Search for an Astronomical Site in Kenya (SASKYA) using Climate Data

Research output: Contribution to journalArticle

View graph of relations

Original languageEnglish
Pages (from-to)425-449
Number of pages25
JournalTheoretical and Applied Climatology
Volume124
Issue number1-2
Early online date19 Mar 2015
DOIs
StatePublished - 19 Mar 2015

Abstract

The goal of the Search for an Astronomical Site in Kenya (SASKYA) project is to identify the best possible site(s) in Kenya for astronomical optical observation, using ERA-interim climate reanalyses and high-resolution UK Met Office Africa Limited Area meteorological model (Africa-LAM) data. This initial search focuses on a selection of 13 candidate mountain peaks across Kenya. A mixture of 30 years (1981–2010) of relatively coarse-grained ERA-interim reanalyses at a and 12 months’ (2011–2012) of much higher resolution UK Met Office Africa-LAM data were used to determine the best possible sites. Cloud cover, precipitable water vapour (specific humidity), vertical velocity, aerosol loadings and wind data were analysed. The results confirm that many sites in Kenya are reasonably cloud free, with estimated photometric night fractions of possibly 50% at the best sites. Significant seasonal inter-annual and inter-decadal variations in cloud cover can be expected, however. Average precipitable water vapour (PWV) values are uncomfortably high, but periods of much lower PWV can be expected during favourable conditions in the dry seasons. Long-term vertical
velocities (as a proxy to determine areas of improved "seeing" conditions) indicate that good astronomical viewing conditions are likely to be dependent on the season and wind direction across Kenya. Finally, after full consideration of the climatological data, a trade-off is expected between the best possible site in climatological terms, and the practicalities of installing remote equipment in isolated, inaccessible areas with little or no infrastructure.

Related by author

  1. Understanding the Atmosphere: Constraints on Astronomical Observation

    Research output: Contribution to journalArticle

  2. A note on the extreme low pressure of 24 December 2013

    Research output: Contribution to journalLetter

  3. Search for an Astronomical Site in Kenya (SASKYA) update: Installation of on-site automatic meteorological stations

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

ID: 1855183