Drylines in North America
Drylines; strong moisture gradients at low levels, are a consequence of the confluence of moist and warm air from the south and the hot-dry subsident air coming from the west of the Rockies
Drylines; strong moisture gradients at low levels, are a consequence of the confluence of moist and warm air from the south and the hot-dry subsident air coming from the west of the Rockies
How is the dryline related to convective initation?
How is the dryline related to convective initation?
The dryline induces a solenoidal circulation that creates a favorable environment for uplift parcels and thus more chances to form clouds and initiate convection.
The dryline induces a solenoidal circulation that creates a favorable environment for uplift parcels and thus more chances to form clouds and initiate convection.
This is an example of a strong dryline in the Canadian Rockies in July 2013. From the model simulation!
This is an example of a strong dryline in the Canadian Rockies in July 2013. From the model simulation!
the map shows the strong moisture gradient in shaded blue-red colors
the map shows the strong moisture gradient in shaded blue-red colors
And the blue contours hightlight precipitation above 0.1 mm
The cross seciton around 52 deg N shows the vertical moisture gradient in colors.
The cross seciton around 52 deg N shows the vertical moisture gradient in colors.
Arrows represent the zonal and vertical wind and contours are highlighting the magnitude of the vertical winds. Right at the dryline zone!
Our study makes aims to characterize the dryline over North America, and shows the magnitude of the potential changes in a warmer climate.
Our study makes aims to characterize the dryline over North America, and shows the magnitude of the potential changes in a warmer climate.
For this we use two convection-permitting regional climate simulations with 13 years of historical simulations and another 13 years representing a future warmer climate.
For this we use two convection-permitting regional climate simulations with 13 years of historical simulations and another 13 years representing a future warmer climate.
We divide the domain in 4 regions to analyze:
the frequency of the dryline,
seasonal and diurnal cycle of the dryline magnitude and extension.
Changes in a warmer climate
The dryline is automatically identified in all the regions (green contours), using a multiparametric algorithm (Clark et al. 2015).
The dryline is automatically identified in all the regions (green contours), using a multiparametric algorithm (Clark et al. 2015).
This example shows a day in May 2006, in which an strong and extended dryline can be seen in the entire domain. The zoom in to the Canadian Rockies (top right panel) and in the Southern U.S. (bottom panel) shows how the algorithm identifies the drylines
This example shows a day in May 2006, in which an strong and extended dryline can be seen in the entire domain. The zoom in to the Canadian Rockies (top right panel) and in the Southern U.S. (bottom panel) shows how the algorithm identifies the drylines
Drylines are getting more frequent and intense everywhere!
Drylines are getting more frequent and intense everywhere!
This is the frequency and magnitude of drylines in summer
This is the frequency and magnitude of drylines in summer
Left: CTRL represent the historical simulation
Center: PGW represent the future simulation
Right: this is the difference from the last two panels.
This figure shows a model verification of specific humidity at 2 m above surface against the ERA5 reanalysis
This figure shows a model verification of specific humidity at 2 m above surface against the ERA5 reanalysis
check out my poster here!
check out my poster here!