Cyclone Trajectories Research Articles

Impact of tropical cyclone Amang on variability of wind speed, salinity, sea surface temperature, and their relationship to chlorophyll-a in sea waters of Sangihe Island

High concentrations of chlorophyll-a can be used to predict where fish gather. On the other hand, tropical cyclones are one of the triggering factors for vertical stirring and upwelling that cause fertility of waters. The Sangihe Island area is not an effective area for the formation of tropical cyclones. However, due to its geographical location with a tropical cyclone area and trajectory, the potential for disturbances caused by cyclones is impactful on Sangihe Island. The distribution of wind speed, salinity, sea surface temperature and chlorophyll-a concentration can be detected by satellite remote sensing imagery. This study aims to analyze the impact of Tropical Cyclone Amang on the variability of wind speed, salinity, sea surface temperature and on the concentration of chlorophyll-a in Sangihe Island. This study useswind speed, salinity, sea surface temperature and chlorophyll-a data during the Amang Tropical Cyclone (January 6-27, 2019) from the AQUA-MODIS satellite imagery. The results show that the relationship between wind speed and chlorophyll-a concentration has impact on other parameters where both parameters showed a strong correlation value. It was also showed on the relationship between sea surface temperature and chlorophyll-a.However, the relationship between salinity and chlorophyll-a concentration showed lowest effect among those parameters.Indonesian title: Dampak siklon tropis Amang terhadap variabilitas kecepatan angin, salinitas, suhu permukaan laut, dan hubungannya dengan klorofil-a di perairan laut Pulau Sangihe

Near real-time predictions of tropical cyclone trajectory and intensity in the northwestern Pacific Ocean using echo state network

Near real-time predictions of tropical cyclone trajectory and intensity in the northwestern Pacific Ocean using echo state network

Анализ выхода южных циклонов на территорию Республики Башкортостан

Analysis of the arrival of southern cyclones to the Republic of Bashkortostan / Volobueva O.V., Toptunova O.N., Drobzheva Y.V. // Hydrometeorological Research and Forecasting, 2021, no. 2 (380), pp. 66-76. The results of the analysis of the arrival of southern cyclones to the territory of the Republic of Bashkortostan for the period of 1993-2018 are presented. Typical trajectories of cyclones, areas of their origin, as well as accompanying adverse weather phenomena are identified according to the observational network of the Bashkir Administration for Hydrometeorology and Environmental Monitoring. In 70 % of cases, southern cyclones move through the territory of the republic and leave it in the southern direction. About 50 % of the depressions come to the Republic of Bashkortostan from the Black Sea and its coast. The upper-air field for the arrival of southern cyclones is the front part of the pressure trough with high geopotential height gradients. The arrivals of southern cyclones have a significant impact on the study area and are closely related to the formation of severe hydrometeorological events. Keywords: southern cyclone, typical territories, the Republic of Bashkortost

Summer Extreme Cyclone Impacts on Arctic Sea Ice

AbstractIn this study the impact of extreme cyclones on Arctic sea ice in summer is investigated. Examined in particular are relative thermodynamic and dynamic contributions to sea ice volume budgets in the vicinity of Arctic summer cyclones in 2012 and 2016. Results from this investigation illustrate that sea ice loss in the vicinity of the cyclone trajectories during each year was associated with different dominant processes: thermodynamic processes (melting) in the Pacific sector of the Arctic in 2012, and both thermodynamic and dynamic processes in the Pacific sector of the Arctic in 2016. Comparison of both years further suggests that the Arctic minimum sea ice extent is influenced by not only the strength of the cyclone, but also by the timing and location relative to the sea ice edge. Located near the sea ice edge in early August in 2012, and over the central Arctic later in August in 2016, extreme cyclones contributed to comparable sea ice area (SIA) loss, yet enhanced sea ice volume loss in 2012 relative to 2016. Central to a characterization of extreme cyclone impacts on Arctic sea ice from the perspective of thermodynamic and dynamic processes, we present an index describing relative thermodynamic and dynamic contributions to sea ice volume changes. This index helps to quantify and improve our understanding of initial sea ice state and dynamical responses to cyclones in a rapidly warming Arctic, with implications for seasonal ice forecasting, marine navigation, coastal community infrastructure, and designation of protected and ecologically sensitive marine zones.

Arctic Cyclone Activity and the Beaufort High

AbstractThe Beaufort high (BH) and its accompanying anticyclonic winds drive the Arctic Ocean’s Beaufort Gyre, the major freshwater reservoir of the Arctic Ocean. The Beaufort Gyre circulation and its capacity to accumulate or release freshwater rely on the BH intensity. The migration of Nordic seas cyclones into the Arctic has been hypothesized to moderate the strength of the BH. We explore this hypothesis by analyzing reanalysis sea level pressure fields to characterize the BH and identify and track cyclones north of 60°N during 1948–2019. A cluster analysis of Nordic seas cyclone trajectories reveals a western pathway (through the Arctic interior) associated with a relatively weak BH and an eastern pathway (along the Arctic periphery) associated with a relatively strong BH. Furthermore, we construct cyclone activity indices (CAIs) in the Arctic and Nordic seas that take into account multiple cyclone parameters (number, strength, and duration). There are significant correlations between the BH and the CAIs in the Arctic and Nordic seas during 1948–2019, with anomalously strong cyclone activity related to an anomalously weak BH, and vice versa. We show how the Arctic and Nordic seas CAIs experienced a regime shift toward increased cyclone activity between the first four decades analyzed (1948–88) and the most recent three decades (1989–2019). Over the same two time periods, the BH exhibits a weakening. Increased cyclone activity and an accompanying weakening of the BH may be consistent with expectations in a warming Arctic and have implications for Beaufort Gyre dynamics and freshwater.

Metrics for evaluating tropical cyclones in climate data

AbstractThis manuscript describes a software suite that can be used for objective evaluation of tropical cyclones (TCs) in gridded climate data. Using cyclone trajectories derived from 6-hourly data, a comprehensive set of metrics is defined to systematically compare and contrast products to one another. In addition to annual TC climatologies, attention is paid to spatial and temporal patterns of storm occurrence and intensity. Assessment can be performed either on the global scale or regional domains. Simple to visualize ‘scorecards’ allow for rapid credibility assessment. We showcase three key findings enabled by this suite. First, we compare the representation of TCs in seven current-generation global reanalyses and conclude that higher resolution models and those with TC-specific assimilation contain more accurate storm climatologies. Second, using a free-running Earth system model (ESM) we find that full basin refinement is required in variable-resolution configurations to adequately simulate North Atlantic TC frequency. Upstream refinement over northern Africa offers little benefit in simulating storm occurrence but spatial genesis patterns are improved. Finally, we show that TCs simulated by ESMs can be highly sensitive to individual parameterizations in climate models, with North Atlantic TC metrics varying greatly depending on version of the Morrison-Gettelman microphysics package.

Prediction of tropical cyclone trajectories over the Northern Indian Ocean using COSMO

The present study investigates the performance of a regional numerical weather prediction model; namely, the Consortium for Small-scale Modelling (COSMO) in the prediction of the tropical cyclone (TC) trajectories for varying intensities of the storm. A total of 8 TCs formed over the Northern Indian Ocean from 2017 to 2019 are chosen for the evaluation of the COSMO model. The central pressure ( $$P_\mathrm{Central}$$ ), pressure drop ( $$\varDelta P$$ ), and maximum sustained surface wind speed (MSW) simulated by the COSMO model are validated against the concurrent observations from India Meteorological Department. The forecasted mean track errors are 95 km for a lead time of 24 h, whereas it was about 140 km for a lead time of 48 h. The mean initial positional error in identification of the storm was about 50 km. The intensity of a storm is underestimated in terms of $$\varDelta P$$ and MSW, especially for a lead time of 0–24 h, whereas the model shows a consistent overestimation for a lead time of more than 24 h. During the initial stage of a storm, when its intensity is categorized as a Deep Depression, we notice a maximum amount of uncertainty in the prediction of cyclone track. The COSMO model yields improved predictability of the tracks for storms categorized as Very Severe Cyclonic Storms. As the intensity of a storm increases from a Deep Depression to a Very Severe Cyclonic Storm, the track errors associated with model simulations tend to decrease. Results of the present study illustrate the predictability of TCs from COSMO in terms of the trajectory and intensity of the storm.

Траектории движения циклонов над Черным морем по данным атмосферных ре-анализов

The features of the development of cyclones, which can cause the generation of storm surges, depending on the trajectory and parameters of cyclones in the Azov-Black Sea basin, are investigated. An extreme storm surge in the Taganrog Bay and the mouth of the Don River on September 24, 2014 was taken as a test situation. Based on the data of meteorological observations at the posts and ERA5 re-analysis data on atmospheric pressure, wind speed and relative vorticity at the level of 850 hPa, the peculiarities of the movement of the cyclone that caused extreme sea level rise are studied: the trajectory of movement, the speed of the cyclone, diameter, atmospheric pressure in its center, wind speed. The parameters of this cyclone identified in this way were used to identify the tracks of cyclones according to the data of atmospheric re-analyzes (ERA-Interim and ERA-5) for 2014–2020 over the Azov-Black Sea basin to study the spatio-temporal variability of cyclone trajectories and its influence on the characteristics of sea level in the coastal zone of the Crimea and the Azov Sea. A method for calculating of the cyclones movement tracks is proposed, based on the analysis of the relative vorticity of the atmospheric fields of re-analysis at the level of 850 hPa. Further, for each cyclone, a characteristic region was identified, for which the minimum surface atmospheric pressure and the maximum wind speed were determined. Then, according to the coordinates of the center of this area, the path (track) of the cyclone movement for the Azov–Black Sea region was calculated. As a result, criteria for identifying cyclones that are potentially capable of causing extreme storm surges were formulated, estimates of the spatial characteristics of cyclones and patterns of sea level variability in the coastal zone of the Crimea were obtained at different phases of cyclone movement over the region.

ANALYSIS OF AN EXTRATROPICAL CYCLONE IN THE SOUTHWEST ATLANTIC: WRF MODEL BOUNDARY CONDITIONS SENSITIVITY

Abstract. Meteorological conditions characterize the southern Brazilian coast a cyclogenetic area. The current study seeks to analyse the sensitivity of the WRF model to initial and boundary meteorological conditions in the simulation of an extratropical cyclone that occurred on the southern Brazilian coast on October 28, 2018. For this purpose, the WRF model was set up for two experimental simulations using the NCEP FNL and the NCEP CFSv2 reanalysis data as initial/boundary conditions. The sensitivity analysis was carried out with the cyclone trajectory assessment and comparison with wind speed data from meteorological stations. The results show that the initial meteorological conditions significantly influence the simulation of the cyclone track. In a nutshell, the use of NCEP CFSv2 resulted in more accurate wind speed simulations when compared to the values observed in the stations. With correlation coefficient values around 0.7, and the lowest bias (−2.57 m/s) and RMSE (3.68 m/s). In contrast, using the NCEP FNL data, the lowest correlation coefficient and the highest bias and RMSE values were obtained: 0.58, −3.97 m/s and 4.91 m/s, respectively. However, both simulations tend to underestimate observational wind speed values. The superior performance of simulations using CFSv2 tends to be related to the finer horizontal resolution of this reanalysis data source.

Análise Climatológica das trajetórias de Ciclones Extratropicais formados na região da Península Antártica

Cyclones play an important role in the general circulation of the atmosphere, enabling the meridional transport of excess heat, humidity and momentum from low latitudes to high latitudes. In the Southern Hemisphere, the area between southern Brazil and the Peninsula Antarctica (AP) is described as one of the most favorable for the formation of cyclones (30°S to 70°S) due to the existence of strong temperature gradient between the ocean and the surface air layer above the ocean and also because of pre-existing baroclinic instabilities. This study is associated with the Project ATMOS (AnTarctic Modeling Observation System) and explored the role of extratropical cyclones in teleconnections between high and medium latitudes to track the trajectories of extratropical cyclones that are formed in the Antarctic Peninsula (AP) and move towards the central sector of the South Atlantic. The analysis of the tracked trajectories showed that the cyclones reached the central sector of the South Atlantic during the months of autumn (greater number) and winter (greater displacement), while the statistical analysis indicated that the intensity of the cyclones is more linearly linked to the mean sea level pressure field than to Superficial Sea Temperature Anomalies.

A Simple Trajectory Model for Climatological Study of Tropical Cyclones

AbstractThe establishment of a tropical cyclone (TC) trajectory model that can represent the basic physics and is practically advantageous considering both accuracy and computational cost is essential to the climatological studies of various global TC activities. In this study, a simple deterministic model is proposed based on a newly developed semiempirical formula for the beta drift under known conditions of the environmental steering flow. To verify the proposed model, all historical TC tracks in the western North Pacific and the North Atlantic Ocean basins during the period 1979–2018 are simulated and statistically compared with the relevant results derived from observed data. The proposed model is shown to well capture the spatial distribution patterns of the TC occurrence frequency in the two ocean basins. Prevailing TC tracks as well as the latitudinal distribution of the landfall TC number in the western North Pacific Ocean basin are also shown to agree better with the results derived from observed data, as compared to the existing models that took different strategies to include the effect of the beta drift. It is then concluded that the present model is advantageous in terms of not only the accuracy but also the capacity to accommodate the varying climate. It is thus believed that the proposed TC trajectory model has the potential to be used for assessing possible impacts of climate change on tropical cyclone activities.

Seasonal movement prediction of tropical cyclone over the North Indian Ocean by using atmospheric climate variables in statistical models

In this study, the contribution of atmospheric climate variables to the prediction skill of tropical cyclone (TC) activity over the North Indian Ocean (NIO) has been investigated. Statistical forecast models are developed through generalised linear model (GLM) and generalised additive model (GAM) for tropical cyclone trajectories over the NIO using atmospheric climate variables as predictors. TC from the Joint Typhoon Warning Centre and sets of climate predictor data were analysed for a period of 35-year (1979–2013). The velocity field is predicted by fitting GAM in each month and season. Hindcast validation method is applied to assess the reliability of the model. The skill of the GAM model is compared with GLM and found to be more successful in forecasting TC movement over the NIO region.

Variability of southwest Pacific tropical cyclone track geometry over the last 70 years

AbstractVariability in tropical cyclone (TC) track morphology, as it evolves post genesis, presents continued challenges in accurately forecasting TC movement. Therefore, an improved understanding of TC track climatology is essential, given that TCs are one of the most critical natural hazards in the southwest Pacific (SWP) region. We examine the historical variability of TC tracks within the SWP over the last 70 years (1948–2017) using 6‐hourly track data obtained from the South Pacific Enhanced Archive of Tropical Cyclones (SPEArTC) database. A probabilistic clustering technique is applied to separate TC tracks into distinct groups in order to assess the primary cyclone trajectories for the region and its relationship with the El Niño–Southern Oscillation (ENSO). TC tracks are also classified into four sinuosity categories: straight, recurving, sinuous and highly sinuous; and their spatial and temporal characteristics subsequently analysed. The results of the cluster analysis identified five optimal groups of TC tracks, four of which exhibited southeast propagation, except for the southwest moving tracks in Cluster 5. Temporally, significant trends were observed over the last seven decades, with Clusters 1, 3 and 4 becoming less frequent with a substantial increase in the occurrence of Cluster 2 tracks (representing TCs east of dateline), a geometry favoured by El Niño conditions. Further, the sinuosity analysis revealed continued dominance of straight TCs within the eastern SWP with a tendency of encountering TCs of other morphology types. Conversely, the western SWP region is typically exposed to highly sinuous tracks. We also observed a significant decrease (increase) in TCs with straight and quasi‐straight (highly sinuous) tracks, particularly during the last decade. These findings suggest that combined cluster analysis and TC track sinuosity analysis is an important tool in generalising the TC track regimes, refining predicted trajectories and understanding impacts on SWP island nations.

Dependence of Wet Depositions of Sulfates and Nitrates in Primorskii Krai on Cyclone Trajectories

An analysis is made of the cyclone trajectories for 2003–2013 in order to gain insight into the influence of their genesis on the generation of the flow of wet depositions of acid-forming substances over the territory of Primorsky krai and a part of the water area of the Sea of Japan. All the cyclones crossing the region of interest during the period under investigation have been considered. Seven types of cyclones have been identified according to the location of their genesis and trajectories. Annual and seasonal variability of their number of occurrence as well as variability in pressure at the cyclone center has been shown for each of them. Using precipitation data from EANET monitoring station Primorskaya, concentrations and deposition fluxes of sulfates and nitrates have been calculated for each cyclone type. It is shown that more than half of all sulfates and nitrates deposited at the stations with precipitation caused by the cyclones originating outside the territory of the Russian Federation. A significant correlation of variability in mean annual deposition fluxes of sulfates and nitrates in precipitation of these cyclones is indicative of the common sources of input of acid-forming substances into precipitation of the five cyclone types.

Tropical Cyclone Track Forecasting Using Fused Deep Learning From Aligned Reanalysis Data.

The forecast of tropical cyclone trajectories is crucial for the protection of people and property. Although forecast dynamical models can provide high-precision short-term forecasts, they are computationally demanding, and current statistical forecasting models have much room for improvement given that the database of past hurricanes is constantly growing. Machine learning methods, that can capture non-linearities and complex relations, have only been scarcely tested for this application. We propose a neural network model fusing past trajectory data and reanalysis atmospheric images (wind and pressure 3D fields). We use a moving frame of reference that follows the storm center for the 24 h tracking forecast. The network is trained to estimate the longitude and latitude displacement of tropical cyclones and depressions from a large database from both hemispheres (more than 3,000 storms since 1979, sampled at a 6 h frequency). The advantage of the fused network is demonstrated and a comparison with current forecast models shows that deep learning methods could provide a valuable and complementary prediction. Moreover, our method can give a forecast for a new storm in a few seconds, which is an important asset for real-time forecasts compared to traditional forecasts.

Dependence of wet depositions of sulfates and nitrates in Primorskii krai on cyclone trajectories.

Dependence of wet depositions of sulfates and nitrates in Primorskii krai on cyclone trajectories.

Results of sea level studies at RSHU

Study of sea level is being developed at RSHU in several directions: global, regional and local. The global one includes the study of the patterns of interannual fluctuations of the global sea level (GLS), identification of their genesis and development of a set of methods for its long-term forecast. Two approaches to the genesis of GLS are considered. In foreign studies, changes in GLS are determined by changes in the water mass of various cryosphere components, land water reserves and steric level fluctuations. Another approach, implemented at RSHU, is to assess contributions of various factors using the equation of the freshwater balance of the World Ocean as the sum of eustatic and steric factors. A physical-statistical method for two-decade GLS forecasting, based on delay in the GLS response to air temperature over the ocean, has been developed, as well as the GLS projections at the end of the century for climatic scenarios according to the CMIP5 project have been provided. In the regional context, the main attention is paid to identifying the genesis of the interannual variability of the Caspian Sea level with the aim of its long-term forecasting. The entire chain of cause-and-effect relationships in the North Atlantic-atmosphere-Volga basin-Caspian level system is discussed. It has been established that, as a result of the intensification of cyclonic activity in the North Atlantic, especially in the Norwegian Sea, caused by the processes of large-scale interaction between the ocean and the atmosphere, there is an increase in evaporation and in the zonal transfer of water vapour to Europe and then to the Volga basin. Therefore, more precipitation falls in the runoff-forming zone of the basin, the annual runoff of the Volga and the level of the Caspian Sea increasing. The reverse is observed with weakening of cyclonic activity in the North Atlantic. In view of this, the level of the Caspian Sea is an integral indicator of largescale moisture exchange in the ocean-atmosphere-land system. The article discusses the features of interannual sea level fluctuations in Kronstadt since 1836. A simple two-parameter model for forecasting sea level by the end of the 21st century is proposed for major climate scenarios, the predictors being the GSL and the North Atlantic Oscillation. According to the most realistic forecast, the level in Kronstadt may rise to 34-59 cm (Baltic system) by the end of the century, while according to the “pessimistic” one — to 80-90 cm (Baltic system). The estimates of the extreme storm surge at which the level rise north of the Gorskaya can reach 600 cm (Baltic system) are given. The effect of flooding from storm surges is especially strong near Sestroretsk. The total area of possible flooding of the Kurortny district at a 4-m high surge wave exceeds 1260 hectares, all the beaches being completely lost. The trajectories of flood cyclones and their role for periods of climate warming and cooling are considered

Tropical cyclone landfalls south of the Tropic of Capricorn, southwest Indian Ocean

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 79:23-37 (2019) - DOI: https://doi.org/10.3354/cr01575 Tropical cyclone landfalls south of the Tropic of Capricorn, southwest Indian Ocean Micheal T. Pillay, Jennifer M. Fitchett* School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg 2050, South Africa *Corresponding author: jennifer.fitchett@wits.ac.za ABSTRACT: Common perception holds that tropical cyclones occur exclusively within the latitudinal range of 5° to 20°S. However, a few storms have been recorded poleward of this range each decade over the past half century. This study explores tropical cyclone occurrence south of the Tropic of Capricorn in the southwest Indian Ocean (SWIO; defined as 0°-30°S; African East coast up to 110°E). Using observational tropical cyclone and climate data, the small subset of storms making landfall in the region were examined in detail. The records indicate a decrease in storm frequency, while intensity has increased over the study period (1950-2015). Sea surface temperature (SST) reveals the interaction and influence of surface thermodynamics on tropical cyclone trajectory. Zonal wind at the 500 mb level indicates a modulation on track morphology following genesis, and may be responsible for recurving tracks. A decadal variability is observed for landfall location, which is currently in a low-amplitude southward component. SST is significantly related to storm intensity, while the Dipole Mean Index (DMI) and Southern Annular Mode (SAM) are related to and coincide with the highest landfall years. The Multivariate El Niño Southern Oscillation Index (MEI) is related to recurving track trajectories, while DMI and SAM may influence latitudinal and longitudinal track trajectories. These findings are important in understanding recent changes in tropical cyclone dynamics in the southwest Indian Ocean, particularly as the range of storm occurrence has expanded under climate warming. KEY WORDS: Tropical cyclone · Southwest Indian Ocean · Tropic of Capricorn · Climatology · Climate Variability Full text in pdf format PreviousNextCite this article as: Pillay MT, Fitchett JM (2019) Tropical cyclone landfalls south of the Tropic of Capricorn, southwest Indian Ocean. Clim Res 79:23-37. https://doi.org/10.3354/cr01575 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 79, No. 1. Online publication date: October 17, 2019 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2019 Inter-Research.

Tropical cyclones and the organization of mangrove forests: a review.

Many mangrove ecosystems are periodically exposed to high velocity winds and surge from tropical cyclones, and often recover with time and continue to provide numerous societal benefits in the wake of storm events. This review focuses on the drivers and disturbance mechanisms (visible and functional) that tropical cyclones of various intensities have on mangrove ecosystem properties around the world, as well as the potential ecosystem services role offered by mangroves along storm-ravaged coastlines. When viewed together, studies describe repeatable types of impact and a variety of responses of mangroves that make them ecologically resilient to high velocity winds, and which have served to advance the notion that mangroves are disturbance-adapted ecosystems. Studies have documented massive tree mortality and forest structural shifts as well as high variability of spatial effects associated with proximity and direction of the tropical cyclone trajectory that influence biogeochemical processes, recovery of individual trees, and forest regeneration and succession. Mangroves provide coastal protection through surge and wind suppression during tropical cyclones, and yet are able to overcome wind effects and often recover unless some alternative environmental stress is at play (e.g. hydrological alteration or sedimentation). Structural elements of mangroves are influenced by the legacies imposed by past tropical cyclone injury, which affect their current appearance, and presumably their function, at any point in time. However, much is yet to be discovered about the importance of the effects of tropical cyclones on these fascinating botanical ecosystems, including the role of storm-based sediment subsidies, and much more effort will be needed to predict future recovery patterns as the frequency and intensity of tropical cyclones potentially change.

The Tropical Cyclone Tracks and Formation over the Western Indian Ocean, And Impacts on the Iranian Southern Coasts

Cyclones are as one of the most dangerous meteorological phenomena of the tropical region that generate strong winds and heavy rainfall, impacting coastal regions. Behavior of tropical cyclone trajectories needs to be better understood in order to find predictable aspects of landfall potentially. This research aims to analyze the cyclone tracks statistically and then study of the associated meteorological effects of Gonu cyclone in June 2007 as an example. Using the cluster analysis (K-mean method) 5 principal clusters have been derived and spatial – temporal studies including the monthly variation of cyclone trajectories and their intensity and frequencies are performed. The 4th cluster indicated more spatial variability and expansion (4º-31ºN and 48.5º-78ºE). The second cluster showed the highest frequency with 349 events as well as the highest maximum intensity and standard deviation of 235.2km/h and 47.96km/h respectively. During 1-7 June 2007, the Gonu super cyclone traversed the Arabian Sea and reached the Iranian southern regions affecting the coastal infrastructures and communities. In this 7-day period the daily composite maps of different atmospheric levels showed that by intensifying of Gonu cyclone the axis of subtropical high pressures in the lower levels moved to the east and in the 500hp level they moved to the northward over the study region.