Monthly averages of global rainfall amount (mm) for 2070-2099 from CRU TS and UKCP18 RCP2.6, provided on an approximately 60km grid.This data contains a field for each month’s average over the period. They are named 'pr' (precipitation), the month, and 'upper' 'median' or 'lower' as per the description below. E.g. 'pr March Median' is the mean of monthly-total rainfall in March throughout 2070-2099, in the median ensemble member.Data defaults to displaying January averages. Each monthly average is a field in the data. Use 'show table' to view all values, and 'change style' to change which month is displayed in the map.Data has been removed and replaced with 'Null' where the baseline 1981-2010 value was <1mm/month. This is because the percentage change may be unreliable with a very small baseline. 'Null' means that data is not provided, it doesn't mean 0mm precipitation. The grid is a lat-long grid, with cells close to the equator measuring approximately 60kmx60km.More about CRU TS - https://crudata.uea.ac.uk/cru/data/hrg/More about UKCP - https://www.metoffice.gov.uk/research/approach/collaboration/ukcp/indexWhat is the data?The data combines a baseline 1981-2010 value from CRU TS with a percentage change relative to 1981-2010 from UKCP18. Where the baseline value was <1mm/month, the projection value has been replaced with 'Null' because the percentage change may be unreliable with a very small baseline.The percentage change data is from the UKCP18 regional projections using the RCP2.6 scenario. RCP2.6 is a low emissions scenario, representing a mitigation scenario aiming to limit the increase of global mean temperature to around 2°C above preindustrial levels .What do the 'median', 'upper', and 'lower' values mean?This scenario is run as 12 separate ensemble members. To select which ensemble members to use, a single value for the mean global precipitation for the period 2070-2099 was taken from each ensemble member. They were then ranked in order from lowest precipitation to highest. The 'lower' fields are this data is the second lowest ranked ensemble member. The 'higher' fields are the second highest ranked ensemble member. The 'median' fields are the central (7th) ranked ensemble member.This gives a median value, and a spread of the ensemble members indicating the level of uncertainty in the projections.Recommendations for use of this data:1. We don't recommend using this data at the resolution of a single cell.The higher resolution of this data improves representation of topography, coasts, etc. but at the same time increases some of the uncertainty for individual grid cells. And so it is recommended to work with multiple grid cells, or an average of grid cells around a point to improve certainty.2. Consider whether the lower, median, or upper projections, or a combination, are most suitable for your use case.As described above, the spread of the ensemble members shown by the lower, median, and upper values indicates the level of uncertainty in the projections.Data source: CRU TS v. 4.06 - (downloaded 12/07/22)UKCP18 v.20200110 (downloaded 17/08/22)This dataset forms part of the Met Office’s Climate Data Portal service. This service is currently in Beta. We would like your help to further develop our service, please send us feedback via the site - https://climate-themetoffice.hub.arcgis.com/
Overview2070-2099CRU TSCRUTSMet OfficeRCP2.6UKCP18averageclimateglobalmonthlyprecipitationprojectionsrainrainfallworld
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dcat_issued2022-08-23T09:44:14.000Z
dcat_modified2022-09-01T12:28:29.636Z
dcat_publisher_nameMet Office
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