Lastly, there is no mention (at least, I could not find it) of how NCEP / NCAR grid point data was interpolated to station locations and
station observation time (the gridded data is available only 4 times daily and how the author makes these times match is rather critical).
Not exact matches
The sensors from the pit and from the seafloor above are all linked in a network of cables that sends real -
time observations to monitoring
stations and to local governments and businesses.
Some of the discontinuities (which can be of either sign) in weather records can be detected using jump point analyses (for instance in the new version of the NOAA product), others can be adjusted using known information (such as biases introduced because changes in the
time of
observations or moving a
station).
John Finn points out problems with Santa Barbara and if you look at any
station, there are a host of problems (roughly 40 to 50 different types) involving instrument changes,
observation time changes, micro-climate changes, and so forth.
For those not enjoying the zip lining, feel free to spend as much
time as you like on the
observation deck and take any Tram you like back to the main
station.
The lab supplies our students with resources that are normally available only from a major publisher, including 10 group testing
stations, a living room style lab with an
observation booth for real - world evaluations, and real -
time high definition recording and broadcasting equipment.
Some of the discontinuities (which can be of either sign) in weather records can be detected using jump point analyses (for instance in the new version of the NOAA product), others can be adjusted using known information (such as biases introduced because changes in the
time of
observations or moving a
station).
To me, with enough
stations,
time of
observation is a non-issue.
Only an amateur with no concept of the material (Stokes) derivative and
time - series aliasing would conclude that lack of serial
observations, such as provided by land -
station data, of diurnally varying temperature at fixed oceanic locations is «not a problem.»
Suppose that a
station changed their
time of
observation, which produced a biasing of its max or min temperature readings.
I'd love to see a graph made from
station metadata that shows the average
time of
observation.
Unlike many data sets that have been used in past climate studies, these data have been adjusted to remove biases introduced by
station moves, instrument changes,
time - of -
observation differences, and urbanization effects.
This adjustment is made for
station changes other than
time of
observation.
From the site you referenced: «To save space on this server, only the data adjusted for urbanization effects are available here (i.e., this data has also been adjusted for
time - of -
observations,
station moves, and instrument changes).»
In the paper1, the authors used data from weather
stations around the world; those in China «were selected on the basis of
station history: we chose those with few, if any, changes in instrumentation, location or
observation times», they wrote.
Those statements imply that the quoted claim from Jones et al. is impossible: «
stations were selected on the basis of
station history: we chose those with few, if any, changes in instrumentation, location or
observation times».
I've seen a credible explanation for why, beginning in 1950,
time of
observation bias (TOBS) and
station homogeneity (SHAP) became so skewed.
Yet in the paper he co-authored on the subject with Watts, Christy apparently did not know to take the first and most critical step of homogenizing the data and removing the climate - unrelated biases introduced by factors like
stations moving and
time of
observation changing.
I would also say that, although TOBS corrections are not done for all global data, the TOBS error uncertainty shown in this chart is probably present in most global data, as probably relatively few
stations have an effective
observation time of midnight.
There has been a systematic tendency over
time for American
stations to shift from evening to morning
observations, resulting in an artificial cooling of temperature data at the
stations affected, as noted by Karl et al. 1986.
Preliminarily, I would submit, therefore, that no conclusions regarding long - term trends can reasonably be made based on
stations with afternoon
observation times.
«There is practically no
time of
observation bias in urban - based
stations which have taken their measurements punctually always at the same
time, while in the rural
stations the
times of
observation have changed.
Ultimately Watts et al. fail to account for changing
time of
observations, that instruments change, or that weather
stations are sometimes relocated, causing them to wrongly conclude that uncorrected data are much better than data that takes all this into account.
forecast lead -
time at which the continuous ranked probability skill score (CRPSS) for ENS probabilistic forecasts of 24 - hour total precipitation reaches 10 % for the extra-tropics (northern and southern hemispheres); verification against
station observations
Parker noted that Peterson found no impact of urbanization in trends between sites, when controlling for «elevation, latitude,
time of
observation, and instrumentation...» Parker went on to say «One possible reason for this finding was that many «urban»
observations are likely to be made in cool parks, to conform to standards for siting of
stations.»
This database includes temperature
observations made between 1890 (or from the
time when
observations were initiated) and 1999, and has been obtained from meteorological
stations in the Nordic countries (3).
These differences may be as much a function of different interpolation methods and
station densities as they are of errors in
observations or the result of sampling different
time periods (Hulme and New, 1997; New, 1999).
The
stations were selected on the basis of
station history; we selected those with few, if any changes in instrumentation, location or
observation times.
The intermediate (TOB) data has been adjusted for changes in
time of
observation such that earlier
observations are consistent with current observational practice at each
station.
The USHCN TOB adjustments are made month by month, and
station by
station, and seem quite plausible if the records of
times of
observation are correct.
«The identified biases include
station moves, changes in instrumentation, localized changes in instrumentation location, changes in
observation practices, and evolution of the local and microsite
station environment over
time.»
The only right way to make a TO correction is to do it one
station at a
time when that
station changes its
time of
observation.
See, the first thing to do is do determine what the temperature trend during the recent thermometer period (1850 — 2011) actually is, and what patterns or trends represent «data» in those trends (what the earth's temperature / climate really was during this period), and what represents random «noise» (day - to - day, year - to - random changes in the «weather» that do NOT represent «climate change»), and what represents experimental error in the plots (UHI increases in the temperatures, thermometer loss and loss of USSR data, «metadata» «M» (minus) records getting skipped that inflate winter temperatures, differences in sea records from different measuring techniques, sea records vice land records, extrapolated land records over hundreds of km, surface temperature errors from lousy
stations and lousy maintenance of surface records and
stations, false and malicious
time - of -
observation bias changes in the information.)
Select the map tab and notice that the location of the
observation stations has moved five
times since the mid-40's spread out over a 2 mile area.
For a
station, when the
time of
observation is shifted from early evening to early morning, the number of «duplicate» minimum readings in the raw data should increase greatly if there is no other resetting.
Anomalies provide a useful way of salvaging temperature records corrupted by problems of
station loss, relocation, changing
observation times etc. etc..
It is because both contain
stations like Las Vegas that have been compromised by changes in their environment, that
station itself, the sensors, the maintenance,
time of
observation changes, data loss, etc..
For example, changes in
time of
observation, adjustment for a move of a
station that was previously sited next to a heat source to a better location (that now allows the
station to be classed as Class 1 or 2), switch to a different temperature measurement device or system, etcetera, could explain why smaller classes of raw data don't track well with the overall trend calculated from homogenized
station trend data.
Instead of just performing a statistical analysis of the weather
station and sea surface
observations, the reanalysis attempts to construct a complete model of the state of the Earth's atmosphere at any point in
time.
A) When a
station moves, its a new fricking
station because temperature is a function of SITING B) When the instrument changes, its a new fricking
station C) when you change the
time of
observation, its a new
station.
These surface networks have had so many changes over
time that the number of
stations that have been moved, had their
time of
observation changed, had equipment changes, maintenance issues, or have been encroached upon by micro site biases and / or UHI using the raw data for all
stations on a national scale or even a global scale gives you a result that is no longer representative of the actual measurements, there is simply too much polluted data.
eliability of readings through quality of instrumentation and methodology - height, screening, correct
times of
observation etc. — could not be guaranteed until the advent of the Automatic Weather
Station in the 1980's, but even then some of these have arguably been compromised by concerns over siting.
Having worked with many of the scientists in question, I can say with certainty that there is no grand conspiracy to artificially warm the earth; rather, scientists are doing their best to interpret large datasets with numerous biases such as
station moves, instrument changes,
time of
observation changes, urban heat island biases, and other so - called inhomogenities that have occurred over the last 150 years.
Documented
time of
observation changes and instrument changes by year in the co-op and USHCN
station networks.
The same could be done with
time of
observation changes,
station moves, etc..
Historic data were already compromised by
station moves, urbanization, and changes in
observation time.
Non-reporting
stations were associated in Menne with a
time of
observation, which is puzzling.
The
stations change in
observation time is NOT random.
For a
station that switched
observation time from late afternoon to morning, there should be a TOBS adjustment to reduce the Tmax prior to the switch, and a TOBS adjustment to raise the Tmin after the switch.
If the
stations had
observation times that were uniformly distributed over these 24 hours and Then you changed the TOB randomly, THEN you would expect the biases to sum to zero.