On some characteristics of the field intensity of atmospherics ant at Calcutta due to local active monsoon clouds

The paper examines some characteristics of the field intensity level of atmospherics at three harmonically related frequencies due to local active monsoon clouds. Seasonal variations of the ratio of afternoon maximum to morning minimum as well as that of the afternoon minimum to morning minimum of atmospherics and the local rainfall have been critically analysed. The differences of the two ratios exhibit a pronounced seasonal variation, having minimum values during the monsoon months and also the significance ratio at such times decreases with the increase of rainfall. which. in turn. is related to local sferics. The results further indicate how the overhead cloud amount in okta contributes significantly over the intensity level of different frequencies and width of atmospherics.

Associations Between Strong Earthquakes and Local Rainfall in China

Strong earthquakes are a major cause of natural disasters and may also be related to heavy rainfall events. Both phenomena have received considerable attention in seismology and meteorology, two relatively independent disciplines, but we do not yet know whether there is a connection between them. We investigated the characteristics of daily rainfall over seismic areas in China. Our statistical analyses showed that there is a strong correlation between strong earthquakes (Ms ≥ 6.0) and rainfall over the seismic area, with 74.9% of earthquakes in China accompanied by seismic epicenter rainfall and 86.6% by seismic area rainfall. The statistics also showed that the daily precipitation over the seismic area, including the epicenter, was mainly light rain, with only a few instances of torrential or storm rain, with 80% of the rainfall events lasting two or more days. The maximum cumulative precipitation corresponded well with the strong earthquakes occurring over steep terrain, such as the Taiwan central mountains and the eastern Tibetan Plateau. The earthquake area rainfall had a higher frequency than the 30-years climatological average and was dominated by earthquake events in the wet season. The WRF-ARW numerical simulation of seismic local rainfall during the devastating Ms 8.0 Wenchuan earthquake in May 2008 showed that the geothermal heat from the earthquake strengthened the local convergence of moisture and vertical motion near the epicenter and the upward transport of the sensible heat flux, which favored seismic rainfall. The results of this study show that rainfall in the seismic area is closely related to strong earthquakes and can be triggered and enhanced by geothermal heat.

Measuring urban resilience to flooding under climate change

<p>Flooding is one of the most challenging weather-induced risks in urban areas, due both to the typically high exposures in terms of people, buildings, and infrastructures, and to the uncertainties lying in the modelling of the involved physical processes. The modelling of urban flooding is usually performed by means of different strategies in accordance with the specific purpose of the analysis, ranging from detailed simulations, requiring large modelling and computational efforts, and typically adopted for design purposes, to simplified evaluations, particularly feasible for scenario analyses, when a large number of simulations is required perturbing one or more input parameters.</p><p>According to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, intensity of precipitation events could be greatly impacted by the expected climate change primarily due to the increase in temperature, entailing an increase in the atmospheric moisture retention capability. However, the effect of climate change on the rainfall regime of local areas is not straightforward, but deeply depends on local features such as latitude, topography, distance from the coast. Over Europe, an ensemble of climate simulations coming from the application of different Regional Climate Models (RCMs) (able to perform a dynamical downscaling of General Circulation Models, GCMs, available at the global scale) is freely available within the EURO-CORDEX initiative, which is the current standard for climate change analysis over EU countries. The spatial resolution of EURO-CORDEX simulations (about 12km) is too coarse to be directly used in local impact analyses; in this case, bias corrections are usually performed using local rainfall observations, to adjust climate simulation results to the local rainfall regime. The availability of multiple climate projections coming from different Climate Simulation Chains (in other words, different RCM/GCM couplings) allows to quantify the uncertainty in climate modelling, that should be accounted for in impact analyses.</p><p>In the present work, an approach is proposed that aims to quantify the uncertainty caused by the use of an ensemble of climate projections on urban flood modelling, taking a limited area within the City of Naples (Italy) as test case. The specific purpose is that of understanding the resilience of the area with respect to any variation in rainfall intensity such as those possibly caused by climate change, building on 19 climate projections available within the EURO-CORDEX initiative and bias-corrected to make them suitable to be used for impact analyses at the local scale. The concept of resilience is expressed by a selection of indicators considered useful both in the framework of classical hazard analysis and for transport network, considered a strategic service for the test case. Urban flood modelling is undertaken by using two different numerical codes characterized by two different levels of complexity. In this way, it will be possible to draw conclusions about the computational costs that are actually needed, in terms of input data and resources, when integrating uncertainties due to climate projections in urban flood modelling for multi-purpose analyses.</p>

Value Addition to Forecasting: Towards Kharif Rice Crop Predictability Through Local Climate Variations Associated With Indo-Pacific Climate Drivers.

The Indian Institute of Tropical Meteorology (IITM) has generated seasonal and extended range hindcast products for 1981-2008 and 2003-2016 respectively using the IITM-Climate Forecast System (IITM-CFS) coupled model at various resolutions and configurations. Notably, our observational analysis suggests that for the 1981-2008 period, the tropical Indo-Pacific drivers, namely, the canonical El Niño-Southern Oscillation (ENSO), ENSO Modoki, and Indian Ocean Dipole (IOD) are significantly associated with the observed Kharif rice production (KRP) of various rice-growing Indian states. In this paper, using the available hindcasts, we evaluate whether these state-of-the-art retrospective forecasts capture the relationship of the KRP of multiple states with the local rainfall as well as the tropical Indo-Pacific drivers, namely, the canonical ENSO, ENSO Modoki and the IOD. Using techniques of anomaly correlation, partial correlation, and pattern correlation, we surmise that the IITM-CFS successfully simulate the observed association of the tropical Indo-Pacific drivers with the local rainfall of many states during the summer monsoon. Significantly, the observed relationship of the local KRP with various climate drivers is predicted well for several Indian states such as United Andhra Pradesh, Karnataka, Odisha, and Bihar. The basis seems to be the model's ability to capture the teleconnections from the tropical Indo-Pacific drivers such as the IOD, canonical and Modoki ENSOs to the local climate, and consequently, the Kharif rice production.

Human Adaptation to Environmental Change in the Northern Dongola Reach

Survey on the east bank of the Nile by the Sudan Archaeological Research Society between 1993 and 1996 was able to chart in detail changes in human settlement patterns. These reflect the political situation and developments in the agro-economy, but most importantly, fundamental changes in the hydrology of the Nile and in the local climate. In the Kerma periods the braided Nile channel was able to support a large population probably aided by greater local rainfall. With the demise of the eastern Nile channels and increasing aridity this population density became unsustainable and by the early 1st millennium bce the region, apart from the bank of the main Nile channel, was largely abandoned.

Rapid Flood Mapping Using Multi-temporal SAR Images: An Example from Bangladesh

In the HKH region, large areas in Afghanistan, Bangladesh, China, India, Myanmar, Nepal, and Pakistan get inundated by floodwater during every rainy season. Among them, Bangladesh has been experiencing record-high floods where four types prevail: flash flood, local rainfall flood, monsoon river flood, and storm-surge flood; and these occur almost every year due to Bangladesh’s unique geographical setting as the most downstream country in the HKH region.

The Role of Slope Runoff in Flooding of Settlements in the Foothills of the Krasnodar Region When Local Rainstorms Fall (on the Example of Bagovskaya Village on May 20, 2019)

In the articles the authors have assessed the role of slope runoff formed during local storm precipitation in flooding of settlements in the foothill part of the region using the example of flooding of a part of the territory of the Bagovskaya village in the Krasnodar region on May 20, 2019. Hydrometeorological conditions that contribute to the formation of intensive slope runoff have been considered. It was identified that in the case of the development of the elementary circulation mechanism, the probability of local rainfall increases in the territory of the region, the intensity of which in the foothill zone can reach more than 100 mm/day. Precipitation is, as a rule, are of an areal character, but the field distribution of precipitation is uneven. In the case of major precipitation in the high-altitude zone of 300-700 m, rivers cope with the passage of rainwater and flooding of settlements occurs because of the slope runoff coming from the surrounding slopes. In the case of precipitation intensity of 10 mm/10 min the flow modulus is 16.7 m3/skm2. When intense precipitation shifts to a high-altitude zone of more than 1000 m, a flood occurs on rivers and watercourses. In this case, flooding of localities will occur first as a result of runoff of slope drains, and then, as a result of rising water levels in the river, above dangerous levels.