Wrf eta levels are designed for setting vertical eta levels. 0000 as such: using new automatic levels program 1 50. 0000000 50. 8 will give you the real altitude of each model level. If the test runs okay then you know it's your specific eta levels causing the problem. Prototype function wrf_interp_3d_z ( v3d : numeric, vert : numeric, loc [1] : numeric ) return_val: float or double Arguments v3d. I have not read through the new document of WRF3. Previous message: [ncl-talk] Interpolate WRF eta levels to pressure levels Next message: [ncl-talk] Interpolate WRF eta levels to pressure levels Messages sorted by:. Apr 8, 2021 · I am running WRF model with three two-way nested domains of 9,3 an 1km resolutions. 1. The HYSPLIT scheme calculates the change in height using the hypsometric equation while the WRF scheme uses the eta level, WRF dry mass, and WRF dry inverse density. How do I decide the number of vertical levels to use? And, how do I decide the eta levels manually? Oct 13, 2022 · 在一般的模式研究中，当涉及到下垫面对于模拟的影响，就会使用到eta_levels。 不同的地区的下垫面不同，有的是平原、有的是高原、有的是湖泊有的是高山。 地面的海拔高度不同，所以按照位势高度来分层，对于模拟结果会有较大影响. edu Wed Jan 8 11:31:25 MST 2020. fierro at gmail. If you stretched your vertical grid with dense-enough sigma levels near the surface you can interpolate any 3D parameter to Apr 11, 2021 · 1) Try to just use the model levels that are provided by WRF. input? Dec 31, 2020 · DZBOT, DZSTRETCH etc. , don't set eta_levels. 993814707 2 64. e. zap_close_levels = 500 ! ignore isobaric level above surface if delta p (Pa) < zap_close_levels lowest_lev_from_sfc = . 6. My study will primarily be focused on storms and the boundary layer, so ideally, I would like to have very high Aug 31, 2021 · Smoothly varying vertical levels can be very important for model stability. input). exe for this test. 97 , 0. Previous message: [ncl-talk] Interpolate WRF eta levels to pressure levels Next message: [ncl-talk] Interpolate WRF eta levels to pressure levels Messages sorted by: Dec 27, 2022 · WRF模式中关于eta_levels的设置以及对应的高度 产品 解决方案 文档与社区 权益中心 定价 云市场 合作伙伴 支持与服务 了解阿里云 AI 助理 I am working WRF outputl file and require to extract wind and temp values at 850 hPa, 700 hPa and 500 hPa pressure levels. Oct 26, 2024 · Thank you for your reply, Ming Chen. Tests have shown that two different sets of vertical levels gives different numbers of CFL prints. 95 , . com Thu May 22 13:11:14 MDT 2014. May 21, 2020 · Based on the automatically generated eta levels, you can add extra levels in lower atmosphere. How should i set space 1] Does the model height locate in the middle of two eta_levels in WRF? For example, is the first model height in the middle of the eta_level 1 and the eta_level 2? WRF implements staggered grid estruture. edu Wed Jan 8 11:48:20 MST 2020. If 'k' refers to the eta levels of WRF, what method or principle should I use to set the values of k_zfac_uv, k_zfac_t, and k_zfac_ph? If I set them to 10, which specific height does that refer to? Does the total number of nudging layers correspond to 47 eta_levels in namelist. Previous message: NCL Home > Documentation > Functions > WRF, Interpolation wrf_interp_3d_z. " The number of levels must agree with the number of eta surfaces allocated (e_vert). 762 m. As the WRF vertical coordinates are based on eta level, I am having trouble in getting parameters at different pressure level. Eta levels are automatically computed by the real program, based on the number of levels set by the namelist option "e_vert. 0000000 Oct 27, 2021 · Hi, e_vert can be specified based on your case. The AGL (Above Ground Level) of the same eta level varied slightly during simulation Oct 31, 2022 · Hi, If I don't define e_vert in the namelist. Just let the model choose for you. 以青藏高原为例，对于模式模拟的结果会造成较大的误差。 P代表某一层的气压，也就是你需要研究的那一层，Ptop (p_top_requested)代表模式顶层气压，Pbot代表海平面气压或地面气压。 （WRF 中好像是10hpa，不太确定）。 从表达式可以看出，地面的eta值就是1，顶层就是0。 这样一来，无论某个地区的下垫面的海拔高度是多少，它的eta坐标值都统一成1。 You can customize the vertical levels with "eta_levels" in WRF namelist (namelist. 99 , 0. For ideal cases, vertical levels are calculate based on ZTOP, which corresponds to real attitude. For cases with dz > dx (as can occur for dx < 1 km at the top), tests have also shown that continuous stretching works through to the model top better than having many From WRF output, you have elevation and pressure for each sigma level. In wrfout, you can find variables PH and PHB, (PH + PHB)/9. input, I can check the generated eta levels and their height, thickness information in the real log file rsl. You can explicitly specify eta_levels in namelist by setting The new interpolated eta levels may be rational as they are generated based on the default eta levels of WRF. I am trying to set up WRF model and I would like to specify explicit eta levels. false. I. The levels just distribute the model levels between the model top and the surface. Unlike the sigma coordinate system, which uses a dimensionless variable, the eta coordinate system is based on pressure levels. " However, full eta levels may be explicitely defined with the namelist option "eta_levels. for ncl, you should check out ncl website, where you can interpolate 3d data from wrf to specified pressure levels, while for wrf_interp, you have to download it from wrf user website, and compile it. I am working python. I am working WRF outputl file and require to extract wind and temp values at 850 hPa, 700 hPa and 500 hPa pressure levels. Dec 9, 2023 · The eta vertical coordinate system, also known as the pressure vertical coordinate system, is an alternative option available in the WRF model. Jul 22, 2019 · I know vertical levels can be set in namelist. This article aims to present an evaluation of the Weather Research and Forecasting (WRF) model with multiple instruments when applied to a humid continental region, in this case, the region I have WRF output in native model grid (eta levels) and the variables pressure, geopotential height (among other obviously). Interpolates to a specified pressure/height level. 0000000 0. 00000 , 0. 2) Are you running multiple different tests, with different dates? Mar 28, 2024 · I would like to ask about eta level setting. 1 should be the sigma vertical coordinate. You'll need to re-run real. It would be nice if anyone point in right direction. For example, suppose REAL produces the following eta levels: eta_levels = 1. Mar 15, 2019 · You cannot specify WRF eta levels to specific height levels like 10m, 25m, 50m, etc. ” The number of levels must agree with the number of eta surfaces allocated (e_vert). It usually should be larger than 40 with p_top = 50 hPa. o. If your model top goes higher, for example p_top = 1hPa, you will need to increase e_vert to 61 or more. [Wrf-users] Transforming eta levels to p levels Alex Fierro alexandre. Since pressure will vary at the surface, both horizontally and temporally, then the level value of 1 will be the surface level (versus the model top, with the sigma value of 0, which will Jan 8, 2020 · [ncl-talk] Interpolate WRF eta levels to pressure levels Anahita Amiri Farahani aamir003 at ucr. 98 , 0. Should the eta level be considered with the p-top requested value? If the p-top requested value is 50 hpa, how many levels can we set? Jan 8, 2020 · [ncl-talk] Interpolate WRF eta levels to pressure levels Dennis Shea shea at ucar. Although i set up eta 85 levels in namelist. I am currently studying wind turbines and want to set about 20 vertical levels below 200m AGL to refine my solution. out. 1. Could you be willing to tell me about how to interpolate variables of WRF to pressure level? I tried to do such conversion by the function "wrf_user_interp_level". This is because WRF implements hybrid vertical coordinate, which is roughly terrain following in lower levels and pressure levels in the upper. I added a new variable with cdo, height (z), where z=geopotential/grav. input by setting e_vert and p_top_requested variables and we can explicitly define eta_levels from 1 to 0. But you can always calculate the height if eta levels based. I think the coordinate system in WRF 3. I would like to have very high vertical resolution (~ 100m) upto 3 km as I want to study the boundary layer. For example, in the following lines I have made the settings for 39 levels. Although the example provided in the documentation does this for the pressure coordinate, I would like to do this for the height (z Jan 23, 2017 · the eta might or might not correspond exactly to your desired pressure levels, if you want to get the data, you have to use "ncl" or "wrf_interp". The difference between the two schemes is how they estimate the change in height between vertical levels. Actually, WRF output vertical coordinates (eta levels) are just indexes. ” However, full eta levels may be explicitely defined with the namelist option “eta_levels. And the maximum geopotential height is only 2657. ! place the surface value into the lowest eta location Dec 9, 2023 · I am new to using xWRF, and have been following the vertical interpolation example provided in the documentation to learn how to convert the native WRF sigma or Eta levels into a different coordinate system. Input array to interpolate. 9. In the vertical, we have full model levels (specified by eta_levels and e_vert) and half model levels ( e_vert - 1). Nov 20, 2019 · The version of WRF I used is WRF 3. input file, there are just only 60 levels in PH file of ts list. Dec 22, 2023 · Setting Model Vertical Levels Eta levels are automatically computed by the real program, based on the number of levels set by the namelist option “e_vert. gvtkhfn czz mimnqp ipmjt kui wlvinl etaz djwkpkp laelg pozxes