Abstract
This study focuses on potential impacts of climate change on the early spring (March–April) temperature and its extremes in the mid-latitudes of North America, discriminated between the 1.5 °C and 2 °C levels of global warming, as projected by a suit of numerical experiments. The results suggest relatively mild seasonal average warming (0.25 °C–1.5 °C), but also an intensification of both warm and cold temperature extremes. The derived changes feature much stronger warming over the West of the United States and weak to no warming to the East, which is congruent with the ventilating effect of the intensified northerly wind over central Canada and the East of the United States. The intensified northerly component of the mid-latitude jet is likely a contributing factor to the derived increased seasonal variability of March–April temperatures over parts of Manitoba and Ontario in Canada, and the Midwest of the United States. The projected changes in temperature extremes agree to some extent with the previous studies: warm extremes intensify especially over southern mid-latitudes, while cold extremes are weakening over the north mid- to high-latitudes. However, high-resolution simulations with the Community Atmospheric Model 5 (CAM5) indicate much sharper spatial gradients, which translate into higher magnitudes and also more complex patterns of changes. Particularly, cold extremes feature not only reductions north of ∼45°N latitudes, but also a very strong intensification of cold extremes (by −4 °C for 20 year return values) in the band 25°–45°N, centered in the Midwest of the United States. While general warming and intensification of the warm extremes may accelerate the arrival of early spring, the intensifying cold extremes may increase the risk of early spring frost damage, and hence may yield a profound impact on the regional agriculture of North America. Combined with reliable information on expected temperature variability at interannual-to-decadal timescales, the background longer-term projections can help inform decision makers in the food security sector.
Highlights
Climate variability and change cause profound socioeconomic impact, especially when expressed in the form of weather extremes
In this research we focus on the future changes projected for early spring in mid-latitudes of North America, using simulations with the Community Atmospheric Model version 5 (CAM5) provided at 0.25° horizontal resolution
Representation of the simulated present climate in early spring, at different horizontal resolution we wish to assess the fidelity of the Community Atmospheric Model 5 (CAM5) model in simulating the early spring climatology in the mid-latitudes of North America at three different spatial resolutions
Summary
Climate variability and change cause profound socioeconomic impact, especially when expressed in the form of weather extremes. The negative consequences of an early spring arrival is that an earlier start of growth for plants exposes them to increased frost risk (Bigler and Bugmann 2018, Sgubin et al 2018, Vitasse et al 2018). This was underlined by a probabilistic study of Rigby and Porporato (2008), showing that the risk of spring frost damage to vegetation is sensitive to increases in daily temperature variance (which increases frost risk) and to increases in mean temperature (which reduces frost risk)
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
