North Winds Research Articles

Influence of aerosol forcing on the seasonal march of East Asia summer monsoon

Focusing on the anthropogenic aerosols effects on the East Asian Summer Monsoon (EASM) progression, we found that aerosols delay the northward progression of EASM by one pentad in the south of the middle-lower reaches of the Yangtze River (PD1: pentads 25-35) and the North-Northeast China (PD3: pentads 38-42). However, aerosols have minimal impact on the seasonal march of EASM over the Yangtze-Huai River basin (PD2: pentads 36-37). In PD1 and PD3, aerosols reduce sea-land temperature differences. Also, a southward shift in the westerly jet causing lower-level north winds, which weakens the EASM in PD3. The delayed EASM progress shows its weakness in PD1 and PD3. While in PD2, EASM intensity weakens without affecting its northward progression. Aerosols, though affecting the position and intensity of Western Pacific Subtropical High, minimally influence its northward movement speed, hence no effect on the seasonal march of EASM in PD2.

Local Ecological Knowledge of the Whitemouth Croaker, Micropologias furneri among the Caiçaras in the Sepetiba Bay, SE Brazil

Local Ecological Knowledge of artisanal fishers (Caiçaras) was employed to investigate various biological aspects of the Whitemouth croaker (Micropogonias furnieri) in the Sepetiba Bay, in the state of Rio de Janeiro. This included migration patterns, reproduction, feeding habits, and interactions such as parasitism. Semi-structured interviews were carried out with 40 fishers in two communities using the “snowball” technique. It was found that the fisher’s information coincides with the academic literature for some aspects of the biology and ecology of the species. Furthermore, the fishers provided descriptions of novel patterns, which contributed to a deeper understanding of the species' natural history. These included observations of reproduction occurring almost throughout the entire year, the influence of east and north winds on the species' entry into the bay, interactions with marine catfish (Ariidae), and notable records of the isopod Cymothoidae as an important parasite of the Whitemouth croaker. This study contributes new insights to the ecological understanding of this fish species, which holds significant socio-environmental importance. It also documents changes in the livelihoods of artisanal Caiçaras communities resulting from the increasing anthropogenic activities in the region. Finally, it highlights the species' significance in terms of its sale and consumption within these communities, owing to its relative abundance in the area, despite the environmental impacts.

Influence of lunar phases and meteorological factors on rainfall in Karachi City, Pakistan

Climate change is responsible for unpredictable weather patterns in Southeast Asia, especially in Pakistan. To better understand the influence of lunar phases and meteorological factors on extreme rainfall events in Karachi City, 42 years of rainfall data and 12 years of sea level data were analyzed. The study used wavelet transform coherence to assess the influence of lunar phases and sea level fluctuations on extreme rainfall. Additionally, three machine learning algorithms - random forest, decision tree, and extreme gradient boosting - were applied first to meteorological data (Case A) and then to combined meteorological and lunar data (Case B) to evaluate their influence on extreme rainfall. Humidity in case A, and cloud cover in case B were the most influential meteorological factors along with west winds, and north winds in both cases, while the waning crescent, waning gibbous, and waxing gibbous lunar phases were the most dominant lunar phases in Case B. The coefficient of determination (R2) in random forest increased from 0.871 in Case A, to 0.893 in Case B and proved to be the most accurate algorithm in both cases. A rainfall threshold of 50 mm, above which urban pluvial flooding occurred, was consistently observed during the waxing gibbous, waning crescent, and waning gibbous lunar phases. The study improves our understanding of lunar influenced extreme rainfall temporal variations values of machine learning models for rainfall analysis and extreme events projection and provide essential information to develop efficient adaptation and mitigation policies in pluvial flood-prone urban areas.

Impacts of atmospheric copper and cadmium deposition on the metal accumulation of camphor leaves and rings around a large smelter.

The atmospheric deposition of copper (Cu) and cadmium (Cd) was monitored in eight sites around a Cu smelter with similar distance to verify whether tree leaf and ring can be used as bio-indicators to track spatial pollution record. Results showed that total atmospheric deposition of Cu (103-1215 mg/m2/year) and Cd (3.57-11.2 mg/m2/year) were 4.73-66.6 and 3.15-12.2 times higher than those in background site (164 mg/m2/year and 0.93 mg/m2/year). The frequencies of wind directions significantly influenced the atmospheric deposition of Cu and Cd, and the highest atmospheric deposition of Cu and Cd were at the prevalent northeastern wind (JN), and low frequency south (WJ) and north (SW) winds for the lowest deposition fluxes. Since the bioavailability of Cd was higher than that of Cu, the atmospheric deposition of Cd was more easily adsorbed by tree leaf and ring, resulting in only significant relation between atmospheric Cd deposition and Cinnamomum camphora leaves and tree ring Cd. Although tree rings cannot correctly record the atmospheric Cu and Cd deposition, higher concentrations in the indigenous tree rings than the transplanted tree rings suggested that tree rings can reflect to some extent the variations of atmospheric deposition. Generally, spatial pollution of atmospheric deposition of heavy metals cannot reflect the distribution of soil total and available metals around the smelter, and only camphor leaf and tree ring can bio-indicate Cd deposition. A major implication of these findings is that leaf and tree ring can serve for biomonitoring purposes to assess the spatial distribution of atmospheric deposition metal with high bioavailability around a pollution source with similar distance.

What causes bird-building collision risk? Seasonal dynamics and weather drivers.

Bird-building collisions are a major source of wild bird mortality, with hundreds of millions of fatalities each year in the United States and Canada alone. Here, we use two decades of daily citizen science monitoring to characterize day-to-day variation in building collisions and determine the factors that predict the highest risk times in two North American cities. We use these analyses to evaluate three potential causes of increased collision risk: heightened migration traffic during benign weather, increased navigational and flight errors during inclement weather, and increased errors in response to highly directional sunlight that enhances reflected images. The seasonal phenology of collisions was consistent across sites and years, with daily collision rates approximately twofold higher in autumn as compared to spring. During both migration seasons, collision risk was best predicted by the weather conditions at dawn. In spring, peak collision risk occurs on days with warm temperatures, south winds, and a lack of precipitation at dawn. In autumn, peak collision occurs on days with cool temperatures, north winds, high atmospheric pressure, a lack of precipitation, and clear conditions with high visibility. Based on these results, we hypothesize that collisions are influenced by two main weather-driven mechanisms. First, benign weather at dawn and winds that are favorable for migration cause an increase in migration traffic in both spring and autumn, creating greater opportunity for collisions to occur. Second, for autumnal migrants, cold clear conditions may cause an additional increase in collision risk. We propose that these conditions may be particularly hazardous in autumn because of the high abundance of naïve and diurnal migrants at that time of year. Our analysis also establishes that a relatively small proportion of days (15%) are responsible for 50% of the total collision mortality within a season, highlighting the importance of targeting mitigation strategies to the most hazardous times.

Evaluation of environmental impact of red tide around Pearl River Estuary, Guangdong, China

This paper presents a case study of red tide hazards around the Pearl River Estuary (PRE). Red tide hazards, meteorological data, and seawater monitoring data were collected from 1996 to 2020 at different locations around the PRE to investigate the internal and external factors influencing the occurrence of red tides. The enhancement of the assessment of estuarine trophic status (ASSETS) method enables us to evaluate the effects of meteorological factors and seawater eutrophication status on the red tide risk level. Using ASSETS, we established a framework for red tide risk assessment of the Pearl River Estuary. We analysed the external and internal factors causing the red tide based on meteorological data and seawater monitoring data in the PRE. The results show that the temperature was higher than the annual monthly average temperature of 1.265 °C, and east and north winds at velocities of 3–4 m/s could result in the formation of red tides. However, precipitation inhibits the formation of the red tide in PRE.

Variability of the coastal currents, waves and wind surge along the shore of the South-Eastern Baltic (Kaliningrad Oblast, Russian Federation)

The coastline of the Kaliningrad Oblast is an area of the South-East Baltic, which continues from the Vistula Spit to the Curonian Spit via Sambia Peninsula. The coastline has been subject to severe erosion over the past years. The goal of the paper is to analyse whether the alongshore variations of the storm surge water level, field of waves and currents are the reason for the erosion alongshore variability. The numerical simulations were carried out using the quasi-stationary approach for the model wind. The offshore wave breaking distance and the non-linear dependence between wind surge and wind speed were estimated for four typical coastline sites. The alongshore velocity on most of the coastline was enough powerful to transport the fine, medium and coarse sands. West, northern-west and north winds were defined as the most dangerous for coastal erosion. The convergence and divergence of alongshore currents as well as the vortex zones were identified for each wind direction. The results were used to analyse the alongshore current velocity, wind surge, and significant wave height variability against the shore erosion characteristics. The hypothesis that the places of convergence and divergence of alongshore currents correspond to the accumulative and erosion zones was not confirmed with one exception on the western shore of the Sambia Peninsula. Three options were supposed to explain the absence of correlation between the monitoring results on coastal erosion and modelled hydrodynamic conditions: the studied shore has not had enough free sand to demonstrate the typical behaviour of dissipative shores; the erosion characteristics depend on the very local conditions which were not resolved by numerical model; the main erosion has happened at the short term event basis when waves reach the shore at the background of a general Baltic Sea high-water level and is not a result of the general alongshore distribution of waves, wave surge and current characteristics.

Spatio-temporal patterns of sponge strandings in the southern Gulf of Mexico: The role of cold front events

Remnants of marine invertebrates are common in the wrack line of the coasts of many regions worldwide. However, little is known about its spatial and temporal variation. This study aimed to investigate the inter-site and intra-annual variability in species composition, abundance, and biomass of sponge strandings on the coast of a southern Gulf of Mexico tropical island. The environmental factors (oceanographic and meteorological) influencing such spatio-temporal variations on abundance and biomass of sponge strandings were also investigated. From a total of 21 demosponge species identified, three species of genus Clathria (with erect growth forms and a small basal area) were dominant in terms of abundance (93%) and biomass (89%). Both, the monthly average abundance and biomass varied significantly throughout the year, with maximum peaks during the cold fronts season. Only in the case of abundance, a combination of four predictor variables (wind speed, wave height, frequency of southeast winds, and frequency of north winds) explained 84.2% of its intra-annual variability. Results also showed that cold fronts (especially the stronger ones), aside from cyclonic events, can act as disruptive events regulating sponge populations in the coastal zone. Regarding the spatial variability, it was attributed to inter-site differences in the degree of exposure to hydrodynamic forces and the type of substrate. This study contributes to the knowledge of the biodiversity of sponge species in this coastal region of the Gulf of Mexico and demonstrates that large-scale seasonal events such as cold fronts can influence their temporal dynamics. • Sponge strandings varied spatio-temporally and erect growth forms were dominant. • Sponge strandings were more abundant during the cold fronts season. • Cold fronts act as disruptive events regulating shallow water sponge populations.

Study on Improving the Air Quality with Emission Enhanced Control Measures in Beijing during a National Parade Event

Research on the enhanced control and emission-reduction measures to improve air quality during major events could provide data theory and scientific support for air-quality improvement during non-activities. Based on the air-quality data published by the China Environmental Monitoring Station and the meteorological elements and weather conditions released by the China Meteorological Administration, this paper explored the characteristics of air-quality evolution in Beijing from 5 August to 18 September 2015 and the weather situation during the Military Parade. The results showed that: (1) Emission-reduction measures implemented for air quality by Beijing and its surrounding area were induced, and we explored the contribution of these measures to pollutants or AQI in the locality. (2) During the 2015 Military Parade, Beijing was in the front or lower part of the high-pressure system. Due to the strong effect of North or Northeast winds, the weather situation was conducive to the diffusion of pollutants. When before or after the implementation, once the atmospheric diffusion was poor, the pollutants would accumulate gradually. Thus, it can be seen that the weather situation had a great impact on air quality. (3) During the implementation, PM2.5, PM10, NO2 and other pollutants decreased significantly, of which the concentration of PM10 decreased the most, from 109 μg·m−3 down to 34 μg·m−3, and the concentration of PM2.5 decreased by 72.73%. According to the changes between before and during the implementation or during and after the implementation, the concentration of PM10 and PM2.5 increased when the implementation of the emission-reduction measures had been finished, indicating that the enhanced control measures made a great contribution to the emission reduction in particles. (4) In addition, the annual average of AQI in the three years is 87.49, and the average value of a normal year was the average value of 2013 and 2014. The average value of the normal year during the military parade is 64.63, which was 70.40% lower than the average value of AQI during the military parade. The goal of reaching the secondary standard of GB-3095-2012 was achieved, and there was still a long way to go from the primary standard. In a few words, in order to achieve the goal of better air quality throughout the year, all parties still needed to coordinate control and make joint efforts.

Storm emissions of macrophytes at the cape Martyan (Southern coast of Crimea, Black Sea)

Information about the peculiarities of the formation of storm emissions of macrophyte on the coast, at cape Martyan (the Southern coast of the Crimea) is presented. The studies were conducted from June 2019 to August 2020. Storm emissions on this part of the coast are formed with winds from the eastern (including north-eastern and south - eastern), southern and south-western directions and the corresponding direction of the waves. With north and west winds, the accumulated algae are carried back to the sea. Along the leveled coastal areas, storm emissions are distributed fairly evenly, without forming abundant accumulations. Stable zones accumulation of emissions are formed near the block heap, as well as at the bases of hydraulic structures. During one storm, cast ashore 40 kg to 7784 kg of phytomass. In total, 33061 kg of storm emissions were received on the shore during the year, which is about one percent of the annual production and a little more than two percent of the bottom vegetation reserves of the adjacent water area. The volume of storm emissions depends on the intensity of wave activity, the direction and strength of winds, on the morphology of the coast, as well as on seasonal phenomena in the life cycle of macrophytes.

Fitoplancton en el sistema lagunar tropical Carmen Pajonal Machona, Tabasco

Background. Phytoplankton is considered an important indicator of natural and anthropogenic processes that take place in basins and coastal environments. An example of these systems is the formed by the El Car- men, Pajonal and La Machona lagoons, in which there is intense fishing and oyster farming activity, as well as agricultural activities, oil extraction and forestry in their surroundings. Goals.Identifying the phytoplankton species, with emphasis on the potentially harmful and / or toxic ones, their distribution and differences between the samplings, north winds (2015) and rainy (2016), as well as reporting the physicochemical variables was the aimed of this work. Methods. Net samples with a mesh size of 20 μm were taken and physicoche- mical variables were measured with a water quality sonde. 300 organisms were counted and the specific richness, relative abundances and diversity index were calculated. To identify differences between the two seasons sampled the Mann-Whitney U test was performed. In addition, the most important physicochemical variables were identified to explore their relationship with the species through a distance-based redundancy analysis (dbRDA). Results. A total of 86 species were identified, of which ten are new records and 15 are potentially harmful and / or toxic ones. The taxonomic group with the most species in both seasons was Bacillaryophyta (43 Northeast and 22 Rains). Specific richness was significantly different between seasons. In the north winds season, the most abundant species were from the Cyanoprokaryota and Bacillaryophyta groups, while for rainy season they were from the Dinoflagellata. Conclusions. Water temperature and salinity were the physicochemical variables that defined the phyto- plankton composition in the CPM lagoons; the presence of potentially toxic species is an alert for the lagoon system because it reflects a latent situation that could trigger blooms at any time.

VOCs pollution characteristics and potential of ozone generation in Kaifeng City

In recent years, the exhausted gas from factories has become an important part of environmental pollution in Kaifeng City. Air samples were collected for 57 kinds of volatile organic compounds (VOCs) and 13 kinds of aldehydes and ketones from the Cancer Hospital of Kaifeng city between May and October 2019. The pollutants were measured by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) technique. Combined with the 8-hour automatic monitoring data of air ozone automatic monitoring at this sampling site, a total of 31 observations on volatile organic compounds (VOCs) were carried out over between May and October 2019. The results showed that the average concentration of VOCs was in the order of oxygen-containing organic matters > alkanes > olefins > aromatic hydrocarbons > alkynes. Using SPSS26 statistical software, representative key species were selected from VOCs, and correlation analysis was conducted with ozone concentration and meteorological factors. The ozone concentration was significantly correlated with air temperature. Acrolein & propionaldehyde, acetaldehyde, and formaldehyde, had a significant negative correlation with ethylene and ethane. The highest ethylene and ethane concentrations appeared when there was west wind, while toluene showed a significantly high value in the southwest wind. The oxygenated organics had obvious wind direction characteristics and the four kinds of oxygenated organics were rarely affected by the west, northwest and north winds.

Forage yield of Urochloa cultivars in a warm sub-humid environment

Objective: To evaluate for 10 weeks the growth of five Urochloa cultivars: Camello,Cobra, Cayman, Convert 330, Mavuno and Xaraés; during the North Winds (NS), Dry(DS) and Rainy (RS) seasons in a warm sub-humid environment. Design/Methodology/Approach: The variables were crop growth rate (CGR; kg ha-1 d-1 ) and total dry matter yield (TDM; t ha -1 ); which were analyzed under a completelyrandomized design (Tukey; p=0.05). Results: During NS, Mavuno and Xaraés presented, on average, the highest values ??ofCGR (p<0.05), 23.7 and 19.4 kg ha-1 d-1, respectively. In DS the cultivars Xaraés,2Convert 330, Mavuno, and Cayman presented the highest values, with 20.7 and 26.8 kgha-1 d-1 , in week 2 and 4, respectively. During RS, in the second and fourth week ofregrowth, the Xaraés and Mavuno cultivars presented the highest CGR (p<0.05), 119.8and 144.7 kg ha-1 d-1 , on average. In the NS, the Mavuno hybrid presented the highestyields (p<0.05) of TDM, 0.886, 1.553 and 2.156 t ha -1 in week 6, 8 and 10, respectively.For RS, the cultivars Camello, Cayman, Mavuno, and Xaraés presented similar yields ofTDM; which, on average, were 4.652, 5.312 and 6.278 t ha -1 , at 6, 8 and 10 weeks,respectively. Findings/Conclusions: The cultivars Xaraés, Mavuno and Cayman presented goodforage potential in a warm sub-humid environment; mainly for showing greater growthand accumulation of total dry matter.

Variation of main rainy‐season precipitation in eastern China and relevance to regional warming

AbstractChina has experienced dramatic warming in summer mean temperature since the early 1990s, leading to precipitation variation across the region. We have studied the variation of rainy‐season (April–September) precipitation in eastern China during 1961–2016. Overall, we found that rainy‐season precipitation increased in the south and decreased in the north during 1992–2016 (PII) compared to 1961–1991 (PI). By defining rainfall‐belt indices of intensity and central location, we found that the southern rainfall‐belt during the main rainy‐season tends to produce much more‐intense precipitation during PI relative to PII, in contrast to the northern rainfall‐belt, which tends to have less‐intense precipitation during PII. Despite some fluctuations, the central positions of neither the northern nor the southern rainfall‐belts exhibit a statistically significant difference between the two periods. Unlike during PI, during PII, there is an obvious anticyclone over the Lake Baikal region. This anticyclone has caused anomalous north winds flowing from north‐central to southwestern China, leading to weakening of the northward moisture transport. Also, regions such as northeastern, north‐central, and southwestern China have been controlled by negative geopotential height anomalies and weak vertical air‐motion anomalies, resulting in drying from north to southwestern China. At the same time, the enhanced water‐vapour convergence in the southeastern coastal region of China favours increased precipitation there. These processes working in concert created the drying‐north–wetting‐south pattern in the main rainy‐season during 1961–2016. The change in rainfall‐belt intensity in eastern China has also shown a close relationship with the change in vapour transport from low latitudes. The weakened land‐sea thermal difference in the East Asia–Northwest Pacific region, which has weakened water‐vapour and atmospheric circulation, has also played a role in the change of rainfall‐belt intensity.

Osobennosti sezonnoy izmenchivosti gidrologicheskogo rezhima bukhty Novik (ostrov Russkiy, zaliv Petra Velikogo, Yaponskoye more)

Purpose. The paper is aimed at studying the hydrological regime of the Novik Bay (Russky Island, Peter the Great Bay, Sea of Japan). Methods and Results. Regular ship and ice cover CTD observations (more 1000 water column profiling stations) carried out in the Novik and Amur bays in 2013–2018 were used. Weather conditions in the region under study were analyzed based on the data of the Vladivostok weather station archive (WMO_ID=31960). Quantitative estimates of the drift and gradient currents in the bay are represented. Conclusions. Seasonal changes in the thermohaline stratification of the Peter the Great Bay coastal waters are conditioned by the monsoon climate features. The Novik Bay hydrological regime is additionally affected by its isolation and shallowness, as well as by the Russky Island relief. Weak water dynamics in the bay is observed during the summer monsoon (April – August) that is a result of the south winds blocking by the hills. The autumn-winter monsoon (when the north winds dominate) induces the water surge to the bay that, in its turn, blocks its circulation. The winter Siberian cold anticyclone forms the ice cover in the bay, and just in such an ice-forming season the salinity increase in the bottom layer is observed. In the shallow southern part of the Novik Bay, the process of ice formation begins. The downwelling flow of salty heavy water directed to the north out of the bay along the bottom relief is compensated by the counter flow of fresh waters from the Amur Bay which inflow to the upper sub-ice layer. The freeze-up period is most favorable for water renewal. The efficiency of this process is additionally influenced by a heat flow from bottom sediments and by the ice conditions in the adjacent water areas of the Peter the Great Bay

The effect of meteorological variables on spontaneous pneumothorax in two regions with different altitudes

Spontaneous pneumothorax (SP) is defined as the presence of free air inside the pleural space. Many studies have reported that meteorological variables may trigger SP, but the mechanism is unknown. The aim of this study was to compare the effects of meteorological variables on the development of SP in two regions with different altitudes. The study was conducted in the Çanakkale (2m above sea level) and the Erzurum region (1758m). A total of 494 patients with SP who presented to the hospitals of the two regions between January 2011 and December 2016 were included in the study. The meteorological variables used included ambient temperature, atmospheric pressure, relative humidity, precipitation amount, wind speed, and wind direction (as north and south). The total 2192days were divided into two as days with and without an SP case presentation. A 4-day period prior to the day a case presented was compared with the other days without any cases to investigate the presence of any lagged effect. Statistical significance was accepted at p < 0.05. Comparison of these two regions showed a significant difference between them. The meteorological variables of the regions that affect SP development were found to be low mean minimum temperature, high daily temperature change, low precipitation, low wind speed and north winds for Erzurum, and only rainy days for Çanakkale. The results have demonstrated that cold weather, sudden temperature changes, north winds, and low wind speed are risk factors for the development of SP at high altitudes.

The Strong, Dry Winds of Central and Northern California: Climatology and Synoptic Evolution

AbstractStrong, dry downslope winds over Northern and central California have played a critical role in regional wildfires. These events, sometimes called Diablo or North winds, are more frequent over the Bay Area and nearby coastal terrain than along the western slopes of the Sierra Nevada, where the highest frequency occurs over the midslopes of the barrier. For the Bay Area, there is a frequency minimum during midsummer, a maximum in October, and a declining trend from November to June. The Sierra Nevada locations have their minimum frequency from February to August, and a maximum from October to January. There is little trend in event frequency during the past two decades over either region. For the Bay Area sites, there is a maximum frequency during the early morning hours and a large decline midday, while the Sierra Nevada locations have a maximum frequency approximately three hours earlier. Before the onset of these downslope wind events, there is substantial amplification of upper-level ridging over the eastern Pacific, with sea level pressure increasing first over the Pacific Northwest and then over the Intermountain West. The coincident development of a coastal sea level pressure trough leads to a large pressure gradient over the Sierra Nevada and Northern California. Diablo–North wind events are associated with below-normal temperatures east of the Sierra Nevada, with rapid warming of the air as it subsides into coastal California. The large horizontal variability in the frequency and magnitude of these events suggests the importance of exposure, elevation, and mountain-wave-related downslope acceleration.

EUTROPHICATION IN THE LOWER COASTAL BASIN OF THE JAMAPA RIVER IN VERACRUZ, MEXICO

The aim of this study was to determine parameters of dissolved oxygen, temperature and nitrogen in the coastal basin of the Jamapa River as indicators of eutrophication. Six sampling sites were selected in the lower basin, where samples were collected in triplicate in each site, during three seasons; north winds, dry and rainy. Results of the research, analyzed using the Minitab statistical program, were: site 2 showing the maximum value of dissolved oxygen with 5.83 mg/L; site 5 with the maximum temperature value of 30.3 ºC, during the dry season. Whereas, maximum mean values of total nitrogen were at site 2 (4.596 mg/L) and site 5 (4.281 mg/L). Coastal basins can change markedly the nitrogen concentration with respect to weather and environmental conditions. As well as, reduced forms of nitrogen cause alterations in dissolved oxygen and the increase in water temperature, along with high concentrations of nutrients.

Inclement weather and American woodcock building collisions during spring migration

Weather appears to influence collisions of migratory birds with human-built structures including buildings, but formal analyses are lacking. In 2018, as part of a two-year study at 21 buildings in Minneapolis, Minnesota, USA, we observed a large number of American woodcock Scolopax minor collisions during two early spring snowstorms. We describe these events, analyze associations between weather and woodcock collisions during spring 2018, and compare observations to past studies across the woodcock's range. Most spring 2018 woodcock collisions (11 of 15; 73.3%) occurred in association with the two snowstorms. Analyses indicated collisions were positively associated with maximum and average wind speeds the night before collision surveys, and most collisions occurred with north winds. Collisions also increased with lower cloud base height two nights before surveys. These results support that woodcock collisions were greatly influenced by inclement weather, specifically the coincidence of strong north wind and low clouds. Comparing results to past studies illustrates that building collisions could be a major range-wide source of woodcock mortality, especially in spring migration when mortality is likely additive. Although more research is needed to understand range-wide, population-level effects of woodcock collisions, management to reduce building collisions during migration may benefit woodcock populations. Additional research is needed to clarify effects of weather on bird collisions because management efforts could be refined if collisions of woodcocks and other bird species were forecastable like the weather.

Possible medium and long range effects of depleted U-238 used in ammunition

In recent years a new type of ammunition has been included in the modern arsenals of Western countries. Depleted Uranium is used in the AlO's 30-mm gun and in a large variety of other projectiles used by Army, the Marines and Aviation. Due to the radioactive nature of this type of ammunition, it is important to know the distance of dispersion of the material produced. On account of its probable usage some hundred of km north from Greece we are interested in the evaluation of its impact on Greece. We assumed an amount of DU, equal to that daily released during the Gulf War, as being released in South Yugoslavia (Pristina). We examined the possibility of its transport to Greece at a distance more than 150 km far from the release point. For concentration, deposition, dose estimations and health effects evaluation COSYMA code is used. We assumed constant north winds of 5 m/s of speed, no rain, a mixing height equal to about 1000 m and D atmospheric stability conditions. Moreover taking account of the real wind situation during March and April 1999, we calculated the probable impact of daily releases, on selected days, to regions of Greece affected by air masses movement. The results indicate that in spite of the big amount considered as released in a single site, in no cases there has been found any appreciable radiological health effect.