WRF地形敏感几个疑问

悠然一梦123

毕业论文需要做有关土地类型、土壤质地、地形高度敏感性试验，但是不知道该怎么着手。
问题一，土地类型·，发现WRF自带有USGS和MODIS两类土地类型数据，因为自己手头上没有可以替换的土地类型数据，我是否可以用WRF自带的这两类数据做敏感性试验？或者网上哪里还有可以下载的地形数据？还是选择其中一种地形数据，比如MODIS，21中土地类型，所研究区域分别都替换成裸地、草地或者城市建筑用地，做敏感性试验呢？
问题二，土壤质地，16种类型，是将研究区域全部替换成壤土、砂土或者粘土来进行敏感性试验吗？
问题三，地形高度，是将研究区域高度增加或者减少多少吗？如果是，是只需要改变wrfinput_d0*中HGT-M吗，还有需要改变的其他参数吗？

lorraineni

请问楼主解决了吗？

weiyuntao

Questions about topography sensitivity experiment
Post by Jacky Wei » Wed Nov 25, 2020 12:33 pm

Hi, all!
I am trying to do some sensitivity experiments using WRF ARW v4.0. The three-level nesting domain is attached here ("wps_show_dom.pdf").

Question 1: I would like to examine the role of high topography (~700 m) in domain d03, but domains d01 and d02 also include topography. So, do I need to remove or reduce the topography in only d03 or all domains (d01-d03)? I have this question because I worry that the "topographic effect" from the domains d01 and d02 may also exert an influence on the innermost domain d03.

Question 2: Now, assuming that question 1 is well addressed, for example, only terrain height ("HGT_M" in geo_em_d0* file) in domain d03 is changed (such as reduced to one-third of the original value). The trouble is that although "HGT_M" is reduced, the perturbation induced by the high topography is still there in other dynamical and thermodynamical variables such as wind, pressure, humidity, temperature, etc. My idea is to fill in these variables over the region where the topography is reduced using the averaged value of the surrounding oceans or surface level. So, is it the right way?

Question 3: Now, question 2 also see its solution. However, the boundary conditions (BIs) that are generally derived from the NCEP GFS will also bring in the topographic influence. Do I also need to remove this topographic influence from BIs? For example, using the mean value of the entire simulation period to replace the corresponding value in BIs.

I have checked some references and tutorials and it seems that the only thing they suggested to do is to change the variable "HGT_M". But, as I have mentioned above, I am not sure if other factors will cause a topographic effect either that influences the domain d03.

Thank you very much for your answers!

Jacky Wei
ATTACHMENTS
wps_show_dom.pdf
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Ming Chen
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Re: Questions about topography sensitivity experiment
Post by Ming Chen » Wed Nov 25, 2020 2:23 pm

Jacky,
Are you going to run 1-way nesting or two-way nesting case? The terrain height modification should depend on what style of nosing you want to implement.
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Jacky Wei
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Contact: Contact Jacky Wei
Re: Questions about topography sensitivity experiment
Post by Jacky Wei » Wed Nov 25, 2020 4:49 pm

Hi, Ming:
Thanks for your reply!
I want to run the WRF model using the two-way nesting domain.
Jacky

yuzhuolei

你好，看到你的问题，也是我现在迫切想明白的问题，不知你现在做到什么程度了，可否指点我一下？谢谢谢谢