scholarly journals Development of the long-range forecast system at Hydrometcentre of Russia in 2020

2021 ◽  
pp. 58-72
Author(s):  
R. Yu. Fadeev ◽  
◽  
V.V. Shashkin . ◽  
M.A. Tolstykh ◽  
S.V. Travova ◽  
...  
Keyword(s):  
Initial Data ◽  
Long Range ◽  
Deep Convection ◽  
Subgrid Scale ◽  
Precipitation Field ◽  
Forecast System ◽  
Atmosphere Model ◽  
Range Forecasts

A brief description is given for the works carried out in 2020 to implement the longrange forecast technology based on the SLAV072L96 multiscale hydrodynamic atmosphere model. The purpose of these works was an improvement in simulating the deep convection and stratosphere dynamics. The works comprised the improvement and verification of the parameterizations for subgrid-scale processes and the whole model using long-range forecasts computed from historical initial data. As a result, the model correctly reproduces the main features of the annual mean precipitation field and zonal mean wind in the stratosphere. Keywords: long-range forecasts, global atmosphere model, parameterizations of subgrid-scale processes

ASSESSMENT OF LONG-RANGE FORECASTS

Weather ◽  
1975 ◽  
Vol 30 (6) ◽  
pp. 172-181 ◽  
Author(s):  
I. T. Jolliffe ◽  
J. F. Foord
Keyword(s):  
Long Range ◽  
Range Forecasts

scholarly journals A REMARK ON LONG RANGE SCATTERING FOR THE NONLINEAR KLEIN–GORDON EQUATION

2005 ◽  
Vol 02 (01) ◽  
pp. 77-89 ◽  
Author(s):  
HANS LINDBLAD ◽  
AVY SOFFER
Keyword(s):  
Asymptotic Expansion ◽  
Initial Data ◽  
Long Range ◽  
Gordon Equation ◽  
Scattering Problem ◽  
One Dimension ◽  
Complete Asymptotic Expansion ◽  
Arbitrary Size ◽  
Klein Gordon ◽  
Klein Gordon Equation

We consider the scattering problem for the nonlinear Klein–Gordon Equation with long range nonlinearity in one dimension. We prove that for all prescribed asymptotic solutions there is a solution of the equation with such behavior, for some choice of initial data. In the case the nonlinearity has the good sign (repulsive) the result hold for arbitrary size asymptotic data. The method of proof is based on reducing the long range phase effects to an ODE; this is done via an appropriate ansatz. We also find the complete asymptotic expansion of the solutions.

scholarly journals Sensitivities of Summertime Mesoscale Circulations in the Coastal Carolinas to Modifications of the Kain–Fritsch Cumulus Parameterization

2017 ◽  
Vol 145 (11) ◽  
pp. 4381-4399 ◽  
Author(s):  
Aaron P. Sims ◽  
Kiran Alapaty ◽  
Sethu Raman
Keyword(s):  
Numerical Models ◽  
Deep Convection ◽  
Coastal Region ◽  
Turnover Time ◽  
Cumulus Parameterization ◽  
Parameterization Scheme ◽  
Subgrid Scale ◽  
Mesoscale Circulations ◽  
Near Surface ◽  
The Impact

Two mesoscale circulations, the Sandhills circulation and the sea breeze, influence the initiation of deep convection over the Sandhills and the coast in the Carolinas during the summer months. The interaction of these two circulations causes additional convection in this coastal region. Accurate representation of mesoscale convection is difficult as numerical models have problems with the prediction of the timing, amount, and location of precipitation. To address this issue, the authors have incorporated modifications to the Kain–Fritsch (KF) convective parameterization scheme and evaluated these mesoscale interactions using a high-resolution numerical model. The modifications include changes to the subgrid-scale cloud formulation, the convective turnover time scale, and the formulation of the updraft entrainment rates. The use of a grid-scaling adjustment parameter modulates the impact of the KF scheme as a function of the horizontal grid spacing used in a simulation. Results indicate that the impact of this modified cumulus parameterization scheme is more effective on domains with coarser grid sizes. Other results include a decrease in surface and near-surface temperatures in areas of deep convection (due to the inclusion of the effects of subgrid-scale clouds on the radiation), improvement in the timing of convection, and an increase in the strength of deep convection.

scholarly journals Simulations of Monsoon Intraseasonal Oscillation Using Climate Forecast System Version 2: Insight for Horizontal Resolution and Moist Processes Parameterization

Atmosphere ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 429 ◽  
Author(s):  
Snehlata Tirkey ◽  
P. Mukhopadhyay ◽  
R. Phani Murali Krishna ◽  
Ashish Dhakate ◽  
Kiran Salunke
Keyword(s):  
Deep Convection ◽  
Intraseasonal Oscillation ◽  
Horizontal Resolution ◽  
Specific Humidity ◽  
Climate Forecast ◽  
Forecast System ◽  
Climate Forecast System ◽  
The North ◽  
Northward Propagation ◽  
Moist Processes

In the present study, we analyze the Climate Forecast System version 2 (CFSv2) model in three resolutions, T62, T126, and T382. We evaluated the performance of all three resolutions of CFSv2 in simulating the Monsoon Intraseasonal Oscillation (MISO) of the Indian summer monsoon (ISM) by analyzing a suite of dynamic and thermodynamic parameters. Results reveal a slower northward propagation of MISO in all models with the characteristic northwest–southeast tilted rain band missing over India. The anomalous moisture convergence and vorticity were collocated with the convection center instead of being northwards. This affected the northward propagation of MISO. The easterly shear to the north of the equator was better simulated by the coarser resolution models than CFS T382. The low level specific humidity showed improvement only in CFS T382 until ~15° N. The analyses of the vertical profiles of moisture and its relation to rainfall revealed that all CFSv2 resolutions had a lower level of moisture in the lower level (< 850 hPa) and a drier level above. This eventually hampered the growth of deep convection in the model. These model shortcomings indicate a possible need of improvement in moist process parameterization in the model in tune with the increase in resolution.

scholarly journals Regional pollution potentials of megacities and other major population centers

2007 ◽  
Vol 7 (14) ◽  
pp. 3969-3987 ◽  
Author(s):  
M. G. Lawrence ◽  
T. M. Butler ◽  
J. Steinkamp ◽  
B. R. Gurjar ◽  
J. Lelieveld
Keyword(s):  
Long Range ◽  
Atmospheric Chemistry ◽  
Atmospheric Transport ◽  
Deep Convection ◽  
Vertical Mixing ◽  
Geographical Location ◽  
Point Sources ◽  
High Latitudes ◽  
Near Surface ◽  
Regional Pollution

Abstract. Megacities and other major population centers represent large, concentrated sources of anthropogenic pollutants to the atmosphere, with consequences for both local air quality and for regional and global atmospheric chemistry. The tradeoffs between the regional buildup of pollutants near their sources versus long-range export depend on meteorological characteristics which vary as a function of geographical location and season. Both horizontal and vertical transport contribute to pollutant export, and the overall degree of export is strongly governed by the lifetimes of pollutants. We provide a first quantification of these tradeoffs and the main factors influencing them in terms of "regional pollution potentials", metrics based on simulations of representative tracers using the 3-D global model MATCH (Model of Atmospheric Transport and Chemistry). The tracers have three different lifetimes (1, 10, and 100 days) and are emitted from 36 continental large point sources. Several key features of the export characteristics emerge. For instance, long-range near-surface pollutant export is generally strongest in the middle and high latitudes, especially for source locations in Eurasia, for which 17–34% of a tracer with a 10-day lifetime is exported beyond 1000 km and still remains below 1 km altitude. On the other hand, pollutant export to the upper troposphere is greatest in the tropics, due to transport by deep convection, and for six source locations, more than 50% of the total mass of the 10-day lifetime tracer is found above 5 km altitude. Furthermore, not only are there order of magnitude interregional differences, such as between low and high latitudes, but also often substantial intraregional differences, which we discuss in light of the regional meteorological characteristics. We also contrast the roles of horizontal dilution and vertical mixing in reducing the pollution buildup in the regions including and surrounding the sources. For some regions such as Eurasia, dilution due to long-range horizontal transport governs the local and regional pollution buildup; however, on a global basis, differences in vertical mixing are dominant in determining the pollution buildup both around and further downwind of the source locations.

An application of chaotic theory in long range forecasts

1992 ◽  
Vol 50 (4) ◽  
pp. 231-236 ◽  
Author(s):  
Zhen-Shan Lin ◽  
Shi-Da Liu
Keyword(s):  
Long Range ◽  
Chaotic Theory ◽  
Range Forecasts
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