Abstract:In a recent publication, we discussed and presented a semi-empirical phytoplankton primary production model. In the present paper, our main purpose is to determine how the algorithms of a primary production model change when different values of specific absorption coefficient by phytoplankton are used in the model. A new version of our earlier model was quantified for this purpose. Differences between the previous and the new models are as follows: (a) the spectra of the specific absorption coefficient of ligh… Show more
“…where Fmax = 0.08 mol C (mol photons) −1 , and M is the parameter that can depend on incident irradiance as well as on the bio-optical characteristics of the waterbody. In this study we used algorithms by Arst et al (2012) to calculate M according to the Cchl values: The details of the model are explained in previous studies by Arst et al (2008Arst et al ( , 2012 that describe the development of this model.…”
Section: Bio-optical Primary Production Modelmentioning
Lake productivity is fundamental to biogeochemical budgets as well as estimating ecological state and predicting future development. Combining modelling with Earth Observation data facilitates a new perspective for studying lake primary production. In this study, primary production was modelled in the large Lake Geneva using the MEdium Resolution Imaging Spectrometer (MERIS) image archive for 2002-2012. We used a semi-empirical model that estimates primary production as a function of photosynthetically absorbed radiation and quantum yield of carbon fixation. The necessary input parameters of the model-concentration of chlorophyll a, downwelling irradiance, and the diffuse attenuation coefficient-were obtained from MERIS products. The primary production maps allow us to study decennial temporal (with daily frequency) and spatial changes in this lake that a single sample point cannot provide. Modelled estimates agreed with in situ results (R 2 = 0.68) and showed a decreasing trend (~27%) in production in Lake Geneva for the selected decade. Yet, in situ monitoring measurements missed the general increase of productivity near the incoming Rhône River. We show that the temporal and spatial resolution provided by satellite observations allows to estimates of primary This document is the accepted manuscript version of the following article:
“…where Fmax = 0.08 mol C (mol photons) −1 , and M is the parameter that can depend on incident irradiance as well as on the bio-optical characteristics of the waterbody. In this study we used algorithms by Arst et al (2012) to calculate M according to the Cchl values: The details of the model are explained in previous studies by Arst et al (2008Arst et al ( , 2012 that describe the development of this model.…”
Section: Bio-optical Primary Production Modelmentioning
Lake productivity is fundamental to biogeochemical budgets as well as estimating ecological state and predicting future development. Combining modelling with Earth Observation data facilitates a new perspective for studying lake primary production. In this study, primary production was modelled in the large Lake Geneva using the MEdium Resolution Imaging Spectrometer (MERIS) image archive for 2002-2012. We used a semi-empirical model that estimates primary production as a function of photosynthetically absorbed radiation and quantum yield of carbon fixation. The necessary input parameters of the model-concentration of chlorophyll a, downwelling irradiance, and the diffuse attenuation coefficient-were obtained from MERIS products. The primary production maps allow us to study decennial temporal (with daily frequency) and spatial changes in this lake that a single sample point cannot provide. Modelled estimates agreed with in situ results (R 2 = 0.68) and showed a decreasing trend (~27%) in production in Lake Geneva for the selected decade. Yet, in situ monitoring measurements missed the general increase of productivity near the incoming Rhône River. We show that the temporal and spatial resolution provided by satellite observations allows to estimates of primary This document is the accepted manuscript version of the following article:
“…The main sources of uncertainties are (a) the semi-empirical formulation of the model itself; (b) errors in the measurements of PAR ( 0), q z = chl , C and d,PAR ; K (c) frequent interpolation of the values of chl C and d,PAR . K Some irregular profiles of ( , meas) P z suggest uncertainties in the measurement results as well (Arst et al, 2008a(Arst et al, , 2012. In shallow, well-mixed lakes in which chl C and d,PAR K do not change vertically one cannot expect an irregular depth profile of ( , meas).…”
For estimations of the ecological state of a lake and its future trends, data on seasonal and long-term variations of primary production are most necessary. The methods of in situ measurements of production are time consuming, rather complicated, and very expensive. Bio-optical model calculations provide a good alternative here. A semi-empirical model for estimating phytoplankton primary production (Arst et al., 2008, Aquatic Biology, Vol. 3, No. 1, pp. 19-30) allows calculating the vertical profiles and areal (integrated over water column) values of primary production using chlorophyll a concentration, incident irradiance, and light attenuation coefficient in the water. In the present study this model was developed further by elaborating its automated version. It enables performing rapid and greatly replicated estimations of the circumstantial variability of phytoplankton primary production at hourly intervals from morning to evening and as daily and monthly sums based on a table of initial parameters and depths. For demonstrating the practical application of the model we calculated primary production in two large eutrophic North-European lakes (Võrtsjärv and Peipsi), using a database collected during four warm months in 2009 (123 days in both lakes).
“…The PP model, originally developed by Arst et al [20,52] and further adapted for remote sensing data by Kauer et al [41] and Soomets et al [42] was used in this study. The main principle of this model is that the PP is a function of photosynthetically absorbed radiation and the quantum yield of carbon fixation [63]:…”
Section: The Primary Production (Pp) Modelmentioning
confidence: 99%
“…For meaningful PP results over a longer time period (days, months, and years), a large number of direct consecutive contact measurements of photosynthesis rate (e.g., using the 14 C [16], 13 C [17], or dissolved oxygen method [18,19]) are needed. However, these methods are costly, time-consuming, in some cases need the manipulation of radioactive material, and are difficult to apply for large-scale routine monitoring [20]. Therefore, a complementary modelling approach is necessary.…”
Phytoplankton primary production (PP) in lakes play an important role in the global carbon cycle. However, monitoring the PP in lakes with traditional complicated and costly in situ sampling methods are impossible due to the large number of lakes worldwide (estimated to be 117 million lakes). In this study, bio-optical modelling and remote sensing data (Sentinel-3 Ocean and Land Colour Instrument) was combined to investigate the spatial and temporal variation of PP in four Baltic lakes during 2018. The model used has three input parameters: concentration of chlorophyll-a, the diffuse attenuation coefficient, and incident downwelling irradiance. The largest of our studied lakes, Võrtsjärv (270 km2), had the highest total yearly estimated production (61 Gg C y−1) compared to the smaller lakes Lubans (18 Gg C y−1) and Razna (7 Gg C y−1). However, the most productive was the smallest studied, Lake Burtnieks (40.2 km2); although the total yearly production was 13 Gg C y−1, the daily average areal production was 910 mg C m−2 d−1 in 2018. Even if lake size plays a significant role in the total PP of the lake, the abundance of small and medium-sized lakes would sum up to a significant contribution of carbon fixation. Our method is applicable to larger regions to monitor the spatial and temporal variability of lake PP.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.