A scenario-based approach was used to test air and ground response to warming with and without changes to inverted surface lapse rates in four Yukon valleys. Generally, climate warming coupled with weakening of temperature inversions resulted in the greatest increase in air temperature at low elevations. However, ground temperatures at high elevations showed the greatest response to warming and variability between scenarios due to increased connectivity between air and ground. Low elevations showed less of a response to warming and permafrost was largely preserved in these locations. Local models also predicted higher permafrost occurrence compared to a regional permafrost probability model, due to the inclusion of differential surface and thermal offsets. Results show that the spatial warming patterns in these mountains may not follow those predicted in other mountain environments following elevation-dependent warming (EDW). As a result, the concept of EDW should be expanded to become more inclusive of a wider range of possible spatial warming distributions. The purpose of this paper is not to provide exact estimations of warming, but rather to provide hypothetical spatial warming patterns, based on logical predictions of changes to temperature inversion strength, which may not directly follow the distribution projected through EDW.
2024-11-14 Web of ScienceUnderstanding temperature variability especially elevation dependent warming (EDW) in high-elevation mountain regions is critical for assessing the impacts of climate change on water resources including glacier melt, degradation of soils, and active layer thickness. EDW means that temperature is warming faster with the increase of altitude. In this study, we used observed temperature data during 1979-2017 from 23 meteorological stations in the Qilian Mountains (QLM) to analyze temperature trend with Mann-Kendall (MK) test and Sen's slope approach. Results showed that the warming trends for the annual temperature followed the order of T_min > T_mean > T_max and with a shift both occurred in 1997. Spring and summer temperature have a higher increasing trend than that in autumn and winter. T_mean shifts occurred in 1996 for spring and summer, in 1997 for autumn and winter. T_max shifts occurred in 1997 for spring and 1996 for summer. T_min shifts occurred in 1997 for spring, summer and winter as well as in 1999 for autumn. Annual mean diurnal temperature range (DTR) shows a significant decreasing trend (-0.18 degrees C/10a) from 1979 to 2017. Summer mean DTR shows a significant decreasing trend (-0.26 degrees C/10a) from 1979 to 2017 with a shift occurred in 2010. After removing longitude and latitude factors, we can learn that the warming enhancement rate of average annual temperature is 0.0673 degrees C/km/10a, indicating that the temperature warming trend is accelerating with the continuous increase of altitude. The increase rate of elevation temperature is 0.0371 degrees C/km/10a in spring, 0.0457 degrees C/km/10a in summer, 0.0707 degrees C/km/10a in autumn, and 0.0606 degrees C/km/10a in winter, which indicates that there is a clear EDW in the QLM. The main causes of warming in the Qilian Mountains are human activities, cloudiness, ice-snow feedback and El Nino phenomenon.
2024-02-01 Web of ScienceMany studies have focused on elevation-dependent warming (EDW) across high mountains, but few studies have examined both EDW and LDW (latitude-dependent warming) on Antarctic warming. This study analyzed the Antarctic amplification (AnA) with respect to EDW and LDW under SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5 from Coupled Model Intercomparison Project Phase 6 (CMIP6) during the period 2015-2100. The results show that the AnA appears under all socioeconomic scenarios, and the greatest signal appears in austral autumn. In the future, Antarctic warming is not only elevation-dependent, but also latitude-dependent. Generally, positive EDW of mean temperature (T-mean), maximum temperature (T-max) and minimum temperature (T-min) appear in the range of 1.0-4.5 km, and the corresponding altitudinal amplification trends are 0.012/0.012/0.011 (SSP1-2.6)- 0.064/0.065/0.053 (SSP5-8.5) degrees C decade(-1)center dot km(-1). Antarctic EDW demonstrates seasonal differences, and is strong in summer and autumn and weak in winter under SSP3-7.0 and SSP5-8.5. For T(mea)n, T-max and T-min, the feature of LDW is varies in different latitude ranges, and also shows seasonal differences. The strongest LDW signal appears in autumn, and the warming rate increases with increasing latitude at 64-79 degrees S under SSP1-2.6. The similar phenomenon can be observed at 68-87 degrees S in the other cases. Moreover, the latitude component contributes more to the warming of T-mean and T-max relative to the corresponding altitude component, which may relates to the much larger range of latitude (similar to 2600 km) than altitude (similar to 4.5 km) over Antarctica, while the EDW contributes more warming than LDW in the changes in T-min in austral summer. Moreover, surface downwelling longwave radiation, water vapor and latent heat flux are the potential factors influencing Antarctic EDW, and the variation in surface downwelling longwave radiation can also be considered as an important influencing factor for Antarctic LDW. Our results provide preliminary insights into EDW and LDW in Antarctica.
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