Documentation of a highly ENSO‐related sst region in the equatorial pacific: Research note

Abstract

A new ENSO SST index is documented that is strongly correlated to the core ENSO phenomenon. The SST anomaly in much of the east‐central and eastern tropical Pacific is closely related to ENSO. However, the anomaly from approximately the centre of the eastern half of the equatorial Pacific westward to near the date line is suggested to be most strongly ENSO‐related when data spanning the most recent several decades are used. This is the case both with respect to (1) strength of association with other oceanic/atmospheric ENSO‐related anomalies (both simultaneously and as a time‐delayed predictand), and (2) impact on remote worldwide climate anomalies. This observational insight was lacking in the early 1980s when the four “Niño” regions were developed. While a firmer dynamical foundation for this regional preference still needs to be established, the region straddling Niño 3 and Niño 4 may be regarded as an appropriate general SST index of the ENSO state by researchers, diagnosticians and forecasters. A dataset of this index, called “Niño 3.4” (5°N‐5°S, 120–170°W), is maintained on the Internet, shown in the Climate Diagnostics Bulletin, and provided in the Appendix of this note.     

Coagulant proteins identified in Mustard: a potential water treatment agent

The use of natural coagulant protein in drinking water treatment has been discussed for a long time, though the method is still not in practice, probably due to limited knowledge and availability of material. In the present work, different Mustard varieties were tested for the presence of coagulant protein compared with Moringa seed extract and their potential application in water treatment. The coagulation activity of the protein extract was measured using synthetic clay solution as well as water from pond. The protein content was determined by Bradford method, molecular mass determined by Sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and peptide sequence was analyzed by Mass spectrometry. Extract of Mustard (large) and Moringa seed showed coagulation activity of ?70 and ?85 % after 90 min, respectively. Interestingly, seed extracts from other Mustard varieties had coagulation activity after heat activation at 95 °C for 5 h. However, the coagulation activity of Mustard seed extract against turbid pond water was higher (?60 %) compared to Moringa seed extract (?50 %). The peptide sequence analysis of 6.5 and 9 kDa proteins was found to be homologous to Moringa coagulant protein and napin3, respectively. To our knowledge, this could be the first report on Mustard seed having coagulant protein. The coagulation activity of Mustard (large) against highly turbid pond water suggested that it could be a potential natural coagulant for water treatment.     

Short-period oscillations in outgoing longwave radiation over the summer monsoon region

Empirical orthogonal function (EOF) analysis is applied to daily outgoing longwave radiation (OLR) data to identify the major modes of oscillation over the summer monsoon region (7·5° N-32·5° N, 62·5° E-142·5° E) for two summers 1975 and 1977, each consisting of 120 days from 18 May through 14 September. Power spectrum analysis of time-dependent coefficients of the dominant eigenvectors exhibit spectral peaks in the long (<15 days) and short (4–8 days) period ranges. A detailed study is confined to 4–8 day filtered OLR perturbations. Standard deviation patterns of filtered OLR show large intraseasonal variability in the activity of monsoon disturbances over the Bay of Bengal. Lag-correlations reveal systematic westward movement of 4–8 day OLR perturbations from the Western Pacific to the Bay of Bengal in both summers. EOF analysis is also applied to 4–8 day filtered OLR data to further investigate possible teleconnections in disturbance activity between the Western Pacific and the Bay of Bengal. A compositing technique is utilized to detail the structural features (zonal wavelength and phase speed) of 4–8 day OLR disturbances. Composite diagrams for summer 1975 showed that OLR disturbances which originated near northeastern Burma moved west ward with phase speed (wavelength) of about 3–4° per day (≈20–25° longitude) reaching maximum intensity in the Bay of Bengal. In summer 1977, the disturbance activity in the Bay of Bengal was associated with OLR perturbations which originated in the Western Pacific and moved westward across the South China Sea and Indochina with phase speed (wavelength) of above 8° per day (40° longitude).