[Test] Water Clarity

[This is a Test] Historic Secchi Depth of Lake Tahoe 2021-10-07 Shohei Watanabe ([e-mail]) Tahoe Environmental Research Center, UC Davis 1. Description of Secchi depth measurement The 25cm (10 inch) matte white disk is lowered from shaded side of the boat. The depth where disk disappear when lowering and re-appear when recovering are recorded and then averaged. Also, subjective measure of viewing condition by the observer (explained below) and also observation of general weather and lake conditions are recored. 2. Description of the data table Col 1 Date_Time_Local: Measured date and time in local time (PST/PDT) Col 2 Secchi: Secchi depth in m. Average of Col 3 and Col 4. Col 3 Secchi_Disappear: Depth where the disk disappear when lowering from observer's view in m. Col 4 Secchi_Reappear: Depth where the disk re-appear when recovering in m. Col 5 Viewing_Condition: Subjective measure of viewing condition (details provided below) Col 6 Lake_Condition: Subjective description of general weather and lake condition at the time of Secchi measurement 3. Viewing Condition The viewing condition is determined by the observer subjectively as follow. (Note: The measurement taken under poor or poor to fair conditions are never used for any publications and not included) 1 Poor 2 Poor-to-Fair 3 Fair 4 Fair-to-Good 5 Good 6 Good-to-Excellent 7 Excellent 4. Data update This data file is updated on January 15th of each year with previous water year data. (e.g., Data from 2019-10-31 to 2020-9-30 are added by 2021-01-15)