Search

The authors developed and used a game ( Tigo-Tigo) to collect data on people’s emotional experience in their environment in an area hit by a typhoon (Philippines). With the aim of encouraging the use of games for data collection in the field, they provide an in-depth analysis of all phases of the process, from the game development to the experience of the game sessions and the quality of the data produced. Designing a data collection game is creating an immersive experience that get people to share information with the researcher. However challenging to develop as it has to meet both data gathering and game requirements, Tigo-Tigo successfully produced complex data and a positive experience. By following its simple rules, the respondents were led to formulate and share both quantitative (emotion levels) and qualitative (explanations for emotion-environment associations) data. Moreover, the game was motivating and changed the status of participation, as the researchers played with the respondents in an inversed power setting. Finally, its particular interactional structure also improved the quality of the data produced by reducing expectation as well as cultural and translation barriers encountered in the field.

A new species Pavania foliata sp. n. (Acari: Heterostigmata: Dolichocybidae), phoretic on dung beetle Scarabaeus typhon Fischer-Waldheim (Coleoptera: Scarabaeidae) from southwest Russia, is described. The updated key to the species of the genus Pavania is provided.

The main goal of this thesis is develop a new multifractal nowcasting approach based on radar data, particularly for extreme events. Whereas the previous attempts where based on scalar cascades focused on the rain rate, this thesis will take into account the vector velocity field (and its multifractal variability, e.g. of its horizontal divergence), as well the terrain complexity and the consequent orographic effects. It will take hold on recent development of multivariate multifractal techniques (Schertzer and Tchiguirinskaia, 2015) that makes theoretically possible to represent together the advecting velocity field and the advected scalar field. However, there are still large uncertainties on the choice of the adequate class of models and their parameters, comparison with mesoscale models will be therefore quite helpful. The first stage of this thesis will be devoted to drastically reduce these uncertainties with the help of empirical data analyses, as well as possible theoretical insights (e.g. connectivity properties) and comparison with mesoscale models (e.g. selected key mechanism). The second stage will be devoted to develop and test a concrete nowcasting procedure based on these findings and attempting to use at best the radar data (including their Doppler information) and numerical weather prediction products., L'approche multifractale a été utilisée pour analyser le taux de précipitations de trois typhons (Khanun, Bolaven et Sanba) qui ont frappé la Corée du Sud en passant par l'île de Jeju vers la péninsule coréenne en 2012. Les données sur le taux de précipitations sont obtenues à partir d'un radar en bande S exploité par la Corée Administration météorologique (KMA) et la simulation de modèle CReSS. L'analyse multifractale a été réalisée à l'aide de l'analyse Trace Moment (Schertzer et Lovejoy, 1987) et de l'analyse Double Trace Moment (Lavallée et al., 1992) pour quantifier l'intermittence moyenne à l'aide de sa co-dimension fractale C1 et de sa multifractalité. index α, qui mesure la rapidité avec laquelle évolue l'intermittence pour l'ordre statistique supérieur avec une grande quantité de données spatio-temporelles. Premièrement, avec les données radar, l’analyse spectrale a été réalisée pour vérifier la prudence du champ. Dans le cas des typhons Khanun, Bolaven et Sanba, les valeurs moyennes de l’exposant d’échelle β pour l’analyse spectrale sont respectivement de 1,92 (Khanun), 1,710 (Bolaven) et 2,233 (Sanba), toutes ii hauteurs des domaines de 256 km. × 256 km. Alors que 2.515 (Khanun), 2.553 hauteurs des domaines de 256 km. × 256 km. Alors que 2.515 (Khanun), 2.553 (Bolaven) et 2.513 (Sanba) dans la taille du domaine 64 km × 64 km. Tous les champs de différentes tailles de domaines à différentes altitudes étaient conservateurs. En analyse TM et DTM, avec l'ordre des moments q et (q, η), il est montré que K (q) et K (q, η) satisfont à la forme universelle présentant les paramètres de messagerie unifiée α et C_1. Chaque paramètre indique le degré de multifractalité du processus (α) et la codimension de la singularité moyenne du champ (C_1). Dans tous les cas, les champs pluviométriques étaient constants en basse altitude (1, 2 km), alors que les fluctuations étaient plus marquées en haute altitude. Pour vérifier le résultat de l'observation radar, nous avons également utilisé le taux de précipitation obtenu par simulation du modèle CReSS. En conséquence des paramètres de messagerie unifiée de tous les cas du modèle CReSS, uniquement dans le cas de Khanun, α est inférieur à 1 dans les deux domaines. D'autre part, α est supérieur à 1 avec Bolaven et Sanba dans les deux domaines. Avec le résultat, il est montré qu'il existe une dépendance de α] avec l'altitude qui montre la déduction de la configuration du champ de précipitations dans chaque altitude avec les paramètres UM. Cela permet de voir l'évolution du champ de précipitations. Lorsque le typhon a traversé l’île de Jeju, où se trouve le mont Halla, il a commencé à diminuer les cyclones, libérant ainsi son humidité sous forme de pluie torrentielle sur l’île. Étant donné que le stade de tous les typhons était en phase d'affaiblissement ou de dissipation, les paramètres UM montrent que le cisaillement du vent a incliné le vortex pour obtenir les différentes configurations des champs de précipitations à chaque altitude

Communities settled in volcanic areas have been affected by volcanic manifestations and have consequently tried to understand these phenomena, an interest developed since the most ancient times and which predate philosophical and scientific speculations. The study of myths can, however, shed light on the behaviour of ancient communities and on past beliefs towards volcanoes. The present contribution will focus on a peculiar and highly interesting geo-myth: the fight of Typhon and Zeus, which can be seen as a mythological description of Etna eruptions. Through a comparison with legends from Pacific Islands, we will examine how the geomythological approach can provide new insights in the study of ancient volcanism.; Les habitants des terres environnant des volcans et affectées par leurs manifestations ont toujours été intéressés par ces phénomènes. Depuis l'Antiquité, ils ont essayé de les comprendre. En dehors des spéculations philosophiques, l'analyse de certains récits mythologiques peut dévoiler des pistes de recherche intéressantes pour la compréhension de l'attitude des Anciens face aux volcans. Nous allons présenter ici un géomythe en particulier, celui du combat de Typhon, représentatif de la violence des éruptions de l'Etna. À travers une comparaison avec des légendes des îles du Pacifique nous allons examiner les nouvelles perspectives que l'approche géomythologique permet d'explorer.

The third generation wind-wave model Mike21-SW was used to study spectral characteristics of waves generated by the historical Cyclone Gonu in June 2007 along and off the Iranian coasts on the northern Oman Sea. The model was forced with the cyclone wind field generated using a Holland (1980) model based on cyclone data obtained from the Joint Typhon Warning Center (JTWC). The wave model was calibrated for the northern Oman Sea using bulk and spectral wave data at a station out of the Chabahar Bay. Evolution of directional-frequency spectra during the cyclone was investigated for two locations near the entrance and off the Chabahar Bay. At the offshore station, energy was contributed to the spectrum over an approximately 180 degree directional span that included different local and remotely generated waves. As the cyclone proceeded northwestward, all spectral directions continuously rotated in the clockwise direction at both locations. Frequency spectra at these locations were investigated for four different times corresponding to different locations of Cyclone’s eye and were justified using the sea growth parameter of the Joint North Sea Wave Project (JONSWAP) experiment. Using the modified JONSWAP parameters for hurricane conditions resulted in a frequency spectrum consistent with simulation results.

This chapter discusses how Valerius Flaccus in his Argonautica extends Pindar’s location of Typhon beneath the Bay of Naples (Pyth. 1.15–28) to associate mythology’s most notorious theomach with the Phlegraean Fields (V. Fl. 6.169–70) and, by conjunction with Ischia’s volcano Inarime, possibly even with Mount Vesuvius itself. In Flavian literature gigantomachy becomes symbolic of civil conflict and empire. Although Valerius’ epic narrative is played out far from Italy, the menace of Campania’s incarcerated giant reappears through digression, intertext, imagery, and genealogy, to the point that the adventures of Jason’s Argonauts seem Romanized through these recurrent reminders of civil war.

In 1987 an Archaic Argive-type shield and shield-band were discovered in the sanctuary on the acropolis of Oisyme. Such shields are found in the cemeteries of the northern Aegean, including those at Sindos and Archontiko. However, the Oisyme shield is as yet the only one to come from a sanctuary - a fact due, at least in part, to the limited exploration of early sanctuaries on the coast of Aegean Thrace. It is also the earliest known example of its type in the north-eastern Aegean. Considered alongside earlier literary evidence, such as Archilochus 5W, it helps to trace the introduction and development of the hoplite panoply in Thasos and its peraea. The shield and shield-band can be dated to c.575-550 bce on the basis of their repoussé decoration. The dies employed may have been imported from Peloponnesian (Argive or Corinthian) workshops or produced locally. They show stylistic influence from the contemporary Peloponnese, yet they have no known exact parallels. Metalworkers from the polis of Thasos and its peraea are likely to have imitated the products of southern workshops in much the same way that Thasian potters based their own early production on Cycladic, Chian and other wares. The deity worshipped in the Oisyme sanctuary was an ergane and/or a kourotrophic goddess, such as Artemis and Athena at nearby Thasos or the 'Parthenos' at neighbouring Neapolis. It is unlikely that rites of passage for hoplites were a central feature of the cult, since we lack the extensive corpus of weaponry (miniature and/or functional) typical in such cases. The limited number of weapons recovered from the sanctuary fits the established model for female poliad deities in smaller poleis. The shield was probably a personal gift, dedicated either by a retiring hoplite or as a thank offering after a military victory., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

Among the current population of the 81 known trans-Neptunian binaries (TNBs), only two are in orbits that cross the orbit of Neptune. These are (42355) Typhon-Echidna and (65489) Ceto-Phorcys. In the present work, we focused our analyses on the temporal evolution of the Typhon-Echidna binary system through the outer and inner planetary systems. Using numer- ical integrations of the N-body gravitational problem, we explored the orbital evolutions of 500 clones of Typhon, recording the close encounters of those clones with planets. We then analysed the effects of those encounters on the binary system. It was found that only 22% of the encounters with the giant planets were strong enough to disrupt the binary. This binary system has an ~3.6% probability of reaching the terrestrial planetary region over a time scale of approximately 5.4 Myr. Close encounters of Typhon-Echidna with Earth and Venus were also registered, but the probabilities of such events occurring are low (~0.4%). The orbital evolution of the system in the past was also investigated. It was found that in the last 100 Myr, Typhon might have spent most of its time as a TNB crossing the orbit of Neptune. Therefore, our study of the Typhon-Echidna orbital evolution illustrates the possibility of large cometary bodies (radii of 76 km for Typhon and 42 km for Echidna) coming from a remote region of the outer Solar System and that might enter the terrestrial planetary region preserving its binarity throughout the journey., Comment: 10 pages, 8 figures

Following a numerical simulation study, we analyze the effect of the parameter of the cloud condensation nuclei concentration (CNP) on Typhoon Chanchu in convective, stratiform, and mixed precipitation areas based on the following three experiments: (1) a control (CTL) experiment using a mesoscale model and the Reisner-2 cloud scheme with the CNP value specified as 100 cm − 3 ; (2) a very clean marine (VCM) CNP experiment (CNP = 25 cm − 3 ); (3) and a severe contamination (SC) CNP experiment (CNP = 1000 cm − 3 ). We compare and analyze the simulated cloud structure and microphysical processes of the three experiments within the convective, stratiform, and mixed areas. The three precipitating areas are classified based on the ratio of cloud ice content to cloud water content at all precipitating grids proposed by Sui et al. (2007) . The results show that the intensities of most microphysical processes are the largest in the convective area and the smallest in the stratiform area. Ice is dominant in the stratiform region and the water hydrometeor is dominant in the convective region. Furthermore, cloud water develops more quickly than cloud ice do in the mixed area. The response of the convective area to a varying CNP is greater than that of the stratiform area, and the mixed area is only slightly sensitive to the CNP. The dominance of cloud microphysical processes related to the growth of water hydrometeors weakens as the CNP increases.

Abstract Various mythical ‘exiles’, gods (Cronus), heroes (Cadmus), and other individuals (Ophion, Typhon, Ogygus, Briareus) or groups (Cyclopes) were conceived as exiled for various reasons, but mainly because of a struggle with Zeus. Locations of their mythical exile were regularly conceived as distant, extreme, inaccessible, and, sometimes, out of this world. Consequently, the terms sometimes associated with those mythical exiles are ἔσχατα, ἄκρος, and πέρατα. Most of the exiles were at some point placed in Tartarus, a term more or less applicable to a section of Hades; but they were regularly conceived as continuing their existence by the shore of the mythical Oceanus, most probably in the farthest West. In a number of cases, both versions of the story existed, and they probably referred to the same thing: one can be at the ἔσχατα, ἄκρος, or πέρατα both under earth and at its western extremity. This fact is explained by the existence of two mythical models accounting for the diurnal solar movement.

Tropical cyclones, also known as typhoons, in the northwest Pacific are an important air–sea interaction process that transports massive amounts of heat and moisture. In this article, we present detailed observations of the ocean responses to Typhoon Lupit, formed on 14 October 2009. The maximum sea surface temperature SST drop of 7°C appeared on 25 October 2009, and the area of the negative sea-level anomaly expanded under the influence of Typhoon Lupit. After passage of the typhoon, the chlorophyll- a concentration increased by 0.3 mg m−3, showing the primary production blooming. A further analysis indicates that Typhoon Lupit caused a rightward bias on the SST change due to the resonance of rotation of the wind vector with wind-driven inertial currents. By a regression analysis, it is found that the increase of the chlorophyll- a concentration and the SST decrease follow a linear relationship with different slopes for the different typhoon stages.

Southeast coastal region is the most developed and populated area in China, and also is one of the regions most seriously impacted by typhoons in the world. In this paper, typhoon wind hazard analysis for 11 major cities, Shanghai, Ningbo, Wenzhou, Fuzhou, Xiamen, Taipei, Guangzhou, Shenzhen, Hong Kong, Zhanjiang, and Haikou, in the southeast China coastal regions, is conducted for the first time. The historical typhoon data from the China Meteorological Administration (CMA) and the State Oceanic Administration is carefully processed and the probabilistic distributions of the key typhoon parameters for the 11 cities are established. The correlations between the key typhoon parameters are carefully evaluated. The wind field model given by Thompson and Cardone is introduced, and the radial pressure profile is properly addressed with validation of the model by six cyclones. Monte Carlo random sampling method is employed to generate virtual typhoons and 1000 years of typhoons are simulated for the 11 cities. Extreme wind speeds of different return periods are then predicted. There is a reasonable agreement between the predictions of wind speed in the code of Hong Kong and available literature, suggesting that the approach is effective in determining the design wind speeds for critical structures in the southeast China coastal regions.

Typhoon Morakot pounded Taiwan in 2009 with record-breaking rainfall, washing an unprecedented amount of driftwood into the sea that was partially deposited at the coastal areas. According to the satellite imagery analysis, more than three million trees fell and were washed away to occupy 83.2% of the Taiwanese coastline, including 52 fishing harbors. The amount cleaned-up was only 1/7 of the total coastal driftwood. It was found that the amount of coastal driftwood is not only related to the amount of precipitation but is also related to the distance from the location of the landslide to the river mouth and to the landslide area. The amount of accumulated coastal driftwood demonstrated log-profile declines with increasing distance to the river mouth. Nearshore current and wave motion are the critical factors for driftwood deposition. Much of the driftwood washed into the sea harmed the tourism and fishing industries, endangered navigation and oceanic activities, and impacted the marine environment and ecosystem.

We studied how typhoon strength affects the daily dynamics of ecosystem metabolism of a subtropical alpine lake in Taiwan. We identified proximal agents of typhoon disturbance and assessed the resistance (the extent of change induced by a disturbance) and resilience (the rate of recovery after a disturbance) of lake metabolism to them. Gross primary production (GPP), ecosystem respiration (ER), and net ecosystem production were estimated from high-frequency dissolved oxygen data provided by an instrumented buoy. Typhoons resulted in significantly lower GPP (3%–81% decrease), and higher ER (7%–828% increase) compared with immediately before the events, and thus the lake became more heterotrophic (28%–852% increase in heterotrophy). The resistance and resilience of lake metabolism depended on the intensity of the typhoon. Smaller typhoons (with average daily accumulated precipitation (ADAP) < 200 mm·day–1) had greater effects on lake metabolism than medium (ADAP = 200–350 mm·day–1) and large (ADAP > 350 mm·day–1) typhoons. However, metabolism also recovered more quickly after smaller typhoons than after medium or larger typhoons. Typhoon effects on ecosystem metabolism is likely mediated by the magnitude and duration of typhoon-induced changes in lake mixing, the quantity and quality of dissolved organic carbon, and the biomass of primary producers.

Typhoon passages across Taiwan can generate sudden surface warming in downslope regions. Special characteristics and mechanisms for 54 such warming events that were identified during the 1961–2007 period are examined. Preferred warming regions were identified in northwest Taiwan, where warming is generated by downslope flow from east or northeast winds in westward-moving typhoons, and in southeast Taiwan, where it is generated by downslope flow from west or northwest winds in northwestward-moving typhoons. In addition to the orographic effect, warmings occurred exclusively within nonprecipitation zones of typhoons. Most northwest (southeast) warmings occur during the day (night) with an average lifetime of 4 (5) h, which roughly corresponds to the average time a nonprecipitation zone remains over a station. During the period examined, three typhoons generated warming events in both northwest and southeast Taiwan, and only Typhoon Haitang (2005) generated warmings with comparable magnitudes (∼12-K increase) in both regions. For Typhoon Haitang as an example, diagnostic analyses with two different approaches reveal that the majority of the warming is contributed by downslope adiabatic warming, but the warming associated with the passage of a nonprecipitation zone is not negligible. Similar results were found when these two diagnostic approaches were applied to the other warming events. The diurnal mode of the atmospheric divergent circulation over East Asia–western North Pacific undergoes a clockwise rotation. The vorticity tendency generated by this diurnal divergent circulation through vortex stretching may modulate the arrival time of typhoons to cause daily (nighttime) warming in the northwest (southeast).

The interaction of the storm circulation with the Central Mountain Range (CMR) of Taiwan is studied with a wind profiler located at the leeside during the invasions of two (Kaemi (200605) and Bopha (200609)) typhoons. The moderate typhoon Kaemi upgraded from a tropical depression on 21 July 2006. It then was made landfall at 15:45 UTC on 24 July 2006 near Cheng-Kung. The weak typhoon Bopha formed at about 12:00 UTC on 5 August 2006 and also landed near Cheng-Kung at around 19:20 UTC on 8 August. A new finding from both typhoons is the vortex splitting into upper and lower parts with the two typhoons that have passed the observation site nearly. For the typhoon Kaemi, demarcation height of the upper-level vortex and lower level is at 2.8 km and passed the site about 3 h earlier than the low-level one. For the typhoon Bopha, the center of the lower-level vortex at 3.5 km locates to the north of the upper-level one at 5.2 km. The re-organization of the split vortexes is found in typhoon Kaemi but not for typhoon Bopha.

L-band wind profiler data are utilized to diagnose the vertical structure of the typhoon precipitating cloud systems in Taiwan. For several typhoons, a pronounced bright band (BB) around 5 km is commonly observed from the observation. Since strong convection within typhoon circulation may disturb and/or disrupt the melting layer, the BB shall not appear persistently. Hence, an understanding of the vertical structure of the BB region is important because it holds extensive hydrometeors information on the type of precipitation and its variability. Wind profiler observational results suggest that the mixture of convective and stratiform (embedded type) clouds are mostly associated with typhoons. In the case of one typhoon, BB is appeared around 5.5 km with embedded precipitation and also BB height of 1 km higher than ordinary showery precipitation. This is evident from the long-term observations of wind profiler and Tropical Rainfall Measuring Mission. The Doppler velocity profiles show hydrometers (ice/snow) at 6 km but liquid below 5 km for typhoons and 4 km for showery precipitation. In the BB region the melting particles accelerations of 5.8 ms−1 km−1 and 3.2 ms−1 km−1 are observed for typhoon and showery precipitation, respectively.

The Hangzhou Bay faces frequent threats from typhoon-induced storm surge and has attracted considerable attentions of coastal researchers and environmental workers. A three-dimensional storm surge model system based on Finite-Volume Coastal Ocean Model (FVCOM) and analytical cyclone model is applied to investigate the hydrodynamic response in the Hangzhou Bay to tropical typhoon. This model has been used to reproduce the storm surge generated by Typhoon Agnes (No. 8114) and the simulated wind field and water elevations have been compared with the available field observations. A series of numerical experimental cases have been conducted to study the effects of land reclamation project (shoreline relocation and seabed deformation) and cyclonic parameters (minimal central pressure (MCP), radius to maximal wind (RMW) and translation speed (TS)) on the hydrodynamics in the Hangzhou Bay. The results show that the shoreline relocation and seabed deformation could generate much higher storm surge in the vicinity of reclamation project with the shoreline relocation making main contribution (about 70%) to this increase. It is found that among the cyclonic parameters, RMW is the most important factor affecting the peak surge in the Hangzhou Bay.

Typhoon No. 14 in 2005 caused significant rainfall in Yamaguchi Prefecture of Japan, and, due to this, an embankment of Sanyo Expressway at Hataki in Iwakuni city failed. Detailed investigation was conducted after this event in order to identify the mechanism of this failure, which consisted of the field studies as well as laboratory tests and numerical analyses. It was consequently shown that the combined effects of heavy rainfall and the local geological and topographic conditions as well as the reduction of drainage capability due to the breakage of perforated pipe in the underdrainage system were the causes of the failure.

Eleven (10 Pacific, 1 Atlantic) tropical cyclones (TCs), which include typhoons/hurricanes and tropical storms, are examined using the latest 40-yr ECMWF Re-Analysis (ERA-40) dataset and Joint Typhoon Warning Center (JTWC) best-track data to determine if and how tropical upper-tropospheric trough (TUTT) cells influence TC tracks. This type of interaction has led to rather large TC track forecast errors at 72 h (2000+ km) in the northwest Pacific and is often ignored or poorly forecast due to inadequate numerical model TUTT cell predictions. Ten selected cases out of the initial 25 potential Pacific cases exhibited a “nonstandard” TC track; a TUTT cell was the sole large-scale transient feature within 2000 km of the TC’s center, and the TC intensity was >17 m s−1. The circulations’ separation distance, orientation, intensity, and TUTT cell’s closed circulation size are critical characteristics in determining the likelihood of a TUTT cell influencing a TC track. Interactions occur at distances greater than 1700 km, continue for periods from 24 to 48 h, and occur 2–3 times per year in the NW Pacific. Examination of the TC’s tropospheric winds’ deep layer mean (100–1000 hPa), and upper (100–500 hPa), middle (300–850 hPa), and lower (500–1000 hPa) layers, along with various quadrants of the upper layer, demonstrate a link between the TUTT cell’s wind field and the nonstandard TC tracks. A conceptual model of how a TUTT cell can influence TC track is presented. The model provides decision-grade operational guidance for TC forecasters using pattern recognition scenarios. Application of the conceptual model at the JTWC is currently under way.

An Observing System Experiment (OSE) has been performed to investigate the effectiveness of dropwindsonde observations and a sensitivity analysis technique on a typhoon track forecast. Using dropwindsonde observations for Typhoon Conson at 1200 UTC 8 June 2004, which are derived from Dropwindsonde Observation for Typhoon Surveillance near the Taiwan Region (DOTSTAR), four numerical experiments are conducted, which are different only in terms of the number of dropwindsonde observations used in a data assimilation system: (i) no observation is assimilated; (ii) all observations are assimilated; (iii) observations within a sensitive region as revealed by a singular vector method at the Japan Meteorological Agency (JMA) are assimilated; and (iv) observations outside the sensitive region are assimilated. In the comparison of the four track forecasts, Conson’s northeastward movement is expressed in the second and third simulations while in the first and fourth experiments Conson stays at almost the same position as its initial position. Through the OSE, it is found that DOTSTAR observations had a positive impact on the track forecast for Conson, and that observations within the sensitive region are enough to predict the northeastward movement of Conson, indicating that the JMA singular vector method would be useful for the sampling strategy of targeted observations like DOTSTAR.

The visible spectra of (42355) Typhon showed evidence for aqueously altered materials. Therefore we seek to understand if such an event is possible.We use data from the ESO/Very Large Telescope together with the Hapke Hapke radiative transfer model to interpret the surface composition of (42355) Typhon over the whole spectral range (~0.5 − 2.4 μm).Our results points that (42355) Typhon could be a fragment from a larger parent body that suffered aqueous alteration.

This paper presents a new approach for forecasting the typhoon frequency of the western North Pacific (WNP). The year-to-year increase or decrease in typhoon frequency is first forecasted to yield a net typhoon frequency prediction. Five key predictors for the year-to-year increment in the number of typhoons in the WNP have been identified, and a forecast model is established using a multilinear regression method based on data taken from 1965 to 2001. Using the forecast model, a hindcast of the typhoon frequency of the WNP during 2002–07 is made. The model exhibited a reasonably close fit for the period 1965–2007, including the larger anomalies in 1997 and 1998. It also accounted for the smaller variability of the typhoon frequency of the WNP during the validation period 2002–07 with an average root-mean-square error (RMSE) of 1.3 (2.85) during 2002–07 (1965–2001). The cross-validation test of the prediction model shows that the new approach and the prediction model demonstrate better prediction skill when compared to the models established based on typhoon frequency rather than the typhoon frequency increment. Thus, this new approach has the potential to improve the operational forecasting skill for typhoon frequency in the WNP.

A heavy rainfall event in the Taiwan area associated with the interaction between Typhoon Babs (1998) and the East Asia winter monsoon is studied. Typhoon Babs is a case in point demonstrating the often-observed phenomenon that heavy rainfall can be induced in the eastern and/or northeastern region of Taiwan. Such heavy rainfall was caused by the joint convergent flow associated with the outer circulation of typhoons and the strengthening northeasterly monsoon in late typhoon season, even though Babs remained distant from Taiwan when it moved through the island of Luzon in the Philippines and stayed over the South China Sea. This heavy rainfall event is simulated in this study using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) with three nested domains and a highest horizontal resolution of 6.67 km. The control experiments with Kain–Fritsch cumulus parameterization perform well in terms of both simulated track and intensity. The 20-km resolution simulation reproduces the correct rainfall distribution during the three days studied, and the fine domain with 6.67-km resolution further improves the maximum simulated rainfall to very close to the observations. A series of sensitivity experiments that include model physics, terrain effect, typhoon vortex structure, and monsoon strength is performed, aiming at investigating the predictability of this typhoon–monsoon–terrain system when some of its components are perturbed. The rainfall event is analyzed based on two rainfall modes of different dominant mechanisms: monsoon mode during 0000 UTC 24–25 October and topographic mode during 0000 UTC 25–26 October. Removal of the Taiwan terrain in one of the sensitivity experiments results in completely different rainfall distribution due to the lack of the convection by orographic lifting, and the terrain is also found to play a key role in changing the low-level convergence pattern between the typhoon circulation and monsoonal northeasterlies. When the radius of the bogus vortex is reduced, the cold front to the north migrates southward in a faster pace than in the control simulation, and rain rate at the front also increases such that total accumulated rainfall at northern Taiwan is comparable with that in the control simulation but with shifted maximum position. In the extreme case in which no bogus vortex is implanted at all, rainfall is mainly associated with evolution of the cold front (pure frontal mode). In addition, a technique is developed to modify the monsoon strength over China. It is found that low-level (1000–700 hPa) reduction in monsoon strength weakens interaction with the typhoon, and rain distribution remains the same as in the control simulation. However, the simulated typhoon track is considerably sensitive to the deep-layer (1000–300 hPa) monsoon strength.

Bayesian analysis is applied to detect changepoints in the time series of seasonal typhoon counts in the vicinity of Taiwan. An abrupt shift in the typhoon count series occurs in 2000. On average, 3.3 typhoons per year have been noted before 2000 (1970–99), with the rate increasing to 5.7 typhoons per year since 2000 (2000–06). This abrupt change is consistent with a northward shift of the typhoon track over the western North Pacific–East Asian region and an increase of typhoon frequency over the Taiwan–East China Sea region. The northward shift of the typhoon track tends to be associated with typhoon-enhancing environmental conditions over the western North Pacific, namely, the weakening of the western North Pacific subtropical high, the strengthening of the Asian summer monsoon trough, and the enhanced positive vorticity anomalies in the lower troposphere. Based on observational analysis and model simulations, warm sea surface temperature anomalies over the equatorial western and central Pacific appear to be a major factor contributing to a northward-shifted typhoon track.

This paper presents a subjective search for North Sea Draupner-like freaque waves from wave measurement data available in the northeastern coastal waters of Taiwan during Typhoon Krosa, October 2007. Not knowing what to expect, we found rather astonishingly that there were more Draupner-like freaque wave types during the build-up of the storm than we ever anticipated. As the conventional approach of defining freaque waves as Hmax/Hs>2 is ineffective to discern all the conspicuous cases we found, we also tentatively proposed two new indices based on different empirical wave grouping approaches which hopefully can be used for further development of effective indexing toward identifying freaque waves objectively.

The tropical rainfall potential (TRaP) technique is a simple concept that serves as a useful tool for forecasters in predicting the accumulated rainfall from typhoons. This research seeks to propose an algorithm for improving the accuracy of the results retrieved from the TRaP technique by taking into account the terrain’s influence on a typhoon’s rainfall pattern over Taiwan. The climatological percentages of the accumulated rainfall in Taiwan for six different typhoon tracks were established via statistical methods. By using the rainfall percentages with the original TRaP technique, results showed that the original TRaP technique could retrieve a graphical representation of the accumulated rainfall from typhoons for both oceans and flat land areas. When factoring in Taiwan’s terrain, the accuracy in a typhoon’s accumulated rainfall estimation is seen to further improve.

To quantitatively investigate the dynamic and thermal responses of the South China Sea (SCS) during and subsequent to the passage of a real typhoon, a three-dimensional, regional coupled air–sea model is developed to study the upper ocean response of the SCS to Typhoon Krovanh (2003). Owing to the scarcity of ocean observations, the three-dimensional numerical modeling with high resolution, as a powerful tool, offers a valuable opportunity to investigate how the air–sea process proceeds under such extreme conditions. The amplitude and distribution of the cold path produced by the coupled model compare reasonably well with the TRMM/TMI-derived data. The maximum SST cooling is 5.3 °C, about 80 km to the right of the typhoon track, which is consistent with the well-documented rightward bias in the SST response to typhoons. In correspondence to the SST cooling, the mixed layer depth exhibits an increase; the increases in the mixed layer depth on the right of typhoon track are significantly higher than those on the left, with maxima of 58 m. This correspondence indicates that the SST cooling is caused mainly by entrainment. Under the influence of typhoon, a cyclonic, near-surface current field is generated in the upper ocean layer, which moves with the typhoon. The typhoon-induced horizontal currents in the wake of the storm have strong near-inertial oscillation, which gradually propagates downward. The unique features of the SCS response to Typhoon Krovanh are also discussed, such as Kuroshio intrusion and coastal subsurface jets.

An automatic measuring system for the partial pressure, pCO2, of atmospheric and oceanic carbon dioxide was developed. The system was mounted on a moored buoy for routine observation of maritime meteorology in the East China Sea. CO2 observations were conducted from June 29, 1997 to January 6, 1998. During the observation period, the atmospheric pCO2 showed little variation (341–365 μatm), whereas pCO2 in the surface water varied significantly (308–408 μatm). In the summer, pCO2 was higher in the surface water than in the overlying atmosphere, implying that this area was a source for atmospheric CO2, though it became a sink after late September. Time-series data clearly exhibited significant short-term variations in the oceanic pCO2, i.e. sudden variations during the passage of typhoons, and diurnal variations driven by the diurnal variations in the sea-surface temperature under calm conditions. The effects of typhoons on ocean–atmosphere CO2 exchange at the surface could differ, depending on the relative position of the mooring site with respect to the center of the moving typhoons. These differences result from the different contributions of sea-surface cooling, entrainment, and upwelling. The efflux enhanced by three typhoons accounted for 60% of the efflux of CO2 in the warm season. It is suggested that typhoons have a significant impact on the carbon cycle in the western subtropical North Pacific.

Typhoon Herb in 1996 caused widespread debris flows in central Taiwan. The 7.3 Chi-Chi earthquake on September 21, 1999, which also took place in central Taiwan, induced many landslides in the region. These landslides turned into debris flows when Typhoon Toraji struck Taiwan in 2001. This research selects three regions which suffered a ground motion class of 5, 6, and 7 on the Richter scale during the Chi-Chi earthquake as study areas. Air photos from 1997 and 2001 of these regions are used to map the gully-type debris flows that took place after Typhoons Herb and Toraji, respectively. The gullies adjacent to the debris flow, but without a trace of debris flows, are also mapped as the non-debris flow data. The topography, hydrogeology, and rainfall factors – where debris flow occurred and in which there was no occurrence of debris flows in these gullies were retrieved from DTM, geological maps, and iso-countour maps, and of rainfall through GIS processing. These characteristic are introduced into a probabilistic neural network to build a predicting model for the probability of the occurrence of debris flows. Three series of cross analyses are conducted to compare the probability of the occurrence of debris flows of the same dataset predicted by different prediction models. The results reveal that the susceptibility of debris flows was elevated after the Chi-Chi earthquake struck. The upsurge of susceptibility was more obvious for the regions that received a higher class of ground motion.

In Pindar’s Pythian I, 15-28 and Aeschylus’ Prometheus, 347-376 we find the first approach to the phenomenon of Etna (c. 479 b.C. / 475 b.C.). Both poets connected it with the old giant Typhon; at ...

An interesting eyewall evolution occurred in Typhoon Zeb (1998) when it devastated Luzon. The eyewall of Zeb contracted before landfall and broke down and weakened after landfall; then a much larger new eyewall formed and strengthened as it left Luzon and reentered the ocean. The fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) with four nested domains was used to perform numerical experiments to understand the effects of terrain and land surface variation on the observed eyewall evolution. Results show that the presence of Luzon plays a critical role in the observed eyewall evolution. Quite different from the conventional concentric eyewall replacement, the eyewall replacement that occurred in Typhoon Zeb was triggered by the mesoscale landmass and terrain variation with a horizontal scale similar to the core of the typhoon. In Typhoon Zeb, the original eyewall contracted and broke down because of enhanced surface friction after landfall. The outer eyewall was triggered by convective rainbands near the western coastal region of Luzon and formed as a result of axisymmetrization well after the dissipation of the inner eyewall convection. Several sensitivity experiments were conducted to elucidate the roles of both condensation heating and planetary boundary layer processes in the evolution of the typhoon eyewall. It is found that although condensational heating is the key to the maintenance of the annular potential vorticity (PV) structure, surface friction plays dual roles. Although friction is a sink to PV and thus dissipates PV in the eyewall, it helps keep the PV annulus narrow by enhancing the stretching deformation in the lower troposphere when condensational heating is present. In the absence of condensational heating, however, surface friction enhances the inward PV mixing by boundary layer frictional inflow and thus destroys the PV annulus.

The landslide area along the Tachia River catchment of central Taiwan was investigated using the remote sensing images of various typhoon and earthquake events taken from 1996 to 2004 and the sediment discharge measured at hydrometric stations. Our findings indicate that 88% of the coseismic landslides triggered by the 1999 Chi-Chi earthquake were first-time occurrences. After the Chi-Chi earthquake, 59% of the landslide area was reactivated during typhoon Toraji and 66% during typhoon Mindulle. The landslides prone to reactivation were on the formations with closely spaced discontinuities. It is suggested that further rock-mass defects in the formations were added or opened by the earthquake, and that the landslide areas continued to extend until the end of 2004. Post-1999 rainstorms delivered large amounts of colluvial sediment into the main channel, leading to a 2-fold increase in post-seismic sediment discharge while the precipitation was only half that of the pre-earthquake rate.