Level-3.1: Storage correction

Level-3.1: Storage correction#

Info

Level-3.1 calculates storage-corrected fluxes by adding the storage term from single point measurement to the respective flux.

  • The storage term was calculated by EddyPro during flux calculations (Level-1)

  • Storage-corrected fluxes are: NEE_L3.1 (from FC), LE_L3.1 (from LE), H_L3.1 (from H), FN2O_L3.1 (from FN2O), FCH4_L3.1 (from FCH4)

  • The suffix _L3.1 is added to all fluxes to make it clear that the respective flux is storage corrected. Only for NEE it is clear that it is the storage-corrected flux because the name changes from FC to NEE after the correction, but all other variables do not have such a name change, thus the suffix.

  • Note that no quality flags are used here, only the storage term is added to the fluxes and new variables with the suffix are generated.

  • Example output from diive for NEE (in this step still called FC, after the storage correction this becomes NEE_L3.1):

========================================
REPORT: STORAGE CORRECTION FOR FC
========================================
Swiss FluxNet processing chain, _L3.1: Storage Correction

The gap-filled storage term SC_SINGLE_gfRMED_L3.1 was added to flux FC.
The storage-corrected flux was stored as NEE_L3.1.

The flux was available for 295350 records (FC).
The original, non-gapfilled storage term was available for 290861 records (SC_SINGLE).
The original storage term SC_SINGLE was missing for 7259 flux records.
Without gap-filling the storage term (SC_SINGLE), 7259 measured flux records (FC) are lost.

For this run, gap-filling of SC_SINGLE was * SELECTED *.
After gap-filling the storage term, it was available for an additional 7259 records (SC_SINGLE_gfRMED_L3.1).

In the storage-corrected flux NEE_L3.1 with 295350 records, 
  - 97.5% (290861 records) of used storage terms come from originally calculated data (SC_SINGLE)
  - 2.5% (7259 records) of used storage terms come from gap-filled data (SC_SINGLE_gfRMED_L3.1)

Stats for gap-filled storage terms:
                        NOV       P01    MEDIAN       P99
SC_SINGLE_gfRMED_L3.1  7259 -8.395369 -0.167553  6.810566

Stats for measured storage terms:
                          NOV       P01    MEDIAN       P99
SC_SINGLE_gfRMED_L3.1  288091 -7.555871 -0.015403  6.739739