Sensitivity of a western Great Basin terminal lake to winter northeast Pacific storm track activity and moisture transport

2019 ◽  
Author(s):  
Benjamin J. Hatchett ◽  
Douglas P. Boyle ◽  
Chris B. Garner ◽  
Michael L. Kaplan ◽  
Scott D. Bassett ◽  
...  
Keyword(s):  
Great Basin ◽  
Moisture Transport ◽  
Storm Track ◽  
Northeast Pacific ◽  
Storm Track Activity

Influence of the Subtropical High and Storm Track on Low-Cloud Fraction and Its Seasonality over the South Indian Ocean

2018 ◽  
Vol 31 (10) ◽  
pp. 4017-4039 ◽  
Author(s):  
Ayumu Miyamoto ◽  
Hisashi Nakamura ◽  
Takafumi Miyasaka
Keyword(s):  
Indian Ocean ◽  
Storm Track ◽  
Cloud Fraction ◽  
Subtropical High ◽  
The South ◽  
South Indian Ocean ◽  
Mascarene High ◽  
South Indian ◽  
Low Cloud ◽  
Storm Track Activity

Abstract The south Indian Ocean is characterized by enhanced midlatitude storm-track activity around a prominent sea surface temperature (SST) front and unique seasonality of the surface subtropical Mascarene high. The present study investigates the climatological distribution of low-cloud fraction (LCF) and its seasonality by using satellite data, in order to elucidate the role of the storm-track activity and subtropical high. On the equatorward flank of the SST front, summertime LCF is locally maximized despite small estimated inversion strength (EIS) and high SST. This is attributable to locally augmented sensible heat flux (SHF) from the ocean under the enhanced storm-track activity, which gives rise to strong instantaneous wind speed while acting to relax the meridional gradient of surface air temperature. In the subtropics, summertime LCF is maximized off the west coast of Australia, while wintertime LCF is distributed more zonally across the basin unlike in other subtropical ocean basins. Although its zonally extended distribution is correspondent with that of LCF, EIS alone cannot explain the wintertime LCF enhancement, which precedes the EIS maximum under continuous lowering of SST and enhanced SHF in winter. Basinwide cold advection associated with the wintertime westward shift of the subtropical high contributes to the enhancement of SHF, especially around 15°–25°S, while seasonally enhanced storm-track activity augments SHF around 30°S. The analysis highlights the significance of large-scale controls, particularly through SHF, on the seasonality of the climatological LCF distribution over the south Indian Ocean, which reflect the seasonality of the Mascarene high and storm-track activity.

Influences of the Kuroshio/Oyashio Extensions on Air–Sea Heat Exchanges and Storm-Track Activity as Revealed in Regional Atmospheric Model Simulations for the 2003/04 Cold Season*

2009 ◽  
Vol 22 (24) ◽  
pp. 6536-6560 ◽  
Author(s):  
Bunmei Taguchi ◽  
Hisashi Nakamura ◽  
Masami Nonaka ◽  
Shang-Ping Xie
Keyword(s):  
Frontal Zone ◽  
Storm Track ◽  
Cold Season ◽  
Sign Reversal ◽  
Meridional Gradient ◽  
Oceanic Fronts ◽  
Storm Track Activity ◽  
Heat Exchanges ◽  
Heat And Moisture ◽  
The Kuroshio

Abstract Influences of oceanic fronts in the Kuroshio and Oyashio Extension (KOE) region on the overlying atmosphere are investigated by comparing a pair of atmospheric regional model hindcast experiments for the 2003/04 cold season, one with the observed finescale frontal structures in sea surface temperature (SST) prescribed at the model lower boundary and the other with an artificially smoothed SST distribution. The comparison reveals the locally enhanced meridional gradient of turbulent fluxes of heat and moisture and surface air temperature (SAT) across the oceanic frontal zone, which favors the storm-track development both in winter and spring. Distinct seasonal dependency is found, however, in how dominantly the storm-track activity influences the time-mean distribution of the heat and moisture supply from the ocean. In spring the mean surface sensible heat flux (SHF) is upward (downward) on the warmer (cooler) side of the subarctic SST front. This sharp cross-frontal contrast is a manifestation of intermittent heat release (cooling) induced by cool northerlies (warm southerlies) on the warmer (cooler) side of the front in association with migratory cyclones and anticyclones. The oceanic frontal zone is thus marked as both the largest variability in SHF and the cross-frontal sign reversal of the SHF skewness. The cross-frontal SHF contrasts in air–sea heat exchanges counteract poleward heat transport by those atmospheric eddies, to restore the sharp meridional gradient of SAT effectively for the recurrent development of atmospheric disturbances. Lacking this oceanic baroclinic adjustment associated with the SST front, the experiment with the smoothed SST distribution underestimates storm-track activity in the KOE region. In winter the prevailing cold, dry continental airflow associated with the Asian winter monsoon induces a large amount of heat and moisture release even from the cooler ocean to the north of the frontal zone. The persistent advective effects of the monsoonal wind weaken the SAT gradient and smear out the sign reversal of the SHF skewness, leading to weaker influences of the oceanic fronts on the atmosphere in winter than in spring.

Interdecadal changes in the storm track activity over the North Pacific and North Atlantic

2011 ◽  
Vol 39 (1-2) ◽  
pp. 313-327 ◽  
Author(s):  
Sun-Seon Lee ◽  
June-Yi Lee ◽  
Bin Wang ◽  
Kyung-Ja Ha ◽  
Ki-Young Heo ◽  
...  
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Storm Track ◽  
The North ◽  
Storm Track Activity ◽  
The North Pacific ◽  
Interdecadal Changes

scholarly journals Eddy-Induced Growth Rate of Low-Frequency Variability and Its Mid- to Late Winter Suppression in the Northern Hemisphere

2014 ◽  
Vol 71 (7) ◽  
pp. 2281-2298 ◽  
Author(s):  
Hong-Li Ren ◽  
Fei-Fei Jin ◽  
Jong-Seong Kug
Keyword(s):  
Northern Hemisphere ◽  
Storm Track ◽  
Low Frequency ◽  
Lower Troposphere ◽  
Surface Friction ◽  
Late Winter ◽  
Wind Maximum ◽  
Low Frequency Variability ◽  
Storm Track Activity ◽  
Effect Of Surface

Abstract Synoptic eddy and low-frequency flow (SELF) feedback plays an important role in reinforcing low-frequency variability (LFV). Recent studies showed that an eddy-induced growth (EIG) or instability makes a fundamental contribution to the maintenance of LFV. To quantify the efficiency of the SELF feedback, this study examines the spatiotemporal features of the empirical diagnostics of EIG and its associations with LFV. The results show that, in terms of eddy vorticity forcing, the EIG rate of LFV is generally larger (smaller) in the upper (lower) troposphere, whereas, in terms of eddy potential vorticity forcing, it is larger in the lower troposphere to partly balance the damping effect of surface friction. The local EIG rate shows a horizontal spatial distribution that corresponds to storm-track activity, which tends to be responsible for maintaining LFV amplitudes and patterns as well as sustaining eddy-driven jets. In fact, the EIG rate has a well-defined seasonality, being generally larger in cold seasons and smaller in the warmest season, and this seasonality is stronger in the Northern Hemisphere than in the Southern Hemisphere. This study also reveals a mid- to late winter (January–March) suppression of the EIG rate in the Northern Hemisphere, which indicates a reduced eddy feedback efficiency and may be largely attributed to the eddy kinetic energy suppression and the midlatitude zonal wind maximum in the midwinter of the Northern Hemisphere.

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