Since 1991, civil war in Somalia has given rise to lucrative ship-hijackings and routine international warnings to commercial vessels to stay at least 600 miles off the Somalia coast. The piracy, especially since 2008, has pulled ship traffic away from the east Africa coast and the pathway of the seasonal Somali jet.
While some short-term studies are able to overcome this loss of weather-observing measurements from commercial shipping, the FSU team notes that longer-term climate studies rely on a record of data developed long before satellite-borne observations became available.
The researchers warned that the blip in the data will never go away, and future scientists need to be aware of its "geopolitical" origins.
"For example," they wrote, "a naive scientist might look at the wind anomaly fields and assume that the August 2009 northerly anomalies off Somalia have physical meaning. The evidence that piracy affects the long-term record of the Somali jet is a cautionary tale to those who are using surface-based analyses in the northwest Indian Ocean for the period beginning in mid-2008."