Analysis of 2017 Precipitation
March 9, 2018 08:22 AM
GPCP Precipitation Climatology
© Robert Adler
CICS-MD Scientist Robert Adler works with NCEI to produce a monthly Global Precipitation Climatology Project (GPCP) precipitation product (https://www.ncdc.noaa.gov/cdr/atmospheric/precipitation-gpcp-monthly ). He has recently released his analysis of 2017 global precipitation. He identified four big trends this year:
La Niña effects continue into 2017 for global totals and pattern: While the usual precipitation maxima appeared in the tropics and mid-latitude for 2017, there was obviously greater magnitude of mean rainfall over the Maritime Continent and surrounding areas ig the La Niña persistence.
Positive global mean precipitation trend becoming evident with GPCP: The global number is slightly (1%) higher than the 1979-2016 climatology, with land areas contributing a value about 4% higher than the land climatology.
Global land precipitation at or near all-time high in 2017: 2017 has an estimated record-setting high GPCP land value, compensated by a relatively low ocean value.
2017 contributes to ongoing trends in precipitation intensity in the Tropics: The mean tropical rainfall has had a positive trend since 1987 but it is also evident that there are even stronger positive trends in the higher percentiles (more intense rainfall), with significant trends at percentiles greater than 70%.
The figure above shows the linear trend of GPCP precipitation (mm day-1 per decade) during 1979-2017. Adler, Robert, Guojun Gu and Jian-Jian Wang: Review of Global Precipitation for 2017 (January 30, 2018). Download the Report.