On page 130 in Eq. 3 and on p.15 in Eq. 15, the right hand side should be multiplied by 1/2. This is a typo in the paper only. The collision operator is correct in the initial value code.

This was verified by Bill Dorland on April 7, 1999.

A conservative form for the differencing of the first part of Eq. 17 would result in

(Gamma_el - Gamma_{el-1}) / (xsi_{el+1/2} - xsi_{el-1/2})

which is what is actually done in GS2.

On page 135, in Eq. 20, in the first and third terms (which involve D_1 and D_3), the factor f_{1 i+1}^{* n} should be replaced with f_{1 i}^{* n}. This is clear from its derivation from Eq. 14.

Likewise, in Eq. 21, in the 4th term (which involves D_4), the factor f_{i+1}^{* n+1} should be replaced with f_{2 i+1}^{* n+1}.

In the inline equation just after Eq. 20, the equation $f_1^n = f^n$ should be replaced with $f_1^{* n} = f_1^n = f^n$ to be clearer. Also, the inline equation after Eq. 21 should read $f_2^{* n} = 0$.

The second reference to Eq. 20 in the paragraph after Eq. 22 should refer to Eq. 18 instead.

In Eq. 23, the left hand side of the first equation is a sum over species $s$, not over $j$. In the second equation, the left hand side should be multiplied by k_theta^2.