All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 904 346 50
PDF Downloads 258 94 18

Effects of Recent Thermometer Changes in the Cooperative Station Network

Robert G. QuayleGlobal Climate Laboratory, NOAA/NESDIS/National Climatic Data Center, Asheville, NC 28801

Search for other papers by Robert G. Quayle in
Current site
Google Scholar
PubMed
Close
,
David R. EasterlineGlobal Climate Laboratory, NOAA/NESDIS/National Climatic Data Center, Asheville, NC 28801

Search for other papers by David R. Easterline in
Current site
Google Scholar
PubMed
Close
,
Thomas R. KarlGlobal Climate Laboratory, NOAA/NESDIS/National Climatic Data Center, Asheville, NC 28801

Search for other papers by Thomas R. Karl in
Current site
Google Scholar
PubMed
Close
, and
Pamela Y. HughesGlobal Climate Laboratory, NOAA/NESDIS/National Climatic Data Center, Asheville, NC 28801

Search for other papers by Pamela Y. Hughes in
Current site
Google Scholar
PubMed
Close
Full access

During the past five years, the National Weather Service (NWS) has replaced over half of its liquid-in-glass maximum and minimum thermometers in wooden Cotton Region Shelters (CRSs) with thermistor-based Maximum–Minimum Temperature Systems (MMTSs) housed in smaller plastic shelters. Analyses of data from 424 (of the 3300) MMTS stations and 675 CRS stations show that a mean daily minimum temperature change of roughly +0.3°C, a mean daily maximum temperature change of−0.4°C, and a change in average temperature of −0.1 °C were introduced as a result of the new instrumentation. The change of −0.7°C in daily temperature range is particularly significant for climate change studies that use this element as an independent variable. Although troublesome for climatologists, there is reason to believe that this change (relative to older records) represents an improvement in absolute accuracy. The bias appears to be rather sharp and well defined. Since the National Climatic Data Center (NCDC) station history database contains records of instrumentation, adjustments for this bias can be readily applied, and we are reasonably confident that the corrections we have developed can be used to produce homogeneous time series of area-average temperature.

During the past five years, the National Weather Service (NWS) has replaced over half of its liquid-in-glass maximum and minimum thermometers in wooden Cotton Region Shelters (CRSs) with thermistor-based Maximum–Minimum Temperature Systems (MMTSs) housed in smaller plastic shelters. Analyses of data from 424 (of the 3300) MMTS stations and 675 CRS stations show that a mean daily minimum temperature change of roughly +0.3°C, a mean daily maximum temperature change of−0.4°C, and a change in average temperature of −0.1 °C were introduced as a result of the new instrumentation. The change of −0.7°C in daily temperature range is particularly significant for climate change studies that use this element as an independent variable. Although troublesome for climatologists, there is reason to believe that this change (relative to older records) represents an improvement in absolute accuracy. The bias appears to be rather sharp and well defined. Since the National Climatic Data Center (NCDC) station history database contains records of instrumentation, adjustments for this bias can be readily applied, and we are reasonably confident that the corrections we have developed can be used to produce homogeneous time series of area-average temperature.

Save