Diagnostic study of generalized moist potential vorticity in a non-uniformly saturated atmosphere with heavy precipitation

2010 ◽  
Vol 136 (650) ◽  
pp. 1275-1288 ◽  
Author(s):  
Zhaoming Liang ◽  
Chungu Lu ◽  
Edward I. Tollerud
Keyword(s):  
Potential Vorticity ◽  
Heavy Precipitation ◽  
Diagnostic Study ◽  
Saturated Atmosphere ◽  
Moist Potential Vorticity

scholarly journals Perturbing the potential vorticity field in mesoscale forecasts of two Mediterranean heavy precipitation events

2012 ◽  
Vol 64 (1) ◽  
pp. 17224 ◽  
Author(s):  
Maria-Del-Mar Vich ◽  
Romualdo Romero ◽  
Evelyne Richard ◽  
Philippe Arbogast ◽  
Karine Maynard
Keyword(s):  
Potential Vorticity ◽  
Heavy Precipitation ◽  
Vorticity Field ◽  
Precipitation Events

scholarly journals The Use of Moist Potential Vorticity Vector as Diagnostic Variable of Rainfall Events in Tanzania

2017 ◽  
Vol 9 (5) ◽  
pp. 1
Author(s):  
Philbert Modest Luhunga ◽  
Agnes Kijazi ◽  
Ladislaus Chang a ◽  
Chuki A Sangalugembe ◽  
Doreen Mwara Anande ◽  
...  
Keyword(s):  
Potential Vorticity ◽  
Wrf Model ◽  
Lower Troposphere ◽  
Topographic Effects ◽  
New Paradigm ◽  
Rainfall Events ◽  
North Eastern ◽  
Vorticity Vector ◽  
Moist Potential Vorticity ◽  
Thermodynamic Variables

The work of this paper is a first step of the new paradigm, to use the Moist Potential Vorticity Vector (MPVV) as a diagnostic variable of rainfall events in Tanzania. The paper aims at computing and assessing the usefulness of MPVV in the diagnosis of rainfall events that occurred on 08th and 09th May 2017 over different regions in Tanzania. The relative contributions of horizontal, vertical components and the magnitude of MPVV on diagnosis of rainfall events are assessed. Hourly dynamic and thermodynamic variables of wind speed, temperature, atmospheric pressure and relative humidity from the numerical output generated by the Weather Research and Forecasting (WRF) Model, running at Tanzania Meteorological Agency (TMA) are used in computation of MPVV. The computed MPVV is then compared with WRF model forecasts and observed rainfall. It is found that in most parts of the country, particularly over coastal areas and North-Eastern Highlands, MPVV exhibited positive values in the lower troposphere (925hPa) and (850hPa) indicating local instability possibly associated with topographic effects, and continent/ocean contrast. MPVV is mostly positive with slightly negative values indicating instabilities (due to possible convective instability). Moreover, MPVV provides remarkably accurate tracking of the locations received rainfall, suggesting its potential use as a dynamic diagnostic variable of rainfall events in Tanzania.

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 Dynamical contribution of mean potential vorticity pseudo-observations derived from MetOp/GOME2 ozone data into short-range weather forecast during high precipitation events

2015 ◽  
Vol 4 (2) ◽  
pp. 206
Author(s):  
Siham Sbii ◽  
Mimoun Zazoui ◽  
Noureddine Semane
Keyword(s):  
Potential Vorticity ◽  
Short Range ◽  
Initial Conditions ◽  
Weather Prediction ◽  
Dynamical Behavior ◽  
Heavy Precipitation ◽  
Limited Area ◽  
Total Column Ozone ◽  
Ozone Data ◽  
Precipitation Events

<p>Satellites are uniquely capable of providing uniform data coverage globally. Motivated by such capability, this study builds on a previously described methodology that generates numerical weather prediction initial conditions from satellite total column ozone data. The methodology is based on two principal steps. Firstly, the studied linear regression between vertical (100hPa-500hPa) Mean Potential Vorticity (MPV) and MetOp/GOME2 total ozone data (O3) generates MPV pseudo-observations. Secondly, the 3D variational (3D-Var) assimilation method is designed to take into account MPV pseudo-observations in addition to conventional observations.</p><p>After a successful assimilation of MPV pseudo-observations using a 3D-Var approach within the Moroccan version of the ALADIN limited-area model, the present study aims to assess the dynamical behavior of the short-range forecast at upper levels during heavy precipitation events (HPEs). It is found that MPV assimilation offers the possibility to internally monitor the model upper-level dynamics in addition to the use of Water Vapor Satellite images.</p>

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