An extended reconstruction of monthly mean oceanic historical sea level pressure (SLP) based on Comprehensive Ocean–Atmosphere Data Set (COADS) release-2 observations is produced for the 1854–1997 period. The COADS data are first screened using an adaptive quality-control procedure. Land SLP data from coastal and island stations are used to supplement the COADS data. The SLP anomalies are analy...

The leading empirical orthogonal function (EOF) of the sea level pressure (SLP) field, referred to as the Arctic Oscillation (AO) or Northern Hemisphere annular mode (NAM), consists of a dipole between the polar cap region and the surrounding zonal ring centered along 458N. Embedded within the outer ring are centers of action over the Euro-Atlantic and Pacific sectors in which SLP fluctuates in...

This study compares the distribution of surface climate trends over the Southern Ocean in austral summer between 1979–2011 and 1950–1978, using a wide variety of data sets including uninterpolated griddedmarine archives, land station data, reanalysis, and satellite products. Apart from the Antarctic Peninsula and adjacent regions, sea surface temperatures and surface air temperatures decreased ...

Past studies have described large-scale sea level pressure (SLP) variations in the Southern Hemisphere that lead to El Nino–Southern Oscillation (ENSO) warm and cold events (WE and CE). By relying on this description and the importance of the related variability in the lead up to WE and CE, Southern Hemisphere SLP variations in May-June-July (MJJ) are shown here to be excellent predictors for t...

Two distinct low-frequency fluctuations are suggested from a joint frequency domain analysis of the Pacific Ocean (30°S-60°N) sea surface temperature (SST) and sea level pressure (SLP). The lowest frequency signal reveals a spatially coherent interdecadal evolution. In-phase SST and SLP anomalies are found along the subarctic frontal zone (SAFZ). It is symmetric about the equator, with tropical...

the aim of this research is the assessment of the relation between rainfall and large scale synoptically patterns at khorasan razavi province. in this study, using adaptive neuro fuzzy inference system, the rainfall estimation has been done from april to june in the area under study. spring rainfall data including the information of 38 synoptic, climatologic and rain gauge stations from 1970 to...

13 The Arctic Oscillation (AO) under increased atmospheric concentration of greenhouse gases 14 (GHG) was studied by comparing an ensemble of simulations from 13 coupled general circulation 15 models with GHG at the pre-industrial level and at the late 20th century level, for November to 16 March. The change in the linear AO pattern as GHG increased reveals positive sea level pressure 17 (SLP) ...

Corresponding to the pronounced amplitude asymmetry for the central Pacific (CP) and eastern Pacific (EP) types of El Niño, an asymmetry in the strength of the Bjerknes positive feedback is found between these two types of El Niño, which is manifested as a weaker relationship between the zonal wind anomaly and the zonal gradient of sea surface temperature (SST) anomaly in the CP El Niño. The st...

emissions, the large scale pattern of changes in land–sea thermal contrast, atmospheric circulation and local precipitation over East Asia from days 40 onward exhibits similar structures, indicating a preferred response, and suggesting that emissions from both regions likely contributed to the observed weakening of the EASM. Cooling and drying of the troposphere over Asia, together with warming...

Near-global 48 3 48 gridded analysis of marine sea level pressure (SLP) from the Comprehensive Ocean– Atmosphere Data Set for monthly averages from 1854 to 1992 was produced along with its estimated error using a reduced space optimal interpolation method. A novel procedure of covariance adjustment brought the results of the analysis to the consistency with the a priori assumptions on the signa...