diff --git a/topic-hierarchy/earth-system-discipline/ocean/index.csv b/topic-hierarchy/earth-system-discipline/ocean/index.csv
index 1860f2e..d5d5471 100644
--- a/topic-hierarchy/earth-system-discipline/ocean/index.csv
+++ b/topic-hierarchy/earth-system-discipline/ocean/index.csv
@@ -1,2 +1,3 @@
 Name,Description,Source
 experimental,Experimental topics,
+surface-based-observations,Surface based observations,
diff --git a/topic-hierarchy/earth-system-discipline/ocean/surface-based-observations/index.csv b/topic-hierarchy/earth-system-discipline/ocean/surface-based-observations/index.csv
new file mode 100644
index 0000000..52de55e
--- /dev/null
+++ b/topic-hierarchy/earth-system-discipline/ocean/surface-based-observations/index.csv
@@ -0,0 +1,14 @@
+Name,Description,Source
+moored-buoys,Data from moored buoys,
+drifting-buoys,Data from drifting buoys,
+sea-ice,Sea ice observations,
+ocean-profilers,"Data from ocean profilers, e.g. Argo",
+ship-surface,Along track surface observations from ships,
+ship-sub-surface,"Profile data measured from ships, e.g. XBT, CTD, etc.",
+wave-buoys,Data from wave buoys,
+tsunami-buoys,"Data from tsunami buoys, e.g. DART buoys",
+autonomous-surface-vehicles,Data from autonomous surface vehicles,
+gliders,Data from gliders,
+animal-borne-sensors,Data from animal borne sensors,
+fixed-marine-platforms,Data from fixed surface platforms,
+sea-level,Sea level data from tide gauges and other sources,
\ No newline at end of file