scholarly journals The Relationship of Lightning Activity with Microwave Brightness Temperatures and Spaceborne Radar Reflectivity Profiles in the Central and Eastern Mediterranean

2007 ◽  
Vol 46 (11) ◽  
pp. 1901-1912 ◽  
Author(s):  
D. K. Katsanos ◽  
K. Lagouvardos ◽  
V. Kotroni ◽  
A. A. Argiriou
Keyword(s):  
Eastern Mediterranean ◽  
Tropical Rainfall Measuring Mission ◽  
Radar Reflectivity ◽  
Lightning Activity ◽  
Brightness Temperatures ◽  
Maximum Reflectivity ◽  
Total Lightning ◽  
Relationship Of ◽  
Imaging Sensor ◽  
The Relationship

Abstract In this paper, the relationship of lightning activity in the central and eastern Mediterranean with the 85-GHz polarization-corrected temperature (PCT) and radar reflectivity provided by the Tropical Rainfall Measuring Mission (TRMM) satellite is investigated. Lightning observations were mainly provided by the Met Office’s Arrival Time Difference system as well as by the TRMM Lightning Imaging Sensor. The studied period spans from September 2003 to April 2004 and focuses on the events with the most important lightning activity. It was found that 50% of the cases with flashes have PCTs lower than 225 K, while only 3% of the “no lightning” cases have PCTs below this value. Further, if PCT is used as a proxy for the presence of lightning, the value of 217 K gives the best statistical scores for the presence of at least one observed flash. In addition, the ratio of cloud-to-ground lightning to total lightning activity has higher values for the “colder” PCT values and decreases as PCT increases. In addition, the mean and maximum reflectivity profiles with collocated lightning are from 3 to 10 dB and from 6 to 15 dB, respectively, higher than that without lightning. Further, a reflectivity profile with values greater than 53 dBZ in the low levels (below 3 km), of ∼45 dBZ at 5 km and 40 dBZ at 7 km is associated with a probability of 80% for lightning occurrence.

Changes of Lightning Activity and Vertical Structure in the Inner Core Preceding Tropical Cyclone Rapid Intensification

2020 ◽  
Author(s):  
Weixin Xu
Keyword(s):  
Tropical Cyclone ◽  
Inner Core ◽  
Radar Reflectivity ◽  
Lightning Activity ◽  
Intensity Change ◽  
Complete Understanding ◽  
Radar Echo ◽  
Storm Dynamics ◽  
Total Lightning ◽  
Imaging Sensor

<p>Previous studies suggested that lightning activity could be an indicator of Tropical Cyclone (TC) intensity change but their relationships vary greatly and at times appear contradictory. The importance of total lightning for TC intensification study and forecasting applications has also been pinpointed by several studies. Recently, we revisited this problem using 16 years of TRMM Lightning Imaging Sensor (LIS) measurements and found that reduced (elevated) inner-core total lightning marked rapidly intensifying (weakening) TCs, whereas outer rainband total lightning had opposite trends. It is also shown that the reduced lightning frequency in the inner cores of rapidly intensifying storms was coincident with reduced volumes of 30-dBZ radar reflectivity in the mixed-phase cloud region (-5 to -40 oC), suggesting the lack of large ice particles (e.g., graupel) in the inner cores of rapidly intensifying TCs (which is considered to be important for cloud electrification). To better understand the physical process responsible for these results, we have examined the vertical profiles of radar reflectivity, distribution of precipitation/convection, overshooting radar echo tops (CloudSat), and microwave ice scattering signatures provided by GPM and CloudSat overpasses. This data fusion exercise uniquely provides a more complete understanding of storm electrification, convective intensity, ensemble precipitation microphysics, and storm dynamics in relation to TC intensity change. For example, we have distinguished the convective and microphysical structures between rapidly intensifying (RI) TCs with and without enhanced lightning activity, RI and steady-state TCs, and RI and rapidly weakening TCs.</p>

scholarly journals Spatiotemporal Variability of Lightning Flash Distribution over Sri Lanka

2019 ◽  
Vol 82 ◽  
pp. 1-13
Author(s):  
U.G.Dilaj Maduranga ◽  
Mahesh Edirisinghe ◽  
L. Vimukthi Gamage
Keyword(s):  
Sri Lanka ◽  
Monsoon Season ◽  
Tropical Rainfall Measuring Mission ◽  
Spatiotemporal Variability ◽  
Spatial And Temporal Variation ◽  
Lightning Flash ◽  
Northeast Monsoon ◽  
Time Period ◽  
Total Lightning ◽  
Imaging Sensor

The variation of the lightning activities over Sri Lanka and surrounded costal belt (5.750N-10.000N and 79.50E-89.000E) is studied using lightning flash data of Lightning Imaging Sensor (LIS) which was launched in November 1997 for NASA’s Tropical Rainfall Measuring Mission (TRMM). The LIS data for the period of 1998 to 2014 are considered for this study. The spatial and temporal variation of lightning activities is investigated and respective results are presented. The diurnal variation over the studied area presents that maximum and minimum flash count recorded at 1530-1630 Local Time (10-11UTC) and 0530-0630LT (00-01UTC) respectively. Maximum lightning activities over the observed area have occurred after the 1330LT (08UTC) in every year during the considered time period. The seasonal variation of the lightning activities shows that the maximum lightning activities happened in First inter monsoon season (March to April) with 30.90% total lightning flashes and minimum lightning activities recorded in Northeast monsoon season (December to February) with 8.51% of total lightning flashes. Maximum flash density of 14.37fl km-2year-1 was observed at 6.980N/80.160E in First inter monsoon season. These seasonal lighting activities are agree with seasonal convective activities and temperature variation base on propagation of Intra-Tropical Convection Zone over the studied particular area. Mean monthly flash count presents a maximum in the month of April with 29.12% of lightning flashes. Variation pattern of number of lightning activities in month of April shows a tiny increment during the time period of 1998 to 2014. Maximum annual flash density of 28.09fl km-2yr-1 was observed at 6.980N/80.170E. The latitudinal variation of the lightning flash density is depicted that extreme lightning activities have happened at the southern part of the county and results show that there is a noticeable lack of lightning activities over the surrounded costal belt relatively landmass.

scholarly journals Space–Time Characteristics of Areal Reduction Factors and Rainfall Processes

2020 ◽  
Vol 21 (4) ◽  
pp. 671-689 ◽  
Author(s):  
Korbinian Breinl ◽  
Hannes Müller-Thomy ◽  
Günter Blöschl
Keyword(s):  
Return Period ◽  
Lightning Activity ◽  
Convective Activity ◽  
Convective Rainfall ◽  
The West ◽  
Rain Gauges ◽  
Fixed Area ◽  
Relationship Of ◽  
The Relationship ◽  
Reduction Factors

AbstractWe estimate areal reduction factors (ARFs; the ratio of catchment rainfall and point rainfall) varying in space and time using a fixed-area method for Austria and link them to the dominating rainfall processes in the region. We particularly focus on two subregions in the west and east of the country, where stratiform and convective rainfall processes dominate, respectively. ARFs are estimated using a rainfall dataset of 306 rain gauges with hourly resolution for five durations between 1 h and 1 day. Results indicate that the ARFs decay faster with area in regions of increased convective activity than in regions dominated by stratiform processes. Low ARF values occur where and when lightning activity (as a proxy for convective activity) is high, but some areas with reduced lightning activity exhibit also rather low ARFs as, in summer, convective rainfall can occur in any part of the country. ARFs tend to decrease with increasing return period, possibly because the contribution of convective rainfall is higher. The results of this study are consistent with similar studies in humid climates and provide new insights regarding the relationship of ARFs and dominating rainfall processes.

Investigation of Lightning Distribution Using LIS Data from TRMM Satellite

2014 ◽  
Vol 695 ◽  
pp. 836-839
Author(s):  
Norbayah Yusop ◽  
Siti Hawa Zainal ◽  
Nor Azlan Mohd Aris ◽  
S.A.M. Chachuli ◽  
Mawarni Mohamed Yunus
Keyword(s):  
Initial Data ◽  
Lightning Discharge ◽  
Winter Season ◽  
Tropical Rainfall Measuring Mission ◽  
Washington Dc ◽  
Spring Season ◽  
Seasonal Basis ◽  
Earth’S Climate ◽  
Total Lightning ◽  
Imaging Sensor

This paper presents an investigation on lightning distribution using Lightning Imaging Sensor (LIS) data from Tropical Rainfall Measuring Mission (TRMM) satellite. The investigation is carried out on distribution and variability of total lightning occurred in the area of Washington DC (38.54°N, 77.2°W) during January to April 2011. LIS captures emissions that occurred in the atmosphere which emitted by lightning discharge by covering the most between ±35o in latitude. The lightning distributions are characterized based on monthly, daily, hourly and seasonal basis. The maps of global distribution of lightning flashes have been used as initial data. This analysis shows that a total number of 3.5 million flashes were detected during four months observation. The highest number of flashes recorded in April is about 3.4 million flashes compared to the 3,993 flashes in January. In terms of seasonal, this observation show that the spring season during March and April has highest occurrence of lightning which is 53.2% compared to the winter season in January and February which only 46.8%. This study can provides expected variations of the lightning distribution on the diurnal and seasonal basis, thus make it useful in describing the Earth’s climate.

Three Years of TRMM Precipitation Features. Part I: Radar, Radiometric, and Lightning Characteristics

2005 ◽  
Vol 133 (3) ◽  
pp. 543-566 ◽  
Author(s):  
Daniel J. Cecil ◽  
Steven J. Goodman ◽  
Dennis J. Boccippio ◽  
Edward J. Zipser ◽  
Stephen W. Nesbitt
Keyword(s):  
Brightness Temperature ◽  
Tropical Rainfall Measuring Mission ◽  
Radar Reflectivity ◽  
Lightning Flash ◽  
Frequency Of Occurrence ◽  
Areal Extent ◽  
Flash Rate ◽  
Brightness Temperatures ◽  
Rate Minimum ◽  
Trmm Precipitation

Abstract During its first three years, the Tropical Rainfall Measuring Mission (TRMM) satellite observed nearly six million precipitation features. The population of precipitation features is sorted by lightning flash rate, minimum brightness temperature, maximum radar reflectivity, areal extent, and volumetric rainfall. For each of these characteristics, essentially describing the convective intensity or the size of the features, the population is broken into categories consisting of the top 0.001%, top 0.01%, top 0.1%, top 1%, top 2.4%, and remaining 97.6%. The set of “weakest/smallest” features composes 97.6% of the population because that fraction does not have detected lightning, with a minimum detectable flash rate of 0.7 flashes (fl) min−1. The greatest observed flash rate is 1351 fl min−1; the lowest brightness temperatures are 42 K (85 GHz) and 69 K (37 GHz). The largest precipitation feature covers 335 000 km2, and the greatest rainfall from an individual precipitation feature exceeds 2 × 1012 kg h−1 of water. There is considerable overlap between the greatest storms according to different measures of convective intensity. The largest storms are mostly independent of the most intense storms. The set of storms producing the most rainfall is a convolution of the largest and the most intense storms. This analysis is a composite of the global Tropics and subtropics. Significant variability is known to exist between locations, seasons, and meteorological regimes. Such variability will be examined in Part II. In Part I, only a crude land–ocean separation is made. The known differences in bulk lightning flash rates over land and ocean result from at least two differences in the precipitation feature population: the frequency of occurrence of intense storms and the magnitude of those intense storms that do occur. Even when restricted to storms with the same brightness temperature, same size, or same radar reflectivity aloft, the storms over water are considerably less likely to produce lightning than are comparable storms over land.

scholarly journals Revisiting Lightning Activity and Parameterization Using Geostationary Satellite Observations

2021 ◽  
Vol 13 (19) ◽  
pp. 3866
Author(s):  
Xin Zhang ◽  
Yan Yin ◽  
Julia Kukulies ◽  
Yang Li ◽  
Xiang Kuang ◽  
...  
Keyword(s):  
Robust Statistics ◽  
Detection Efficiency ◽  
Lightning Activity ◽  
Power Relationship ◽  
Lightning Flash ◽  
Flash Rate ◽  
The Difference ◽  
Total Lightning ◽  
The Tropics ◽  
The Relationship

The Geostationary Lightning Mapper (GLM) on the Geostationary Operational Environmental Satellite 16 (GOES-16) detects total lightning continuously, with a high spatial resolution and detection efficiency. Coincident data from the GLM and the Advanced Baseline Imager (ABI) are used to explore the correlation between the cloud top properties and flash activity across the continental United States (CONUS) sector from May to September 2020. A large number of collocated infrared (IR) brightness temperature (TBB), cloud top height (CTH) and lightning data provides robust statistics. Overall, the likelihood of lightning occurrence and high flash density is higher if the TBB is colder than 225 K. The higher CTH is observed to be correlated with a larger flash rate, a smaller flash size, stronger updraft, and larger optical energy. Furthermore, the cloud top updraft velocity (w) is estimated based on the decreasing rate of TBB, but it is smaller than the updraft velocity of the convective core. As a result, the relationship between CTH and lightning flash rate is investigated independently of w over the continental, oceanic and coastal regimes in the tropics and mid-latitudes. When the CTH is higher than 12 km, the flash rates of oceanic lightning are 38% smaller than those of both coastal and continental lightning. In addition, it should be noted that more studies are necessary to examine why the oceanic lightning with low clouds (CTH < 8 km) has higher flash rates than lightning over land and coast. Finally, the exponents of derived power relationship between CTH and lightning flash rate are smaller than four, which is underestimated due to the GLM detection efficiency and the difference between IR CTH and 20 dBZ CTH. The results from combining the ABI and GLM products suggest that merging multiple satellite datasets could benefit both lightning activity and parameterization studies, although the parallax corrections should be considered.

scholarly journals Relationship between lightning and model simulated microphysical parameters over the central and eastern Mediterranean

2009 ◽  
Vol 9 (5) ◽  
pp. 1719-1726
Author(s):  
D. K. Katsanos ◽  
K. Lagouvardos ◽  
V. Kotroni
Keyword(s):  
Eastern Mediterranean ◽  
Temporal Distribution ◽  
Development Stage ◽  
Lightning Activity ◽  
Decay Phase ◽  
National Observatory ◽  
Convective Rainfall ◽  
Mm5 Model ◽  
Microphysical Parameters ◽  
The Relationship

Abstract. In this study the relationship between lightning and simulated microphysical parameters of clouds, is examined. In order to investigate such a relationship, a number of cases with significant lightning activity that occurred during the wet period of the year over the central and eastern Mediterranean have been selected, based on the lightning activity reported by the ZEUS lighting detection network, operated by the National Observatory of Athens. For the same cases, simulations with the non-hydrostatic MM5 model were performed with the aim of reproducing the dynamical and microphysical parameters associated with the weather systems that produced lightning. The analysis showed that the temporal distribution of convective rainfall is not well correlated with that of lightning, while on the contrary, the temporal distribution of the simulated concentrations of solid hydrometeors correlates well with lightning and there is also a general coincidence of their maxima. Further, it was shown that the best correlation was found during the development stage of the storms, while during the decay phase the number of lightning decreases much faster that the simulated concentrations of solid hydrometeors.

scholarly journals Where Are the Lightning Hotspots on Earth?

2016 ◽  
Vol 97 (11) ◽  
pp. 2051-2068 ◽  
Author(s):  
Rachel I. Albrecht ◽  
Steven J. Goodman ◽  
Dennis E. Buechler ◽  
Richard J. Blakeslee ◽  
Hugh J. Christian
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
Low Earth Orbit ◽  
Congo Basin ◽  
Sea Breezes ◽  
Mountain Ranges ◽  
Flash Rate ◽  
Temporal Smoothing ◽  
Total Lightning ◽  
Lake Waters ◽  
Imaging Sensor

Abstract Previous total lightning climatology studies using Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) observations were reported at coarse resolution (0.5°) and employed significant spatial and temporal smoothing to account for sampling limitations of TRMM’s tropical to subtropical low-Earth-orbit coverage. The analysis reported here uses a 16-yr reprocessed dataset to create a very high-resolution (0.1°) climatology with no further spatial averaging. This analysis reveals that Earth’s principal lightning hotspot occurs over Lake Maracaibo in Venezuela, while the highest flash rate density hotspot previously found at the lower 0.5°-resolution sampling was found in the Congo basin in Africa. Lake Maracaibo’s pattern of convergent windflow (mountain–valley, lake, and sea breezes) occurs over the warm lake waters nearly year-round and contributes to nocturnal thunderstorm development 297 days per year on average. These thunderstorms are very localized, and their persistent development anchored in one location accounts for the high flash rate density. Several other inland lakes with similar conditions, that is, deep nocturnal convection driven by locally forced convergent flow over a warm lake surface, are also revealed. Africa is the continent with the most lightning hotspots, followed by Asia, South America, North America, and Australia. A climatological map of the local hour of maximum flash rate density reveals that most oceanic total lightning maxima are related to nocturnal thunderstorms, while continental lightning tends to occur during the afternoon. Most of the principal continental maxima are located near major mountain ranges, revealing the importance of local topography in thunderstorm development.

scholarly journals The Polarization of Type V Bursts

1980 ◽  
Vol 86 ◽  
pp. 333-338 ◽  
Author(s):  
D.E. Gary ◽  
S. Suzuki ◽  
G.A. Dulk
Keyword(s):  
Statistical Study ◽  
The Sun ◽  
Frequency Range ◽  
Type Iii ◽  
Brightness Temperatures ◽  
Type V ◽  
Relationship Of ◽  
The Relationship

From observations with the Culgoora spectropolarimeter operating in the frequency range 24–200 MHz, we find that Type V bursts are often polarized in the opposite sense from the preceding Type III bursts. We present here the results of a statistical study of how frequently this occurs and the relationship of such polarization reversals to the position of the source on the disk of the Sun. We then examine two possible reasons for the reversal of polarization. In a paper published elsewhere (Dulk et al., 1979) we give a more detailed description and include observations of source sizes, positions and brightness temperatures of Type III-V bursts.

ABSENT-MINDED LANDLORDS AND INNOVATING PEASANTS? THE PRESS IN AFRICA AND THE EASTERN MEDITERRANEAN

2008 ◽  
Vol 4 (1) ◽  
pp. 119-139 ◽  
Author(s):  
Tamara Lewit
Keyword(s):  
North Africa ◽  
Late Antiquity ◽  
Eastern Mediterranean ◽  
Diffusion Of Technology ◽  
The Press ◽  
Screw Mechanism ◽  
The Many ◽  
Relationship Of ◽  
The Relationship ◽  
Do So

The screw mechanism for wine and oil presses was widely applied in the eastern Mediterranean only in Late Antiquity, about half a millennium after its invention. This occurred in relation to a great intensification of commercial production in this region, including the bringing into cultivation of marginal land and the occupation of new areas. However, why was a screw mechanism not used in other important export regions, such as North Africa? Case studies of settlement patterns in a number of regions suggest that the absentee landlords of large estates seem to have been less inclined to adopt changed technology, whereas resident owners—whether of large or small estates—living close to their land, and directly involved in the processes of production, may have been more likely to do so. Among the many factors at play—technical, geographic, cultural, chronological, environmental, and commercial—the relationship of the landowner to his land may have played an important role in the diffusion of technology.

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