adding o2d/o3d to more type of level in tables 27
17 sfc Departure level of the most unstable parcel of air (MUDL)
18 sfc Departure level of a mixed layer parcel of air with specified layer depth (Pa)
# 19 Reserved
-20 20 Isothermal level (K)
+20 o2d Isothermal level (K)
21 21 Lowest level where mass density exceeds the specified value (base for a given threshold of mass density) (kg m-3)
22 22 Highest level where mass density exceeds the specified value (top for a given threshold of mass density) (kg m-3)
23 23 Lowest level where air concentration exceeds the specified value (base for a given threshold of air concentration) (Bq m-3)
151 sol Soil level (Numeric)
152 sol Sea ice level (Numeric)
# 153-159 Reserved
-160 160 Depth below sea level (m)
+160 o2d Depth below sea level (m)
161 161 Depth below water surface (m)
162 162 Lake or river bottom (-)
163 163 Bottom of sediment layer (-)
165 165 Bottom of sediment layer penetrated by thermal wave (-)
166 166 Mixing layer (-)
167 167 Bottom of root zone (-)
-168 168 Ocean model level (Numeric)
-169 169 Ocean level defined by water density (sigma-theta) difference from near-surface to level (kg m-3)
-170 170 Ocean level defined by water potential temperature difference from near-surface to level (K)
+168 o3d Ocean model level (Numeric)
+169 o2d Ocean level defined by water density (sigma-theta) difference from near-surface to level (kg m-3)
+170 o2d Ocean level defined by water potential temperature difference from near-surface to level (K)
# 171-173 Reserved
-174 174 Top surface of ice on sea, lake or river
-175 175 Top surface of ice, under snow cover, on sea, lake or river
+174 o2d Top surface of ice on sea, lake or river
+175 o2d Top surface of ice, under snow cover, on sea, lake or river
176 176 Bottom surface (underside) ice on sea, lake or river
177 sfc Deep soil (of indefinite depth)
# 178 Reserved
