IMAGe Brown Bag Seminar - Interpolation uncertainties in global temperature fields

03/13/2017 - 12:00pm to 1:00pm
ML - Chapman Room (245)

Interpolation uncertainties in global temperature fields
Maryam Ilyas
University College London

Long-term increases in temperatures across the globe are one of the key indicators of climate change.

Measurements of air temperature from ground based-stations and sea surface temperature (SST) from ships and buoys in the oceans are combined to generate global surface temperature estimates. Initially these raw data undergo a quality control process. Homogeneity assessment is further carried out to eliminate systematic biases. Treatment of varying spatial coverage has also been highlighted as an important issue that can, for example, lead to underestimation of the global mean temperature trend by poor sampling in the Arctic which is warming particularly quickly.

This talk will discuss the quantification and impact of coverage uncertainties using HadCRUT4 temperature anomalies (which clearly flags locations missing data) and multi-resolution lattice kriging. The uncertainties arising from poor coverage are greater at the local scale. This will be illustrated by looking at the El Niño Southern Oscillation (ENSO) using an enhanced probabilistic definition of El Niño.

(Bring your lunch)