An external view of the Met Office building at night.

Dr Kate Willett

Areas of expertise

  • Observational data - issues of policy, stewardship and quality/homogeneity;

  • Recent climate change in the atmospheric system;

  • Surface humidity.

My Publications - Willett, K

Current activities

Kate produces the surface humidity monitoring product HadISDH. This is a monthly mean gridded global product from 1973 onwards for a range of humidity variables and also surface air temperature. At present it only contains land data but work is nearing completion to expand this to a include a marine component from ship and buoy data. This has led to investigation of recent trends in humidity, particularly the decline in relative humidity over land that has been apparent since around 2000.

Kate has been the lead editor of the Global Climate chapter of NOAA's annual State of the Climate reports since 2010 with an international team of co-editors. These reports bring together summaries for as many essential climate variables as possible, describing their behaviour over the current year in context of the historical record and known modes of variability such as the El Niño Southern Oscillation.

Kate sits on the steering committee of the International Surface Temperature Initiative (International Surface Temperature Initiative (ISTI)). The ISTI is working to improve the state of land surface temperature data in terms of comprehensive, open access and version controlled archiving with provenance to source origin. The ISTI is also working to provide robust assessments of methods used to build climate data products. Kate is chair of an ISTI working group building benchmark systems to test the skill of methods used to perform homogenisation on station data. Homogenisation is an essential process in creating climate quality data sets where changes resulting from events such as station moves or instrument changes are removed from a time series. This work focuses on monthly time scales. Kate had a PhD student with Exeter University working on daily timescale benchmarks which is now successfully completed.

Kate has led a small piece of work under the FP7 CLIPC project to get some of the HadOBS climate monitoring datasets hosted in the CLIPC data portal and also on the CEDA archive. This has led to important developments in data format, discoverability and understanding of the complexities of data policy relating to climate data with the ultimate aim of making Met Office Hadley Centre climate monitoring data more easily accessible and usable to a wide range of users.

Kate runs the Machine Learning for Weather and Climate Forum at the Met Office. This is a cross-office group with interests in developing skills in machine learning and exploring its application to weather and climate data.

Career background

Kate joined the Met Office Hadley Centre in 2007, where she spent the first year working on human thermal comfort and climate. Prior to that, Kate spent a year working as a post-doc at Yale University studying the exceedence of thermal comfort thresholds in a warmer and moister climate. She attained her PhD from the Climate Research Unit at the University of East Anglia on the creation and analysis of a global surface humidity data set. This followed a BSc in Environmental Sciences also at the University of East Anglia.

External recognition

  • Contributing author, IPCC AR5 (Working Group 1, Chapter 2)
  • Contributing author, BAMS State of the Climate reports since 2011
  • Lead Editor, Global Climate Chapter of the BAMS State of the Climate reports since 2010
  • Steering committee member of the ISTI from 2010
  • Working group Chair for benchmarking and assessment, ISTI from 2010
  • WCRP/GCOS International Data Prize 2016 award