Annual fire weather season length anomaly maps for a subset of known severe fire years are presented in Fig. 4 and anomalies for all years are presented in Supplementary Figs 1 — 4 and annual ensemble -
mean anomaly data are available as Supplementary Data 1.
Not exact matches
To obtain consistent changes over time, the main analysis is actually of
anomalies (departures from the climatological
mean at each site) as these are more robust to changes in
data availability.
This can be seen if we show annual
mean anomalies (as shown below for exactly the same
data), rather than the monthly
anomalies (again, done with the same R - script)
About taking differences (current period figures less prior period figures) of
anomalies: the
anomalies are the value less the monthly
mean (i.e., the
mean for the particular month over the years, in this case 32 full years), as is the usual practice with climate
data (most notably temperature).
I suspect that the complaints are because the
anomalies have little
meaning when looking at
data for any specific year or other time period.
«The average global temperature
anomaly for combined land and ocean surfaces for July (based on preliminary
data) was 1.1 degrees F (0.6 degrees C) above the 1880 - 2004 long - term
mean.
So, what I
mean is, to get the output to match the
data, either you fiddle with internal parameterizations or you fiddle with the «input» — aka forcing
anomalies.)
The Dome C temperature
anomaly record with respect to the
mean temperature of the last millennium8 (based on original deuterium
data interpolated to a 500 - yr resolution), plotted on the EDC3 timescale13, is given as a black step curve.
2) erlhapp asks, «Is this simply de-seasonalised
data obtained by averaging over 12 months, or
anomalies with respect to the monthly
mean or what of?»
Is this simply de-seasonalised
data obtained by averaging over 12 months, or
anomalies with respect to the monthly
mean or what of?
The temperature
data are recorded as
anomalies, or differences between the actual temperature and the long - term
mean.
Just for the record, here are the global
mean temperature
anomaly data in degree centigrade from CRU for this century.
HotSpots were computed as positive
anomalies above the
mean temperature of the climatologically warmest month at each satellite
data pixel, based on the NOAA operational climatology from years 1985 — 1990 and 1993.
The general question is this: how ought one to calculate global
mean anomalies, when areas such as the high Arctic have very little
data from either SSTs or surface stations?
When an
anomaly calculated using normal
means and
data that are contaminated with systematic error, the error in the
anomaly is (+ / --RRB- sqrt -LSB-(error in normal) ^ 2 + (error in the measurement) ^ 2].
All
data are shown as global
mean temperature
anomalies relative to the period 1901 to 1950, as observed (black, Hadley Centre / Climatic Research Unit gridded surface temperature
data set (HadCRUT3); Brohan et al., 2006) and, in (a) as obtained from 58 simulations produced by 14 models with both anthropogenic and natural forcings.
The estimated variance of the
data is thus the sum of the variance of the individual - station fluctuations, and the variance of the differences between station
means and
anomaly offsets.
They point out that if we assume the
data are normally distributed, then the July 2010 average temperature
anomaly value was more than 4 standard deviations above the July
mean (and they have a lovely graph to emphasize it):
I've only done the UK and USA using BEST
data, but here are the
mean temperature
anomaly of certain decades.
When Folland and Parker's correction is adopted to the historical SST
data, the systematic biases in monthly
mean SST
anomalies have been corrected almost perfectly at three stations, and the biases at the other two stations have been reduced by 40 - 50 %.»
Data Files: Jonesdata.txt and Jonesdata.xls contain the original series in normalised units as well as
anomalies in Degreees C vs 1961 - 90
mean.
I have problems giving any credence to the land temperature
anomalies, seems to be an incredible precision of measurement & calculation claimed, compared to the
data, the shifting
mean global temperature, the fogging around this value.
So, for example, HadCRU and GISS each provide a climatological
datum of
mean global temperature for a single year and present it as a difference (i.e. an
anomaly) from the average
mean global temperature of a 30 year period.
SOI
data are presented as annual
mean sea level pressure
anomalies at Tahiti and Darwin.
(Graph
data: The 1980 - 2015 seasonal cycle
anomaly in MERRA2 along with the 95 % uncertainties on the estimate of the
mean.)
Anomalies are defined as the difference from the 1981 - 2010
means (1971 - 2000 for the climate division
data).
Each new
data integration processing is compared with earlier releases, and significant
anomalies (e.g. changes in monthly
mean values) are investigated in more detail.
To create the CRUTEM surface temperature analysis, CRU scientists take temperature
data from 4,138 stations, and for each station they calculate the
mean temperature for 1961 - 1990 and temperature
anomalies relative to that period.
Taking 1880 from Manley as 1 degree below the long term
mean and adjusting current CRU / HADCRUT figures by -0.6 degrees to correct as suggested by the UAH
data / study that brings the CRU / HADCRUT corrected rise /
anomaly down to just 0.7 degrees.
... then why do the vertical
mean temperature
anomalies (NODC 0 - 2000 meter
data) of the Pacific Ocean as a whole and of the North Atlantic fail to show any warming over the past decade, a period when ARGO floats have measured subsurface temperatures, providing reasonably complete coverage of the global oceans?
This is actually what the fuss with Phil Jones of CRU was largely about — his refusal to show how he «homogenised» non-existent
data, in his case from 1850 - 1910, to produce «
anomalies» for Khartoum etc in the CRU «global»
mean anomalies from 1850.
The
data I use is the GISS global annual
mean anomalies.