Both mostly use the same network of surface stations, but they differ in how they extrapolate temperature changes in areas with
few measurement stations.
There are very
few measurement stations in the Arctic over land and even fewer over the oceans.
Not exact matches
We were unaware of any other
stations with daily
measurements over a period of more than 80 years, with
few missing values or large data gaps.
(1) In addition to the data of the near - surface temperatures, which are composed of
measurements from weather
stations and sea surface temperatures, there is also the microwave data from satellites, which can be used to estimate air temperatures in the troposphere in a
few kilometers altitude.
Some regions have
few temperature
measurement stations (e.g., the Sahara Desert) and interpolation must be made over large, data - sparse regions.
re # 67 My read was that the effects might be strongest in the lowest
few meters of the atmosphere, where we happen to take the temperature
measurements at the land - based
stations.
If some really think methods can fabricate a better answer than the actual
measurements, why don't we just put a
few hundred
stations in a sq mile or two, and just use that to calculate a global average, we have a model of how that temps relates to temps thousands of km's away, so what's not to like?
While there are
few ground - based weather
stations in the North Pacific to tally how much rain fell over the ocean, satellites such as those participating in the Global Precipitation
Measurement (GPM) mission can estimate precipitation rates from above.