TY - JOUR
T1 - Projected changes in South Asian monsoon low pressure systems
AU - Dong, Wenhao
AU - Ming, Yi
AU - Ramaswamy, V.
N1 - Funding Information:
Acknowledgments. The authors thank Yanluan Lin, Jonathon Wright, Steve Garner, and Spencer Clark for their helpful comments on earlier versions of this paper. This research from the Geophysical Fluid Dynamics Laboratory is supported by NOAA’s Science Collaboration Program and administered by UCAR’s Cooperative Programs for the Advancement of Earth System Science (CPAESS) under Awards NA16NWS4620043 and NA18NWS4620043B.
Funding Information:
The authors thank Yanluan Lin, Jonathon Wright, Steve Garner, and Spencer Clark for their helpful comments on earlier versions of this paper. This research from the Geophysical Fluid Dynamics Laboratory is supported by NOAA?s Science Collaboration Program and administered by UCAR?s Cooperative Programs for the Advancement of Earth System Science (CPAESS) under Awards NA16NWS4620043 and NA18NWS4620043B.
Publisher Copyright:
© 2020 American Meteorological Society.
PY - 2020/9/1
Y1 - 2020/9/1
N2 - Monsoon low pressure systems (MLPSs) are among the most important synoptic-scale disturbances of the South Asian summer monsoon. Potential changes in their characteristics in a warmer climate would have broad societal impacts. Yet, the findings from a few existing studies are inconclusive. We use the Geophysical Fluid Dynamics Laboratory (GFDL) coupled climate model CM4.0 to examine the projected changes in the simulated MLPS activity under a future emission scenario. It is shown that CM4.0 can skillfully simulate the number, genesis location, intensity, and lifetime of MLPSs. Global warming gives rise to a significant decrease in MLPS activity. An analysis of several large-scale environmental variables, both dynamic and thermodynamic, suggests that the decrease in MLPS activity can be attributed mainly to a reduction in low-level relative vorticity over the core genesis region. The decreased vorticity is consistent with weaker large-scale ascent, which leads to less vorticity production through the stretching term in the vorticity equation. Assuming a fixed radius of influence, the projected reduction in MLPSs would significantly lower the associated precipitation over north-central India, despite an overall increase in mean precipitation.
AB - Monsoon low pressure systems (MLPSs) are among the most important synoptic-scale disturbances of the South Asian summer monsoon. Potential changes in their characteristics in a warmer climate would have broad societal impacts. Yet, the findings from a few existing studies are inconclusive. We use the Geophysical Fluid Dynamics Laboratory (GFDL) coupled climate model CM4.0 to examine the projected changes in the simulated MLPS activity under a future emission scenario. It is shown that CM4.0 can skillfully simulate the number, genesis location, intensity, and lifetime of MLPSs. Global warming gives rise to a significant decrease in MLPS activity. An analysis of several large-scale environmental variables, both dynamic and thermodynamic, suggests that the decrease in MLPS activity can be attributed mainly to a reduction in low-level relative vorticity over the core genesis region. The decreased vorticity is consistent with weaker large-scale ascent, which leads to less vorticity production through the stretching term in the vorticity equation. Assuming a fixed radius of influence, the projected reduction in MLPSs would significantly lower the associated precipitation over north-central India, despite an overall increase in mean precipitation.
UR - http://www.scopus.com/inward/record.url?scp=85091590396&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85091590396&partnerID=8YFLogxK
U2 - 10.1175/JCLI-D-20-0168.1
DO - 10.1175/JCLI-D-20-0168.1
M3 - Article
AN - SCOPUS:85091590396
SN - 0894-8755
VL - 33
SP - 7275
EP - 7287
JO - Journal of Climate
JF - Journal of Climate
IS - 17
ER -