Differences in Mechanisms of Orographic Rainfall over West Sumatra (Case Study: 10 April and 23 April 2004)

Wendi Harjupa; Toyoshi Shimomai; Hiroyuki Hashiguchi; Yasushi Fujiyoshi; Masayuki Kawashima

doi:10.25077/jif.13.1.8-17.2021

Relationship between meningitis occurrence and atmospheric conditions over the African meningitis belt

10.5194/egusphere-egu2020-7924 ◽

2020 ◽

Author(s):

Cheikh Dione ◽

Mame Diarra Diouf ◽

Bob Alex Ogwang ◽

Elijah Adesanya Adefisan ◽

Steve Woolnough ◽

...

Keyword(s):

Large Scale ◽

Climate Models ◽

Lassa Fever ◽

Atmospheric Conditions ◽

Numerical Weather ◽

Endemic Diseases ◽

Meningitis Belt ◽

Weather And Climate

<p> The alternation of seasons over tropical northern Africa is associated with the occurrence of devastating diseases such as meningitis, Lassa fever and malaria. These tropical diseases are associated with specific atmospheric conditions. Thus, meningitis is one of the most endemic diseases observed over this region with a prevalence period up to 7 months (December-June). Previous studies based on the link between atmospheric conditions and the occurrence of meningitis outbreaks have shown that this disease develops under dry and dusty atmospheric conditions which are difficult to represent in numerical weather and climate models. However, the onset, breakup, and sub-seasonal variability of meningitis outbreaks are not well documented. The objective of this study is to identify the local and synoptic drivers favoring the large occurrence of this disease over the meningitis belt in order to improve its predictability by numerical weather and climate models on intra-seasonal and seasonal timescales. This study focuses on two cases studies of meningitis epidemics over Niger in 2009 and 2015. The case study of 2009 started early with a duration of more than eight weeks. The second case study was shorter than the first one. It took three weeks and was observed at the end of the dry season. Based on ERA5 data, surface dust concentration observations and satellite data, a further analysis of the role of climate metrics on the triggering of meningitis epidemics on intra-seasonal timescales at local and large scale atmospheric conditions will be presented.</p>

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Potential of high-resolution detection and retrieval of precipitation fields from X-band spaceborne synthetic aperture radar over land

Hydrology and Earth System Sciences ◽

10.5194/hess-15-859-2011 ◽

2011 ◽

Vol 15 (3) ◽

pp. 859-875 ◽

Cited By ~ 25

Author(s):

F. S. Marzano ◽

S. Mori ◽

M. Chini ◽

L. Pulvirenti ◽

N. Pierdicca ◽

...

Keyword(s):

High Resolution ◽

Spatial Resolution ◽

Rain Rate ◽

Central Italy ◽

Synthetic Aperture ◽

Simple Method ◽

Near Surface ◽

Orographic Rainfall ◽

X Band

Abstract. X-band Synthetic Aperture Radars (X-SARs), able to image the Earth's surface at metric resolution, may provide a unique opportunity to measure rainfall over land with spatial resolution of about few hundred meters, due to the atmospheric moving-target degradation effects. This capability has become very appealing due to the recent launch of several X-SAR satellites, even though several remote sensing issues are still open. This work is devoted to: (i) explore the potential of X-band high-resolution detection and retrieval of rainfall fields from space using X-SAR signal backscattering amplitude and interferometric phase; (ii) evaluate the effects of spatial resolution degradation by precipitation and inhomogeneous beam filling when comparing to other satellite-based sensors. Our X-SAR analysis of precipitation effects has been carried out using both a TerraSAR-X (TSX) case study of Hurricane "Gustav" in 2008 over Mississippi (USA) and a COSMO-SkyMed (CSK) X-SAR case study of orographic rainfall over Central Italy in 2009. For the TSX case study the near-surface rain rate has been retrieved from the normalized radar cross section by means of a modified regression empirical algorithm (MREA). A relatively simple method to account for the geometric effect of X-SAR observation on estimated rainfall rate and first-order volumetric effects has been developed and applied. The TSX-retrieved rain fields have been compared to those estimated from the Next Generation Weather Radar (NEXRAD) in Mobile (AL, USA). The rainfall detection capability of X-SAR has been tested on the CSK case study using the repeat-pass coherence response and qualitatively comparing its signature with ground-based Mt. Midia C-band radar in central Italy. A numerical simulator to represent the effect of the spatial resolution and the antenna pattern of TRMM satellite Precipitation Radar (PR) and Microwave Imager (TMI), using high-resolution TSX-retrieved rain images, has been also set up in order to evaluate the rainfall beam filling phenomenon. As expected, the spatial average can modify the statistics of the high-resolution precipitation fields, strongly reducing its dynamics in a way non-linearly dependent on the rain rate local average value.

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Potential of high-resolution detection and retrieval of precipitation fields from X-band spaceborne Synthetic Aperture Radar over land

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-7-7451-2010 ◽

2010 ◽

Vol 7 (5) ◽

pp. 7451-7484

Author(s):

F. S. Marzano ◽

S. Mori ◽

M. Chini ◽

L. Pulvirenti ◽

N. Pierdicca ◽

...

Keyword(s):

High Resolution ◽

Spatial Resolution ◽

Central Italy ◽

Synthetic Aperture ◽

Spatial Average ◽

Simple Method ◽

Near Surface ◽

Orographic Rainfall ◽

X Band

Abstract. X-band Synthetic Aperture Radars (X-SARs), able to image the Earth's surface at metric resolution, may provide a unique opportunity to measure rainfall over land with spatial resolution of about few hundred meters, due to the atmospheric moving-target degradation effects. This capability has become very appealing due to the recent launch of several X-SAR satellites, even though several remote sensing issues are still open. This work is devoted to: (i) explore the potential of X-band high-resolution detection and retrieval of rainfall fields from space using X-SAR signal backscattering amplitude and interferometric phase; (ii) evaluate the effects of spatial resolution degradation by precipitation and inhomogeneous beam filling when comparing to other satellite-based sensors. Our X-SAR analysis of precipitation effects has been carried out using both a TerraSAR-X (TSX) case study of Hurricane "Gustav" in 2008 over Mississippi (USA) and a COSMO-SkyMed (CSK) X-SAR case study of orographic rainfall over Central Italy in 2009. For the TSX case study the near-surface rain rate has been retrieved from the normalized radar cross section by means of a modified regression empirical algorithm (MREA). A relatively simple method to account for the geometric effect of X-SAR observation on estimated rainfall rate and first-order volumetric effects has been developed and applied. The TSX-retrieved rain fields have been compared to those estimated from the Next Generation Weather Radar (NEXRAD) in Mobile (AL, USA). The rainfall detection capability of X-SAR has been tested on the CSK case study using the repeat-pass coherence response and qualitatively comparing its signature with ground-based Mt. Midia C-band radar in central Italy. A numerical simulator to represent the effect of the spatial resolution and the antenna pattern of TRMM satellite Precipitation Radar (PR) and Microwave Imager (TMI), using high-resolution TSX-retrieved rain images, has been also set up in order to evaluate the rainfall beam filling phenomenon. As expected, the spatial average can modify the statistics of the high-resolution precipitation fields, strongly reducing its dynamics in a way non-linearly dependent on the rainrate local average value.

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Perbandingan Karakteristik Distribusi Butiran Hujan yang Berasal dari Awan Laut dan Awan Darat di Kototabang

Jurnal Fisika Unand ◽

10.25077/jfu.5.3.273-282.2016 ◽

2016 ◽

Vol 5 (3) ◽

pp. 273-282

Author(s):

Nur Fadillah ◽

Marzuki Marzuki ◽

Wendi Harjupa ◽

Toyoshi Shimomai ◽

Hiroyuki Hashiguchi

Keyword(s):

Size Distribution ◽

Doppler Radar ◽

Radar Reflectivity ◽

Two Dimensional ◽

Raindrop Size Distribution ◽

X Band ◽

Raindrop Size ◽

Coupling Processes

Karakteristik distribusi ukuran butiran hujan atau raindrop size distribution (RDSD) dari hujan yang berasal dari awan laut dan awan darat di Kototabang, Sumatera Barat, telah dibandingkan. Asal hujan diamati menggunakan X-band Doppler radar (XDR) selama proyek Coupling Processes in the Equatorial Atmosphere (CPEA)-I (10 April 2004 - 9 Mei 2004). Data RDSD berasal dari pengamatan two-dimensional video disdrometer (2DVD). RDSD dimodelkan dengan distribusi gamma dan parameternya didapatkan menggunakan metode momen. Dari penelitian ini terlihat bahwa intensitas curah hujan yang tinggi lebih banyak pada hujan dari awan darat dibandingkan dengan yang dari awan laut. Selain itu, butiran hujan yang berukuran besar pada awan darat lebih banyak daripada awan laut. Banyaknya butiran hujan dengan ukuran yang besar ini berdampak kepada nilai radar reflectivity (Z) pada awan darat yang lebih besar dibandingkan dengan awan laut untuk intensitas curah hujan yang sama. Hal ini mengakibatkan persamaan Z-R antara awan darat dan awan laut berbeda dimana nilai koefisien A dari persamaan Z-R untuk awan darat lebih besar daripada awan laut. Dengan demikian, perbedaan karaktersitik RDSD antara awan darat dan laut sebaiknya dipertimbangkan dalam pengembangan radar meteorologi di kawasan tropis. Penggunaan Z-R tunggal (Z = 200R1,6) untuk mengkoversi data radar cuaca di Sumatera terutama Sumatera Barat tidak akan akurat terutama untuk hujan dari awan laut.Kata kunci: distribusi butiran hujan (RDSD), awan darat, awan laut, Kototabang

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Tornadogenesis and Early Tornado Evolution in the El Reno, Oklahoma, Supercell on 31 May 2013

Monthly Weather Review ◽

10.1175/mwr-d-18-0338.1 ◽

2019 ◽

Vol 147 (6) ◽

pp. 2045-2066 ◽

Cited By ~ 12

Author(s):

Howard B. Bluestein ◽

Kyle J. Thiem ◽

Jeffrey C. Snyder ◽

Jana B. Houser

Keyword(s):

Doppler Radar ◽

Leading Edge ◽

Radar Data ◽

Vertical Column ◽

Low Level ◽

X Band ◽

Main Circulation ◽

Coherent Vortex ◽

The Right

Abstract This study documents the formation and part of the early evolution of a large, violent tornado near El Reno, Oklahoma, based on data from a mobile, polarimetric, rapid scan, X-band, Doppler radar. The main circulation associated with the tornado formed near the ground initially, ~90 s prior to the development of the vertically coherent vortex, which built upward through a vertical column of at least 3.5 km in less than 20 s, the update time of the Doppler radar data. Strong but broad rotation from 500 m to 1.5 km AGL also preceded the formation of the tornado at the surface by several minutes. A precipitation-loaded downdraft was observed in the right-forward flank of the storm, which could have enhanced evaporative cooling and allowed for a faster rate of baroclinic generation of low-level horizontal vorticity, while descending reflectivity cores in the right-rear quadrant might have enhanced low-level convergence to the rear of or along the leading edge of the rear-flank gust front. The intensification of the tornado occurred in spurts, not steadily, perhaps owing to surges in momentum at the surface associated with the precipitation-laden downdrafts. The tornado was highly tilted even when it was intensifying, calling into question the importance of a vertical juxtaposition of the mesocyclone aloft and the tornado at the surface. In this case study, while the development of a weak-echo hole was evidence of rotation, the absence of one did not mean that there was not a strong vortex, owing to the lofting of debris.

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A Family With Autosomal-Dominant Progressive Sensorineural Hearing Loss

American Journal of Audiology ◽

10.1044/1059-0889.0501.23 ◽

1996 ◽

Vol 5 (1) ◽

pp. 23-32 ◽

Cited By ~ 3

Author(s):

Chris Halpin ◽

Barbara Herrmann ◽

Margaret Whearty

Keyword(s):

Speech Production ◽

Hearing Aids ◽

Role Models ◽

Speech Intelligibility ◽

Large Scale ◽

Speech Language Pathology ◽

The Family ◽

Patient Will ◽

Language Pathology

The family described in this article provides an unusual opportunity to relate findings from genetic, histological, electrophysiological, psychophysical, and rehabilitative investigation. Although the total number evaluated is large (49), the known, living affected population is smaller (14), and these are spread from age 20 to age 59. As a result, the findings described above are those of a large-scale case study. Clearly, more data will be available through longitudinal study of the individuals documented in the course of this investigation but, given the slow nature of the progression in this disease, such studies will be undertaken after an interval of several years. The general picture presented to the audiologist who must rehabilitate these cases is that of a progressive cochlear degeneration that affects only thresholds at first, and then rapidly diminishes speech intelligibility. The expected result is that, after normal language development, the patient may accept hearing aids well, encouraged by the support of the family. Performance and satisfaction with the hearing aids is good, until the onset of the speech intelligibility loss, at which time the patient will encounter serious difficulties and may reject hearing aids as unhelpful. As the histological and electrophysiological results indicate, however, the eighth nerve remains viable, especially in the younger affected members, and success with cochlear implantation may be expected. Audiologic counseling efforts are aided by the presence of role models and support from the other affected members of the family. Speech-language pathology services were not considered important by the members of this family since their speech production developed normally and has remained very good. Self-correction of speech was supported by hearing aids and cochlear implants (Case 5’s speech production was documented in Perkell, Lane, Svirsky, & Webster, 1992). These patients received genetic counseling and, due to the high penetrance of the disease, exhibited serious concerns regarding future generations and the hope of a cure.

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