Four days of LIFL-11 transects over the full length of Lake Balaton, 11 to 14 August 2026, from the Siófok basin to Keszthely bay, recording chlorophyll-a, CDOM, and elastic backscatter as ratios to the water Raman line
Preliminary figures
Interpolated campaign fields from the team's first processing pass, before calibration and review; values may change.
Fig. 1CHL
Fig. 2CDOM
Fig. 3TSS
Lake BalatonCentral Europe
● Lake Balaton 2026, 2026-08-11100,608 measurements
IDW interpolation, 600 samples
Chl-a0.501.04r.u.
CDOM0.921.43r.u.
Elastic 3552.084.16r.u.
Fig. 4Measurement record, 11 August 2026. 100,608 lidar returns are plotted along the vessel track
for Chl-a, CDOM, Elastic 355. The field view applies
inverse-distance weighting to the same observations; the shoreline is from OpenStreetMap.
Lake BalatonCentral Europe
● Lake Balaton 2026, 2026-08-1228,187 measurements
IDW interpolation, 600 samples
Chl-a0.421.65r.u.
CDOM0.954.80r.u.
Elastic 3552.248.94r.u.
Fig. 5Measurement record, 12 August 2026. 28,187 lidar returns are plotted along the vessel track
for Chl-a, CDOM, Elastic 355. The field view applies
inverse-distance weighting to the same observations; the shoreline is from OpenStreetMap.
Lake BalatonCentral Europe
● Lake Balaton 2026, 2026-08-1339,429 measurements
IDW interpolation, 600 samples
Chl-a0.581.11r.u.
CDOM0.901.48r.u.
Elastic 3552.744.05r.u.
Fig. 6Measurement record, 13 August 2026. 39,429 lidar returns are plotted along the vessel track
for Chl-a, CDOM, Elastic 355. The field view applies
inverse-distance weighting to the same observations; the shoreline is from OpenStreetMap.
Lake BalatonCentral Europe
● Lake Balaton 2026, 2026-08-1432,889 measurements
IDW interpolation, 600 samples
Chl-a0.661.34r.u.
CDOM1.081.64r.u.
Elastic 3552.964.32r.u.
Fig. 7Measurement record, 14 August 2026. 32,889 lidar returns are plotted along the vessel track
for Chl-a, CDOM, Elastic 355. The field view applies
inverse-distance weighting to the same observations; the shoreline is from OpenStreetMap.
From 11 to 14 August 2026 the LIFL-11 ran four transects over Lake Balaton from a mooring off Balatonföldvár, as part of a campaign of 10 to 21 August with the Balaton Limnological Research Institute on which the LIFL-11, two mFL-12 lidars and the mHR-2 radiometer worked together. The first day covered the eastern half, east into the Siófok basin and back along the north shore past Alsóörs. The 12th and 13th ran west along the south shore past Fonyód and Szigliget to Keszthely bay and back, and on the 14th the boat started in Keszthely bay and worked east to Balatonboglár in the morning, under the Sentinel-2B pass that the campaign had been timed to.
The instrument logged chlorophyll-a fluorescence, CDOM fluorescence and the 355 nm elastic return on every shot, each expressed as a ratio to the water Raman line at 404 nm, a relative index with no concentration unit. On every day the western third of the track read higher than the eastern third on chlorophyll-a and CDOM alike, from a median chlorophyll-a ratio of 0.57 against 0.88 on the 11th to 0.74 against 1.17 on the 14th, which follows the trophic gradient of the lake towards the Zala inflow in the west.
