ABSTRACT:

This dataset includes daily water table elevations (cm) measured at Bog Lake Peatland (sometimes referred to as Bog Lake Fen) from 2009 to 2019 at the Marcell Experimental Forest (MEF). Daily precipitation (cm) over the same period from a nearby bog S2 is also included.

More information on the site can be found on: https://www.nrs.fs.fed.us/EF/Marcell/sites/JuncBogLkFens/ and in Chapter 2 of Peatland Biogeochemistry and Watershed Hydrology at the Marcell Experimental Forest (2011). Edited by Randall K. Kolka, Stephen D. Sebestyen, Elon S. Verry, and Kenneth N. Brooks. CRC Press, Boca Raton, FL. (a PDF of this chapter can be found at https://www.fs.usda.gov/treesearch/pubs/37979).

Methodology for daily precipitation:
The S2 site at MEF had Belfort Universal Recording Precipitation Gauges that generated daily precipitation data from 1961-2014. Gauges are supported on 2 ft diameter circular wooden platforms and the gauge tops were 5 ft above the ground, painted silver to reduce evaporation, and leveled each spring after the frost goes out of the ground. A 45° clear opening from the gauge top is also maintained. They have USWB Alter-Type Windshields installed, and are cleaned, lubricated and calibrated with weights each year, and visited weekly. The Belfort Universal Recording Precipitation Gauges were replaced with digital NOAH IV total precipitation gauges on 2010-09-22. The NOAH IV gauges recorded total precipitation amounts at 15-minute intervals, and the 15-minute intervals were summed to calculate daily total precipitation. Missing values were interpolated for 15-minute intervals as the median of the total precipitation measured at the other sites over the same time interval.

Methodology for water table elevations:
Peatland water table elevation is measured in a well near the peatland center of each of six research watersheds and within the Bog Lake Peatland. All of the peatwell sites have Belfort model FW-1 strip chart recorders with a float and pulley system to monitor water levels (data resolution 0.3 cm). Water tables are at or near the peat surface. The peat is not stable for data recorders. Therefore, shelters for the recorders are mounted on four 3.2 cm pipes anchored through the peat into the mineral soil below. A 0.3 m section of spiral auger was welded to the end of each pipe. A recorder sits on a wooden platform that is about 0.6 m x 0.9 m in dimension and 0.9-1.2 m above the peat surface. Peat below the platform was excavated to a depth of about 1.2 m. A stilling well (~0.3 m diameter galvanized pipe) was originally placed into the hole and secured to the pipes. The stilling wells have been replaced with wooden enclosures that extend into the subsurface to prevent peat from collapsing into the excavations. A float rises and falls in the stilling well with water table fluctuations and rotates the recorder pulley via a flat metal tape that is connected to a counterweight. Peatland wells are visited weekly and recorder stripcharts are changed at that time. Every several years, elevations are measured relative to known benchmarks to determine the platform elevation in feet above mean sea level. Propane lamp heaters were added to the shelters incrementally between 1990 and 2005 to maintain an unfrozen pool for year-round operation.

ABSTRACT:

The global distribution hydroclimatic seasonality was evaluated using seven existing metrics (Maps_seasonality_indices.pdf). Each .txt file contains the metric values calculated from the mean monthly climatological precipitation (P) and/or potential evapotranspiration (PET) data within the CRU TS dataset version 4.03 (Harris et al. 2014), at 0.5 degree grid resolution. More information on how each metric value was calculated can be found in the included Table_seasonality_indices.pdf. The Python code simulate_sinusoid_P_PET.py produces different synthetic variations of sinusoidal seasonal distributions of P and PET that vary in terms of their relative amplitudes and phases, and calculates their associated asynchronicity index values.

1. Asynchro.txt: the asynchronicity index proposed in Feng et al. (2019).
2. dCentroid: the centroid difference (in months) between the seasonal precipitation and PET pmfs
3. WalshS.txt: seasonality index of Walsh & Lawler (1981)
4. MillyS.txt: seasonality index of Milly (1994)
5. dP*.txt: seasonality index of Woods (2009)
6. SI.txt: seasonality index of Feng et al. (2013)
7. Imr.txt: seasonality index of Knoben et al. (2018)

References:
Feng, X., Porporato, A., & Rodriguez-Iturbe, I. (2013). Changes in rainfall seasonality in the tropics. Nature Climate Change, 3(9), 811–815. https://doi.org/10.1038/nclimate1907

Feng, X. Thompson, S.E., Woods, R., & Porporato, I. (2019). Quantifying asynchronicity of precipitation and potential evapotranspiration in Mediterranean climates. Geophysical Research Letters.

Harris, I., Jones, P. D., Osborn, T. J., & Lister, D. H. (2014). Updated high-resolution grids of monthly climatic observations - the CRU TS3.10 Dataset. International Journal of Climatology, 34(3), 623–642. https://doi.org/10.1002/joc.3711

Knoben, W. J. M., Woods, R. A., & Freer, J. E. (2018). A Quantitative Hydrological Climate Classification Evaluated With Independent Streamflow Data. Water Resources Research, 54(7), 5088–5109. https://doi.org/10.1029/2018WR022913

Milly, P. C. D. C. D. (1994). Climate, interseasonal storage of soil water, and the annual water balance. Advances in Water Resources, 17(1–2), 19–24. https://doi.org/10.1016/0309-1708(94)90020-5

Walsh, R. P. D., & Lawler, D. M. (1981). Rainfall Seasonality: Description, Spatial Patterns and Change Through Time. Weather, 36(7), 201–208. https://doi.org/10.1002/j.1477-8696.1981.tb05400.x

Woods, R. A. (2009). Analytical model of seasonal climate impacts on snow hydrology: Continuous snowpacks. Advances in Water Resources, 32(10), 1465–1481. https://doi.org/10.1016/j.advwatres.2009.06.011