A unified approach to trace surface heat and cold events by using height anomaly

Qian, Weihong; Yu, Ting; Du, Jun

doi:10.1007/s00382-015-2666-2

Cited by 36 publications

(42 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this approach, an atmospheric variable is decomposed into a climatic component and an anomaly (Qian, ). This decomposition method has been used in analyses and predictions of extreme weather events in China, such as freezing rain (Qian and Zhang, ), cold surge (Jiang et al , ; Qian et al , ), heavy rain events (Qian et al , ), and unusual typhoon tracks (Qian et al , ; Huang et al , ). In improving cold surge predictions, Qian et al () found that the centre of geopotential height anomalies (or maximum height anomaly; MHA) in the upper troposphere is a strong indicator of the temperature anomaly at the surface.…”

Section: Introductionmentioning

confidence: 99%

Anomaly based analysis of extreme heat waves in Eastern China during 1981-2013

Chen

Yinming

et al. 2016

Int. J. Climatol.

Self Cite

View full text Add to dashboard Cite

This study shows applications of an anomaly based analysis method to describe extreme summer heat waves in Eastern China during 1981-2013 using two reanalysis products. These events are defined in an area of a spatial size larger than 300 × 500 km (0.15 × 10 6 km 2 ) when its daily maximum surface air temperature (DMSAT) exceeds 35 ∘ C, and the DMSAT anomaly is no less than 5 ∘ C for at least five consecutive days. Results show that by extracting the transient anomalies, the anomaly based method can substantially improve descriptions of key synoptic features of heat waves in their central location, spatial coverage, intensity, and duration as well as their spatial structure of geopotential height and temperature anomalies. They also show the capability of the method in helping identify and trace the early disturbances that evolved into extreme heat wave events in Eastern China in 12 summers during 1981-2013. Over that period, the statistics of heat waves indicate an increase in the number of extreme heat wave events in China, especially in the 21st century. The method is further applied to the National Centres for Environmental Prediction (NCEP) and European Centre for Medium-Range Weather Forecasts (ECMWF) model predictions to illustrate its usefulness in interpreting model predictions for heat waves.

show abstract

Section: Introductionmentioning

confidence: 99%

Anomaly based analysis of extreme heat waves in Eastern China during 1981-2013

Chen

Yinming

et al. 2016

Int. J. Climatol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…During positive surface air temperature events, in the warm and thin air column, the geopotential levels are shifted upwards, while in the cold air, adiabatic processes cause subsidence of air masses and lowering the geopotential levels. Atmospheric processes in the middle troposphere influence surface weather conditions; anomalies of geopotential heights are regarded as predictors of air temperature extremes occurrence (Qian et al 2015(Qian et al , 2016Chen et al 2017).…”

Section: Resultsmentioning

confidence: 99%

If not NAO then what?—regional circulation patterns governing summer air temperatures in Poland

Bednorz

Czernecki

Tomczyk

et al. 2018

Theor Appl Climatol

View full text Add to dashboard Cite

The correlation between the daily/monthly North Atlantic Oscillation (NAO) index and the daily/monthly anomalies of the summer (JJA) surface air temperatures in Poland is close to 0.00, being positive in most of the country (but hardly exceeding 0.15) and negative in the southeast. Therefore, the regional scale circulation patterns other than NAO were determined using principal component analysis (PCA) to establish the relationship between the air circulation and the daily anomalies of the mean, maximum and minimum air temperatures in Poland. Regression and correlation analysis were applied to define the strengths and spatial distributions of these relationships. The best results were obtained for the mean and maximum daily temperature anomalies, for which the Pearson correlation coefficient (r) between the modelled and observed values exceeded 0.75 in the vast areas of central and southeastern Poland, while, over the rest of the country, it amounted to 0.7. The weaker influence of the circulation on air temperatures is observed in the northwestern part of the country, along the Baltic Sea shore (r < 0.65). The weakest results were obtained for the anomalies of the daily minimum temperatures (r equals 0.5-0.6 over most of the country and drops below 0.4 in the northwest). Furthermore, the influences of each PCA-based regional circulation pattern on the variabilities of the surface temperatures were analysed. The circulation pattern recognized as the second principal component, distinguished in the positive phase by the high-pressure conditions with the anticyclonic centre located right over central and southeastern Poland, revealed the strongest positive relationship with the air temperature.

show abstract

“…Figure c shows the vertical height and temperature trends averaged along the central North Pacific using the ERA Interim data set. The trend displays a pattern similar to hydrostatic balance between daily height and temperature anomalies vertically in the analysis of synoptic extreme events [ Qian et al ., , ]. In the vertical subtropical North Pacific, a positive height trend center “H1” at 300 hPa separates a negative temperature trend center “C1” at 200 hPa and a positive temperature trend center “W1” at 500 hPa.…”

Section: Meridional Cell Intensity and Arctic Sea Ice Declinementioning

confidence: 99%

“…The strengthening subsidence flow associated with the Polar and Arctic cells can partly explain the warming surface air temperature and declining sea ice concentration through the increasing tropospheric height and temperature trends. These results provide new insights for understanding the interdecadal relationship between atmospheric circulation and climate change in the Arctic region.Recently, using four reanalysis products and a climate model simulation, Qian et al [2015bQian et al [ , 2015c confirmed, through the analyses of the zonal mean streamline and mass stream function, that the Arctic cell, a meridional circulation cell, exists to the north of 80°N. Dynamical analyses of stationary eddy heat and momentum fluxes, as well as the global precipitation rate data, further confirmed its existence.…”

mentioning

confidence: 92%

“…Recently, using four reanalysis products and a climate model simulation, Qian et al [2015bQian et al [ , 2015c confirmed, through the analyses of the zonal mean streamline and mass stream function, that the Arctic cell, a meridional circulation cell, exists to the north of 80°N. Dynamical analyses of stationary eddy heat and momentum fluxes, as well as the global precipitation rate data, further confirmed its existence.…”

mentioning

confidence: 92%

See 1 more Smart Citation

Long‐term trends of the Polar and Arctic cells influencing the Arctic climate since 1989

Qian

Leung

et al. 2016

JGR Atmospheres

Self Cite

View full text Add to dashboard Cite

The strengthening and broadening trends of the Hadley cell have been revealed, while the existence of the Arctic cell has also been confirmed in previous studies. This study extends previous strengthening trend analyses of the Hadley cell to the Polar and Arctic cells in the Northern Hemisphere and explores their climate influences. Results show that the Polar cell experienced an abrupt change from a slow to a rapid strengthening trend in 1989, while the Arctic cell showed an insignificant strengthening trend and a significant weakening trend successively. The strengthening subsidence flow associated with the Polar and Arctic cells can partly explain the warming surface air temperature and declining sea ice concentration through the increasing tropospheric height and temperature trends. These results provide new insights for understanding the interdecadal relationship between atmospheric circulation and climate change in the Arctic region.

show abstract

A unified approach to trace surface heat and cold events by using height anomaly

Cited by 36 publications

References 18 publications

Anomaly based analysis of extreme heat waves in Eastern China during 1981-2013

Anomaly based analysis of extreme heat waves in Eastern China during 1981-2013

If not NAO then what?—regional circulation patterns governing summer air temperatures in Poland

Long‐term trends of the Polar and Arctic cells influencing the Arctic climate since 1989

Contact Info

Product

Resources

About