-
Notifications
You must be signed in to change notification settings - Fork 3
/
system.html
238 lines (172 loc) · 13.5 KB
/
system.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
<html>
<head>
<title>WRFDA SYSTEM</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="KEYWORDS" content="meteorology, mesoscale, microscale, weather modeling, forecasting weather, weather prediction, predictability, cloud systems, boundary layers, surface-atmosphere interactions, convective cloud systems, atmospheric chemistry, precipitating weather systems, wildfire research, National Center for Atmospheric Research">
<meta name="DESCRIPTION" content="WRF Mesoscale Model Users homepage">
<meta name="ROBOTS" content="INDEX,FOLLOW">
<meta name="resource-type" content="document">
<meta http-equiv="expires" content="0">
<meta name="author" content="MMM Webmaster">
<meta name="copyright" content="Copyright (c) 2017 by UCAR">
<meta name="revisit-after" content="1 days">
<meta name="distribution" content="Global">
<meta name="rating" content="General">
<SCRIPT language=JavaScript src="scripts/menu_array.js" type=text/javascript></SCRIPT>
<SCRIPT language=JavaScript src="scripts/mmenu.js" type=text/javascript></SCRIPT>
<link href="images/wrfstyle.css" rel="stylesheet" type="text/css">
<style type="text/css">
<!--
.style2 {
font-size: 8pt;
color: #141518;
}
.style8 {
color: #FFFFFF;
font-size: 9pt;
}
-->
</style>
</head>
<body bgcolor="#FFFFFF" link="#000099" vlink="#000099" alink="#FF3300" leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr bgcolor="#000000">
<td height="10" bgcolor="#000000"><div align="left"><img src="images/transgif.gif" width="1" height="1"></div>
</td>
</tr>
<tr valign="top">
<td height="10" bgcolor="#DDFFDD"><img src="images/header_new_cropped.png" height="56" border="0"></td>
</tr>
<tr bgcolor="#FFCC33">
<td height="6" background="images/goldrule.jpg" bgcolor="#009933"><img src="images/goldrule.jpg" width="1" height="1"></td>
</tr>
<tr>
<td height="34" bgcolor="#009933"> </td>
</tr>
<tr>
<td height="2" bgcolor="#ffcc66"><img src="images/transgif.gif" width="1" height="1"></td>
</tr>
</table>
<table width="100%" height="89%" border="0" cellpadding="0" cellspacing="0" class="background">
<tr>
<td height="1155" valign="top" bgcolor="#CBFFCD"><table width="1122" height="1155" border="0" cellpadding="0" cellspacing="0"><tr valign="top"><td width="117" height="1155" bgcolor="#009933"><table width="1122" border="0" cellpadding="0" cellspacing="0">
<tr valign="top">
<td width="117" height="1155" bgcolor="#009933"><table width="117" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td height="316" align="right" valign="top"><p align="right"> </p>
<p align="center" style="border-width: 5px;border-style: solid;border-color: #CBFFCD;background-color: #CBFFCD;font-family: Arial; line-height: 10pt;font-weight: bold;">System Overview</p>
<p align="center"><a href="updates-3.8.1.html" class="leftnavlink">WRFDA V3.8.1</a></p>
<p align="center"><a href="updates-3.8.html" class="leftnavlink">WRFDA V3.8</a></p>
<p align="center"><a href="updates-3.7.1.html" class="leftnavlink">WRFDA V3.7.1</a></p>
<p align="center"><a href="updates-3.7.html" class="leftnavlink">WRFDA V3.7</a></p>
<p align="center"><a href="updates-3.6.1.html" class="leftnavlink">WRFDA V3.6.1</a></p>
<p align="center"><a href="updates-3.6.html" class="leftnavlink">WRFDA V3.6</a></p>
<p align="center"><a href="updates-3.5.1.html" class="leftnavlink">WRFDA V3.5.1</a></p>
<p align="center"><a href="updates-3.5.html" class="leftnavlink">WRFDA V3.5</a></p>
<p align="center"><a href="updates-3.4.1.html" class="leftnavlink">WRFDA V3.4.1</a></p>
<p align="center"><a href="updates-3.4.html" class="leftnavlink">WRFDA V3.4</a></p>
<p align="center"><a href="updates-3.3.1.html" class="leftnavlink">WRFDA V3.3.1</a></p>
<p align="center"><a href="updates-3.3.html" class="leftnavlink">WRFDA V3.3</a></p>
<p align="center"><a href="updates-3.2.1.html" class="leftnavlink">WRFDA V3.2.1</a></p>
<p align="center"><a href="updates-3.2.html" class="leftnavlink">WRFDA V3.2</a></p>
<p align="center"><a href="updates-older.html" class="leftnavlink">Older versions</a></p>
<p align="center"><a href="tutorial.html" class="leftnavlink">Tutorials</a></p>
<p align="center"><a href="download/tools.html" class="leftnavlink">Tools</a></p>
<p align="center"><a href="known-problems.html" class="leftnavlink">Known Problems and Fixes</a></p></td>
</td>
</tr>
</table>
<p> </p>
<p> </p>
<img src="images/shim112.gif" width="112" height="1"></td>
<td bgcolor="#CBFFCD"><p> </p>
<p class="pagetitle">WRFDA System Overview</p>
<p class="bodytext">The WRF Data Assimilation system (WRFDA, formerly known as WRF-VAR) is a unified (global/regional, multi-model, 3/4D-Var) model-space data assimilation system for use by the NCAR staff and collaborators, and is also freely available to the general community, together with further documentation, test results, plans, etc.</p>
<p class="bodytext">Data assimilation is the technique by which <b>observations</b> are combined with an NWP product (the <b>first guess</b> or background forecast) and their respective error statistics to provide an improved estimate (the <b>analysis</b>) of the atmospheric (or oceanic, Jovian, etc.) state. Variational (Var) data assimilation achieves this through the iterative minimization of a prescribed cost (or penalty) function. Differences between the analysis and observations/first guess are penalized (damped) according to their perceived error. The difference between three-dimensional (3D-Var) and four-dimensional (4D-Var) data assimilation is the use of a numerical forecast model in the latter.</p>
<blockquote>
<p><strong>WRFDA System Components</strong></p>
</blockquote>
<p class="bodytext">Various components of the WRFDA system are shown in blue in the sketch below, together with their relationship with the rest of the WRF system.</p>
<table width="586" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td width="757" height="600" class="bodytext"><div align="center"><a href="images/wrfda_flowchart_white_bg.png"><img src="images/wrfda_flowchart_white_bg_small.png" alt="WRFDA Flowchart. Click to view larger version."></a></div></td>
</tr>
</table>
<blockquote>
<blockquote>
<p><i><b>x<sup>b</sup></b></i> first guess, either from a previous WRF forecast or from WPS/REAL output</p>
<p><i><b>x<sup>lbc</sup></b></i> lateral boundary from WPS/REAL output</p>
<p><i><b>x<sup>a</sup></b></i> analysis from the WRFDA system</p>
<p><i><b>x<sup>f</sup></b></i> WRF forecast output</p>
<p><i><b>y<sup>o</sup></b></i> observations processed by OBSPROC (NOTE: PREPBUFR input, radar, radiance, and rainfall data are not processed through OBSPROC)</p>
<p><i><b>B<sub>0</sub></b></i> background error statistics from generic BE data (CV3) or gen_be</p>
<p><i><b>R</b></i> observational and representative error statistics</p>
<p class="bodytext">Before using your own data, we suggest that you start by running through the WRFDA-related programs using the supplied test case (can be downloaded <a href="./download/testdata.html">here</a>). This serves two purposes: First, you can learn how to run the programs with data we have tested ourselves, and second you can test whether your computer is capable of running the entire modeling system. After you have done the tutorial, you can try running other, more computationally intensive, case studies and experimenting with some of the many namelist variables. </p>
<p><strong>Platforms capable of running WRFDA</strong></p>
<p class="bodytext">Running WRFDA requires a Fortran 90 compiler. We have tested the WRFDA on the following platforms: IBM (XLF), SGI Altix (INTEL), PC/Linux (PGI, INTEL, GFORTRAN), and Apple (G95/PGI). Please let us know if this does not meet your requirements, and we will attempt to add other machines to our list of supported architectures, as resources allow. Although we are interested in hearing about your experiences in modifying compiler options, we do not recommend making changes to the configure file used to compile WRFDA.</p>
<p class="bodytext"><strong>WARNING:</strong> It is impossible to test every permutation of computer, compiler, number of processors, case, namelist option, etc. for every WRFDA release. The namelist options that are supported are indicated in the <kbd>WRFDA/var/README.namelist</kbd> file of the source code, and these are the default options. </p>
<p class="bodytext">We hope our test cases will prepare you for the variety of ways in which you may wish to run your own WRFDA experiments. Please inform us about your experiences through <a href="wrfhelp.html">wrfhelp</a>.</p>
<p class="bodytext">As a professional courtesy, we request that you include the following reference in any publication that uses the community WRFDA system, in whole or in part:</p>
<blockquote>
<p class="citetext">Barker, D., X.-Y. Huang, Z. Liu, T. Auligné, X. Zhang, S. Rugg, R. Ajjaji, A. Bourgeois, J. Bray, Y. Chen, M. Demirtas, Y.-R. Guo, T. Henderson, W. Huang, H.-C. Lin, J. Michalakes, S. Rizvi, and X. Zhang, 2012: <a href="http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-11-00167.1">The Weather Research and Forecasting Model's Community Variational/Ensemble Data Assimilation System: WRFDA</a>. <i>Bull. Amer. Meteor. Soc.</i>, <b>93</b>, 831–843.</p>
</blockquote>
<p class="bodytext">You can find additional publications on specific portions of the WRFDA system at our <a href="publications.html">Publications Page</a>.</p>
<a name="methods_and_obs"><p><strong>WRFDA assimilation methods and observation types</strong></p>
<p class="bodytext">WRFDA is an assimilation system which contains several different methods of data assimilation:</p>
<ul class="bodytext"><li>3DVAR</li>
<li>4DVAR</li>
<li>Ensemble DA</li>
<li>Hybrid 3DVAR/Ensemble</li></ul>
<p class="bodytext">Using these assimilation methods, WRFDA is capable of ingesting a wide variety of observation types. Most data types can be assimilated in LITTLE_R (ASCII text) or PREPBUFR (binary) format, but satellite radiances are assimilated in BUFR format unless otherwise noted.</p>
<ul class="bodytext"><li><b>In-situ</b>
<ul class="bodytext"><li>Surface (SYNOP, METAR, SHIP, BUOY)</li>
<li>Upper air (TEMP, PIBAL, AIREP, ACARS, TAMDAR)</li></ul></ul>
<ul class="bodytext"><li><b>Remote sensing (derived products)</b>
<ul class="bodytext"><li>Atmospheric Motion Vectors (GOES, Polar)</li>
<li>GPS Refractivity (COSMIC)</li>
<li>GPS Precipitable Water (PW) and Zenith Total Delay (ZTD)</li>
<li>Radar reflectivity and velocity</li>
<li>QuikScat and ASCAT oceanic surface winds</li>
<li>SSM/I oceanic surface wind speed</li>
<li>SSM/I Total Precipitable Water (TPW)</li>
<li>Stage IV precipitation/rain rate data <em>(4DVAR only)</em></li>
<li>SATEM Thickness</li></ul></ul>
<ul class="bodytext"><li><b>Satellite radiance</b>
<ul class="bodytext"><li>HIRS (NOAA 16–19, METOP A)</li>
<li>AMSU-A (NOAA 15–19, EOS-Aqua, METOP A)</li>
<li>AMSU-B (NOAA 15–17)</li>
<li>MHS (NOAA 18–19, METOP A)</li>
<li>AIRS (EOS-Aqua)</li>
<li>SSMIS (DMSP 16–18)</li>
<li>IASI (METOP A)</li>
<li>ATMS (Suomi-NPP)</li>
<li>MWTS (FY-3) <em>Binary format</em></li>
<li>MWHS (FY-3) <em>Binary format</em></li>
<li>SEVIRI (Meteosat 8–10)</li>
<li>AMSR2 (GCOM-W1) <em>HDF5 format</em></li></ul></ul>
<p class="bodytext">Satellite radiance assimilation requires the use of a radiative transfer model. WRFDA supports the use of CRTM (included) and RTTOV (must be downloaded separately).</p>
<p><br></p>
</blockquote>
<p class="bodytext"><big>A more complete introduction to WRFDA, along with instructions on how to compile and run the various components, can be found in the <a href="usersguide.html">WRFDA User Guide</a>.</big></p>
<p class="bodytext">
<p class="bodytext"> </p>
<p align="center" class="detailtextRed">
<script language="JavaScript">
<!--
document.write("updated " + document.lastModified);
// -->
</script>
</p>
<p align="center" class="bodytext"> </p>
<img src="images/transgif.gif" width="1" height="1"><img src="images/shim162.gif" width="162" height="1"></td>
</tr>
</table></td>
</tr>
</table></td>
</tr>
<tr>
<td height="50" valign="bottom" bgcolor="#009933"> </td>
</tr>
</table>
</body>
</html>