kdfVca/kh; pØokrksa ds laca/k esa ,- vks- Mh- Vh- ds dk;Z & fu"iknu dk ewY;kdau fd;k x;k gSA buds rqYukRed fo’ys"k.k ls ;g irk pyk fd ,- vks- Mh- Vh- rduhd M~oksjd rduhd ds vk/kkj ij fd, x, pØokr dh rhozrk ds vkdyuksa] tks m".kdfVca/kh; fo’ys"k.k dsUnzksa ds mixzg ls izkIr fp=ksa ds fo’ys"kdksa }kjk O;kogkfjd :Ik ls rS;kj fd, x,] ds  eqdkcys dh jghA  Dvorak technique operationally used all over the world for estimating the tropical cyclone intensity is based on satellite observations. It involves image pattern recognition based on certain empirical rules along with the analyst interpretation of organized convection.  The computer-based algorithm can minimize these subjective judgement discrepancies between different analysis centers estimating the same storm.  This modified version is called Advanced Objective Dvorak Technique (AODT) and which is applicable for well-developed tropical cyclones. In this paper the performance of the AODT is evaluated on three cases of the year 2004 tropical cyclones. Comparative analysis indicates the technique to be competitive with, the Dvorak-based intensity estimates produced operationally by satellite analysts from tropical analysis centers.

scholarly journals WEATHER PERTURBATIONS ASSOCIATED WITH THE TRANSIT OF TROPICAL CYCLONES IN THE COAST OF BANGLADESH

2020 ◽  
Vol 4 (1) ◽  
pp. 23-27
Author(s):  
Razat Suvra Das ◽  
Sayedur Rahman Chowdhury ◽  
Milan Kumar Shiuli ◽  
Shubha Sarker
Keyword(s):  
Wind Speed ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Atmospheric Pressure ◽  
Dew Point ◽  
Pressure Perturbation ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Weather Parameters ◽  
Bangladesh Coast

During the transition of tropical cyclone in the coast of Bangladesh, it is normally observed that there is a noticeable perturbation of weather parameters around the cyclone landfall zone. Through this research the extent of perturbation is assessed. To make the inventory 4 recent cyclones were selected that had made landfall in Bangladesh coast. They are cyclone MORA, cyclone ROANU, cyclone KOMEN and cyclone MAHASEN. Weather parameters selected to check their perturbation are wind speed, temperature, dew point temperature, atmospheric pressure, relative humidity and precipitation. The dispersion of these parameters from their normal state was measured also in accordance of their distance from the landfall area. To perform the task a time scale of 15 days was selected for each cyclone. Middle 3 days window were considered as most affected weather, 6 days prior and after the event were considered as normal (prevailing) weather. The Synop (observed) data was downloaded from the Ogimet.com. The data was then processed and decoded by Synop decoder and then further analyzed in MS Excel. In case of atmospheric pressure perturbation the highest perturbation was found 5.8 mb low on average than prevailing pressure up to 50 km from cyclone landfall. Wind speed perturbation was highest in 50 to 100 km area. Perturbation of temperature was highest in 0 to 50 km (about 2.1 °C low on average). Perturbation of dew point temperature was found negligible and humidity perturbation was found highest 6.63% high on average up to 50 km of landfall. In case of precipitation perturbation highest was found in 0 to 50 km area of landfall (38.76 mm high on average than prevailing weather), however precipitation perturbation was irregular beyond 100 km of landfall. The most perturbed weather parameter was found atmospheric pressure and the least affected was dew point temperature.

scholarly journals The Boundary Layer Dynamics of Tropical Cyclone Rainbands

2018 ◽  
Vol 75 (11) ◽  
pp. 3777-3795 ◽  
Author(s):  
Jeffrey D. Kepert
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
Surface Wind ◽  
Three Dimensional ◽  
Surface Wind Speed ◽  
Wind Maximum ◽  
Boundary Layer Dynamics ◽  
Spiral Bands

Abstract Spiral bands are ubiquitous features in tropical cyclones and significantly affect boundary layer thermodynamics, yet knowledge of their boundary layer dynamics is lacking. Prompted by recent work that has shown that relatively weak axisymmetric vorticity perturbations outside of the radius of maximum winds in tropical cyclones can produce remarkably strong frictional convergence, and by the observation that most secondary eyewalls appear to form by the “wrapping up” of a spiral rainband, the effect of asymmetric vorticity features that mimic spiral bands is studied. The mass field corresponding to an axisymmetric vortex with added spiral vorticity band is constructed using the nonlinear balance equation, and supplied to a three-dimensional boundary layer model. The resulting flow has strong low-level convergence and a marked updraft extending along the vorticity band and some distance downwind. There is a marked along-band wind maximum in the upper boundary layer, similar to observations, which is up to about 20% stronger than the balanced flow. A marked gradient in the inflow-layer depth exists across the band and there is an increase in the surface wind factor (the ratio of surface wind speed to nonlinear-balanced wind speed) near the band. The boundary layer dynamics near a rainband therefore form a continuum with the flow near a secondary eyewall. None of these features are due to convective momentum transports, which are absent from the model. The sensitivities of the flow to band length, width, location, crossing angle, and amplitude are examined, and the possible contribution of boundary layer dynamics to the formation of the tropical cyclone rainbands discussed.

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