Global patterns of lake ice phenology and climate: Model simulations and observations

Abstract

Abstract. Lake ice phenology parameters (dates of ice onset and thaw) provide an integrative climatic description of autumn to springtime conditions. Interannual variations in lake ice duration and thickness allow estimates of local climatic variability. In addition, long-term changes in lake ice phenology may provide a robust indication of climatic change. The relationship between lake ice and climate enables the use of process-based models for predicting the dates of freeze-up and thaw. LIMNOS (Lake Ice Model Numerical Operational Simulator) is one such model, which was originally designed to simulate the ice phenology of several lakes in southern Wisconsin. In this study, LIMNOS is modified to run globally on a 0.5 ø by 0.5 ø latitude-longitude grid using average monthly climate data. We initially simulate the ice phenology for lakes of 5-and 20-m mean depths across the northern hemisphere to demonstrate the effects of lake depth, latitude, and elevation on ice phenology. To evaluate the results of LIMNOS we also simulate the ice phenology of 30 lakes across the northern hemisphere which have long-term ice records. LIMNOS reproduces the general geographic patterns of ice-on and ice-off dates, although ice-off dates tend to occur later in the model. Lakes with extreme depths, surface areas, or precipitation are simulated less accurately than small, shallow lakes. This study reveals strengths and weaknesses of LIMNOS and suggests aspects which need improving. Future investigations should focus on the use of geographically extensive lake ice observations and modeling to elucidate patterns of climatic variability and/or climate change. In this study, we attempt to describe the global-scale patterns of lake ice phenology in relation to climate. First, we use a numerical model of lake ice physics (Lake Ice Model Numerical Operational Simulator (LIMNOS)) to simulate the phenology of lake ice for lakes across the entire globe. Second, the model is applied to a 0.5 ø by 0.5 ø latitude-longitude grid and is driven by long-term average (30-year; 1931-1960) climatic data. Third, in each 0.5 ø by 0.5 ø grid cell we simulate lake ice development over hypothetical lakes of 5-and 20-m mean depths to help quantify the role of lake morphometry. Fourth, we compare model simulations against a compilation of 30 long-term lake ice phenology records spanning the northern hemisphere. By comparing the model simulations against these observations we evaluate the potential skill of using computer models to describe the physical relationships between lake ice and climate across continental and global scales. 28,825

Simulation of North American lake‐ice cover characteristics under contemporary and future climate conditions

“…Examples of the former include the work by a) Vavrus et al (1996) who tested the sensitivity of lake-ice phenology for three lakes in Wisconsin, USA, to variable climate inputs using a numerical lake-ice model, LIMNOS and found that simulated ice-off date is more sensitive to air temperature changes than the ice-on date; b) Menard et al (2002) and Duguay et al (2003) who used the one-dimensional thermodynamic lake-ice model CLIMo to simulate ice-growth processes on sub-arctic lakes showing that lake morphometry, depth in particular, is a determinant of ice-off dates for shallow lakes at high latitudes, and c) Gao and Stefan (2004) who incorporated the water temperature and lake-ice model MINILAKE to simulate the impact of 2 × CO 2 climate scenario on ice characteristics of five north American lakes and concluded that lake-ice duration would be reduced by 25-33 days, and maximum ice thickness by 18-30 cm. In terms of broader regional analyses, Walsh et al (1998) used a modified form of the LIMNOS model on a 0.5 × 0.5°latitude-longitude grid over the Northern Hemisphere to simulate lake-ice phenology of hypothetical lakes with mean depths of 5 and 20 m. Changes, however, were only modelled using monthly air temperature values and hence, could not properly represent the physical dynamics in lake thermal budgets controlling ice formation, growth, and ablation. Williams et al (2004) analysed lake-ice data for 143 North American freshwater lakes and applied single variable linear regression and factor analysis methods to determine correlations with air temperature, lake morphometry, latitude, and topographic elevation, and used the derived relationships to estimate the effects of 1°C rise in average air temperature on lake-ice characteristics to be that, ice-in date occurs 5 days later, ice-out date occurs 6 days earlier, and maximum ice thickness is reduced by 7 cm.…”

The fate of lake ice in the North American Arctic

“…While most work involving ice cover changes has been done for specific locations, Walsh et al (1998) produced gridded ice phenology for the entire Northern Hemisphere using historical mean climate data to create the first wide-scale examination of lake ice phenology. A recent study using climate model output examining possible changes to the lake ice regime in North America from 40 • N to 75 • N under future climates suggests break-up will advance by 10-20 days, while freezeup will be delayed by 5-15 days, resulting in a reduction of the ice cover duration by 15-35 days (Dibike et al, 2011).…”

The under‐ice microbiome of seasonally frozen lakes

“…Knowledge about the year-round ecological and biogeochemical traits of typical freshwater microorganisms is required to understand when and where certain microorganisms will appear and how they will influence other organisms or biogeochemical processes and, hence, water quality. Together, this information will improve our ability to predict and model freshwater ecosystem and biogeochemical dynamics and to determine their role in the landscapes in the face of environmental change.A large number of lakes, particularly those situated at high altitude and the numerous high-latitude lakes in the temperate and boreal climate zones, are seasonally covered by ice for more than 40% of the year (Walsh et al 1998). Despite this, surprisingly little is known about the ecology, diversity, and metabolism of microorganisms that reside under the ice cover in such lakes (Salonen et al 2009).…”

“…A large number of lakes, particularly those situated at high altitude and the numerous high-latitude lakes in the temperate and boreal climate zones, are seasonally covered by ice for more than 40% of the year (Walsh et al 1998). Despite this, surprisingly little is known about the ecology, diversity, and metabolism of microorganisms that reside under the ice cover in such lakes (Salonen et al 2009).…”