Details:

Journal Title:
Journal of Climate
Personal Author:
Ting, Mingfang ; Seager, Richard ; Li, Cuihua ; Liu, Haibo ; Henderson, Naomi
Ting, Mingfang ; Seager, Richard ; Li, Cuihua ; Liu, Haibo ; Henderson, Naomi Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office)
OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office) Less -
Description:
The net surface water budget, precipitation minus evaporation (P − E), shows a clear seasonal cycle in the U.S. Southwest with a net gain of surface water (positive P − E) in the cold half of the year (October–March) and a net loss of water (negative P − E) in the warm half (April–September), with June and July being the driest months of the year. There is a significant shift of the summer drying toward earlier in the year under a CO2 warming scenario, resulting in substantial spring drying (March–May) of the U.S. Southwest from the near-term future to the end of the current century, with gradually increasing magnitude. While the spring drying has been identified in previous studies, its mechanism has not been fully addressed. Using moisture budget analysis, it was found that the drying is mainly due to decreased mean moisture convergence, partially compensated by the increase in transient eddy moisture flux convergence. The decreased mean moisture convergence is further separated into components as a result of changes in circulation (dynamic changes) and changes in atmospheric moisture content (thermodynamic changes). The drying is found to be dominated by the thermodynamic-driven changes in column-averaged moisture convergence, mainly due to increased dry zonal advection caused by the climatological land–ocean thermal contrast, rather than by the well-known “dry get drier” mechanism. Furthermore, the enhanced dry advection in the warming climate is dominated by the robust zonal mean atmospheric warming, leading to equally robust spring drying in the southwestern United States.
Keywords:
[+]
Climatology
Mathematical Models

Source:
J. Clim. (2018) 31(11): 4265–4279
DOI:
https://doi.org/10.1175/JCLI-D-17-0574.1
Document Type:
Journal Article
Funding:
Grant no. NA14OAR4310223
Place as Subject:
United States
Rights Information:
Other
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:e3dbef28cbbef174527229e62daecb2c35613e04840606fbc923aad6855b6fb8
File Type:

Supporting Files

• No Additional Files

More +