A practical approach to predict the duration of the growing season for European lakes

Håkanson, Lars; Boulion, V. V.

doi:10.1016/s0304-3800(01)00319-2

Cited by 20 publications

(10 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Idso 1973), thermocline depth (m) and difference between surface and bottom temperature (ΔT, °C). In addition, we calculated the length of the growing season for each year, which is defined as the number of days in which epilimnetic temperature exceeds 9 °C (Håkanson and Boulion, 2001).…”

Section: Statistical Analysis 25mentioning

confidence: 99%

Historical modelling of changes in Lake Erken thermal conditions

Moras¹,

Ayala²,

Pierson³

2019

Preprint

View full text Add to dashboard Cite

Abstract. The thermal structure of lakes is strictly related to climate and to the variability of thermal and mixing dynamics. In this study, a physical hydrodynamic model (GOTM) was used to reconstruct daily time-step water temperature of Lake Erken (Sweden) over the period 1961–2017, using seven climatic parameters as forcing data: wind speed (WS), air temperature (Air T), atmospheric pressure (Air P), relative humidity (RH), cloud cover (CC), precipitation (DP) and shortwave radiation (SWR). The model was calibrated against real water temperature data collected during the study interval, and the calibrated model revealed a good match between modelled and observed temperature (RMSE = 1.112 °C). From the long-term simulations of water temperature, this study focused on detecting possible trends in water temperature over the entire study interval 1961–2017 and in the sub-intervals 1961–1987 and 1988–2017. The analysis of the simulated temperature showed that epilimnetic temperature has increased on average by +0.43 °C/decade and +0.809 °C/decade in spring and autumn in the sub-interval 1988–2017. Summer epilimnetic temperature has increased by +0.348 °C/decade over the entire interval 1961–2017. Hypolimnetic temperature has increased significantly in the sub-interval 1988–2016 by +0.827 °C/decade in autumn. Whole-lake temperature showed a significant increasing trend in the sub-interval 1988–2017 during spring (+0.378 °C/decade) and in autumn (+0.809 °C/decade). Moreover, this study showed that changes in the phenology of thermal stratification, have occurred over the 57-years period of study. Since 1961 the stability of stratification (Schmidt Stability) has increased by 5.535 J m−2/decade. The duration of thermal stratification has increased by 7.083 days/decade, correspondent with an earlier onset of stratification of ~ 16 days and to a delay of stratification termination of ~ 26 days. The average thermocline depth during stratification became shallower by ~ 1.242 m, and surface-bottom temperature difference increased over time by +0.249 °C/decade. The creation of daily-time step water temperature dataset not only provided evidence of changes in Erken thermal structure over the last decades, but it is also a valuable resource of information that can help in future research on the ecology of Lake Erken. The use of readily available meteorological data to reconstruct Lake Erken's past water temperature is shown to be a useful method to evaluate long-term changes in lake thermal structure, and it is a method that can be extended to other lakes.

show abstract

Section: Statistical Analysis 25mentioning

confidence: 99%

Historical modelling of changes in Lake Erken thermal conditions

Moras¹,

Ayala²,

Pierson³

2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Data autocorrelation was tested using the acf and pacf functions in RStudio. For autocorrelated data, the modified version of the Mann-Kendall test proposed by Hamed and Rao (1998) was used instead of the traditional Mann-Kendall test, which does not account for autocorrelation. We used the Pettitt test (Pettitt, 1979) to assess whether an abrupt change in annual mean air temperature occurred during the study period.…”

Section: Calibration Interval Model Statistics Valuementioning

confidence: 99%

Historical modelling of changes in Lake Erken thermal conditions

Moras

Ayala

Pierson

2019

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Historical lake water temperature records are a valuable source of information to assess the influence of climate change on lake thermal structure. However, in most cases such records span a short period of time and/or are incomplete, providing a less credible assessment of change. In this study, the hydrodynamic GOTM (General Ocean Turbulence Model, a hydrodynamic model configured in lake mode) was used to reconstruct daily profiles of water temperature in Lake Erken (Sweden) over the period 1961–2017 using seven climatic parameters as forcing data: wind speed (WS), air temperature (Air T), atmospheric pressure (Air P), relative humidity (RH), cloud cover (CC), precipitation (DP), and shortwave radiation (SWR). The model was calibrated against observed water temperature data collected during the study interval, and the calibrated model revealed a good match between modelled and observed temperature (RMSE =1.089 ∘C). From the long-term simulations of water temperature, this study focused on detecting possible trends in water temperature over the entire study interval 1961–2017 and in the sub-intervals 1961–1988 and 1989–2017, since an abrupt change in air temperature was detected in 1988. The analysis of the simulated temperature showed that epilimnetic temperature increased on average by 0.444 and 0.792 ∘C per decade in spring and autumn in the sub-interval 1989–2017. Summer epilimnetic temperature increased by 0.351 ∘C per decade over the entire interval 1961–2017. Hypolimnetic temperature increased significantly in spring over the entire interval 1961–2017, by 0.148 and by 0.816 ∘C per decade in autumn in the sub-interval 1989–2016. Whole-lake temperature showed a significant increasing trend in the sub-interval 1989–2017 during spring (0.404 ∘C per decade) and autumn (0.789 ∘C per decade, interval 1989–2016), while a significant trend was detected in summer over the entire study interval 1961–2017 (0.239 ∘C per decade). Moreover, this study showed that changes in the phenology of thermal stratification have occurred over the 57-year period of study. Since 1961, the stability of stratification (Schmidt stability) has increased by 5.365 J m−2 per decade. The duration of thermal stratification has increased by 7.297 d per decade, corresponding to an earlier onset of stratification of ∼16 d and to a delay of stratification termination of ∼26 d. The average thermocline depth during stratification became shallower by ∼1.345 m, and surface-bottom temperature difference increased over time by 0.249 ∘C per decade. The creation of a daily time step water temperature dataset not only provided evidence of changes in Erken thermal structure over the last decades, but is also a valuable resource of information that can help in future research on the ecology of Lake Erken. The use of readily available meteorological data to reconstruct Lake Erken's past water temperature is shown to be a useful method to evaluate long-term changes in lake thermal structure, and it is a method that can be extended to other lakes.

show abstract

“…The complete LakeWeb-model Ha˚kanson and Boulion (2002a) Uncertainty analyses of ecosystem models Ha˚kanson (2003a) The fish sub-model Ha˚kanson and Boulion (2004a) The zoobenthos sub-model Ha˚kanson and Boulion (2003d) The zooplankton sub-model The phytoplankton sub-model Boulion (2001a, 2003c) The bacterioplankton sub-model Boulion and Ha˚kanson (2003) The benthic algae sub-model Ha˚kanson and Boulion (2004b) The macrophyte sub-model Ha˚kanson and Boulion (2002b) The water clarity sub-model The mass-balance sub-model for phosphorus The sub-model for the duration of the growing season Ha˚kanson and Boulion (2001b) Practical applications using the LakeWeb-model 1. User knowledge.…”

Section: Model Descriptionmentioning

confidence: 99%

Setting Fish Quotas Based on Holistic Ecosystem Modelling Including Environmental Factors and Foodweb Interactions – A New Approach

Håkanson

Gyllenhammar

2005

Aquat Ecol

Self Cite

View full text Add to dashboard Cite

We present a new approach to set fish quotas from holistic aquatic foodweb modelling (the LakeWeb-approach). This modelling includes changes in environmental conditions (nutrients, salinity, temperature, oxygen), process-based mass-balance calculations of nutrient concentrations from inflow, internal processes and outflow, calculations of how changes in nutrient concentrations affect primary production, how such changes influence secondary production and how this influence fish production and biomass. This approach gives dynamic, quantitative responses to alterations in driving variables and abiotic/biotic feedbacks. We have applied this approach for preliminary simulations of the cod biomass in the Baltic. We also show that this approach adds a new dimension in setting fish quotas, which in the future could complement, rather than compete with, the more established methods used today based on fish catch statistics and models based on other presuppositions. Our preliminary results indicate that under present environmental conditions (2003), the cod is likely to be extinct if the annual catch is between 95 and 100 kt. The present fish quota is 75 kt/yr in the Baltic, but the overfishing may be 35 kt/yr. We discuss cause-effect relationships regulating fish production, key factors influencing thresholds and points of no return connected to overfishing and changes in environmental conditions, factors regulating recovery and methods for setting optimal fish quotas using this modelling approach. Introduction and aim

show abstract

A practical approach to predict the duration of the growing season for European lakes

Cited by 20 publications

References 7 publications

Historical modelling of changes in Lake Erken thermal conditions

Historical modelling of changes in Lake Erken thermal conditions

Historical modelling of changes in Lake Erken thermal conditions

Setting Fish Quotas Based on Holistic Ecosystem Modelling Including Environmental Factors and Foodweb Interactions – A New Approach

Contact Info

Product

Resources

About