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The Emirates Mars Mission carries the Emirates eXploration Imager instrument, which captured hourly images on 15 and 24 September 2024. That is equivalent to Martian Year 37, solar longitude 329° and 335°, respectively. These observations recorded two nearly identical dust storms in the Amazonis/Arcadia region. We analyze the hour‐by‐hour evolution of both dust storms, using seven to eight unique images each. We track the onset and growth of the dust storms from around 10 through 16 local true solar time. We also analyze nearby water‐ice clouds and discuss large‐scale meteorological conditions. Both dust storms start in late morning, in or near the warm sector of a low pressure system. There is no evidence that the dust storms form directly on the associated cold front. There are different scenarios how dust storms form and develop. We show a specific scenario for two dust storms.

Keto in an Instant features over 100 ketogenic recipes all designed to be made in the Instant Pot. Each recipe includes key nutritional data for keto followers, as well as clear, detailed instructions for using the Instant Pot to create the recipes. In addition to the recipes, readers will gain insight on how the ketogenic diet works, and benefit from practical guidance for following a ketogenic eating plan. Also included is useful information on using and maintaining the Instant Pot, tips and tricks for using the Instant Pot in the kitchen, and much more.-- Amazon.

A systematic analysis of the main weather types influencing southern Australian rainfall is presented for the period 1979–2015. This incorporates two multi-method datasets of cold fronts and low pressure systems, which indicate the more robust fronts and lows as distinguished from the weaker and less impactful events that are often indicated only by a single method. The front and low pressure system datasets are then combined with a dataset of environmental conditions associated with thunderstorms, as well as datasets of warm fronts and high pressure systems. The results demonstrate that these weather types collectively account for about 86% of days and more than 98% of rainfall in Australia south of 25° S. We also show how the key rain-bearing weather systems vary throughout the year and for different regions, with the co-occurrence of simultaneous lows, fronts and thunderstorm conditions particularly important during the spring and summer months in southeast Australia.

The July 2021 flood in central Europe was one of the five costliest disasters in Europe in the last half century, with an estimated total damage of EUR 32 billion. The aim of this study is to analyze and assess the flood within an interdisciplinary approach along its entire process chain: the synoptic setting of the atmospheric pressure fields, the processes causing the high rainfall totals, the extraordinary streamflows and water levels in the affected catchments, the hydro-morphological effects, and the impacts on infrastructure and society. In addition, we address the question of what measures are possible to generate added value to early response management in the immediate aftermath of a disaster. The superposition of several factors resulted in widespread extreme precipitation totals and water levels well beyond a 100-year event: slow propagation of the low pressure system Bernd, convection embedded in a mesoscale precipitation field, unusually moist air masses associated with a significant positive anomaly in sea surface temperature over the Baltic Sea, wet soils, and steep terrain in the affected catchments. Various hydro-morphodynamic processes as well as changes in valley morphology observed during the event exacerbated the impact of the flood. Relevant effects included, among many others, the occurrence of extreme landscape erosion, rapidly evolving erosion and scour processes in the channel network and urban space, recruitment of debris from the natural and urban landscape, and deposition and clogging of bottlenecks in the channel network with eventual collapse. The estimation of inundation areas as well as the derived damage assessments were carried out during or directly after the flood and show the potential of near-real-time forensic disaster analyses for crisis management, emergency personnel on-site, and the provision of relief supplies. This study is part one of a two-paper series. The second part (Ludwig et al., 2022) puts the July 2021 flood into a historical context and into the context of climate change.

The cities of Chengdu, Deyang, and Mianyang in the northwest Sichuan Basin are part of a rapidly developing urban agglomeration adjoining the eastern slopes of the Tibetan Plateau. Heavy air pollution events have frequently occurred over these cities in recent decades, but the effects of meteorological conditions on these pollution events are unclear. We explored the effects of weather systems on winter heavy air pollution from 1 January 2006 to 31 December 2012 and from 1 January 2014 to 28 February 2017. A total of 10 heavy air pollution events occurred during the research period and 8 of these took place while the region was affected by a dry low-pressure system at 700 hPa. When the urban agglomeration was in front of the low-pressure system and the weather conditions were controlled by a warm southerly air flow, a strong temperature inversion appeared above the atmospheric boundary layer acting as a lid. Forced by this strong inversion layer, the local secondary circulation was confined to the atmospheric boundary layer, and the horizontal wind speed in the lower troposphere was low. As a result, vertical mixing and horizontal dispersion in the atmosphere were poor, favoring the formation of heavy air pollution events. After the low-pressure system had transited over the region, the weather conditions in the urban agglomeration were controlled by a dry and cold air flow from the northwest at 700 hPa. The strong inversion layer gradually dissipated, the secondary circulation enhanced and uplifted, and the horizontal wind speed in the lower troposphere also increased, resulting in a sharp decrease in the concentration of air pollutants. The strong inversion layer above the atmospheric boundary layer induced by the low-pressure system at 700 hPa thus played a key role in the formation of heavy air pollution during the winter months in this urban agglomeration. This study provides scientific insights for forecasting heavy air pollution in this region of China.

In contrast to earlier studies, the authors describe the climatological deep low pressure system that exists over the South Pacific sector of the Southern Ocean, referred to as the Amundsen–Bellingshausen Seas low (ABSL), in terms of its relative (rather than actual) central pressure by removing the background area-averaged mean sea level pressure (MSLP). Doing so removes much of the influence of large-scale variability across the ABSL sector region (e.g., due to the southern annular mode), allowing a clearer understanding of ABSL variability and its effect on the regional climate of West Antarctica. Using ECMWF Interim Re-Analysis (ERA-Interim) fields, the annual cycle of the relative central pressure of the ABSL for the period from 1979 to 2011 shows a minimum (maximum) during winter (summer), differing considerably from the earlier studies based on actual central pressure, which suggests a semiannual oscillation. The annual cycle of the longitudinal position of the ABSL is insensitive to the background pressure, and shows it shifting westward from ∼250° to ∼220°E between summer and winter, in agreement with earlier studies. The authors demonstrate that ABSL variability, and in particular its longitudinal position, play an important role in controlling the surface climate of West Antarctica and the surrounding ocean by quantifying its influence on key meteorological parameters. Examination of the ABSL annual cycle in 17 CMIP5 climate models run with historical forcing shows that the majority of them have definite biases, especially in terms of longitudinal position, and a correspondingly poor representation of West Antarctic climate.

El Niño‐Southern Oscillation (ENSO) is the main driver of interannual east Australian rainfall variability, but its link with rain‐producing synoptic weather systems is unclear. By tracking low pressure systems in ERA5 over 1979 to 2021, we find that springtime cyclones are linked to variations in the large‐scale atmospheric circulation during ENSO events. On spring days with a cyclone during La Niña, a pressure dipole occurs with a strong anticyclonic anomaly southeast of Australia and a cyclonic anomaly over eastern Australia. The northeasterly circulation directs tropical moisture toward eastern Australia, and coupled with induced ascent, promotes rainfall in this region. Both dynamical and thermodynamical changes are important for the rainfall response. An almost opposite circulation response occurs on cyclone days during El Niño events: high‐pressure over the Australian continent reduces rainfall in eastern Australia. These synoptic setups resemble the seasonal‐mean Rossby wave teleconnections, indicating a link between weather systems and ENSO. Plain Language Summary El Niño‐Southern Oscillation (ENSO) is the main driver of year‐to‐year rainfall variability in eastern Australia. La Niña is generally associated with increased rain and flooding, while El Niño is associated with a reduced likelihood of rain and sometimes drought. However, ENSO is a large‐scale phenomenon that persists on timescales longer than the day‐to‐day weather systems that are responsible for producing rain in this region. In this study, we examine differences in the characteristics of low‐pressure systems or cyclones on daily timescales between El Niño and La Niña events in Southern Hemisphere spring. We find that during La Niña, on days when a cyclone is present over eastern Australia, a high‐pressure system also occurs to the southeast of Australia in the Tasman Sea. This setup is conducive to rainfall in the region as it promotes moisture transport from the tropical Pacific Ocean and upward air flow, both of which are essential ingredients for rain. In contrast, during El Niño, there is an almost opposite circulation response; notably high‐pressure over the Australian continent reduces rainfall in eastern Australia. These patterns on daily timescales resemble the seasonal‐mean teleconnection patterns, thus indicating a link between weather systems and ENSO. Key Points Rain‐producing weather systems in eastern Australia are linked to the El Niño‐Southern Oscillation (ENSO) via Rossby wavetrains Synoptic‐scale pressure dipole increases rain during spring of La Niña events and high pressure over Australia reduces rain during El Niño Changes in both the large‐scale atmospheric circulation and moisture availability are important for the ENSO‐related rainfall response

The South Asian summer monsoon brings copious rain to agriculture-dependent country India and bulk of the precipitation in central India is attributed to monsoon low pressure systems (LPS). Large uncertainty exists in the statistics of LPS during the historical period and in future projections. In this study, we have developed an LPS tracking approach which considers geopotential height anomaly and relative vorticity thresholds. The approach is validated by comparing characteristics of LPS from our tracking scheme with those from previous studies. Our analysis indicates around 14 LPS per year (over 68 LPS-days). 60–70% of monsoon rainfall in north, east and central India is found to be associated with LPS (location is within 1000 km radii of LPS). Over the central Indian region, around 82% of extreme precipitation events occur during LPS days, out of which 47% are on depression and deep depression days and 78% is associated with LPS. 15–25% of monsoon precipitation in central and East Indian states is in the form of extreme precipitation associated with LPS. At many locations in central India, very heavy precipitation (≥ 124.5 mm/day) due to LPS is estimated to have a return period less than 5 years. Further, our analysis shows that the intensity of extreme precipitation is larger by 50% (95th percentile precipitation) to 100% (99th percentile) when the extreme is associated with LPS. Our analysis of extreme precipitation related to LPS has the potential to provide valuable information for flood risk assessment during monsoon season in central India.