Sums are for heights of skyscrapers visible from the edges. Only those higher than the previous one(s) count toward the sums.
Therefore each sum must include 9, the height of the highest skyscraper, which can be seen from each edge. This is a KiMo, with the totals being xn where it has been specified that x is never 0.
1a. R2 and R9 are the only rows with right-hand total unspecified, cannot make upper total x9 in C9 with 9 in R2C9 -> R9C9 = 9, no 8 in R8C9 + R9C8 (NC)
1b. C4 and C9 are the only columns with lower total unspecified, and none of the lower totals are x7, R9C9 = 9 -> R9C4 = 8, no 7,9 in R8C4, no 7 in R9C35 (NC)
1c. R1 and R5 are the only rows with left-hand total unspecified, and none of the left-hand totals are x7 -> R15C1 = {89}, locked for C1
1d. C1 and C5 are the only columns with upper total unspecified, and none of the left-hand totals are x7 -> R1C15 = {89}, locked for R1
1e. R2 and R9 are only rows with right-hand total unspecified, R6 has right-hand total x7, R9C9 = 9 -> 8 in C9 must be in one of R26C9, locked for C9
1f. No 8,9 in R2C5 and R5C2 (NC)
2a. Row starting 7 must total either 16 or 24, R9 is the only row with left-hand total either x4 or x6 (unspecified totals already used) -> R9C1 = 7, no 6 in R8C1 + R9C2 (NC)
2b. Column starting 7 must total either 16 or 24, C2 is the only column with upper total either x4 or x6 (unspecified totals already used) -> R1C2 = 7, no 8 in R1C1, no 6 in R1C3, no 6,8 in R2C2 (NC)
2c. R1C1 = 9, R1C5 = 8, R5C1 = 8, no 7 in R2C5 (NC)
2d. Upper total in C2 = 16 = [79] -> no 8 in C2 above the 9 -> no 8 in R3C2
2e. 8 in C2 only in R78C2, locked for N7
2f. 8 in R78C2 -> no 9 in R78C2 (NC)
2g. 9 in N7 only in R78C3, locked for C3
2h. Lower total in C3 = x8 contains 9 in R78C3 must be 18 = [963] (cannot be [954] because of NC), no 8 in R7C2, no 5 in R8C24, no 2,4 in R9C2 (NC)
2i. R8C2 = 8 (hidden single in C2)
2j. Lower total in C2 = x2 contains 9 in R46C2 and 8 in R8C2 must be 22 -> R9C2 =5
3a. Row ending 7 must total 16, 24 or have unspecified total -> 7 in C9 must be in one of R24C9 (7 cannot be in R8C9 because 8 in R8 is to the left of the 9), locked for C9
3b. 7 in R24C9 -> no 6 in R3C9 (NC)
3c. 8 in N9 only in R7C78 -> no 7 in R7C78 (NC)
3d. 7 in N9 only in R8C7 (7 cannot be in R8C7 because cannot make lower total x4 in C8), no 6,8 in R7C7 (NC)
3e. R7C8 = 8 (hidden single in N9), no 7,9 in R6C8 (NC)
3f. Lower total x4 in C8 contains 8,9 must be 24 -> remaining cells must total 7 -> R89C8 = [52], no 4 in R8C9, no 1 in R9C7 (NC)
3g. Right-hand total in R8 = x4 contains 5,7,9 must total 24 -> R8C9 = 3, no 4 in R7C9 (NC)
3h. 1 in R9 only in R9C56, locked for N8
3i. R8C1 = 1 (hidden single in R8), no 2 in R7C1 (NC)
3j. R7C12 = [42], R7C79 = [16], R9C7 = 4, no 3,5 in R6C1, no 1,3 in R6C2, no 2 in R6C7, no 5 in R6C9 (NC)
4a. Lower total in C5 = x1 cannot be made from [69] or [679] -> R9C5 = 1, R9C6 = 6, no 2 in R8C5 (NC)
4b. Lower total in C5 = x1 cannot be made with 9 in R8C5 -> R8C5 = 4, R8C4 = [29], no 3 in R7C4, no 3,5 in R7C5 (NC)
4c. R7C456 = [573], no 4,6 in R6C4, no 6 in R6C5, no 2,4 in R6C6 (NC)
5a. Left-hand total in R6 = x1 cannot be made from [69] -> R6C1 = 2
5b. 3 in C1 must be in R23C1 (R23C1 cannot be {56} NC)
5c. R4C1 = {56} -> no 5,6 in R3C1, no 6 in R4C2 {NC)
5d. R3C1 = 3 (hidden single in C1), no 4 in R3C2 (NC)
5e. Left-hand total in R4 = x8 cannot be made from [59/69] -> no 9 in R4C2
5f. R6C2 = 9 (hidden single in C2)
6a. Upper total in C3 = x2 contains 8,9 must be 22 = [589] (cannot be [1489] which clashes with R2C2) -> R1C3 = 5, R24C1 = [65], R23C2 = [41], R45C2 = [36], no 4,6 in R1C4, no 2 in R3C3, no 4 in R4C3, no 7 in R5C3 (NC)
6b. R23C3 = [28], no 1,3 in R2C4, no 7,9 in R3C4, no 7 in R4C3 (NC)
6c. R456C3 = [147], no 3 in R5C4 (NC)
6d. Upper total in C4 = x2 must be 12 (cannot be 22) -> R12C4 = [39], R2C5 = 5, R56C4 = [71], no 6 in R4C4 (NC)
6e. R34C4 = [64], R3456C5 = [2693]
6f. 6 in R6 only in R6C78 -> no 5 in R6C7 (NC)
6g. R6C6 = 5 (hidden single in R6) -> R45C6 = [82], no 7 in R3C6, no 9 in R4C7, no 6 in R6C7 (NC)