Using neural network ensembles to separate ocean biogeochemical and physical drivers of phytoplankton biogeography in Earth system models Geoscientific Model Development DOI 10.5194/gmd-15-1595-2022 13 May 2022 It can be challenging to understand why Earth system models (ESMs) produce specific results because one can arrive at the same result simply by changing the values of the parameters. In our paper, we demonstrate that it is possible to use machine learning to figure out how and why particular components of an ESM (such as biology or ocean circulations) affect the output. This work could be applied to observations to improve the accuracy of the formulations used in ESMs. Read more
The Whole Antarctic Ocean Model (WAOM v1.0): development and evaluation Geoscientific Model Development DOI 10.5194/gmd-15-617-2022 15 April 2022 Here we present an improved model of the Antarctic continental shelf ocean and demonstrate that it is capable of reproducing present-day conditions. The improvements are fundamental and regard the inclusion of tides and ocean eddies. We conclude that the model is well suited to gain new insights into processes that are important for Antarctic ice sheet retreat and global ocean changes. The model will ultimately help to improve projections of sea level rise and climate change. Read more
Impact of increased resolution on long-standing biases in HighResMIP-PRIMAVERA climate models Geoscientific Model Development DOI 10.5194/gmd-15-269-2022 11 April 2022 Climate models do not fully reproduce observations: they show differences (biases) in regional temperature, precipitation, or cloud cover. Reducing model biases is important to increase our confidence in their ability to reproduce present and future climate changes. Model realism is set by its resolution: the finer it is, the more physical processes and interactions it can resolve. We here show that increasing resolution of up to ~ 25 km can help reduce model biases but not remove them entirely. Read more
SELF v1.0: a minimal physical model for predicting time of freeze-up in lakes Geoscientific Model Development DOI 10.5194/gmd-14-7527-2021 28 February 2022 The time when lakes freeze varies considerably from year to year. A common way to predict it is to use negative degree days, i.e., the sum of air temperatures below 0°C, a proxy for the heat lost to the atmosphere. Here, we show that this is insufficient as the mixing of the surface layer induced by wind tends to delay the formation of ice. To do so, we developed a minimal model based on a simplified energy balance, which can be used both for large-scale analyses and short-term predictions. Read more
Assessment of the ParFlow–CLM CONUS 1.0 integrated hydrologic model: evaluation of hyper-resolution water balance components across the contiguous United States Geoscientific Model Development DOI 10.5194/gmd-14-7223-2021 14 February 2022 Modeling the hydrologic cycle at high resolution and at large spatial scales is an incredible opportunity and challenge for hydrologists. In this paper, we present the results of a high-resolution hydrologic simulation configured over the contiguous United States. We discuss simulated water fluxes through groundwater, soil, plants, and over land, and we compare model results to in situ observations and satellite products in order to build confidence and guide future model development. Read more
The interpretation of temperature and salinity variables in numerical ocean model output and the calculation of heat fluxes and heat content Geoscientific Model Development DOI 10.5194/gmd-14-6445-2021 14 January 2022 We show that the way that the air–sea heat flux is treated in ocean models means that the model’s temperature variable should be interpreted as being Conservative Temperature, irrespective of whether the equation of state used in an ocean model is EOS-80 or TEOS-10. Read more
fv3gfs-wrapper: a Python wrapper of the FV3GFS atmospheric model Geoscientific Model Development DOI 10.5194/gmd-14-4401-2021 25 August 2021 FV3GFS is a weather and climate model written in Fortran. It uses Fortran so that it can run fast, but this makes it hard to add features if you do not (or even if you do) know Fortran. We have written a Python interface to FV3GFS that lets you import the Fortran model as a Python package. We show examples of how this is used to write “model” scripts, which reproduce or build on what the Fortran model can do. You could do this same wrapping for any compiled model, not just FV3GFS. Read more
A discontinuous Galerkin finite-element model for fast channelized lava flows v1.0 Geoscientific Model Development DOI 10.5194/gmd-14-3553-2021 23 July 2021 Lava flows present a natural hazard to communities around volcanoes and are usually slow-moving (< 1-5 cm/s). Lava flows during the 2018 eruption of Kilauea volcano, Hawai’i, however, reached speeds as high as 11 m/s. To investigate these dynamics we develop a new lava flow computer model that incorporates a nonlinear expression for the fluid viscosity. Model results indicate that the lava flows at Site 8 of the eruption displayed shear thickening behavior due to the flow’s high bubble content. Read more
FaIRv2.0.0: a generalized impulse response model for climate uncertainty and future scenario exploration Geoscientific Model Development DOI 10.5194/gmd-14-3007-2021 9 July 2021 This paper presents an update of the FaIR simple climate model, which can estimate the impact of anthropogenic greenhouse gas and aerosol emissions on the global climate. This update aims to significantly increase the structural simplicity of the model, making it more understandable and transparent. This simplicity allows it to be implemented in a wide range of environments, including Excel. We suggest that it could be used widely in academia, corporate research, and education. Read more
JlBox v1.1: a Julia-based multi-phase atmospheric chemistry box model Geoscientific Model Development DOI 10.5194/gmd-14-2187-2021 28 May 2021 As our knowledge and understanding of atmospheric aerosol particle evolution and impact grows, designing community mechanistic models requires an ability to capture increasing chemical, physical and therefore numerical complexity. As the landscape of computing software and hardware evolves, it is important to profile the usefulness of emerging platforms in tackling this complexity. With this in mind we present JlBox v1.1, written in Julia. Read more