Topic
Thundersnow
About: Thundersnow is a research topic. Over the lifetime, 75 publications have been published within this topic receiving 1281 citations. The topic is also known as: winter thunderstorm & thundersnowstorm.
Papers published on a yearly basis
Papers
TL;DR: In this paper, a strong correlation exists between the fraction of positive ground strokes and the vertical wind shear in the cloud layer, which helps to ensure that an initiating positive streamer will continue down to ground rather than into the negatively charged region that would normally be located directly below it.
Abstract: Lightning charges, locations, and currents have been determined for 12 flashes from four winter storms observed on the Hokuriku coast of Japan during December 1977 through January 1978. Additional data is available from a total of eight winter storms. The heights and magnitudes of the charges in strokes-to-ground were calculated from simultaneous measurements of electric field changes made at seven stations covering an area of about 150 km2. Discharges lowering positive charge to earth often exhibit large continuing currents (>104 A) for periods up to 10 ms. One positive discharge involved a peak current value of ≃105 A and a charge that exceeded 300°C after 4 ms. Negative continuing current strokes are generally an order of magnitude smaller, ≃4×103 A, involving charges of 100°C or less. The positive lightning charges are located higher than the negative charges of the same storm, constituting a ‘normal’ bipolar system similar to the charge configuration found in summer thunderstorms. For the eight storms observed during this study, 26 out of a total of 63 strokes-to-ground were positive. A strong correlation exists between the fraction of positive ground strokes and the vertical wind shear in the cloud layer. On the basis of this study we suggest that the occurrence of positive strokes-to-ground is a consequence of the wind shear. The shear provides a horizontal displacement between the charges that helps to ensure that an initiating positive streamer will continue down to ground rather than into the negatively charged region that would normally be located directly below it. The data suggest that positive strokes-to-ground should appear at a threshold shear value in the cloud layer of about 1.5 m/s/km.
315 citations
TL;DR: In this paper, the authors investigated the winter thunderclouds that frequently visit the southeastern coastal area of the Japan Sea and investigated the field work, operating radars, the sferics direction-finder system, and the field-mill network.
Abstract: The winter thunderclouds that frequently visit the southeastern coastal area of the Japan Sea were investigated by the field work, operating radars, the sferics direction-finder system, and the field-mill network. The clouds take the dipole electrical structure at their developing stage and then take the tripole structure at the mature stage. However, the period covering both dipole and tripole structures is very short (usually less than 10 min in early or late winter and less than several minutes in midwinter), because the graupel particles that carry the main negative charge and the lower positive charge do not stay stationarily in the clouds but fall off rapidly. For the remainder of the period of cloud duration, which lasts relatively long, the positive charge predominates in the clouds. The grade of charge separation and lightning activity is restricted by the altitude of −10°C temperature level. When the altitude is lower than 1.8 km, the clouds exhibit weak or no lightning activity. When it is lower than 1.4 km, the clouds exhibit neither natural lightning discharge nor tripole electrical structure.
118 citations
TL;DR: In this article, the shape and electric charge on particles in Hokuriku winter cumulus clouds have been measured using videosondes, and it was observed that the most active particle-charging process occurred at around the −20°C level.
Abstract: The shape and electric charge on particles in Hokuriku winter cumulus clouds have been measured using videosondes. The sign of the charge on graupel reversed at about −11°C. Charges on graupel and ice crystals are responsible for the tripole structure. The magnitude of the space charge increased as the particle concentrations increased. Graupel concentrations in excess of 1 L−1 and an average charge on the precipitation particles of a few tenths of pC produced an accumulated space charge sufficient to initiate lightning. These findings support the model results reported by Takahashi in which riming electrification mechanisms were emphasized as the primary charge separation process. It was also observed that the most active particle-charging process occurred at around the −20°C level.
96 citations
TL;DR: In this paper, the authors used the TRMM data from six winters (1998 until 2003) to study rainfall and lightning over the central and eastern Mediterranean Sea and found a strong correlation between rain rate and total flash rate.
Abstract: [1] Space-based instruments on the Tropical Rain Measuring Mission (TRMM) have been used to study rainfall and lightning over the central and eastern Mediterranean Sea. Data from six winters (1998 until 2003) were analyzed. Rainfall amounts increase during the winter months, with the maximum precipitation occurring during December, while lightning activity has a maximum during November. Analysis of seasonal rainfall and lightning activity showed a strong correlation with ENSO events. Instantaneous (90 second) analysis of the rain and lightning in individual storms reveals a strong correlation between rain rate and total flash rate. Monthly and seasonal correlation coefficients between rainfall and lightning were found to vary between 0.81 and 0.98, with the rainfall yield (kg/flash) found to vary between 2.5 × 108 and 9.7 × 108 kg/flash. Due to these high correlations we suggest the possibility to use lightning data over the Mediterranean Sea as a proxy for instantaneous rain rate in thunderstorms.
94 citations
TL;DR: In this article, the authors presented the global winter lightning activity for a period of 5 years and created six maps: annual winter lightning stroke density, seasonal variation of the winter lightning and the annual number of winter thunderstorm days.
Abstract: . Lightning is one of the major threats to multi-megawatt wind turbines and a concern for modern aircraft due to the use of lightweight composite materials. Both wind turbines and aircraft can initiate lightning, and very favorable conditions for lightning initiation occur in winter thunderstorms. Moreover, winter thunderstorms are characterized by a relatively high production of very energetic lightning. This paper reviews the different types of lightning interactions and summarizes the well-known winter thunderstorm areas. Until now comprehensive maps of global distribution of winter lightning prevalence to be used for risk assessment have been unavailable. In this paper we present the global winter lightning activity for a period of 5 years. Using lightning location data and meteorological re-analysis data, six maps are created: annual winter lightning stroke density, seasonal variation of the winter lightning and the annual number of winter thunderstorm days. In the Northern Hemisphere, the maps confirmed Japan to be one of the most active regions but other areas such as the Mediterranean and the USA are active as well. In the Southern Hemisphere, Uruguay and surrounding area, the southwestern Indian Ocean and the Tasman Sea experience the highest activity. The maps provided here can be used in the development of a risk assessment.
72 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2020 | 3 |
| 2019 | 5 |
| 2018 | 6 |
| 2017 | 1 |
| 2016 | 5 |