scholarly journals Four-Dimensional Variational Data Analysis of Water Vapor Raman Lidar Data and Their Impact on Mesoscale Forecasts

2008 ◽  
Vol 25 (8) ◽  
pp. 1437-1453 ◽  
Author(s):  
Matthias Grzeschik ◽  
Hans-Stefan Bauer ◽  
Volker Wulfmeyer ◽  
Dirk Engelbart ◽  
Ulla Wandinger ◽  
...  
Keyword(s):  
Water Vapor ◽  
Data Analysis ◽  
Vertical Structure ◽  
Mesoscale Model ◽  
Test Case ◽  
State University ◽  
Raman Lidar ◽  
Initial Water ◽  
Forecast Time ◽  
The Impact

Abstract The impact of water vapor observations on mesoscale initial fields provided by a triangle of Raman lidar systems covering an area of about 200 km × 200 km is investigated. A test case during the Lindenberg Campaign for Assessment of Humidity and Cloud Profiling Systems and its Impact on High-Resolution Modeling (LAUNCH-2005) was chosen. Evaluation of initial water vapor fields derived from ECMWF analysis revealed that in the model the highly variable vertical structure of water vapor profiles was not recovered and vertical gradients were smoothed out. Using a 3-h data assimilation window and a resolution of 10–30 min, continuous water vapor data from these observations were assimilated in the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) by means of a four-dimensional variational data analysis (4DVAR). A strong correction of the vertical structure and the absolute values of the initial water vapor field of the order of 1 g kg−1 was found. This occurred mainly upstream of the lidar systems within an area, which was comparable with the domain covered by the lidar systems. The correction of the water vapor field was validated using independent global positioning system (GPS) sensors. Much better agreement to GPS zenith wet delay was achieved with the initial water vapor field after 4DVAR. The impact region was transported with the mean wind and was still visible after 4 h of free forecast time.

scholarly journals Impact of Four-Dimensional Variational Data Assimilation of Atmospheric Motion Vectors on Tropical Cyclone Track Forecasts

2006 ◽  
Vol 21 (4) ◽  
pp. 663-669 ◽  
Author(s):  
Dongliang Wang ◽  
Xudong Liang ◽  
Yihong Duan ◽  
Johnny C. L. Chan
Keyword(s):  
Tropical Cyclone ◽  
Data Assimilation ◽  
Mesoscale Model ◽  
State University ◽  
Motion Vectors ◽  
Geostationary Meteorological Satellite ◽  
Atmospheric Motion ◽  
Atmospheric Motion Vectors ◽  
Data Assimilation Technique ◽  
The Impact

Abstract The fifth-generation Pennsylvania State University–National Center for Atmospheric Research nonhydrostatic Mesoscale Model is employed to evaluate the impact of the Geostationary Meteorological Satellite-5 water vapor and infrared atmospheric motion vectors (AMVs), incorporated with the four-dimensional variational (4DVAR) data assimilation technique, on tropical cyclone (TC) track predictions. Twenty-two cases from eight different TCs over the western North Pacific in 2002 have been examined. The 4DVAR assimilation of these satellite-derived wind observations leads to appreciable improvements in the track forecasts, with average reductions in track error of ∼5% at 12 h, 12% at 24 h, 10% at 36 h, and 7% at 48 h. Preliminary results suggest that the improvement depends on the quantity of the AMV data available for assimilation.

scholarly journals Impact of the assimilation of lightning data on the precipitation forecast at different forecast ranges

2017 ◽  
Vol 14 ◽  
pp. 187-194 ◽  
Author(s):  
Stefano Federico ◽  
Marco Petracca ◽  
Giulia Panegrossi ◽  
Claudio Transerici ◽  
Stefano Dietrich
Keyword(s):  
Data Assimilation ◽  
Mesoscale Model ◽  
Weather Prediction ◽  
Horizontal Resolution ◽  
Probability Of Detection ◽  
Precipitation Forecast ◽  
Time Range ◽  
False Alarms ◽  
Forecast Time ◽  
The Impact

Abstract. This study investigates the impact of the assimilation of total lightning data on the precipitation forecast of a numerical weather prediction (NWP) model. The impact of the lightning data assimilation, which uses water vapour substitution, is investigated at different forecast time ranges, namely 3, 6, 12, and 24 h, to determine how long and to what extent the assimilation affects the precipitation forecast of long lasting rainfall events (> 24 h). The methodology developed in a previous study is slightly modified here, and is applied to twenty case studies occurred over Italy by a mesoscale model run at convection-permitting horizontal resolution (4 km). The performance is quantified by dichotomous statistical scores computed using a dense raingauge network over Italy. Results show the important impact of the lightning assimilation on the precipitation forecast, especially for the 3 and 6 h forecast. The probability of detection (POD), for example, increases by 10 % for the 3 h forecast using the assimilation of lightning data compared to the simulation without lightning assimilation for all precipitation thresholds considered. The Equitable Threat Score (ETS) is also improved by the lightning assimilation, especially for thresholds below 40 mm day−1. Results show that the forecast time range is very important because the performance decreases steadily and substantially with the forecast time. The POD, for example, is improved by 1–2 % for the 24 h forecast using lightning data assimilation compared to 10 % of the 3 h forecast. The impact of the false alarms on the model performance is also evidenced by this study.

Changes in Water Vapor Transport and the Production of Precipitation in the Eastern Fertile Crescent as a Result of Global Warming

2008 ◽  
Vol 9 (6) ◽  
pp. 1390-1401 ◽  
Author(s):  
J. P. Evans
Keyword(s):  
Global Warming ◽  
Water Vapor ◽  
Climate Model ◽  
Mesoscale Model ◽  
Regional Climate ◽  
Water Vapor Transport ◽  
State University ◽  
Storm Events ◽  
Fertile Crescent ◽  
Emissions Scenarios

Abstract This study investigates changes in the types of storm events occurring in the Fertile Crescent as a result of global warming. Regional climate model [fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5)–Noah] simulations are run for the first and last five years of the twenty-first century following the Special Report on Emissions Scenarios (SRES) A2 experiment. Then the precipitation events are classified according to the water vapor fluxes that created them. At present most of the region’s precipitation is from westerly water vapor fluxes. Results indicate that the region will increasingly get its precipitation from large events that are dominated by southerly water vapor fluxes. The increase in these events will occur in the transition seasons, especially autumn.

scholarly journals The Same-Source Parallel MM5

2000 ◽  
Vol 8 (1) ◽  
pp. 5-12 ◽  
Author(s):  
John Michalakes
Keyword(s):  
Shared Memory ◽  
Distributed Memory ◽  
Mesoscale Model ◽  
State University ◽  
Parallel Performance ◽  
Hybrid Parallelization ◽  
Beowulf Clusters ◽  
Penn State ◽  
Library Support ◽  
The Impact

Beginning with the March 1998 release of the Penn State University/NCAR Mesoscale Model (MM5), and continuing through eight subsequent releases up to the present, the official version has run on distributed -memory (DM) parallel computers. Source translation and runtime library support minimize the impact of parallelization on the original model source code, with the result that the majority of code is line-for-line identical with the original version. Parallel performance and scaling are equivalent to earlier, hand-parallelized versions; the modifications have no effect when the code is compiled and run without the DM option. Supported computers include the IBM SP, Cray T3E, Fujitsu VPP, Compaq Alpha clusters, and clusters of PCs (so-called Beowulf clusters). The approach also is compatible with shared-memory parallel directives, allowing distributed-memory/shared-memory hybrid parallelization on distributed-memory clusters of symmetric multiprocessors.

scholarly journals Influences of Asymmetric Heating on Hurricane Evolution in the MM5

2005 ◽  
Vol 62 (11) ◽  
pp. 3974-3992 ◽  
Author(s):  
J. Dominique Möller ◽  
Lloyd J. Shapiro
Keyword(s):  
Diabatic Heating ◽  
Mesoscale Model ◽  
State University ◽  
Short Term ◽  
Term Change ◽  
Passive Response ◽  
Tangential Wind ◽  
Small Change ◽  
The Impact

Abstract While previous idealized studies have demonstrated the importance of asymmetric atmospheric features in the intensification of a symmetric tropical cyclone vortex, the role of convectively generated asymmetries in creating changes in the azimuthally averaged cyclone is not well understood. In the present study the full-physics nonhydrostatic fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) is used to evaluate the influence of such asymmetries. Rather than adding winds and temperatures in balance with a specified potential vorticity (PV) asymmetry, or temperature perturbations themselves, to a symmetric vortex as in previous studies, a diabatic heating asymmetry is imposed on a spunup model hurricane. The impact of short-duration eyewall-scale monochromatic azimuthal wavenumber diabatic heating on the short- and long-term evolution of the azimuthally averaged vortex is evaluated, and a tangential wind budget is made to determine the mechanisms responsible for the short-term impact. It is found that the small eddy kick created by the additional diabatic heating asymmetry leads to a substantially amplified long-term change in the azimuthally averaged vortex, with episodes of strong relative weakening and strengthening following at irregular intervals. This behavior is diabatically controlled. It is also found that the symmetric secondary circulation can be active in creating short-term changes in the vortex, and is not simply a passive response as in previous studies with dry physics. A central conclusion of the study is that the structure of the spunup hurricane vortex, in particular preexisting asymmetric features, can have a substantial influence on the character of the response to an additional diabatic heating asymmetry. The results also imply that a small change in the factors that control convective activity will have a substantial lasting consequence for the intensification of a hurricane.

scholarly journals The 13–14 December 2001 IMPROVE-2 Event. Part III: Simulated Microphysical Budgets and Sensitivity Studies

2005 ◽  
Vol 62 (10) ◽  
pp. 3535-3558 ◽  
Author(s):  
Brian A. Colle ◽  
Matthew F. Garvert ◽  
Justin B. Wolfe ◽  
Clifford F. Mass ◽  
Christopher P. Woods
Keyword(s):  
Water Vapor ◽  
Mesoscale Model ◽  
Positive Impact ◽  
Cloud Water ◽  
Precipitation Forecast ◽  
State University ◽  
Microphysical Process ◽  
Surface Precipitation ◽  
Sensitivity Studies ◽  
Microphysical Parameterization

Abstract This paper investigates the microphysical pathways and sensitivities within the Reisner-2 bulk microphysical parameterization (BMP) of the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) for the Improvement of Microphysical Parameterization through Observational Verification Experiment (IMPROVE)-2 field experiment on 13–14 December 2001. A microphysical budget over the windward slope at 1.33-km horizontal grid spacing was calculated, in which the importance of each microphysical process was quantified relative to the water vapor loss (WVL) rate. Over the windward Cascades, the largest water vapor loss was associated with condensation (73% of WVL) and snow deposition (24%), and the windward surface precipitation resulted primarily from accretion of cloud water by rain (27% of WVL), graupel fallout and melt (19%), and snowmelt (6%). Two-thirds of the snow generated aloft spilled over into the lee in an area of model overprediction, resulting in windward precipitation efficiency of only 50%. Even with the large amount of precipitation spillover, the windward precipitation was still overpredicted in many locations. A series of experiments were completed using different snowfall speeds, cloud water autoconversion, threshold riming values for snow to graupel autoconversion, and slope intercepts for snow. The surface precipitation was most sensitive to those parameters associated with the snow size distribution and fall speed, while decreasing the riming threshold for snow to graupel conversion had the greatest positive impact on the precipitation forecast. All simulations overpredicted cloud water over the lower windward slopes, had too little cloud water over the crest, and had too much ice at moderate-to-large sizes aloft. Riming processes were important, since without supercooled water there were bull’s-eyes of spurious snow spillover over the lee slopes.

scholarly journals Nature of the Mesoscale Boundary Layer Height and Water Vapor Variability Observed 14 June 2002 during the IHOP_2002 Campaign

2009 ◽  
Vol 137 (1) ◽  
pp. 414-432 ◽  
Author(s):  
F. Couvreux ◽  
F. Guichard ◽  
P. H. Austin ◽  
F. Chen
Keyword(s):  
Boundary Layer ◽  
Water Vapor ◽  
Mesoscale Model ◽  
Surface Flux ◽  
Early Morning ◽  
Surface Fluxes ◽  
Layer Height ◽  
Horizontal Advection ◽  
Boundary Layer Height ◽  
The Impact

Abstract Mesoscale water vapor heterogeneities in the boundary layer are studied within the context of the International H2O Project (IHOP_2002). A significant portion of the water vapor variability in the IHOP_2002 occurs at the mesoscale, with the spatial pattern and the magnitude of the variability changing from day to day. On 14 June 2002, an atypical mesoscale gradient is observed, which is the reverse of the climatological gradient over this area. The factors causing this water vapor variability are investigated using complementary platforms (e.g., aircraft, satellite, and in situ) and models. The impact of surface flux heterogeneities and atmospheric variability are evaluated separately using a 1D boundary layer model, which uses surface fluxes from the High-Resolution Land Data Assimilation System (HRLDAS) and early-morning atmospheric temperature and moisture profiles from a mesoscale model. This methodology, based on the use of robust modeling components, allows the authors to tackle the question of the nature of the observed mesoscale variability. The impact of horizontal advection is inferred from a careful analysis of available observations. By isolating the individual contributions to mesoscale water vapor variability, it is shown that the observed moisture variability cannot be explained by a single process, but rather involves a combination of different factors: the boundary layer height, which is strongly controlled by the surface buoyancy flux, the surface latent heat flux, the early-morning heterogeneity of the atmosphere, horizontal advection, and the radiative impact of clouds.

scholarly journals Improving Student’s Motivation and Learning Outcomes Through Genetics E-Module

2021 ◽  
Vol 9 (1) ◽  
pp. 189
Author(s):  
Hasminar Rachman Fidiastuti ◽  
Anis Samrotul Lathifah ◽  
Mohamad Amin ◽  
Yudhi Utomo ◽  
Riantina Fitra Aldya
Keyword(s):  
Data Analysis ◽  
Learning Outcomes ◽  
Learning Process ◽  
Biology Education ◽  
State University ◽  
Education Department ◽  
Experiment Method ◽  
Motivation And Learning ◽  
The Impact ◽  
Implementation Stage

The purpose of this study was to know the impact of the Genetics E-module to improve students’ motivation and learning outcomes during the learning process. The method applied was Research and Development, limited until the implementation stage, using the quasi-experiment method with one group pretest-posttest. The motivation instruments were modified questionnaire by Keller with ARCS model, consist of 4 aspects including attention, relevance, confidence, and satisfaction. The population were all of the students from class of 2017 in Biology Education department, Tribhuwana Tunggadewi State University. The pretest was held to know students’ motivation and learning outcomes when using a handout from the lecturer, while the posttest was to know students’ motivation and learning outcomes when using Genetics E-module. Data were collected from the motivation questionnaire and test. After using E-module, there were 27 students with high (71,91 ≤ x < 86), 18 students with medium (57,82 ≤ x < 71,91) and 5 students with low criterion (43,74 ≥ x) of motivation, and there were  58% students who passing the grade in Genetics test. Based on the data analysis, E-module was feasible to be used to improve students’ motivation and also learning outcomes in the Biology Education department.

scholarly journals Sensitivity of a Mesoscale Model to Microphysical Parameterizations in the MAP SOP Events IOP2b and IOP8

2007 ◽  
Vol 46 (9) ◽  
pp. 1438-1454 ◽  
Author(s):  
Stefano Serafin ◽  
Rossella Ferretti
Keyword(s):  
Mesoscale Model ◽  
Deposition Velocity ◽  
Rain Gauge ◽  
Forecast Skill ◽  
Windward Side ◽  
State University ◽  
Radar Observations ◽  
Microphysical Processes ◽  
The One ◽  
The Impact

Abstract The sensitivity of a mesoscale model to different microphysical parameterizations is investigated for two events of precipitation in the Mediterranean region, that is, the Mesoscale Alpine Program (MAP) intensive observation periods (IOP) 2b (19–21 September 1999) and 8 (20–22 October 1999). Simulations are performed with the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5); the most commonly used bulk microphysical parameterization schemes are evaluated, with a particular focus on their impact on the forecast of rainfall. To evaluate the forecast skill, the verification is carried out quantitatively by using the observations recorded by a high-resolution rain gauge network during the MAP campaign. The results show that, for the surface rainfall forecast, all microphysical schemes produce a similar precipitation field and none of them perform significantly better than the others. The ability of different schemes to reproduce events with different ongoing microphysical processes is briefly discussed by comparing model simulations and knowledge of hydrometeor fields from radar observations. The vertical profiles of hydrometeors from two of the analyzed schemes show gross similarities with available radar observations. Last, the role of one of the parameterizations appearing in a typical bulk microphysical scheme, that is, the one of the snowfall speed, is evaluated in detail. Adjustments in the semiempirical relationships describing the fall speed of snow particles have a large impact, because a reduced snowfall speed enhances precipitation on the lee side of mountain ridges and diminishes it on the windward side. Anyway, this effect does not appear to be able to largely improve or reduce the forecast skill of the MM5 systematically; the impact of changes in the parameterization of the snow deposition velocity very likely depends on the dynamics of the event under investigation.

scholarly journals The impact of temperature vertical structure on trajectory modeling of stratospheric water vapor

2015 ◽  
Vol 15 (6) ◽  
pp. 3517-3526 ◽  
Author(s):  
T. Wang ◽  
A. E. Dessler ◽  
M. R. Schoeberl ◽  
W. J. Randel ◽  
J.-E. Kim
Keyword(s):  
Water Vapor ◽  
Vertical Structure ◽  
Vertical Resolution ◽  
Tropical Tropopause Layer ◽  
Stratospheric Water Vapor ◽  
Dry Air ◽  
Tropical Tropopause ◽  
Cold Point ◽  
The Impact ◽  
Modern Era

Abstract. Lagrangian trajectories driven by reanalysis meteorological fields are frequently used to study water vapor (H2O) in the stratosphere, in which the tropical cold-point temperatures regulate the amount of H2O entering the stratosphere. Therefore, the accuracy of temperatures in the tropical tropopause layer (TTL) is of great importance for understanding stratospheric H2O abundances. Currently, most reanalyses, such as the NASA MERRA (Modern Era Retrospective – analysis for Research and Applications), only provide temperatures with ~ 1.2 km vertical resolution in the TTL, which has been argued to miss finer vertical structure in the tropopause and therefore introduce uncertainties in our understanding of stratospheric H2O. In this paper, we quantify this uncertainty by comparing the Lagrangian trajectory prediction of H2O using MERRA temperatures on standard model levels (traj.MER-T) to those using GPS temperatures at finer vertical resolution (traj.GPS-T), and those using adjusted MERRA temperatures with finer vertical structures induced by waves (traj.MER-Twave). It turns out that by using temperatures with finer vertical structure in the tropopause, the trajectory model more realistically simulates the dehydration of air entering the stratosphere. But the effect on H2O abundances is relatively minor: compared with traj.MER-T, traj.GPS-T tends to dry air by ~ 0.1 ppmv, while traj.MER-Twave tends to dry air by 0.2–0.3 ppmv. Despite these differences in absolute values of predicted H2O and vertical dehydration patterns, there is virtually no difference in the interannual variability in different runs. Overall, we find that a tropopause temperature with finer vertical structure has limited impact on predicted stratospheric H2O.

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