El Nino and the Indian rainfall in June

We have addressed the question of whether the massive deficit of 42% in rainfall over the Indian region in June 2014 can be attributed primarily to the El Nino. We have shown that the variation of convection over the Northern part of the Tropical West Pacific (NWTP: 120–150E, 20–30N) plays a major role in determining the all-India rainfall in June with deficit (excess) in rainfall associated with enhancement (suppression) of convection over NWTP. In June 2014, the outgoing long wave radiation (OLR) anomaly over this region was unfavourable, whereas in June 2015, the OLR anomaly over NWTP was favourable and the all-India rainfall was 16% higher than the long-term average. We find that during El Niño, when the convection over the equatorial central Pacific intensifies, there is a high propensity for intensification of convection over NWTP. Thus, El Niño appears to have an impact on the rainfall over the Indian region via its impact on the convection over the West Pacific, particularly over NWTP. This occurred in June 2014, which suggests that the large deficit in June 2014, could be primarily attributed to the El Nino acting via intensification of convection over NWT

The aberrant behaviour of the Indian monsoon in June 2009

After an early onset over Kerala on 23 May 2009, further advance of the monsoon over the Indian region was delayed by about two weeks with the monsoon restricted to the west coast and southern peninsula until 24 Jun

A note on new indices for the equatorial Indian Ocean oscillation

It is now well known that there is a strong association of the extremes of the Indian summer monsoon rainfall (ISMR) with the El Niño and southern oscillation (ENSO) and the Equatorial Indian Ocean Oscillation (EQUINOO), later being an east-west oscillation in convection anomaly over the equatorial Indian Ocean. So far, the index used for EQUINOO is EQWIN, which is based on the surface zonal wind over the central equatorial Indian Ocean. Since the most important attribute of EQUINOO is the oscillation in convection/precipitation, we believe that the indices based on convection or precipitation would be more appropriate. Continuous and reliable data on outgoing longwave radiation (OLR), and satellite derived precipitation are now available from 1979 onwards. Hence, in this paper, we introduce new indices for EQUINOO, based on the difference in the anomaly of OLR/precipitation between eastern and western parts of the equatorial Indian Ocean. We show that the strong association of extremes of the Indian summer monsoon with ENSO and EQUINOO is also seen when the new indices are used to represent EQUINOO

Monsoon variability: Links to major oscillations over the equatorial Pacific and Indian oceans

In this article, we first discuss our perception of the factors which are critical for inter-annual variation of the Indian summer monsoon rainfall and the major milestones leading to this understanding. The nature of the two critical modes for monsoon variability, viz. El Nino Southern Oscillation and equatorial Indian Ocean Oscillation is considered and their links to the monsoon elucidated. We suggest possible reasons for the rather poor skill of simulation of the interannual variation of the Indian summer monsoon rainfall by atmospheric general circulation models, run with the observed sea surface temperature as boundary condition. We discuss implications of what we have learned for the monsoon of 2006, and possible use of information on the two important modes for prediction of the rainfall in all or part of the summer monsoon season. We conclude with our view of what the focus of research and development should be for achieving a substantial improvement in the skill of simulation and prediction of the Indian summer monsoon rainfall in the near future

On the decreasing trend of the number of monsoon depressions in the Bay of Bengal

This study unravels the physical link between the weakening of the monsoon circulation and the decreasing trend in the frequency of monsoon depressions over the Bay of Bengal. Based on the analysis of the terms of Genesis Potential Index, an empirical index to quantify the relative contribution of large scale environmental variables responsible for the modulation of storms, it is shown here that the reduction in the mid-tropospheric relative humidity is the most important reason for the decrease in the number of monsoon depressions. The net reduction of relative humidity over the Bay of Bengal is primarily due to the decrease in the moisture flux convergence, which is attributed to the weakening of the low level jet, a characteristic feature of monsoon circulation. Further, the anomalous moisture convergence over the western equatorial Indian Ocean associated with the rapid warming of the sea surface, reduces the moisture advection into the Bay of Bengal and hence adversely affect the genesis/intensification of monsoon depressions. Hence, the reduction in the number of monsoon depression over the Bay of Bengal could be one of the manifestations of the differential rates in the observed warming trend of the Indian Ocean basi

Syphilis screening in pregnancy in the United Kingdom, 2010-2011: a national surveillance study

OBJECTIVE: To evaluate the national antenatal syphilis screening programme and provide evidence for improving screening and management strategies. DESIGN: National population-based surveillance. SETTING: United Kingdom (UK). POPULATION: All pregnant women screening positive for syphilis, 2010-2011. METHODS: Demographic, laboratory and treatment details for each pregnancy were collected from UK antenatal units (~210), along with follow-up information on all infants born to women requiring syphilis treatment in pregnancy. MAIN OUTCOME MEASURES: Proportion of women with newly or previously diagnosed syphilis among those with positive screening tests in pregnancy; proportion requiring treatment. RESULTS: Overall, 77% (1425/1840) of reported pregnancies were confirmed syphilis screen-positive. Of these, 71% (1010/1425) were in women with previously diagnosed syphilis (155 requiring treatment), 26% (374/1425) with newly diagnosed syphilis (all requiring treatment) and 3% (41/1425) required treatment but the reason for treatment was unclear. Thus 40% (570/1425) required treatment overall; of these, 96% (516/537) were treated (missing data: 33/570), although for 18% (83/456), this was not until the third trimester (missing data: 60/537). Follow up of infants born to treated women was poor, with at least a third not followed. Six infants were diagnosed with congenital syphilis; two mothers were untreated, three had delayed treatment and one had incomplete treatment (first trimester). CONCLUSION: Over 2 years, among pregnant women with confirmed positive syphilis screening results in the UK, a quarter had newly diagnosed infections and 40% required treatment. Despite high uptake of treatment, antenatal syphilis management could be improved by earlier detection, earlier treatment, and stronger links between healthcare teams. TWEETABLE ABSTRACT: 25% of pregnant women screening positive for syphilis in the UK were newly diagnosed and 40% needed treatment

Prediction of Indian rainfall during the summer monsoon season on the basis of links with equatorial Pacific and Indian Ocean climate indices

Interannual variation of Indian summer monsoon rainfall (ISMR) is linked to El Niño-Southern oscillation (ENSO) as well as the Equatorial Indian Ocean oscillation (EQUINOO) with the link with the seasonal value of the ENSO index being stronger than that with the EQUINOO index. We show that the variation of a composite index determined through bivariate analysis, explains 54% of ISMR variance, suggesting a strong dependence of the skill of monsoon prediction on the skill of prediction of ENSO and EQUINOO. We explored the possibility of prediction of the Indian rainfall during the summer monsoon season on the basis of prior values of the indices. We find that such predictions are possible for July–September rainfall on the basis of June indices and for August–September rainfall based on the July indices. This will be a useful input for second and later stage forecasts made after the commencement of the monsoon seaso

Predicting the extremes of Indian summer monsoon rainfall with coupled ocean-atmosphere models

An analysis of the retrospective predictions by seven coupled ocean-atmosphere models from major forecasting centres of Europe and USA, aimed at assessing their ability in predicting the interannual variation of the Indian summer monsoon rainfall (ISMR), particularly the extremes (i.e. droughts and excess rainfall seasons) is presented in this article. On the whole, the skill in prediction of extremes is not bad since most of the models are able to predict the sign of the ISMR anomaly for a majority of the extremes. There is a remarkable coherence between the models in successes and failures of the predictions, with all the models generating loud false alarms for the normal monsoon season of 1997 and the excess monsoon season of 1983. It is well known that the El Niño and Southern Oscillation (ENSO) and the Equatorial Indian Ocean Oscillation (EQUINOO) play an important role in the interannual variation of ISMR and particularly the extremes. The prediction of the phases of these modes and their link with the monsoon has also been assessed. It is found that models are able to simulate ENSO-monsoon link realistically, whereas the EQUINOO-ISMR link is simulated realistically by only one model-the ECMWF model. Furthermore, it is found that in most models this link is opposite to the observed, with the predicted ISMR being negatively (instead of positively) correlated with the rainfall over the western equatorial Indian Ocean and positively (instead of negatively) correlated with the rainfall over the eastern equatorial Indian Ocean. Analysis of the seasons for which the predictions of almost all the models have large errors has suggested the facets of ENSO and EQUINOO and the links with the monsoon that need to be improved for improving monsoon predictions by these models

Hindcasting and Validation of Mumbai Oil Spills using GNOME

Oil spill trajectory forecasting became mandatory for providing advisory services to the regulatory authorities during the event of oil spill, for planning their remediation and clean up measures. The present study describes a method to simulate the trajectory of the spilled oil using GNOME and validating it using available Radar data. The trajectory forecasting of two oil spill events, happened in mumbai high region, during 2010- 2011 has been executed in hindcast mode using General NOAA Operational Modeling Environment. The forcing parameters such as, forecasted European Center of Medium Range Weather Forecast winds and Regional Ocean Modeling system currents were used for the execution. The likely areas which are to be affected are found from the prediction. The trajectory obtained from GNOME is compared with oil spill signatures obtained from the radar data of a particular time step. The observed oil slicks were found within the average distance of 3.73 km and 4.16 km from the prediction for MSC chitra spill and Mumbai uran trunk pipeline spill respectively. This trajectory model can be used for making the contingency plans, conducting the mock drills and during oil spill response and preparedness operation