提问

彭小民

请问，要怎么从一个nc文件中提取一层的风场数据

feiji158

这样的？我的这张是500hpa 高度场， 700hpa 风场流线 ，850hpa的 风标 ，海平面气压合成图。

1. 'reinit'
   
2. 'sdfopen e:/nc/slp.2014.nc'
   
3. 'set lon 95 135'
   
4. 'set lat 20 40'
   
5. 'set grads off'
   
6. 'set timelab off'
   
7. 'set grid off'
   
8. 'set gxout shaded'
   
9. 'define x=(slp(time=06Z09apr2014)+slp(time=06Z10apr2014)+slp(time=06Z14apr2014)+slp(time=06Z16may2014)+slp(time=06Z21may2014)+slp(time=06Z29may2014)+slp(time=06Z05jun2014)+slp(time=06Z06jun2014)+slp(time=06Z08jun2014)+slp(time=06Z15jun2014)+slp(time=06Z24jun2014)+slp(time=06Z17jul2014)+slp(time=06Z19jul2014)+slp(time=06Z21jul2014)+slp(time=06Z22jul2014)+slp(time=06Z28jul2014)+slp(time=06Z05aug2014)+slp(time=06Z06aug2014)+slp(time=06Z16aug2014)+slp(time=06Z22aug2014)+slp(time=06Z05sep2014)+slp(time=06Z26sep2014)+slp(time=06Z27sep2014)+slp(time=06Z07oct2014)+slp(time=06Z23oct2014)+slp(time=06Z24oct2014)+slp(time=06Z25oct2014)+slp(time=06Z05nov2014)+slp(time=06Z01jan2014)+slp(time=06Z11jun2014)+slp(time=06Z26jul2014)+slp(time=06Z25sep2014)+slp(time=06Z13jun2014)+slp(time=06Z10jul2014)+slp(time=06Z03aug2014)+slp(time=06Z11aug2014)+slp(time=06Z12jun2014))/37'
   
10. 'e:/nc/12colors.gs'
    
11. 'set csmooth on'
    
12. 'set cint 1'
    
13. 'd x/100'
    
14. 'cbarn 1 0'
    
15. 'sdfopen e:/nc/hgt.2014.nc'
    
16. 'set lev 500'
    
17. 'define y=(hgt.2(time=06Z09apr2014)+hgt.2(time=06Z10apr2014)+hgt.2(time=06Z14apr2014)+hgt.2(time=06Z16may2014)+hgt.2(time=06Z21may2014)+hgt.2(time=06Z29may2014)+hgt.2(time=06Z05jun2014)+hgt.2(time=06Z06jun2014)+hgt.2(time=06Z08jun2014)+hgt.2(time=06Z15jun2014)+hgt.2(time=06Z24jun2014)+hgt.2(time=06Z17jul2014)+hgt.2(time=06Z19jul2014)+hgt.2(time=06Z21jul2014)+hgt.2(time=06Z22jul2014)+hgt.2(time=06Z28jul2014)+hgt.2(time=06Z05aug2014)+hgt.2(time=06Z06aug2014)+hgt.2(time=06Z16aug2014)+hgt.2(time=06Z22aug2014)+hgt.2(time=06Z05sep2014)+hgt.2(time=06Z26sep2014)+hgt.2(time=06Z27sep2014)+hgt.2(time=06Z07oct2014)+hgt.2(time=06Z23oct2014)+hgt.2(time=06Z24oct2014)+hgt.2(time=06Z25oct2014)+hgt.2(time=06Z05nov2014)+hgt.2(time=06Z01jan2014)+hgt.2(time=06Z11jun2014)+hgt.2(time=06Z26jul2014)+hgt.2(time=06Z25sep2014)+hgt.2(time=06Z13jun2014)+hgt.2(time=06Z10jul2014)+hgt.2(time=06Z03aug2014)+hgt.2(time=06Z11aug2014)+hgt.2(time=06Z12jun2014))/37'
    
18. 'set gxout contour'
    
19. 'set cint 4'
    
20. 'set ccolor 1'
    
21. 'd y/10'
    
22. 'sdfopen e:/nc/uwnd.2014.nc'
    
23. 'sdfopen e:/nc/vwnd.2014.nc'
    
24. 'set lev 700'
    
25. 'define j=(uwnd.3(time=06Z09apr2014)+uwnd.3(time=06Z10apr2014)+uwnd.3(time=06Z14apr2014)+uwnd.3(time=06Z16may2014)+uwnd.3(time=06Z21may2014)+uwnd.3(time=06Z29may2014)+uwnd.3(time=06Z05jun2014)+uwnd.3(time=06Z06jun2014)+uwnd.3(time=06Z08jun2014)+uwnd.3(time=06Z15jun2014)+uwnd.3(time=06Z24jun2014)+uwnd.3(time=06Z17jul2014)+uwnd.3(time=06Z19jul2014)+uwnd.3(time=06Z21jul2014)+uwnd.3(time=06Z22jul2014)+uwnd.3(time=06Z28jul2014)+uwnd.3(time=06Z05aug2014)+uwnd.3(time=06Z06aug2014)+uwnd.3(time=06Z16aug2014)+uwnd.3(time=06Z22aug2014)+uwnd.3(time=06Z05sep2014)+uwnd.3(time=06Z26sep2014)+uwnd.3(time=06Z27sep2014)+uwnd.3(time=06Z07oct2014)+uwnd.3(time=06Z23oct2014)+uwnd.3(time=06Z24oct2014)+uwnd.3(time=06Z25oct2014)+uwnd.3(time=06Z05nov2014)+uwnd.3(time=06Z01jan2014)+uwnd.3(time=06Z11jun2014)+uwnd.3(time=06Z26jul2014)+uwnd.3(time=06Z25sep2014)+uwnd.3(time=06Z13jun2014)+uwnd.3(time=06Z10jul2014)+uwnd.3(time=06Z03aug2014)+uwnd.3(time=06Z11aug2014)+uwnd.3(time=06Z12jun2014))/37'
    
26. 'set lev 700'
    
27. 'define k=(vwnd.4(time=06Z09apr2014)+vwnd.4(time=06Z10apr2014)+vwnd.4(time=06Z14apr2014)+vwnd.4(time=06Z16may2014)+vwnd.4(time=06Z21may2014)+vwnd.4(time=06Z29may2014)+vwnd.4(time=06Z05jun2014)+vwnd.4(time=06Z06jun2014)+vwnd.4(time=06Z08jun2014)+vwnd.4(time=06Z15jun2014)+vwnd.4(time=06Z24jun2014)+vwnd.4(time=06Z17jul2014)+vwnd.4(time=06Z19jul2014)+vwnd.4(time=06Z21jul2014)+vwnd.4(time=06Z22jul2014)+vwnd.4(time=06Z28jul2014)+vwnd.4(time=06Z05aug2014)+vwnd.4(time=06Z06aug2014)+vwnd.4(time=06Z16aug2014)+vwnd.4(time=06Z22aug2014)+vwnd.4(time=06Z05sep2014)+vwnd.4(time=06Z26sep2014)+vwnd.4(time=06Z27sep2014)+vwnd.4(time=06Z07oct2014)+vwnd.4(time=06Z23oct2014)+vwnd.4(time=06Z24oct2014)+vwnd.4(time=06Z25oct2014)+vwnd.4(time=06Z05nov2014)+vwnd.4(time=06Z01jan2014)+vwnd.4(time=06Z11jun2014)+vwnd.4(time=06Z26jul2014)+vwnd.4(time=06Z25sep2014)+vwnd.4(time=06Z13jun2014)+vwnd.4(time=06Z10jul2014)+vwnd.4(time=06Z03aug2014)+vwnd.4(time=06Z11aug2014)+vwnd.4(time=06Z12jun2014))/37'
    
28. 'set gxout stream'
    
29. 'set cstyle 4'
    
30. 'set strmden 1'
    
31. 'set ccolor 2'
    
32. 'd j;k'
    
33. 'set lev 850'
    
34. 'define a=(uwnd.3(time=06Z09apr2014)+uwnd.3(time=06Z10apr2014)+uwnd.3(time=06Z14apr2014)+uwnd.3(time=06Z16may2014)+uwnd.3(time=06Z21may2014)+uwnd.3(time=06Z29may2014)+uwnd.3(time=06Z05jun2014)+uwnd.3(time=06Z06jun2014)+uwnd.3(time=06Z08jun2014)+uwnd.3(time=06Z15jun2014)+uwnd.3(time=06Z24jun2014)+uwnd.3(time=06Z17jul2014)+uwnd.3(time=06Z19jul2014)+uwnd.3(time=06Z21jul2014)+uwnd.3(time=06Z22jul2014)+uwnd.3(time=06Z28jul2014)+uwnd.3(time=06Z05aug2014)+uwnd.3(time=06Z06aug2014)+uwnd.3(time=06Z16aug2014)+uwnd.3(time=06Z22aug2014)+uwnd.3(time=06Z05sep2014)+uwnd.3(time=06Z26sep2014)+uwnd.3(time=06Z27sep2014)+uwnd.3(time=06Z07oct2014)+uwnd.3(time=06Z23oct2014)+uwnd.3(time=06Z24oct2014)+uwnd.3(time=06Z25oct2014)+uwnd.3(time=06Z05nov2014)+uwnd.3(time=06Z01jan2014)+uwnd.3(time=06Z11jun2014)+uwnd.3(time=06Z26jul2014)+uwnd.3(time=06Z25sep2014)+uwnd.3(time=06Z13jun2014)+uwnd.3(time=06Z10jul2014)+uwnd.3(time=06Z03aug2014)+uwnd.3(time=06Z11aug2014)+uwnd.3(time=06Z12jun2014))/37'
    
35. 'set lev 850'
    
36. 'define s=(vwnd.4(time=06Z09apr2014)+vwnd.4(time=06Z10apr2014)+vwnd.4(time=06Z14apr2014)+vwnd.4(time=06Z16may2014)+vwnd.4(time=06Z21may2014)+vwnd.4(time=06Z29may2014)+vwnd.4(time=06Z05jun2014)+vwnd.4(time=06Z06jun2014)+vwnd.4(time=06Z08jun2014)+vwnd.4(time=06Z15jun2014)+vwnd.4(time=06Z24jun2014)+vwnd.4(time=06Z17jul2014)+vwnd.4(time=06Z19jul2014)+vwnd.4(time=06Z21jul2014)+vwnd.4(time=06Z22jul2014)+vwnd.4(time=06Z28jul2014)+vwnd.4(time=06Z05aug2014)+vwnd.4(time=06Z06aug2014)+vwnd.4(time=06Z16aug2014)+vwnd.4(time=06Z22aug2014)+vwnd.4(time=06Z05sep2014)+vwnd.4(time=06Z26sep2014)+vwnd.4(time=06Z27sep2014)+vwnd.4(time=06Z07oct2014)+vwnd.4(time=06Z23oct2014)+vwnd.4(time=06Z24oct2014)+vwnd.4(time=06Z25oct2014)+vwnd.4(time=06Z05nov2014)+vwnd.4(time=06Z01jan2014)+vwnd.4(time=06Z11jun2014)+vwnd.4(time=06Z26jul2014)+vwnd.4(time=06Z25sep2014)+vwnd.4(time=06Z13jun2014)+vwnd.4(time=06Z10jul2014)+vwnd.4(time=06Z03aug2014)+vwnd.4(time=06Z11aug2014)+vwnd.4(time=06Z12jun2014))/37'
    
37. 'set gxout barb'
    
38. 'set ccolor 1'
    
39. 'd a;s'
    
40. 'draw title 500hPa Heights 700 850 hPa Wind and Sea Level Pressure'
    
41. 'gxprint e:/g1.ps white'
    

复制代码

风场资料需要uv风量合成绘画，
先读取nc中的u、v文件，例如：'sdfopen e:/nc/uwnd.2014.nc' 'sdfopen e:/nc/vwnd.2014.nc'  
然后设定层次，例如：'set lev 700'
接着定义变量，例如：'define a=(uwnd.3(time=06Z09apr2014)+uwnd.3(time=06Z10apr2014)’ 'define s=(vwnd.4(time=06Z09apr2014)+vwnd.4(time=06Z10apr2014)’ 注意根据Grads读取文件的顺序，在uwnd后面加上.2、.3.....
最后根据需求绘画，例如绘画风标图：'set gxout barb''set ccolor 1''d a;s'

彭小民

我是想要从nc风场数据中提取850hpa的那一层，然后输出为二进制文件。而且我后来发现风场数据的维数环境里只有一层1000hpa，但是那个明明应该是17层的😔

feiji158

https://www.esrl.noaa.gov/psd/da ... lysis.pressure.html
你下个这个风场资料看看