Robert W. Dudley Glenn A. Hodgkins Thomas G. Huntington 2002 <p>We analyzed a long-term record of ice thickness on the Piscataquis River in central Maine to&nbsp;determine whether there were temporal trends that were associated with climate warming. Trends&nbsp;in ice thickness were compared and correlated with regional time series of winter air temperature,&nbsp;heating degree days (HDD) , date of river ice-out, seasonal center-of-volume date (SCVD) (date&nbsp;on which half of the stream runoff volume during the period 1 Jan and 31 May has occurred),&nbsp;water temperature, and lake ice-out date. All of these variables except lake ice-out date showed&nbsp;significant temporal trends during the 20^th century. Average ice thickness around 28 Feb.&nbsp;decreased by about 23 cm from 1912 to 2001. Over the period 1900 to 1999, winter air&nbsp;temperature increased by 1.7 ˚C and HDD decreased by about 7.5%. Final ice-out date on the&nbsp;Piscataquis River occurred earlier (advanced), by 0.23 days yr^–1 over the period 1931 to 2002. The&nbsp;SCVD advanced by 0.11 days yr^–1 over the period 1903 to 2001. Ice thickness was significantly&nbsp;correlated with winter air temperature, HDD, river ice-out, and SCVD (P-value &lt; 0.01). These&nbsp;systematic temporal trends in multiple hydrologic indicator variables indicate a coherent response&nbsp;to climate forcing. </p> application/pdf en U. S. Army Corps of Engineers Historical trend in ice thickness on the Piscataquis River in central Maine. text