Abstract

Abstract. We present multi-seasonal simulations representative of present-day and future environments using the global Model for Prediction Across Scales – Atmosphere (MPAS-A) version 5.1 with high resolution (15 km) throughout the Northern Hemisphere. We select 10 simulation years with varying phases of El Niño–Southern Oscillation (ENSO) and integrate each for 14.5 months. We use analyzed sea surface temperature (SST) patterns for present-day simulations. For the future climate simulations, we alter present-day SSTs by applying monthly-averaged temperature changes derived from a 20-member ensemble of Coupled Model Intercomparison Project phase 5 (CMIP5) general circulation models (GCMs) following the Representative Concentration Pathway (RCP) 8.5 emissions scenario. Daily sea ice fields, obtained from the monthly-averaged CMIP5 ensemble mean sea ice, are used for present-day and future simulations. The present-day simulations provide a reasonable reproduction of large-scale atmospheric features in the Northern Hemisphere such as the wintertime midlatitude storm tracks, upper-tropospheric jets, and maritime sea-level pressure features as well as annual precipitation patterns across the tropics. The simulations also adequately represent tropical cyclone (TC) characteristics such as strength, spatial distribution, and seasonal cycles for most Northern Hemisphere basins. These results demonstrate the applicability of these model simulations for future studies examining climate change effects on various Northern Hemisphere phenomena, and, more generally, the utility of MPAS-A for studying climate change at spatial scales generally unachievable in GCMs.

Highlights

  • We present a novel approach to high-resolution climate modeling with the intent of examining the effects of climate change on high-impact Northern Hemisphere weather phenomena

  • We present a unique set of high-resolution, multi-seasonal, global atmosphere-only simulations conducted with the Model for Prediction Across Scales – Atmosphere (MPASA; Skamarock et al, 2012) in present and future environments for the purpose of studying climate change effects on Northern Hemisphere weather phenomena, including extreme events

  • The North Pacific and North Atlantic storm track regions are clearly evident in the model simulations; the overall spatial correlation coefficient is greater than 0.98, indicating that general patterns of sea-level pressure (SLP) variance are well reproduced in the MPAS-A simulations

Read more

Summary

Introduction

We present a novel approach to high-resolution climate modeling with the intent of examining the effects of climate change on high-impact Northern Hemisphere weather phenomena. Due to current computational limitations, the grid spacing of these simulations is largely restricted to ∼ 1◦ (∼ 100 km) or greater While this coarse resolution is suitable for representing large-scale atmospheric features such as the polar amplification of global warming and teleconnections, it is insufficient for resolving weather extremes, especially those associated with smallerscale systems such as tropical cyclones, mesoscale features within extratropical cyclones, and convective storms (e.g., Mizielinski et al, 2014 and references therein; Small et al, 2014; Prein et al, 2015; Haarsma et al, 2016; Roberts et al, 2018). We present our simulations with the intention of providing an additional realization of a complex system in order to improve our understanding of potential climate change effects on Northern Hemisphere high-impact weather phenomena For such a modeling system to be useful for this purpose, it is necessary that. These applications include ongoing research efforts investigating climate change effects on the extratropical transition of tropical cyclones (TCs), TC seasonality, and persistent anomalies and blocking, all of which will be subjects of future publications

Model configuration
Present-day and future climate simulations
Lower boundary conditions
Strong El Niño
Computational performance
Assumptions and limitations
Extratropical storm tracks
Northern Hemisphere jet and sea-level pressure features
Large-scale precipitation
Model climate: tropical cyclones
Strength
Location
Seasonal cycle
Climate change representation
Summary and conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call