Work Package 1: Monitoring, attribution and reanalysis
Observations of temperature, rainfall, humidity, etc underpin our understanding of our climate and its short- and long-term variations. Such observations have been made for well over a century, but they are not always accessible to us in the form needed for different uses.
Many historical observations are not available digitally, but are kept in original paper records; we aim to unlock the potential of this data by imaging and keying the information. This will enable us to develop a better understanding of how East Asian climate has changed over the historical past and how it might change in the future.
Because we don't have observations everywhere and because the way observations are made has changed over time, we have to be careful to understand and quantify the amount of certainty we have in our analyses. This means understanding things like the way different rain gauges collect rainfall, the impact on temperature measurements of urbanisation around a meteorological station, or the uncertainty that arises from having few observations in a particular region, for example. We will be exploring these kinds of questions both for East Asia and other parts of the world.
We can extract extra value from historical observations when they are brought together and, perhaps, combined with recent information collected by satellites in a "dynamical reanalysis". This uses a weather forecasting model to help us to understand what happened in the past in places or times between the observations where no information is available. These reanalyses can give us detailed information about climate variations and extreme events that is useful for helping people to understand their vulnerability to weather and climate change. We will enable such reanalyses to make the best use of the new data and understanding we collect.
When an extreme climate-related event does happen, e.g. a flood or a drought or a heat-wave, people often want to know whether or not we should expect such events to happen more or less often in the future to help them in their planning. We will develop a collaborative programme on the attribution to likely causes of climate-related extreme events and long-term trends in the East Asian region.
Summary of ongoing work
There are five components to the work we are undertaking at the Met Office in collaboration with our partners in China:
- We are coordinating the development of a project called ACRE China, which is a part of the global ACRE (Atmospheric Circulation Reconstructions over the Earth, initiative. This is a collaboration between Prof. Rob Allan at the Met Office and Prof. Ren Guoyu of CMA and aims to image and key early instrumental observational records for various sites in China and more widely in East Asia.
- David Parker at the Met Office is leading work to develop new methods for the creation of gridded data sets of daily or sub-daily precipitation, together with information on the certainty we can have in those gridded values. Zhang Yiangxian of CMA will visit the Met Office in early 2015 to collaborate on this work.
- Prof Qifeng Lu from CMA-NSMC has visited the Met Office and ECMWF for six months to work together with scientists at the Met Office (Bill Bell and his team) and ECMWF assessing the quality of atmospheric temperature and humidity data from instruments on board the Chinese FY-3 satellites.
- We are collaborating with our CMA partners on how to attribute climate-related events in China to their likely causes. This work is led by Peter Stott at the Met Office and Prof. Ying Sun at CMA.
Year 1 academic partner projects
Six contracts were placed in Year 1 to help to unlock the potential of historical observations for the East Asian and surrounding regions:
- Daily and sub-daily weather observations for the late 19th and early 20th centuries recorded in the China Coast Meteorological Register (CCMR) are being scanned and keyed by Bristol University (led by Prof. Robert Bickers) and the University of Giessen (led by Prof. Juerg Luterbacher);
- Daily data for the early 20th century from 19 locations in and around the Indian and Pacific Oceans are being keyed (led by Gail Kelly);
- New sources of historical observations are being tracked down for countries in the East Asian region (led by Fiona Williamson) and from ships visiting China (led by Clive Wilkinson)
- The Old Weather system which has been successfully used in the past to enable volunteers to digitise historical observations is being updated by the Zooniverse team at the University of Oxford to allow its use with the new types of observations we are recovering
Two contracts were placed in Year 1 to further our understanding of attribution of climate-related events and long-term trends:
- University of Reading (led by Prof. Rowan Sutton) are identifying and exploring specific events, e.g. droughts, and long term trends in temperature extremes and their likely causes ;
- University of Edinburgh (led by Prof. Simon Tett) are investigating likely causes for changes seen in diurnal temperature range over China.
Science highlights from Year 1
Together with our partners in the UK and at CMA, we have already made a difference to the availability of historical daily observations in the East Asian region. Daily pressure and temperature data have been keyed for six Chinese meteorological stations for the pre-1950 period. Complete daily records of weather variables have been keyed for 1920-1930 for 19 island and coastal locations in and around the Indian and Pacific Oceans.
Working with scientists at CMA-NSMC and ECMWF, we have been assessing the quality of data from instruments on board the new FY-3C satellite, launched in 2014. This will enable information gathered on atmospheric temperature and humidity to be used in weather forecasting, in producing new dynamical reanalyses and in climate research.