Daily Archives: July 12, 2019

NASA attempts to rewrite climate history

“In 1998, NASA showed 1934 as the hottest year on record in the US, and declining temperatures for the rest of the century. They have since rewritten the data to eliminate the post 1930s cooling.” click here

Are some climate scientists unnecessarily experiencing pre-traumatic stress syndrome?

“There’s deep grief and anxiety for what’s being lost, followed by rage at continued political inaction, and finally hope that we can indeed solve this challenge. There are definitely tears and trembling voices.”

“Professionally coping with grief is part of the job training for doctors, caregivers, and those working in humanitarian or crisis situations. But for scientists?”  click here

Bias in historical England and Wales precipitation data

Conor Murphy, Robert L. Wilby, Tom, K.R. Matthews, Peter Thorne, Ciaran Broderick, Rowan Fealy, Julia Hall, Shaun Harrigan, Phil Jones, Gerard McCarthy, Neil Macdonald. Multi‐century trends to wetter winters and drier summers in the England and Wales precipitation series explained by observational and sampling bias in early records. International Journal of Climatology, https://doi.org/10.1002/joc.6208

Globally, few precipitation records extend to the 18th Century. The England Wales Precipitation (EWP) series is a notable exception with continuous monthly records from 1766. EWP has found widespread use across diverse fields of research including trend detection, evaluation of climate model simulations, as a proxy for mid‐latitude atmospheric circulation, a predictor in long‐term European gridded precipitation datasets, the assessment of drought and extremes, tree‐ring reconstructions and as a benchmark for other regional series. A key finding from EWP has been the multi‐centennial trends towards wetter winters and drier summers. We statistically reconstruct seasonal EWP using independent, quality‐assured temperature, pressure and circulation indices. Using a sleet and snow series for the UK derived by Profs. Gordon Manley and Elizabeth Shaw to examine winter reconstructions, we show that precipitation totals for pre‐1870 winters are likely biased low due to gauge under‐catch of snowfall and a higher incidence of snowfall during this period. When these factors are accounted for in our reconstructions, the observed trend to wetter winters in EWP is no longer evident. For summer, we find that pre‐1820 precipitation totals are too high, likely due to decreasing network density and less certain data at key stations. A significant trend to drier summers is not robustly present in our reconstructions of the EWP series. While our findings are more certain for winter than summer, we highlight i) that extreme caution should be exercised when using EWP to make inferences about multi‐centennial trends, and; ii) that assessments of 18th and 19th Century winter precipitation should be aware of potential snow biases in early records. Our findings underline the importance of continual re‐appraisal of established long‐term climate datasets as new evidence becomes available. It is also likely that the identified biases in winter EWP have distorted many other long‐term European precipitation series.