## 5 Summary and Conclusions  
The Microwave Sounding Unit/Advanced Microwave Sounding Unit (MSU/AMSU) tropospheric temperature data was used to derive the annual and monthly mid-tropospheric temperature (TMT) and lower tropospheric temperature (TLT) trends over the Hindu Kush-Himalayan (HKH) region, adjacent dust sink areas of Indo-Gangetic (IG) plains, and western arid dust source regions for a period of 45 years (1978-2022). The major highlights of the study are:  
1. The MSU/AMSU-derived temperature trend shows a conspicuous rise in the warming trend over high-altitude regions (Tibet, western Himalayas, and eastern Himalayas) compared to adjacent plains (IG west, IG east). 2. A comparison of the TMT trends for a period from 1979-2008 (previous reports) and 1978-2022 (present study, 45 years) shows a tremendous rise in the warming of the mid-troposphere over the last 14 years, as mentioned below:  
* Tibet: \(\sim\)3.1 times; the eastern Himalayas: \(\sim\)1.7 times; and the western Himalayas: \(\sim\)0.8 times. In contrast, the rise in TMT trend is nearly zero and \(\sim\)0.4 times for the IG west and IG east, respectively. Similarly, for the dust source regions, it is \(\sim\)1.3 times. 3. The monthly breakup of TMT and TLT anomalies also reveals the influence of the east-to-west progression of the southwest monsoon over the IG plains. 4. The current study highlights the acceleration in warming trends in the mid-troposphere over the high-altitude HKH region compared to adjacent IG plains. 5. The current study highlights that the peak in the monthly decadal TMT trend is 0.33 to 0.34 \({}^{\circ}\)K/ decade and 0.41 to 0.45 \({}^{\circ}\)K/ decade for Tibet and the eastern Himalayas, respectively. In contrast, the same for the western Himalayas is only 0.19, 0.15, and 0.06 \({}^{\circ}\)K/decade for May, March, and December, respectively. * According to multiple reports, the rate at which snow or glaciers are melting varies significantly between the western Himalayas and Tibet, as well as the eastern Himalayas. The findings indicate that this divergence can mainly be attributed to the distinct variations in regional tropospheric warming patterns. * The western Himalayan glaciers are therefore expected to decline at a slower rate compared to the eastern Himalayas. 6. A significant increase in tropospheric warming trends (1978-2022) was observed in all the study areas, including the Himalayan region, dust sink areas of the IG plains, and the western arid dust source regions, indicating an overall regional increase in mid-troposphere temperature trends over the past 45 years. 7. The mid-tropospheric temperature warming trend is higher than the lower-tropospheric warming trend over the snow-glacier-covered regions, including the Tibetan region and Himalayas, and the dust sink regions of the IG plains. 8. The higher-altitude snow-glacier-covered regions show higher annual TMT warming trends than the low-lying IG plains. 9. A strong seasonal increase in the TMT warming trend over the western Himalayas and western IG plains is observed during pre-monsoon months (MAM) compared to other months and can be attributed to the influence of increased dust storm activity. 10. In general, the TMT warming anomaly and trend are found to be relatively higher in November-April (ND)FMA months) as compared to May-October (MJ)JASO months) in the Indian sub-continent, leading to increased melting of glaciers and snow cover during the primary phase of the snow accumulation season in November-February (NDJF months). Conceptualization, N.D. and A.K.P. ; methodology, N.D. and A.K.P. ; software, N.D.; validation, N.D.; formal analysis, N.D., A.V., S.M., A.S., S.N. ; investigation, N.D., A.V., S.M., A.S., S.N. ; resources, N.D.; data curation, N.D.; writing--original draft preparation, N.D., A.V., S.M., A.S., S.N. ; writing--review and editing, N.D., A.K.P. ; visualization, N.D., S.M., A.V. ; supervision, A.K.P. ; project administration, A.K.P. ; funding acquisition, A.K.P.