COSIPY v1.2 – An open-source coupled snowpack and ice surface energy and mass balance model

Abstract

Abstract. Glacial changes play a key role both from a socio-economical and political, and scientific point of view. The identification and the understanding of the nature of these changes still poses fundamental challenges for climate, glacier and water research. Many studies aim to identify the climatic drivers behind the observed glacial changes using distributed surface mass and energy balance models. Distributed surface mass balance models, which translate the meteorological conditions on glaciers into local melting rates, thus offer the possibility to attribute and detect glacier mass and volume responses to changes in the climatic forcings. A well calibrated model is a suitable test-bed for sensitivity, detection and attribution analyses for many scientific applications and often serves as a tool for quantifying the inherent uncertainties. Here we present the open-source coupled snowpack and ice surface energy and mass balance model in Python COSIPY, which provides a lean, flexible and user-friendly framework for modelling distributed snow and glacier mass changes. The model has a modular structure so that the exchange of routines or parameterizations of physical processes is possible with little effort for the user. The model has a modular structure so that the exchange of routines or parameterizations of physical processes is possible with little effort for the user. The framework consists of a computational kernel, which forms the runtime environment and takes care of the initialization, the input-output routines, the parallelization as well as the grid and data structures. This structure offers maximum flexibility without having to worry about the internal numerical flow. The adaptive sub-surface scheme allows an efficient and fast calculation of the otherwise computationally demanding fundamental equations. The surface energy-balance scheme uses established standard parameterizations for radiation as well as for the energy exchange between atmosphere and surface. The schemes are coupled by solving both surface energy balance and subsurface fluxes iteratively in such that consistent surface skin temperature is returned at the interface. COSIPY uses a one-dimensional approach limited to the vertical fluxes of energy and matter but neglects any lateral processes. Accordingly, the model can be easily set up in parallel computational environments for calculating both energy balance and climatic surface mass balance of glacier surfaces based on flexible horizontal grids and with varying temporal resolution. The model is made available on a freely accessible site and can be used for non-profit purposes. Scientists are encouraged to actively participate in the extension and improvement of the model code.

COSIPY v1.3 – an open-source coupled snowpack and ice surface energy and mass balance model

“…Appendix A Sauter and Arndt, 2020b). COSIPY can be used for non-profit purposes under the GPLv3 license (http://www.gnu.org/licenses/gpl-3.0.html, last access: 10 November 2020).…”

Recent Climatic Mass Balance of the Schiaparelli Glacier at the Monte Sarmiento Massif and Reconstruction of Little Ice Age Climate by Simulating Steady-State Glacier Conditions

“…In this study we present a detailed estimate of the climatic mass balance (CMB) for recent and past glacier extents of the Schiaparelli Glacier, the largest glacier of the Monte Sarmiento Massif in Tierra del Fuego ( Figure 1). We follow the methodological approach of [27] to simulate the CMB by applying the coupled snowpack and ice surface energy and mass balance model in Python COSIPY (updated version of COSIMA) [28,29]. We force the model with downscaled 6-hourly ERA-interim data.…”

“…Surface energy fluxes and climatic mass balance are estimated using the open-source surface and energy mass balance model COSIPY [29] which is the updated version of the former coupled snowpack and ice surface energy and mass balance model (COSIMA) [28], with updated physics and optimized computational performance. COSIMA is described in detail in [28] and has been successfully applied for selected glaciers at the Southern Patagonia Icefield [27].…”

“…Only a short description of the model physics is therefore provided in the following. COSIPY combines a surface energy balance model with a multi-layer sub-surface snow and ice model to resolve estimated energy fluxes and surface mass balance processes [29]. All energy fluxes F that contribute to the surface energy budget and the energy available for surface melting Q melt [35] are considered in the energy balance model:…”

21st century fate of the Mocho-Choshuenco ice cap in southern Chile

“…Another way of producing more realistic SMB maps for the ice cap would be using explicit models that try to quantify the physical processes which determine glacier mass balance, e.g. the COSIPY Model (Sauter et al, 2020). Drawbacks of these complex models is that they need many input parameters (such as precipitation, relative humidity or wind speed) with a high spatial resolution.…”