TY - JOUR
T1 - Impact of ITCZ width on global climate
T2 - ITCZ-MIP
AU - Pendergrass, Angeline G.
AU - Byrne, Michael P.
AU - Watt-Meyer, Oliver
AU - Maher, Penelope
AU - Webb, Mark J.
N1 - Funding: This research has been supported by the U.S. Department of Energy Office of Science, Biological and Environmental Research (BER) (grant nos. EESM RGMA DE-SC0022070 and NSF IA 1947282), the National Science Foundation (NSF), Directorate for Geosciences (grant no. AGS-1665247), the Alfred P. Sloan Foundation (research fellowship), the NOAA Climate Program Office (Climate and Global Change Postdoctoral Fellowship), the Natural Sciences and Engineering Research Council of Canada (NSERC postdoctoral fellowship), the Met Office (Hadley Centre Climate Programme funded by DSIT), and the Natural Environment Research Council (grant nos. NE/T003863/1 and NE/W005239/1).
PY - 2024/8/29
Y1 - 2024/8/29
N2 - The width of the Inter-Tropical Convergence Zone (ITCZ) affects tropical rainfall, Earth's albedo, large-scale circulation, and climate sensitivity. To better understand the ITCZ width and its effects on global climate, we present a protocol to force changes in ITCZ width in climate models. Starting from an aquaplanet configuration with a slab ocean, adding surface heat fluxes in the deep tropics forces the ITCZ to narrow, and subtracting them causes it to widen. The protocol successfully generates changes in ITCZ width in all four climate models used in this study. ITCZ width in each model responds linearly to forcing magnitude and sign. Comparing across the four climate models, a response to varying ITCZ width that is remarkably consistent among models is the ITCZ strength, which is greater the narrower the ITCZ. On the other hand, the effect of varying ITCZ width on climate sensitivity is divergent among our four models, varying even in sign. Results from this pilot study highlight the connections between surface fluxes, ITCZ width, and the wider climate. A comprehensive model intercomparison project (MIP) has the potential to advance understanding of both the physical processes shaping ITCZ width and its influence on remote atmospheric circulations and global climate.
AB - The width of the Inter-Tropical Convergence Zone (ITCZ) affects tropical rainfall, Earth's albedo, large-scale circulation, and climate sensitivity. To better understand the ITCZ width and its effects on global climate, we present a protocol to force changes in ITCZ width in climate models. Starting from an aquaplanet configuration with a slab ocean, adding surface heat fluxes in the deep tropics forces the ITCZ to narrow, and subtracting them causes it to widen. The protocol successfully generates changes in ITCZ width in all four climate models used in this study. ITCZ width in each model responds linearly to forcing magnitude and sign. Comparing across the four climate models, a response to varying ITCZ width that is remarkably consistent among models is the ITCZ strength, which is greater the narrower the ITCZ. On the other hand, the effect of varying ITCZ width on climate sensitivity is divergent among our four models, varying even in sign. Results from this pilot study highlight the connections between surface fluxes, ITCZ width, and the wider climate. A comprehensive model intercomparison project (MIP) has the potential to advance understanding of both the physical processes shaping ITCZ width and its influence on remote atmospheric circulations and global climate.
UR - https://www.scopus.com/pages/publications/85202813424
U2 - 10.5194/gmd-17-6365-2024
DO - 10.5194/gmd-17-6365-2024
M3 - Article
SN - 1991-959X
VL - 17
SP - 6365
EP - 6378
JO - Geoscientific Model Development
JF - Geoscientific Model Development
IS - 16
ER -