Evergreen and deciduous forest fractions: inconsistencies? – in #9: CCLM

in #9: CCLM

<p> (Sorry, pressed submit too soon, edited the answer afterwards) </p> <p> Dear Burkhardt </p> <p> Thanks a lot for your answer. To be honest, I cannot follow your explanation completely. If you say </p> <p> &gt; veg_part = for_e+for_d+veg_low </p> <p> then the long_name “ground fraction covered by deciduous forest” seems to be more appropriate. It actually is not relative to the vegetation fraction but to the total surface area. As an example, for a vegetation fraction of 0.8, for_e = 0.4, for_d = 0.3 and veg_low = 0.1. This is also consistent with the equation <br/> <pre><code>zsnow_alb = zsalb_snow*(1._ireals-for_e(i,j)-for_d(i,j)) &amp; + csalb_snow_fe * for_e(i,j) &amp; + csalb_snow_fd * for_d(i,j) </code></pre> </p> <p> However, I still think it is <span class="caps"> NOT </span> consistent with the other equation. Ignoring snow cover for simplicity and multiplying the brackets gives <br/> <pre><code>zalso(i,j)= zvege*for_e(i,j) *0.10_ireals + &amp; zvege*for_d(i,j) *0.15_ireals + &amp; zvege*(1._ireals-for_e(i,j)-for_d(i,j))*0.20_ireals + &amp; (1._ireals-zvege) *zalso(i,j) </code></pre> <br/> Here, all vegetation type fractions are multiplied with <code> zvege </code> , the vegetation fraction, indicating </p> <p> &gt; 1 = for_e+for_d+veg_low </p> <p> So, in <span class="caps"> CCLM </span> , we either need to introduce vegetation fraction factor in the first equation and we need to remove in the second one. </p> <p> Cheers </p>

  @sebastianschubert in #2323bf1

<p> (Sorry, pressed submit too soon, edited the answer afterwards) </p> <p> Dear Burkhardt </p> <p> Thanks a lot for your answer. To be honest, I cannot follow your explanation completely. If you say </p> <p> &gt; veg_part = for_e+for_d+veg_low </p> <p> then the long_name “ground fraction covered by deciduous forest” seems to be more appropriate. It actually is not relative to the vegetation fraction but to the total surface area. As an example, for a vegetation fraction of 0.8, for_e = 0.4, for_d = 0.3 and veg_low = 0.1. This is also consistent with the equation <br/> <pre><code>zsnow_alb = zsalb_snow*(1._ireals-for_e(i,j)-for_d(i,j)) &amp; + csalb_snow_fe * for_e(i,j) &amp; + csalb_snow_fd * for_d(i,j) </code></pre> </p> <p> However, I still think it is <span class="caps"> NOT </span> consistent with the other equation. Ignoring snow cover for simplicity and multiplying the brackets gives <br/> <pre><code>zalso(i,j)= zvege*for_e(i,j) *0.10_ireals + &amp; zvege*for_d(i,j) *0.15_ireals + &amp; zvege*(1._ireals-for_e(i,j)-for_d(i,j))*0.20_ireals + &amp; (1._ireals-zvege) *zalso(i,j) </code></pre> <br/> Here, all vegetation type fractions are multiplied with <code> zvege </code> , the vegetation fraction, indicating </p> <p> &gt; 1 = for_e+for_d+veg_low </p> <p> So, in <span class="caps"> CCLM </span> , we either need to introduce vegetation fraction factor in the first equation and we need to remove in the second one. </p> <p> Cheers </p>

(Sorry, pressed submit too soon, edited the answer afterwards)

Dear Burkhardt

Thanks a lot for your answer. To be honest, I cannot follow your explanation completely. If you say

> veg_part = for_e+for_d+veg_low

then the long_name “ground fraction covered by deciduous forest” seems to be more appropriate. It actually is not relative to the vegetation fraction but to the total surface area. As an example, for a vegetation fraction of 0.8, for_e = 0.4, for_d = 0.3 and veg_low = 0.1. This is also consistent with the equation

zsnow_alb = zsalb_snow*(1._ireals-for_e(i,j)-for_d(i,j))       &
            + csalb_snow_fe * for_e(i,j)                       &
            + csalb_snow_fd * for_d(i,j)

However, I still think it is NOT consistent with the other equation. Ignoring snow cover for simplicity and multiplying the brackets gives

zalso(i,j)= zvege*for_e(i,j)                       *0.10_ireals + &
            zvege*for_d(i,j)                       *0.15_ireals + &
            zvege*(1._ireals-for_e(i,j)-for_d(i,j))*0.20_ireals + &
            (1._ireals-zvege)                      *zalso(i,j)

Here, all vegetation type fractions are multiplied with zvege , the vegetation fraction, indicating

> 1 = for_e+for_d+veg_low

So, in CCLM , we either need to introduce vegetation fraction factor in the first equation and we need to remove in the second one.

Cheers