scholarly journals On the relation between large-scale circulation pattern and heavy rain events over the Hawaiian Islands: Recent trends and future changes

2013 ◽  
Vol 118 (10) ◽  
pp. 4129-4141 ◽  
Author(s):  
Oliver Elison Timm ◽  
Mami Takahashi ◽  
Thomas W. Giambelluca ◽  
Henry F. Diaz
Keyword(s):  
Large Scale ◽  
Hawaiian Islands ◽  
Heavy Rain ◽  
Circulation Pattern ◽  
Large Scale Circulation ◽  
Recent Trends ◽  
Rain Events

scholarly journals Reply to “Comments on ‘Incorporating the Effects of Moisture into a Dynamical Parameter: Moist Vorticity and Moist Divergence’”

2016 ◽  
Vol 31 (4) ◽  
pp. 1397-1405
Author(s):  
Weihong Qian ◽  
Ning Jiang ◽  
Jun Du
Keyword(s):  
Large Scale ◽  
Value Added ◽  
Heavy Rain ◽  
Heavy Precipitation ◽  
Small Scale ◽  
Precipitation Efficiency ◽  
Long Duration ◽  
Advection Term ◽  
Rain Events ◽  
Mathematical Derivation

Abstract Mathematical derivation, meteorological justification, and comparison to model direct precipitation forecasts are the three main concerns recently raised by Schultz and Spengler about moist divergence (MD) and moist vorticity (MV), which were introduced in earlier work by Qian et al. That previous work demonstrated that MD (MV) can in principle be derived mathematically with a value-added empirical modification. MD (MV) has a solid meteorological basis. It combines ascent motion and high moisture: the two elements necessary for rainfall. However, precipitation efficiency is not considered in MD (MV). Given the omission of an advection term in the mathematical derivation and the lack of precipitation efficiency, MD (MV) might be suitable mainly for heavy rain events with large areal coverage and long duration caused by large-scale quasi-stationary weather systems, but not for local intense heavy rain events caused by small-scale convection. In addition, MD (MV) is not capable of describing precipitation intensity. MD (MV) worked reasonably well in predicting heavy rain locations from short to medium ranges as compared with the ECMWF model precipitation forecasts. MD (MV) was generally worse than (though sometimes similar to) the model heavy rain forecast at shorter ranges (about a week) but became comparable or even better at longer ranges (around 10 days). It should be reiterated that MD (MV) is not intended to be a primary tool for predicting heavy rain areas, especially in the short range, but is a useful parameter for calibrating model heavy precipitation forecasts, as stated in the original paper.

Ocean carbon storage uniquely linked to ocean heat 

2021 ◽  
Author(s):  
Ben Bronselaer ◽  
Laure Zanna
Keyword(s):  
Carbon Storage ◽  
Large Scale ◽  
Climate Models ◽  
Circulation Pattern ◽  
Secondary Importance ◽  
Large Scale Circulation ◽  
Excess Carbon ◽  
Excess Heat ◽  
Surface Ocean ◽  
Ocean Carbon

<p>As the climate warms due to greenhouse gas emissions, the ocean absorbs excess heat and carbon. The patterns of ocean excess heat and carbon storage appear tightly linked when the large-scale circulation is fixed. This unique link is not shared with any other ocean tracer, such as <span>Chlorofluorocarbons</span> (CFCs). At the same time, ocean excess carbon storage patterns are mostly unchanged whether the large-scale circulation is free to evolve, or fixed to the pre-industrial circulation pattern, as the climate warms. Here, we interpret the reason for this behavior by breaking ocean carbon storage into two parts: uptake of atmospheric anomalies by the surface ocean, and subsequent internal storage by the ocean’s circulation. We show that the patterns of surface ocean carbon anomalies are dictated by mean state biogeochemical properties and therefore mostly unchanged by circulation changes. Furthermore, surface biogeochemical properties are strongly shaped by the ocean temperature, providing a link between ocean heat and carbon uptake. CFCs on the hand, lack chemical buffering and therefore the patterns of CFC storage do not correlate with heat as much as carbon patterns do. The patterns of surface anomalies ultimately explain most of the differences in how temperature, carbon and CFCs are stored by the ocean, while changes in internal pathways are of secondary importance. Furthermore, the ratio of total ocean carbon and heat storage is roughly constant across warming scenarios and climate models, which might have further implications for relating ocean carbon storage to important climate metrics, such as the transient response to cumulative emissions.</p>

The 2010 Pakistan Flood and Russian Heat Wave: Teleconnection of Hydrometeorological Extremes

2012 ◽  
Vol 13 (1) ◽  
pp. 392-403 ◽  
Author(s):  
William K. M. Lau ◽  
Kyu-Myong Kim
Keyword(s):  
Heat Wave ◽  
Rossby Wave ◽  
Large Scale ◽  
Wave Train ◽  
Intraseasonal Oscillation ◽  
Heavy Rain ◽  
Atmospheric Blocking ◽  
Surface Energy Fluxes ◽  
Upper Level ◽  
Rain Events

Abstract In this paper, preliminary results are presented showing that the two record-setting extreme events during 2010 summer (i.e., the Russian heat wave–wildfires and Pakistan flood) were physically connected. It is found that the Russian heat wave was associated with the development of an extraordinarily strong and prolonged extratropical atmospheric blocking event in association with the excitation of a large-scale atmospheric Rossby wave train spanning western Russia, Kazakhstan, and the northwestern China–Tibetan Plateau region. The southward penetration of upper-level vorticity perturbations in the leading trough of the Rossby wave was instrumental in triggering anomalously heavy rain events over northern Pakistan and vicinity in mid- to late July. Also shown are evidences that the Russian heat wave was amplified by a positive feedback through changes in surface energy fluxes between the atmospheric blocking pattern and an underlying extensive land region with below-normal soil moisture. The Pakistan heavy rain events were amplified and sustained by strong anomalous southeasterly flow along the Himalayan foothills and abundant moisture transport from the Bay of Bengal in connection with the northward propagation of the monsoonal intraseasonal oscillation.

scholarly journals Large-Scale Circulation Patterns Associated with Heavy Spring Rain Events over Taiwan in Strong ENSO and Non-ENSO Years

2003 ◽  
Vol 131 (8) ◽  
pp. 1769-1782 ◽  
Author(s):  
Zhihong Jiang ◽  
George Tai-Jen Chen ◽  
Ming-Chin Wu
Keyword(s):  
Coastal Area ◽  
Large Scale ◽  
Eastern China ◽  
Lower Troposphere ◽  
Heavy Rain ◽  
Interdecadal Variation ◽  
Frontal System ◽  
Rain Events ◽  
The Relationship ◽  
Strong Enso

Abstract Daily rainfall data at 15 stations in Taiwan and the grid dataset of the National Centers for Environmental Prediction–National Center for Atmospheric Research during the period of February–March 1951–2000 were used to reveal the characteristics of large-scale circulations associated with spring heavy rain events over Taiwan in strong ENSO and non-ENSO years. The effect of interdecadal variation on the relationship of spring rainfall and ENSO was also examined. Results showed that the different regimes of interdecadal variation that occurred in the late 1970s exert significant effect on the relationship between ENSO and spring rainfall in Taiwan. A pronounced positive correlation with statistical significance between cold season Niño-3 SST and the following spring rainfall over western Taiwan was only found since the late 1970s. Large-scale environmental conditions associated with the heavy spring rain events in strong ENSO and non-ENSO years were found to be quite different. Intrusion of a weak midlatitude frontal system into the eastern China coastal area coupled with an anomalous anticyclone over the Philippine Sea (PSAC) in the lower troposphere were primarily responsible for the spring heavy rain events in strong ENSO years. On the other hand, the intrusion of a much more intense midlatitude frontal system into China and the coastal area was necessary to generate spring heavy rain events in non-ENSO years. This difference is also instrumental for more frequent occurrence of heavy rainfall events and more rainfall amount observed in ENSO years.

scholarly journals Greenland accumulation and its connection to the large-scale atmospheric circulation in ERA-Interim and paleo-climate simulations

2013 ◽  
Vol 9 (4) ◽  
pp. 3825-3870
Author(s):  
N. Merz ◽  
C. C. Raible ◽  
H. Fischer ◽  
V. Varma ◽  
M. Prange ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Large Scale ◽  
Ice Core ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Circulation Pattern ◽  
Local Flow ◽  
Large Scale Circulation ◽  
Circulation Patterns ◽  
Local Accumulation

Abstract. Accumulation and aerosol chemistry records from Greenland ice cores offer the potential to reconstruct variability in Northern Hemisphere atmospheric circulation over the last millennia. However, an important prerequisite for a reconstruction is the stable relationship between local accumulation at the ice core site with the respective circulation pattern throughout the reconstruction period. We address this stability issue by using a comprehensive climate model and performing time-slice simulations for the present, the pre-industrial, the early Holocene and the last glacial maximum (LGM). The relationships between accumulation, precipitation and atmospheric circulation are investigated on on various time-scales. The analysis shows that the relationship between local accumulation on the Greenland ice sheet and the large-scale circulation undergoes a significant seasonal cycle. As the weights of the individual seasons change, annual mean accumulation variability is not necessarily related to the same atmospheric circulation patterns during the different climate states. Within a season, local Greenland accumulation variability is indeed linked to a consistent circulation pattern, which is observed for all studied climate periods, even for the LGM, however these circulation patterns are specific for different regions on the Greenland ice sheet. The simulated impact of orbital forcing and changes in the ice-sheet topography on accumulation exhibits strong spatial variability emphasizing that accumulation records from different ice core sites cannot be expected to look alike since they include a distinct local signature. Accumulation changes between different climate periods are dominated by changes in the amount of snowfall and are driven by both thermodynamic and dynamic factors. The thermodynamic impact determines the strength of the hydrological cycle, and warmer temperatures are generally accompanied by an increase in Greenland precipitation. Dynamical drivers of accumulation changes are the large-scale circulation and the local orography having a distinct influence on the local flow characteristic and hence the amount of precipitation deposited in any Greenland region.

scholarly journals Greenland accumulation and its connection to the large-scale atmospheric circulation in ERA-Interim and paleoclimate simulations

2013 ◽  
Vol 9 (6) ◽  
pp. 2433-2450 ◽  
Author(s):  
N. Merz ◽  
C. C. Raible ◽  
H. Fischer ◽  
V. Varma ◽  
M. Prange ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
Large Scale ◽  
Climate Model ◽  
Ice Core ◽  
Ice Cores ◽  
Circulation Pattern ◽  
Large Scale Circulation ◽  
Atmospheric Circulation Patterns ◽  
The Stability ◽  
The Relationship

Abstract. Changes in Greenland accumulation and the stability in the relationship between accumulation variability and large-scale circulation are assessed by performing time-slice simulations for the present day, the preindustrial era, the early Holocene, and the Last Glacial Maximum (LGM) with a comprehensive climate model. The stability issue is an important prerequisite for reconstructions of Northern Hemisphere atmospheric circulation variability based on accumulation or precipitation proxy records from Greenland ice cores. The analysis reveals that the relationship between accumulation variability and large-scale circulation undergoes a significant seasonal cycle. As the contributions of the individual seasons to the annual signal change, annual mean accumulation variability is not necessarily related to the same atmospheric circulation patterns during the different climate states. Interestingly, within a season, local Greenland accumulation variability is indeed linked to a consistent circulation pattern, which is observed for all studied climate periods, even for the LGM. Hence, it would be possible to deduce a reliable reconstruction of seasonal atmospheric variability (e.g., for North Atlantic winters) if an accumulation or precipitation proxy were available that resolves single seasons. We further show that the simulated impacts of orbital forcing and changes in the ice sheet topography on Greenland accumulation exhibit strong spatial differences, emphasizing that accumulation records from different ice core sites regarding both interannual and long-term (centennial to millennial) variability cannot be expected to look alike since they include a distinct local signature. The only uniform signal to external forcing is the strong decrease in Greenland accumulation during glacial (LGM) conditions and an increase associated with the recent rise in greenhouse gas concentrations.

scholarly journals A new indicator on the impact of large-scale circulation on wintertime particulate matter pollution over China

2015 ◽  
Vol 15 (20) ◽  
pp. 11919-11929 ◽  
Author(s):  
B. Jia ◽  
Y. Wang ◽  
Y. Yao ◽  
Y. Xie
Keyword(s):  
Particulate Matter ◽  
Large Scale ◽  
Lower Troposphere ◽  
Circulation Pattern ◽  
Large Scale Circulation ◽  
High Position ◽  
Siberian High ◽  
Modis Aod ◽  
Longitudinal Position ◽  
The Impact

Abstract. Extreme particulate matter (PM) air pollution of January 2013 in China was found to be associated with an anomalous eastward extension of the Siberian High (SH). We developed a Siberian High position index (SHPI), which depicts the mean longitudinal position of the SH, as a new indicator of the large-scale circulation pattern that controls wintertime air quality in China. This SHPI explains 58 % (correlation coefficient of 0.76) of the interannual variability of wintertime aerosol optical depth (AOD) retrieved by MODIS over North China (NC) during 2001–2013. By contrast, the intensity-based conventional Siberian High index (SHI) shows essentially no skill in predicting this AOD variability. On the monthly scale, some high-AOD months for NC are accompanied with extremely high SHPIs; notably, extreme PM pollution of January 2013 can be explained by the SHPI value exceeding 2.6 times the standard deviation of the 2001–2013 January mean. When the SH extends eastward, thus higher SHPI, prevailing northwesterly winds over NC are suppressed not only in the lower troposphere but also in the middle troposphere, leading to reduced southward transport of pollution from NC to South China (SC). The SHPI hence exhibits a significantly negative correlation of −0.82 with MODIS AOD over SC during 2001–2013, although the robustness of this correlation depends on that of satellite-derived AOD. The suppressed northwesterly winds during high-SHPI winters also lead to increased relative humidity (RH) over NC. Both the wind and RH changes are responsible for enhanced PM pollution over NC during the high-SHPI winters.

scholarly journals A new indictor on the impact of large-scale circulation on wintertime particulate matter pollution over China

2015 ◽  
Vol 15 (13) ◽  
pp. 19275-19304 ◽  
Author(s):  
B. Jia ◽  
Y. Wang ◽  
Y. Yao ◽  
Y. Xie
Keyword(s):  
Particulate Matter ◽  
Large Scale ◽  
North China ◽  
Lower Troposphere ◽  
Circulation Pattern ◽  
Large Scale Circulation ◽  
High Position ◽  
Siberian High ◽  
Modis Aod ◽  
The Impact

Abstract. Extreme particulate matter (PM) air pollution of January 2013 in China was found to be associated with anomalous large-scale circulation patterns characterized by an eastward extension of the Siberian High (SH). We developed a Siberian High position index (SHPI), which depicts the mean longitudinal position of SH, as a new indicator of the large-scale circulation pattern that controls wintertime air quality in China. This SHPI explains 58 % (correlation coefficient of 0.76) of the interannual variability of wintertime aerosol optical depth (AOD) derived by MODIS over north China (NC) during 2000–2013, whereas the intensity-based conventional Siberian High Index (SHI) shows essentially no skill in predicting the AOD variability. On the monthly scale, some high-AOD months for NC are accompanied with extremely high SHPIs; notably, extreme PM pollution of January 2013 can be explained by the SHPI value exceeding 2.6 standard deviation of the 2000–2013 mean. When the SH extends eastward, thus higher SHPI, prevailing northwesterly winds over NC are suppressed not only in the lower troposphere but also in the middle troposphere, leading to reduced southward transport of pollution from NC to south China (SC). As a consequence, the SHPI exhibits a significantly negative correlation of −0.82 with MODIS AOD over SC during 2000–2013, although the robustness of this correlation depends on that of satellite-derived AOD. The suppressed northwesterly winds during high-SHPI winters also lead to increased relative humidity (RH) over NC. Both the wind and RH changes are responsible for enhanced PM pollution over north China during the high-SHPI winters.

scholarly journals The Linkage of the Large-Scale Circulation Pattern to a Long-Lived Heatwave over Mideastern China in 2018

Atmosphere ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 89 ◽  
Author(s):  
Muyuan Li ◽  
Yao Yao ◽  
Dehai Luo ◽  
Linhao Zhong
Keyword(s):  
High Latitude ◽  
Large Scale ◽  
Wave Train ◽  
Eastern China ◽  
Western Pacific Subtropical High ◽  
Circulation Pattern ◽  
Flux Analysis ◽  
Large Scale Circulation ◽  
Wave Source ◽  
Wave Trains

In this study, the large-scale circulation patterns (a blocking high, wave trains and the western Pacific subtropical high (WPSH)) associated with a wide ranging and highly intense long-lived heatwave in China during the summer of 2018 are examined using both observational data and reanalysis data. Four hot periods are extracted from the heatwave and these are related to anticyclones (hereafter referred to as heatwave anticyclone) over the hot region. Further analysis shows a relationship between the heatwave anticyclone and a synthesis of low, mid- and high latitude circulation systems. In the mid-high latitudes, a midlatitude wave train and a high latitude wave train are associated with a relay process which maintains the heatwave anticyclone. The midlatitude wave train acts during 16–21 July, whereas the high latitude wave train takes affect during 22–28 July. The transition between the two wave trains leads to the northward movement of the hot region. With the help of a wave flux analysis, it was found that both wave trains originate from the positive North Atlantic Oscillation (NAO+) which acts as an Atlantic wave source. Serving as a circulation background, the blocking situated over the Scandinavia-Ural sector is maintained for 18 days from 14 to 15 August, which is accompanied by the persistent wave trains and the heatwave anticyclone. Additionally, the abnormal northward movement of the WPSH and its combination with the high latitude wave train lead to the occurrence of extreme hot weather in north-eastern China occurring during the summer of 2018.

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