Spatiotemporal links between meteorological and agricultural droughts impacted by tropical cyclones in China

Both droughts and tropical cyclones (TCs) are among the world's most widespread natural disasters. This paper is concentrated on the effects of TCs on the links between meteorological droughts (MDs) and agricultural droughts (ADs). Specifically, changes in characteristics of drought events and variations in propagation features of matched MD and AD event pairs are quantified by using the renowned three-dimensional connected components algorithm; both alleviation and exacerbation effects of TCs are evaluated; and the Spearman's correlation is employed to identify potential contributors to exacerbated droughts after TCs. The results show that TCs exhibit more pronounced and widespread alleviation effects on MD events compared to AD events. >98 % of small-scale drought events are terminated by TCs, leading to 65 % reduction in the total area of MD events smaller than 50,000 km2 and 32 % reduction in AD events of the same scale. In the meantime, TCs can reshape the spatiotemporal links between MDs and ADs by reducing the overall propagation rate from 77 % to 40 % and ameliorating the characteristics of drought event pairs with higher propagation efficiency, by >40 %. After TCs, over 55 % of drought exacerbations in TC-affected regions occur first in the vicinity of the residual large-scale AD events. This occurrence is partially associated with the reduction in moisture exports from these residual droughts downwind to the interior of TC-affected regions, a process potentially facilitated by the TC-induced temperature cooling. The in-depth evaluation of this paper presents useful information for better drought preparation and mitigation under TCs.

Synoptic-scale precursors of landslides in the western Himalaya and Karakoram

In the Upper Indus Basin (UIB), precipitation associated with synoptic-scale circulations impinges on the complex and steep orography of the western Himalaya and Karakoram. Heavy rainfall often falls over the foothills, frequently triggering landslides there. This study explores the role of these synoptic-scale circulations - extratropical western disturbances (WDs) and tropical depressions (TDs) - in producing the conducive conditions necessary to trigger landslides, using data from the NASA Global Landslide Catalog and WD and TD track databases. During the winter (October to April), UIB landslides peak in February and occur at a rate of 0.05 day^-1, 61% of which are associated with the passage of a WD. They are most common when a WD is located within a few hundred kilometres of 30°N, and significantly rarer if the WD is north of 40°N. WDs provide moist southwesterly flow from the Arabian Sea and Mediterranean Sea to the UIB, resulting in large-scale precipitation, but landslide probability is not related to WD intensity. Non-WD winter landslides are associated with small-scale orographic precipitation that we hypothesise is due to cloudbursts. During the summer (May to September), UIB landslides peak in August and occur at a rate of 0.11 day^-1, 60% of which are associated with TD activity. Many of these TDs are found over central India, slightly south of the climatological monsoon trough, where they provide strong monsoonal southeasterlies to the UIB flowing along the Himalayas. Increased landslide frequency is also associated with TD activity over the southern Bay of Bengal (BoB), and it is hypothesised that this is related to monsoon break conditions. Landslide frequency is significantly correlated with TD intensity. Non-TD landslides are associated with a northwestward extension of the monsoon trough, providing southeasterly barrier flow to the UIB. Implications for forecasting and climate change are discussed.

Analysis of nasal air conditioning in subjects with unilateral cleft lip nasal deformity

This study evaluated the impact of unilateral cleft lip nasal deformity (uCLND) on the ability of the nasal passages to warm and humidify inspired environmental air using computational fluid dynamics (CFD) modeling. Nasal air conditioning was simulated at resting inspiration in ten individuals with uCLND and seven individuals with normal anatomy. The overall heat and water transfer through nasal mucosa was significantly greater (p = 0.02 for both heat and moisture fluxes) on the non-cleft side than on the cleft side. Unilateral median and interquartile range (IQR) for heat flux (W/m²) was 190.3 (IQR 59.9) on the non-cleft side, 160.9 (IQR 105.0) on the cleft side, and 170.7 (IQR 87.8) for normal subjects. For moisture flux (mg/(s·m²), they were 357.4 (IQR 112.9), 298.7 (IQR 200.3) and 320.8 (IQR 173.0), respectively. Significant differences of SAHF50 between cleft side of uCLND and normal existed except for anterior region. Nevertheless, air conditioning ability in subjects with uCLND was generally comparable to that of normal subjects.