North Temperate Lakes LTER: Ice Duration - Trout Lake Area 1981 - current

Data includes day of freeze-up and thaw dates of seven northern primary lakes (Allequash, Big Muskellunge, Crystal, Sparkling, Trout, unnamed 27-02 [Crystal Bog] and 12-15 [Trout Bog]) as well as historic data from Little Rock Lake. Observations are made approximately every other day during times of freeze and thaw. A lake is considered ice covered when the sampling station (the deepest part of the lake) is ice covered. The lake is considered thawed when it is possible to drive a boat from the boat landing to the sampling station without encountering ice. Sampling Frequency: annually. Number of sites: 8.

本数据集包含7处北部主要湖泊的封冻日期（freeze-up date）与解冻日期（thaw date）数据，分别为Allequash湖、Big Muskellunge湖、Crystal湖、Sparkling湖、Trout湖、编号为27-02的未命名湖（Crystal Bog）以及编号为12-15的未命名湖（Trout Bog），同时收录Little Rock湖的历史观测资料。在湖泊封冻与解冻阶段，观测约每隔一日开展一次。当采样站点（sampling station，即湖泊最深区域）被冰层覆盖时，该湖泊即被判定为封冻状态；当可从湖岸船舶停靠码头（boat landing）航行至采样站点且未遭遇任何冰层时，该湖泊即被判定为解冻状态。采样频率：年度采样。观测站点总数：8个。