Cyclonic and anticyclonic contributions to atmospheric energetics

Energetics by cyclonic and anticyclonic vortices. 
Furthermore, the decomposed Eulerian statistics 
can be utilized for evaluating the cyclonic and anticyclonic contributions to the Lorenz energy cycle. The atmos-
pheric energetics for the midwinter Northern Pacific (Fig. 
4
) reveals that anticyclonic EKE accounts for ~ 45% 
of the total EKE, indicating that anticyclones are almost as important as cyclones in the midlatitude energetics. 
Reflecting their baroclinic structure, the ratio of EAPE to EKE for cyclonic vortices is somewhat higher than 
anticyclonic vortices.
The potential energy conversion (CP) to cyclonic vortices from the baroclinic background westerlies is greater 
by ~ 60% compared to anticyclonic vortices, while cyclonic and anticyclonic vortices contribute comparably to the 
barotropic kinetic energy conversion (CK) in maintaining the westerly jet stream. Both cyclonic and anticyclonic 
vortices contribute positively to EAPE generation through diabatic heating (CQ). A striking feature in Fig. 
4
 is the 
predominant role of anticyclonic vortices in carrying eddy energy downstream (EF) out of the Pacific storm track.
Horizontal distributions of the CK and CP terms are overall similar between cyclonic and anticyclonic vor-
tices (Supplementary Fig. S9). Compared to cyclonic vortices, however, anticyclonic vortices give up slightly 
more EKE to the background jet stream just to the south of its exit, while gaining less EKE in the jet core region. 
Figure 4. The Lorenz energetics separated into cyclonic and anticyclonic contributions. a-b, Climatological-
mean energy budget averaged over the midwinter (24Jan) North Pacific [130° − 130°W, 20° − 65°N] for cyclonic 
(a) and anticyclonic (b) vortices. CK denotes the barotropic energy conversion (or KE conversion) into the 
background flow, CP the baroclinic energy conversion (or APE conversion) from the background flow, CQ the 
APE generation through diabatic processes, ET energy transfer from EAPE to EKE, and EF the energy inflow or 
outflow by energy fluxes through lateral boundaries of the domain. EAPE and EKE are in unit of EJ (= 10
18
J), 
while CK, CP, ET and EF in unit of TW (= 10
12
W). All the terms are integrated vertically from the surface to 
100-hPa. The figure was created with Inkscape v1.0.1 (
https:// www. inksc ape. org
).

---

6
Vol:.(1234567890)