They have gone through a number of types of
radiosondes and the satellite
data would indicate the measurement change with the new device since the new
radiosondes wouldn't match the satellite
data and the old
radiosondes would This is the same problem — mandatory objective environmental test standards would
give historic continuity.
Given the
data limitations it is concluded that using
radiosondes to validate multidecadal - scale trends in MSU
data, or vice versa, or trying to use such metrics alone to pick a «winner» is an ill - conditioned approach and has limited utility without one or more of additional independent measurements, or methodological, or physical analysis.»