Trends in the Diurnal Temperature Range Over the Southern Slope of Central Himalaya: Retrospective and Prospective Evaluation

The Diurnal Temperature Range (DTR) profoundly affects human health, agriculture, eco-system, and socioeconomic systems. In this study, we analyzed past and future changes in DTR using gridded Climate Research Unit (CRU) datasets for the years 1950–2020 and an ensemble means of thirteen bias-corrected Coupled Model Intercomparison Project Phase 6 (CMIP6) models under different Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5) scenarios for the rest of the 21st century over the southern slope of Central Himalaya, Nepal. Furthermore, the potential drivers (precipitation and cloud cover) of seasonal and annual DTR were studied using correlation analysis. This study found that the DTR trends generally declined; the highest decrease was observed in the pre-monsoon and winter at a rate of 0.09 °C/decade (p ≤ 0.01). As expected, DTR demonstrated a significant negative correlation with cloudiness and precipitation in all four seasons. Further, the decreased DTR was weakly related to the Sea Surface Temperature variation (SST) in the tropical Pacific and Indian Oceans. We found that the projected DTR changes in the future varied from a marginal increase under the SSP1-2.6 (only pre-monsoon) scenario to continued significant decreases under SSP2-4.5 and SSP5-8.5. Insights based on retrospective and prospective evaluation help to understand the long-term evolution of diurnal temperature variations.

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Factors contributing to diurnal temperature range trends in twentieth and twenty-first century simulations of the CCCma coupled model

Climate Dynamics ◽

10.1007/s00382-002-0288-y ◽

2003 ◽

Vol 20 (5) ◽

pp. 435-445 ◽

Cited By ~ 99

Author(s):

D. Stone ◽

A. Weaver

Keyword(s):

Diurnal Temperature Range ◽

Coupled Model ◽

First Century ◽

Diurnal Temperature ◽

Temperature Range ◽

Twenty First Century

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The Diurnal Temperature Range in CMIP6 Models: Climatology, Variability, and Evolution

Journal of Climate ◽

10.1175/jcli-d-19-0897.1 ◽

2020 ◽

Vol 33 (19) ◽

pp. 8261-8279

Author(s):

Kang Wang ◽

Gary D. Clow

Keyword(s):

Northern Hemisphere ◽

Diurnal Temperature Range ◽

Climate Models ◽

Coupled Model ◽

Spatiotemporal Evolution ◽

Diurnal Temperature ◽

Temperature Range ◽

Intercomparison Project ◽

Land Surfaces ◽

Better Than

AbstractThe diurnal temperature range (DTR) is an identifiable and sensitive indicator of the synchronicity of changes in diurnal temperature extrema, but capturing DTR dynamics is challenging for climate models. This study investigates the climatology, variability, and changes of DTR in recent models participating in phase 6 of the Coupled Model Intercomparison Project (CMIP6). The results show that the CMIP6 models underestimate DTR climatology relative to observations. Most individual models overestimate December–February variability, particularly at high latitudes of the Northern Hemisphere. The models show substantially different changes over land surfaces and do not fully capture the observed spatiotemporal evolution of DTR. Large intermodel differences seem to be controlled by daily minimum air temperature. In the Northern Hemisphere, precipitation and cloud longwave and shortwave radiative effects appear to make important contributions to the intermodel discrepancies. Evaporative fraction is an important factor contributing to the intermodel differences in DTR during the summer in the Northern Hemisphere. In general, CMIP6 models have not improved their ability to simulate temporal DTR changes in a consistent way over the entire analysis period (1901–2005) relative to their CMIP5 counterparts. For periods of rapid DTR decline (e.g., 1951–80) CMIP6 models are typically better than the CMIP5 versions at simulating DTR, whereas for other periods CMIP6 models underperform their CMIP5 counterparts.

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Diurnal Temperature Range in Winter Wheat Growing Regions of China: CMIP6 Model Evaluation and Comparison

10.21203/rs.3.rs-1005239/v1 ◽

2021 ◽

Author(s):

Wenqiang Xie ◽

Shuangshuang Wang ◽

Xiaodong Yan

Keyword(s):

Winter Wheat ◽

Diurnal Temperature Range ◽

Climate Model ◽

Wheat Yield ◽

Coupled Model ◽

Growing Season ◽

Skill Score ◽

Diurnal Temperature ◽

Temperature Range ◽

Winter Wheat Yield

Abstract Diurnal temperature range (DTR) is an important meteorological component affecting the yield and protein content of winter wheat. The accuracy of climate model simulations of DTR will directly affect the prediction of winter wheat yield and quality. Previous model evaluations for worldwide or nationwide cannot answer which model is suitable for the estimation of winter wheat yield. We evaluated the ability of the coupled model intercomparison project phase 6 (CMIP6) models to simulate DTR in the winter wheat growing regions of China using CN05 observations. The root mean square error (RMSE) and the interannual varibility skill score (IVS) were used to quantitatively evaluate the ability of models in simulating DTR spatial and temporal characteristics, and the comprehensive rating index (CRI) was used to determine the most suitable climate model for winter wheat. The results showed that the CMIP6 model can reproduce DTR in winter wheat growing regions. BCC-CSM2-MR simulations of DTR in the winter wheat growing season were more consistent with observations. EC-Earth3-Veg simulated the climatological DTR best in the wheat growing regions (RMSE=0.848). Meanwhile, the evaluation for climatological DTR in China is not applicable to the evaluation of DTR in winter wheat growing regions, and the evaluation for annual DTR is not a substitute for the evaluation for winter wheat growing season DTR. Our study highlights the importance of evaluating winter wheat growing regions' DTR, which can further improve the ability of CMIP6 models simulating DTR to serve the research of climate change impact on winter wheat yield.

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