Roles of Anomalous Tibetan Plateau Warming on the Severe 2008 Winter Storm in Central-Southern China

2010 ◽  
Vol 138 (6) ◽  
pp. 2375-2384 ◽  
Author(s):  
Qing Bao ◽  
Jing Yang ◽  
Yimin Liu ◽  
Guoxiong Wu ◽  
Bin Wang
Keyword(s):  
Tibetan Plateau ◽  
General Circulation ◽  
Extreme Event ◽  
Southern China ◽  
Inversion Layer ◽  
Circulation Model ◽  
Central China ◽  
The Tibetan Plateau ◽  
Freezing Rain ◽  
Mean Sea Surface

Abstract Anomalous warming occurred over the Tibetan Plateau (TP) before and during the disastrous freezing rain and heavy snow hitting central and southern China in January 2008. The relationship between the TP warming and this extreme event is investigated with an atmospheric general circulation model. Two perpetual runs were performed. One is forced by the climatological mean sea surface temperatures in January as a control run; and the other has the same model setting as the control run except with an anomalous warming over the TP that mimics the observed temperature anomaly. The numerical results demonstrate that the TP warming induces favorable circulation conditions for the occurrence of this extreme event, which include the deepened lower-level South Asian trough, the enhanced lower-level southwesterly moisture transport in central-southern China, the lower-level cyclonic shear in the southerly flow over southeastern China, and the intensified Middle East jet stream in the middle and upper troposphere. Moreover, the anomalous TP warming results in a remarkable cold anomaly near the surface and a warm anomaly aloft over central China, forming a stable stratified inversion layer that favors the formation of the persistent freezing rain. The possible physical linkages between the TP warming and the relevant resultant circulation anomalies are proposed. The potential reason of the anomalous TP warming during the 2007–08 winter is also discussed.

scholarly journals The Impacts of Multiscale Weather Systems on Freezing Rain and Snowstorms over Southern China

2010 ◽  
Vol 25 (2) ◽  
pp. 388-407 ◽  
Author(s):  
Jianhua Sun ◽  
Sixiong Zhao
Keyword(s):  
Tibetan Plateau ◽  
Southern China ◽  
Inversion Layer ◽  
Precipitation Event ◽  
The Tibetan Plateau ◽  
The South ◽  
Freezing Rain ◽  
Stationary Front ◽  
Cloud Clusters ◽  
Atmospheric Stratification

Abstract This paper investigated the interactions between the synoptic patterns, quasi-stationary fronts, eastward-propagating cloud clusters from the Tibetan Plateau, surface conditions, and atmospheric stratification processes associated with a 20-day event of freezing precipitation over southern China from January to February 2008. It was found that the long duration of the freezing precipitation process was primarily caused by stationary and anomalous synoptic weather patterns such as a blocking high pressure system in the northern branch and a trough in the south branch of the westerlies, which resulted in the convergence of cold air from northern China and warm, moist air from the south. The cloud clusters over the Tibetan Plateau propagated eastward and showed noticeable impacts in the local areas when they moved over southern China during several similar cloud propagation processes from January to February 2008. An east–west-oriented quasi-stationary front system in southern China, which is rare during the Asian winter monsoon season, is responsible for producing freezing precipitation and snowstorms. A stronger horizontal gradient of the isolines of the pseudo-equivalent potential temperature and higher temperatures at the inversion layer in the western part of the front than that in its eastern part can be found. At the same time, low-level moisture convergence ahead of the front enhanced the formation, development, and persistence of freezing precipitation in the west part of the front. The thickness of the warm layer and the temperature inversion layer also modulated the intensity and duration of freezing rain and ice pellets. Temperature from about −1° to −3°C and weak winds were found to be favorable meteorological factors at the surface level for freezing precipitation. These analysis results are synthesized into a conceptual model that coherently describes the physics processes associated with the synoptic features and quasi-stationary front system as well as the atmospheric stratification process during the freezing precipitation event.

Poleward Stationary Eddy Heat Transport by the Tibetan Plateau and Equatorward Shift of Westerlies during Northern Winter*

2013 ◽  
Vol 70 (10) ◽  
pp. 3288-3301 ◽  
Author(s):  
Hyo-Seok Park ◽  
Shang-Ping Xie ◽  
Seok-Woo Son
Keyword(s):  
Tibetan Plateau ◽  
Heat Transport ◽  
General Circulation ◽  
Hot Spot ◽  
Circulation Model ◽  
The Tibetan Plateau ◽  
Stationary Waves ◽  
Transient Eddy ◽  
Poleward Heat Transport ◽  
Eddy Heat Transport

Abstract The orographic effect of the Tibetan Plateau on atmospheric poleward heat transport is investigated using an atmospheric general circulation model. The linear interference between the Tibetan Plateau–induced winds and the eddy temperature field associated with the land–sea thermal contrast is a key factor for enhancing the poleward stationary eddy heat transport. Specifically, Tibetan Plateau–induced stationary waves produce northerlies over the cold eastern Eurasian continent, leading to a poleward heat transport. In another hot spot of stationary eddy heat transport over the eastern North Pacific, Tibetan Plateau–induced stationary waves transport relatively warm marine air northward. In an experiment where the Tibetan Plateau is removed, the poleward heat transport is mostly accomplished by transient eddies, similar to the Southern Hemisphere. In the presence of the Tibetan Plateau, the enhanced stationary eddy heat transport is offset by a comparable reduction in transient eddy heat transport. This compensation between stationary and transient eddy heat transport is seen in observed interannual variability. Both the model and observations indicate that an enhanced poleward heat transport by stationary waves weakens transient eddies by decreasing the meridional temperature gradient and the associated westerlies in midlatitudes.

Episode of Strengthened Summer Monsoon Climate of Younger Dryas Age on the Loess Plateau of Central China

1993 ◽  
Vol 39 (1) ◽  
pp. 45-54 ◽  
Author(s):  
An Zhisheng ◽  
Stephen C. Porter ◽  
Zhou Weijian ◽  
Lu Yanchou ◽  
Douglas J. Donahue ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
General Circulation ◽  
Younger Dryas ◽  
Circulation Model ◽  
Late Glacial ◽  
Central China ◽  
Monsoon Circulation ◽  
The Tibetan Plateau ◽  
Monsoon Climate ◽  
Younger Dryas Event

AbstractThe Baxie loess section, just east of the Tibetan Plateau, contains evidence showing that the Asian monsoon climate experienced an abrupt reversal near the end of the last glacial age. Rapid deposition of dust under cool, dry full-glacial conditions gave way to an interval of soil development and reduced dust influx attributed to a strengthening of the warm, moist summer monsoon. A subsequent abrupt increase in dust deposition, a response to a weakening of the summer monsoon, was later followed by renewed soil formation as summer monsoon circulation again intensified during the early Holocene. By one interpretation, the thin upper loess is a manifestation of the European Younger Dryas oscillation; however, in this case the available 14C ages require either that (1) onset of loess deposition lagged the beginning of the Younger Dryas event in Europe by as much as 2000 calibrated 14C years or (2) all the 14C ages are too young, possibly due to contamination. Alternatively, the late-glacial paleosol, the top of which is synchronous with the abrupt end of the late-glacial δ18O anomaly in the Dye 3 Greenland ice core, records the Younger Dryas event. Such an interpretation is consistent with general circulation model simulations of Younger Dryas climate that show strong seasonality and a strengthened summer monsoon, and with marine cores from the western Pacific Ocean that contain evidence of pronounced cooling of surface waters during Younger Dryas time.

Sensitivity of East Asian summer monsoon precipitation to the location of the Tibetan Plateau

2021 ◽  
pp. 1-36
Author(s):  
Soo-Hyun Seok ◽  
Kyong-Hwan Seo
Keyword(s):  
Tibetan Plateau ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
General Circulation ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Circulation Model ◽  
Dynamical Response ◽  
The Tibetan Plateau ◽  
Asian Summer

AbstractRecent studies have highlighted that a primary mechanism of the East Asian summer monsoon (EASM) is the fluid dynamical response to the Tibetan Plateau (TP), that is, orographically forced Rossby waves. With this mechanism in mind, this study explores how changes in the location of the TP affect the EASM precipitation. Specifically, the TP is moved in the four cardinal directions using idealized general circulation model experiments. The results show that the monsoon aspects are entirely determined by the location of the TP. Interestingly, the strongest EASM precipitation occurs when the TP is situated near its current location, a situation in which downstream southerlies are well developed from the surface to aloft. However, southerlies into the EASM region weaken as the TP moves, which in turn reduces the precipitation. Nevertheless, as long as it moves in the east–west direction, the TP is likely to force the stationary waves that induce precipitation over the mid-latitudes (not necessarily over East Asia). In contrast, moving the TP well north of its original location does not induce strong monsoon flows over the EASM region, resulting in the driest case. Meanwhile, although the southward movement of the TP triggers downstream southerlies to some extent, it does not lead to an increase in the precipitation. Overall, these results show that the location of the TP is crucial in determining the EASM precipitation, and the latter is much more sensitive to the displacement of the TP in the meridional direction than in the zonal direction.

scholarly journals Origins of East Asian Summer Monsoon Seasonality

2020 ◽  
Vol 33 (18) ◽  
pp. 7945-7965 ◽  
Author(s):  
J. C. H. Chiang ◽  
W. Kong ◽  
C. H. Wu ◽  
D. S. Battisti
Keyword(s):  
Tibetan Plateau ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
General Circulation ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Circulation Model ◽  
Northeastern China ◽  
The Tibetan Plateau ◽  
Asian Summer

AbstractThe East Asian summer monsoon is unique among summer monsoon systems in its complex seasonality, exhibiting distinct intraseasonal stages. Previous studies have alluded to the downstream influence of the westerlies flowing around the Tibetan Plateau as key to its existence. We explore this hypothesis using an atmospheric general circulation model that simulates the intraseasonal stages with fidelity. Without a Tibetan Plateau, East Asia exhibits only one primary convective stage typical of other monsoons. As the plateau is introduced, the distinct rainfall stages—spring, pre-mei-yu, mei-yu, and midsummer—emerge, and rainfall becomes more intense overall. This emergence coincides with a pronounced modulation of the westerlies around the plateau and extratropical northerlies penetrating northeastern China. The northerlies meridionally constrain the moist southerly flow originating from the tropics, leading to a band of lower-tropospheric convergence and humidity front that produces the rainband. The northward migration of the westerlies away from the northern edge of the plateau leads to a weakening of the extratropical northerlies, which, coupled with stronger monsoonal southerlies, leads to the northward migration of the rainband. When the peak westerlies migrate north of the plateau during the midsummer stage, the extratropical northerlies disappear, leaving only the monsoon low-level circulation that penetrates northeastern China; the rainband disappears, leaving isolated convective rainfall over northeastern China. In short, East Asian rainfall seasonality results from the interaction of two seasonally evolving circulations—the monsoonal southerlies that strengthen and extend northward, and the midlatitude northerlies that weaken and eventually disappear—as summer progresses.

scholarly journals Impacts of Tibetan Plateau uplift on atmospheric dynamics and associated precipitation δ<sup>18</sup>O

2016 ◽  
Author(s):  
S. Botsyun ◽  
P. Sepulchre ◽  
C. Risi ◽  
Y. Donnadieu
Keyword(s):  
Tibetan Plateau ◽  
General Circulation ◽  
Climatic Factors ◽  
Precipitation Amount ◽  
Modern Science ◽  
Circulation Model ◽  
Theoretical Expression ◽  
The Tibetan Plateau ◽  
Reduced Height ◽  
Mountain Belts

Abstract. Paleoelevation reconstructions of mountain belts have become a focus of modern science since surface elevation provides crucial information for understanding both geodynamic mechanisms of Earth’s interior and influence of mountains growth on climate. Stable oxygen isotopes paleoaltimetry is one of the most popular techniques nowadays, and relies on the difference between δ18O of paleo-precipitation reconstructed using the natural archives, and modern measured values for the point of interest. Our goal is to understand where and how complex climatic changes linked with the growth of mountains affect δ18O in precipitation. For this purpose, we develop a theoretical expression for the precipitation composition and we use the isotope-equipped atmospheric general circulation model LMDZ-iso. Experiments with reduced height over the Tibetan Plateau and the Himalayas have been designed. Our results show that the isotopic composition of precipitation is very sensitive to climate changes related with the growth of the Himalayas and Tibetan Plateau, notably changes in relative humidity and precipitation amount. The relative contribution of controlling factors and their magnitude differ depending on the uplift stage and the region considered. Thus future paleoaltimetry studies should take into account constraints on climatic factors to avoid misestimating ancient altitudes.

scholarly journals Revised paleoaltimetry data show low Tibetan Plateau elevation during the Eocene

Science ◽  
2019 ◽  
Vol 363 (6430) ◽  
pp. eaaq1436 ◽  
Author(s):  
Svetlana Botsyun ◽  
Pierre Sepulchre ◽  
Yannick Donnadieu ◽  
Camille Risi ◽  
Alexis Licht ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Tibetan Plateau ◽  
General Circulation ◽  
Circulation Model ◽  
Convective Precipitation ◽  
The Tibetan Plateau ◽  
Model Data ◽  
Air Masses ◽  
Data Comparison ◽  
Oxygen Stable Isotopes

Paleotopographic reconstructions of the Tibetan Plateau based on stable isotope paleoaltimetry methods conclude that most of the Plateau’s current elevation was already reached by the Eocene, ~40 million years ago. However, changes in atmospheric and hydrological dynamics affect oxygen stable isotopes in precipitation and may thus bias such reconstructions. We used an isotope-equipped general circulation model to assess the influence of changing Eocene paleogeography and climate on paleoelevation estimates. Our simulations indicate that stable isotope paleoaltimetry methods are not applicable in Eocene Asia because of a combination of increased convective precipitation, mixture of air masses, and widespread aridity. Rather, a model-data comparison suggests that the Tibetan Plateau only reached low to moderate (less than 3000 meters) elevations during the Eocene, reconciling oxygen isotope data with other proxies.

Sign in / Sign up

Export Citation Format

Share Document