Abstract

Uttarakhand, a hill state of India, covers an area of 51,125 km². The geographic position is highly crucial with in the Central Himalayas (CH), for agro-climate, water resource management, food-processing, tourism, etc., having enriched bio-diversity and forest. Present study investigates the spatio-temporal characteristics and distribution of temperature of Uttarakhand state. Observation and model (under different Representative Concentration Pathways (RCPs) at radiative forcing 2.6, 4.5 and 8.5 W/m²) temperature fields are studied to assess the present and future trends. Standard temperature fields from AphroTemp, Climate Research Unit (CRU) and ECMWF Reanalysis-Interim (ERA-Interim) are used. Attempt is to find orographic responses on the surface temperature at seasonal scale. Elevation dependent warming (EDW) is higher at higher elevations as compared to lower elevations. In particular, it reaches to maximum during Indian summer monsoon months (JJAS) as estimated from AphroTemp during 1970–2007. Munsiyari region experiences highest warming rate by 0.038°C/decade. Elevational temperature trends show higher increase with statistical significance at 99% confidence level from <500 to 3000 m elevation belt during JJAS. For elevation >3000 m, highest warming trend is observed during MAM. Further, temperature trends analysed using one of the regional climate models REMO of the CORDEX-SA suite, depict an increase by 0.019°C/yr. Future temperature trends under RCP2.6, RCP4.5 and RCP8.5 show warming trends by 0.008°, 0.022°, and 0.064°C/yr, respectively.

Research Highlights

• Provide process information on temperature across and along the foothills of Himalayas during climate change

• Elevation dependent changes in the temperature

• Orographic interactions.

中文翻译：

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北阿坎德邦喜马拉雅山麓状态的温度：现在和将来

摘要

印度的山邦北阿坎德邦，面积51,125 km ²。地理位置对于喜马拉雅中部（CH）至关重要，对于农业气候，水资源管理，食品加工，旅游业等而言，具有丰富的生物多样性和森林。本研究调查了北阿坎德邦状态的时空特征和温度分布。观测和模型（在辐射强迫为2.6、4.5和8.5 W / m ^2的不同代表性浓度途径（RCP）下）研究温度场以评估当前和未来的趋势。使用AphroTemp，气候研究单位（CRU）和ECMWF临时再分析（ERA-Interim）的标准温度场。尝试在季节性尺度上找到表面温度的地形响应。与海拔较低的海拔相比，海拔较高的海拔依赖于暖化（EDW）更高。特别是，根据AphroTemp在1970-2007年间的估计，在印度夏季风季（JJAS）期间达到了最大值。Munsiyari地区的变暖率最高，达每十年0.038°C。在JJAS期间，海拔高度在<500 m至3000 m高度范围内，上升温度趋势显示出较高的上升，具有统计意义，置信度为99％。对于海拔> 3000 m，在MAM期间观察到最高的变暖趋势。进一步，使用CORDEX-SA套件的区域气候模型REMO之一分析的温度趋势，表明每年增加0.019°C。RCP2.6，RCP4.5和RCP8.5下的未来温度趋势分别显示出每年分别变暖0.008°，0.022°和0.064°C的趋势。

研究重点

• 提供有关气候变化期间喜马拉雅山山麓及沿山麓的温度的过程信息

• 取决于海拔的温度变化

• 地形互动。