Prediction of winter minimum temperature of Kolkata using statistical model

Lkkj & dksydkrk ¼vfyiqj½ ds U;wure rkieku dk okLrfod iwokZuqeku 12 ?kaVs iwoZ tkjh djus ds mn~ns’; ls ik¡p izkpyksa ij vk/kkfjr cgq jSf[kd lekJ;.k ekWMy fodflr fd;k x;k gS A blds iwoZ lwpdksa dk p;u vfyiqj os/k’kkyk ls izkIr lrg vk¡dM+ksa rFkk ekSle dk;kZy; dksydkrk ds fuEu Lrj ds iou vk¡dM+ksa ds vk/kkj ij fd;k x;k gS A ;g ekWMy 237 fnuksa ds ¼o"kZ 1997&2000 dh vof/k ds tuojh ,oa Qjojh ekg ds½ vk¡dM+ksa ds uewuksa rFkk dkQh yach vof/k ¼o"kZ 1988&2004½ ds U;wure rkieku ds vk¡dM+ksa es fLFkjrk dh tk¡p ds vk/kkj ij fodflr fd;k x;k gS A bl ekWMy dh tk¡p 178 fnuksa ds vk¡dM+ksa ds Lora= uewus ds vk/kkj ij dh xbZ gS A bl ekWMy dh {kerk dh tk¡p lkaf[;dh; vk¡dM+ksa ds vk/kkj ij dh xbZ gS vkSj bls ldkjkRed ik;k x;k gSA bl ekWMy dk mi;ksx ekSle iwokZuqekudRrkZ }kjk U;wure rkieku ds iwokZuqeku dk vkdyu djus ds fy, fd;k tk ldrk gS vkSj ;fn ckny rFkk iou dh xfr ds :[k esa ckn esa ifjorZu laHkkfor gks rks mlesa lq/kkj fd;k tk ldrk gS A Five parameter multiple linear regression model for objective forecasting of minimum temperature of Kolkata (Alipore) with 12 hours lead period has been developed. The predictors are chosen from the available surface data of Alipore observatory and low level wind data of M. O. Kolkata. Model has been developed from data sample comprising of 237 days (in January and February, period: 1997 – 2000) after stationarity test of minimum temperature data of much longer period (1988–2004). The model is tested with independent sample of 178 days. Efficiencies of the model have been tested with statistical skill score and found to be positive. The model can be used by the forecaster for assessing prediction minimum temperature and modify if cloud cover and wind flow pattern are expected to change subsequently.

Estimating Return Intervals for Extreme Climate Conditions Related to Winter Disasters and Livestock Mortality in Mongolia

Mass livestock mortality events during severe winters, a phenomenon that Mongolians call dzud, cause the country significant socioeconomic problems. Dzud is an example of a compound event, meaning that multiple climatic and social drivers contribute to the risk of occurrence. Existing studies argue that the frequency and intensity of dzud are rising due to the combined effects of climate change and variability, most notably summer drought and severe winter conditions, on top of socioeconomic dynamics such as overgrazing. Summer droughts are a precondition for dzud because scarce grasses cause malnutrition, which in turn makes livestock more vulnerable to harsh winter conditions. However, these studies typically look at a short time frame (i.e., after 1940); few have investigated either the risk or the recurrence of dzud over a century-scale climate record. This study aims to fill the gaps in technical knowledge about the recurrence probability of dzud by estimating the return levels of relevant climatic variables: summer drought conditions and winter minimum temperature. We divide the country into three regions (Northwest, Southwest, and East Mongolia) based on the mortality index at the soum (county) level. For droughts, our study uses as a proxy the tree-ring reconstructed Palmer Drought Severity Index (PDSI) for three regions between 1700–2013. For winter severity, our study uses observational data of winter minimum temperature after 1901 while inferring winter minimum temperature in Mongolia from instrumental data in Siberia that extends to the early 19th century. The Generalized Extreme Value (i.e., the statistical method to infer the probability of very rare or extreme events) shows that the return levels of drought conditions are changing over time, with variability increasing for all the regions. Winter severity, however, is constant. The median 100-year return levels of the winter minimum temperature in Mongolia have been, over the past 300 years, −26.08 °C for the Southwest, −27.99 °C for the Northwest, and −25.31 °C for the East. This study thus suggests that continued summer drought would lead to increased vulnerability and malnutrition. Here, we link meteorological characteristics to socioeconomic impacts related to livestock populations and draws attention to the need for livestock index insurance.

Climatic Variation of Supercooling Point in the Linden Bug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

Cold tolerance is often one of the key components of insect fitness, but the association between climatic conditions and supercooling capacity is poorly understood. We tested 16 lines originating from geographically different populations of the linden bug Pyrrhocoris apterus for their cold tolerance, determined as the supercooling point (SCP). The supercooling point was generally well explained by the climatic conditions of the population’s origin, as the best predictor—winter minimum temperature—explained 85% of the average SCP variation between populations. The supercooling capacity of P. apterus is strongly correlated with climatic conditions, which support the usage of SCP as an appropriate metric of cold tolerance in this species.

The influence of debris cover and glacial lakes on the recession of glaciers in Sikkim Himalaya, India

We investigated area changes in glaciers covering an area of ∼200 km2 in the Tista basin, Sikkim, Eastern Indian Himalaya, between ∼1990 and 2010 using Landsat Thematic Mapper (TM) and Indian Remote-sensing Satellite (IRS) images and related the changes to debris cover, supraglacial lakes and moraine-dam lakes. The glaciers lost an area of 3.3 ± 0.8% between 1989/90 and 2010. More detailed analysis revealed an area loss of 2.00 ± 0.82, 2.56 ± 0.61 and 2.28 ± 2.01 km2 for the periods 1989–97, 1997–2004/05 and 2004–2009/10, respectively. This indicates an accelerated retreat of glaciers after 1997. On further analysis, we observed (1) the formation and expansion of supraglacial lakes on many debris-covered glaciers and (2) the merging of these lakes over time, leading to the development of large moraine-dam lakes. We also observed that debris-covered glaciers with lakes lose a greater area than debris-covered glaciers without lakes and debris-free glaciers. The climatic data for 24 years (1987–2011), measured at the Gangtok meteorological station (1812 m a.s.l.), showed that the region experienced a 1.0°C rise in the summer minimum temperature and a 2.0°C rise in the winter minimum temperature, indicating hotter summers and warmer winters. There was no significant trend in the total annual precipitation. We find that glacier retreat is caused mainly by a temperature increase and that debris-covered glaciers can retreat at a faster rate than debris-free glaciers, if associated with lakes.

Performance of brassica cultivars from New Zealand and United States seed sources in Southeast Ohio, USA

Four turnip cultivars, two Swede, and one each of kale, rutabaga and Chinese-cabbage turnip hybrid were evaluated for their usefulness in extending the grazing season. The three replicates were planted on 28 July 1994 and harvested on 31 October and 3 November 1994. Dry matter yields ranged from 5460 kg/ha for Premier kale to 8877 kg/ha for Rondo turnip. Rondo turnip total yield of DM was significantly higher (P=O.O5) than all other cultivars except Doon Major Swede. Crude protein levels ranged from 8.5% to 24.3% for the tops and 5.9% to 13.4% for the bulbs, with NDF fibre levels of 17.6% to 21.4% for tops and 15.6% to 20.4% for the bulbs. All cultivars survived temperatures of -1O'C with Premier kale being the most winter hardy, surviving the winter minimum temperature of -21°C. Forage brassicas can provide high levels of quality forage for the late autumn and early winter period, significantly extending the grazing season in Ohio and the midwest US. Keywords: brassica, Chinese cabbage-turnip hybrid, grazing season, kale, rutabaga, Swede, turnip