scholarly journals Comments on “Incorporating the Effects of Moisture into a Dynamical Parameter: Moist Vorticity and Moist Divergence”

2016 ◽  
Vol 31 (4) ◽  
pp. 1393-1396 ◽  
Author(s):  
David M. Schultz ◽  
Thomas Spengler
Keyword(s):  
Relative Humidity ◽  
Potential Vorticity ◽  
Single Case ◽  
Heavy Rain ◽  
Relative Vorticity ◽  
Dynamical Parameter ◽  
Accumulated Rainfall ◽  
Moist Potential Vorticity ◽  
Model Precipitation

Abstract In a recent article, Qian et al. introduced the quantities moist vorticity and moist divergence to diagnose locations of heavy rain. These quantities are constructed by multiplying the relative vorticity and divergence by relative humidity to the power k, where k = 10 in their article. Their approach is similar to that for the previously constructed quantity generalized moist potential vorticity. This comment critiques the approach of Qian et al., demonstrating that the moist vorticity, moist divergence, and by extension generalized moist potential vorticity are flawed mathematically and meteorologically. Raising relative humidity to the 10th power is poorly justified and is based on a single case study at a single time. No meteorological evidence is presented for why areas of moist vorticity and moist divergence should overlap with regions of 24-h accumulated rainfall. All three quantities have not been verified against the output of precipitation directly from the model nor is the approach of combining meteorological quantities into a single parameter appropriate in an ingredients-based forecasting approach. Researchers and forecasters are advised to plot the model precipitation directly and employ an ingredients-based approach, rather than rely on these flawed quantities.

scholarly journals Incorporating the Effects of Moisture into a Dynamical Parameter: Moist Vorticity and Moist Divergence

2015 ◽  
Vol 30 (6) ◽  
pp. 1411-1428 ◽  
Author(s):  
Weihong Qian ◽  
Jun Du ◽  
Xiaolong Shan ◽  
Ning Jiang
Keyword(s):  
Potential Vorticity ◽  
Eastern China ◽  
Heavy Rain ◽  
Systematic Evaluation ◽  
Rain Event ◽  
Dynamical Parameter ◽  
Rain Area ◽  
Moisture Effects ◽  
Moist Potential Vorticity ◽  
Rain Events

Abstract Properly including moisture effects into a dynamical parameter can significantly increase the parameter’s ability to diagnose heavy rain locations. The relative humidity–based weighting approach used to extend the moist potential vorticity (MPV) to the generalized moist potential vorticity (GMPV) is analyzed and demonstrates such an improvement. Following the same approach, two new diagnostic parameters, moist vorticity (MV) and moist divergence (MD), have been proposed in this study by incorporating moisture effects into the traditional vorticity and divergence. A regional heavy rain event that occurred along the Yangtze River on 1 July 1991 is used as a case study, and 41 daily regional heavy rain events during the notorious flooding year of 1998 in eastern China are used for a systematic evaluation. Results show that after the moisture effects were properly incorporated, the improved ability of all three parameters to capture a heavy rain area is significant (statistically at the 99% confidence level): the GMPV is improved over the MPV by 194%, the MD over the divergence by 60%, and the MV over the vorticity by 34% in terms of the threat score (TS). The average TS is 0.270 for the MD, 0.262 for the MV, and 0.188 for the GMPV. Application of the MV and MD to assess heavy rain potential is not intended to replace a complete, multiscale forecasting methodology; however, the results from this study suggest that the MV and MD could be used to postprocess a model forecast to potentially improve heavy rain location predictions.

scholarly journals The Use of Laser Precipitation Monitor (LPM) of Disdrometer and Weather Radar to Determine the Microphysics Characteristics of Extreme Rainfall in Jakarta. (Jakarta Flood Case Study February 25, 2020)

2021 ◽  
Vol 893 (1) ◽  
pp. 012017
Author(s):  
I D G A Putra ◽  
A Sopaheluwakan ◽  
B P Adi ◽  
K A Sudama ◽  
J Rizal ◽  
...  
Keyword(s):  
Extreme Rainfall ◽  
Weather Radar ◽  
Heavy Rain ◽  
Maximum Diameter ◽  
Convective Clouds ◽  
Data Volume ◽  
Accumulated Rainfall ◽  
The One ◽  
The Relationship

Abstract Heavy rains on February 24, 2020, caused flooding in most parts of Jakarta and its surroundings. The one-day observation of accumulated rainfall from the Laser Precipitation Monitor (LPM) was recorded at 358.6 mm/day at the Kemayoran station on February 25, 2020, at 00.00 UTC (07.00 Jakarta Time). In this study, analysis of the microphysical characteristics of extreme rainfall using LPM installed at Kemayoran meteorology station and weather radar at Cengkareng meteorology station with a spatial radius of 250 km. LPM is used to measure the diameter of the raindrops, the velocity of falling raindrops, LPM reflectivity, and the amount of accumulated rainfall with time resolution per minute and stored in excel data format. While the weather radar is used to measure the reflectivity spatially and temporally in the data volume format (.vol). The method used is, first, to find the relationship between LPM reflectivity and the amount of LPM rainfall with regression analysis. Second, the radar reflectivity is converted into estimated rainfall intensity for the Jakarta area and its surroundings. The results of this study found a relationship between LPM reflectivity (X) and rainfall accumulation LPM (Y) to form a regression relationship with the formula Y = 0.013X with R2 = 0.3777. Based on the record of the LPM time series, the peak of rainfall occurred at 18.17 UTC with 1000 raindrops, the maximum fall speed was 10 m/s, and the maximum diameter is 8.5 millimeters. Based on the results of microphysical measurements of LPM, spatial plots, and vertical cross-section radar, it can be concluded that flooding in Jakarta is due to heavy rain from convective clouds.

scholarly journals Case Study of Potential Vorticity Tower in Three Explosive Cyclones over Eastern Asia

2017 ◽  
Vol 74 (5) ◽  
pp. 1445-1454 ◽  
Author(s):  
Huaji Pang ◽  
Gang Fu
Keyword(s):  
Potential Vorticity ◽  
Morphological Characteristics ◽  
Lower Troposphere ◽  
Static Stability ◽  
Relative Vorticity ◽  
Eastern Asia ◽  
The North ◽  
Surface Cyclone ◽  
Explosive Cyclones

AbstractThree cases of explosively developing extratropical cyclones over eastern Asia are analyzed using ERA-Interim data. The morphological characteristics of the upper-tropospheric potential vorticity (PV) were examined. The common feature of all of these three cases is a hook-shaped high-PV streamer wrapping counterclockwise around the center of surface cyclones on the southern and eastern sides and an arch-shaped low-PV tongue that wrapped the high-PV hook head from the north. The hook-shaped high-PV tongue overlaps with the maximum centers of both the relative vorticity and static stability parameter, indicating the stratospheric nature of the PV source inside the hook-shaped high-PV tongue.The analysis indicates that there existed a deep tower of high PV above the surface cyclone at the time when these cyclones underwent explosive cyclogenesis. The high PV in the upper troposphere originates from the polar stratospheric PV reservoir associated with the tropopause-folding process. The high PV in the lower troposphere, however, is associated with the latent heat release, as nearly 70%–90% of the high-PV values in the lower troposphere reside in the region where the rainfall is the heaviest.

scholarly journals Synoptic Characteristics of Torrential Rains in Southwest and Southeast Iraq: A Case Study

2021 ◽  
Vol 32 (3) ◽  
pp. 1
Author(s):  
Aqeel Ghazi Mutar ◽  
Asraa Khtan ◽  
Loay E. George
Keyword(s):  
Satellite Images ◽  
Research Work ◽  
Heavy Rain ◽  
Moisture Flux ◽  
Relative Vorticity ◽  
Water Index ◽  
Normalized Difference Water Index ◽  
Modern Era ◽  
Sentinel 2

Torrential rains cause many losses in city infrastructure, crops, and deaths in several regions of the world including Iraq as in the case that we will discuss in this work, on January 28 and 29, 2019. Torrential rain caused the flow of torrents in several areas of Iraq and the neighboring areas. This research work aims to identify the synoptic characteristics of torrential rains and the causes of this case. This will be done by analyzing and interpreting the weather maps at different pressure levels with focusing on the troughs and fronts locations, relative vorticity, polar jet stream effect as well as the moisture flux. The Geographic Information System (GIS) was used to analyze the satellite images in order to calculate the Normalized Difference Water Index (NDWI) to confirm the heavy rain case. The weather maps were obtained from the Modern-Era Retrospective analysis for Research and Applications Version 2 (MERRA-2).  As for the satellite images we used the satellite imagery from Sentinel-2 and EMUTSAT.

scholarly journals Study of Some Patterns for Severe Rainfalls Over Iraq

2020 ◽  
Vol 31 (4) ◽  
pp. 9
Author(s):  
Yaser Ali Shaghati
Keyword(s):  
Relative Humidity ◽  
Sea Level ◽  
Vertical Velocity ◽  
Geopotential Height ◽  
Cloud Cover ◽  
Heavy Rain ◽  
Relative Vorticity ◽  
Sea Level Pressure ◽  
First Case ◽  
Heavy Rainfalls

Study of rain received particularly great importance in the areas described as semi-arid, which is on the other hand are not well prepared for the drainage of rain that may turned into flash floods. The pressure systems, especially those passing through the country in the winter rainy season and spring also autumn have a role in determining the amount of rainfall falling in the region In addition to climate change and its effects in terms of climate cycles and climate extremes and thus required determine the size of rainfall Whether it is beneficial or harmful. In this study to determine of heavy rainfalls, two important cases of heavy rainfalls were studied in 24, Dec, 2016 and 24, Nov, 2018, which exceeded 50 mm on the Iraq, from one country to another in this account , rainfalls rate, divider from the World Meteorological Organization (WMO) in which the rain intensity is determined according to the schedule and limits (light precipitation I≤2 mm / hour), (moderate precipitation 2<I≤10 mm / Hour), (heavy precipitation 10 <I≤50 mm / hour), (torrential precipitation I> 50 mm / hour). Each case was Analyzed and visualized by using the data analysis and display system (GrADS) The data were obtained from Tropical Rainfall Measuring Mission (TRMM). Show maps results of the first case in (24 December, 2016) in the northeastern region, the central region and the western region of the country the abundant rain condition through maps of rainfall rates on these areas as well as by maps of mean sea level pressure and dense cloud cover, maps showed a decrease the temperature accompanying the low pressure also streamlines, geopotential height, relative vorticity show this. And show the vertical velocity (omega), relative humidity, geopotential height, relative vorticity, and show support of air decline in terms of streamlines, relative humidity, geopotential height and relative vorticity over the country. Maps 700 hPa the vertical velocity (omega), relative humidity, geopotential height and relative vorticity, maps 500 hPa, results of second case, (24 November, 2018) that occurred in the northeastern and eastern part and southeastern part of the country, also appear clear through maps of falling rainfall rates, as well as maps of sea level pressure and the dense cloud cover accompanying the heavy rain situation. maps 850 hPa it shows the low temperature accompanying the atmospheric decline, also streamlines, geopotential height and relative vorticity also maps 700 hPa and 500 hPa lik first case, in differential patterns all of this shows clear support for the atmospheric decline in terms of streamlines, relative humidity, geopotential height, and relative vorticity, and explain the causes of heavy rain situation over Iraq.

Who Has Potatoes?

2003 ◽  
Vol 1 (2) ◽  
pp. 148-159
Author(s):  
Keith V. Bletzer
Keyword(s):  
Substance Use ◽  
Home Country ◽  
Single Case ◽  
Turning Points ◽  
Farm Labor ◽  
Single Case Study ◽  
Long Period ◽  
Migrant Work

Migratory farm labor like other forms of migrant work both in and outside agriculture impedes on the opportunity to make choices. The following essay explores particular phases in the life of one man (a single case study) and examines how he considers turning points in his life that led to a long period of substance use, both as an immigrant in the country and as a working man in his home country, followed by a cessation of use and the beginning stages of recovery. / Para el migrante, viajar en busca de trabajo es díficil, ya sea que trabaje en agricultura o en otras labores. Este ensayo examina ciertas etapas en la vida de un hombre (estudio de un solo caso) que examina los cambios que le han ocurrido durante un período en que él consumía grandes cantidades de alcohol en los estados y en su país, seguido por un período de sobriedad (no tomaba alcohol, no usaba drogas) en este país en que él comienza una etapa de rehabilitación.

Contamination Lab of Turin (CLabTo)

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Eleonora FIORE ◽  
Giuliano SANSONE ◽  
Chiara Lorenza REMONDINO ◽  
Paolo Marco TAMBORRINI
Keyword(s):  
University Students ◽  
Single Case ◽  
Real Life ◽  
Learning By Doing ◽  
Assessment Data ◽  
Entrepreneurial Skills ◽  
Fields Of Study ◽  
Education Levels ◽  
Positive Effect

Interest in offering Entrepreneurship Education (EE) to all kinds of university students is increasing. Therefore, universities are increasing the number of entrepreneurship courses intended for students from different fields of study and with different education levels. Through a single case study of the Contamination Lab of Turin (CLabTo), we suggest how EE may be taught to all kinds of university students. We have combined design methods with EE to create a practical-oriented entrepreneurship course which allows students to work in transdisciplinary teams through a learning-by-doing approach on real-life projects. Professors from different departments have been included to create a multidisciplinary environment. We have drawn on programme assessment data, including pre- and post-surveys. Overall, we have found a positive effect of the programme on the students’ entrepreneurial skills. However, when the data was broken down according to the students’ fields of study and education levels, mixed results emerged.

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