Dust Aerosol trends over the Eastern Mediterranean region during 2003-2019

2021 ◽  
Author(s):  
Abdallah Shaheen ◽  
Renguang Wu ◽  
Robabeh Yousefi
Keyword(s):  
Mediterranean Region ◽  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Dust Aerosol ◽  
Sources Of Uncertainty ◽  
Dust Level ◽  
Fine Mode ◽  
Monitoring Service ◽  
Modern Era

<p>Dust Aerosol Optical Depth (DAOD) is considered as one of the main sources of uncertainty in the assessment of climate change. In this talk, we present results of DAOD trend over the Eastern Mediterranean (EM) region in the dusty season (April- May- June- and July: AMJJ) during the years 2003-2019 using long-term DAOD from the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) and the Copernicus Atmosphere Monitoring Service Reanalysis (CAMSRA). MERRA-2 and CAMSRA DAOD displayed significant positive trends during the years 2003-2010 over the region at the rates of 0.007 year<sup>−1</sup> and 0.005 year<sup>−1</sup>, respectively. In contrast, significant negative MERRA-2 and CAMSRA DAOD trends occurred during the years 2010 -2017 with the rates of -0.009 year<sup>−1</sup> and -0.004 year<sup>−1</sup>, respectively. Moreover, trend analysis was also attempted for the Angstrom Exponent (AE<sub>440-870</sub>) and Fine Mode Fraction (FMF<sub>500</sub>) from 3 AERONET sits in the region.  AERONET data are compatible with the trend of MERRA-2 and CAMSRA DAOD. This suggests that the aerosols trend on the EM region is influenced by aeolian dust level.</p>

scholarly journals Long-Term Tillage Induced Changes in Physical Attributes of a Clayey Soil in Eastern Mediterranean Region

2018 ◽  
Vol 1 (1) ◽  
pp. 32-39
Author(s):  
İsmail Çelik ◽  
Hikmet Günal ◽  
Mert Acar ◽  
Zeliha Barut Bereket ◽  
Nurullah Acir ◽  
...  
Keyword(s):  
Best Management Practices ◽  
Mediterranean Region ◽  
Clayey Soil ◽  
Eastern Mediterranean ◽  
Soil Health ◽  
Eastern Mediterranean Region ◽  
Root Penetration ◽  
Undisturbed Soil ◽  
Available Water

Abstract Comparing responses of the same soil under long-term different treatments is vital in determining the best management practices to conserve soil health and sustain productivity. This study was investigated to determine the effects of longterm (2006-2015) two conventional (CT), three reduced (RT) and a no-till (NT) treatment on bulk density (BD), field capacity (FC), wilting point (WP), available water content (AWC) and total porosity (TP) of a clayey soil in eastern Mediterranean region, Turkey. Undisturbed soil samples were collected from 0-10, 10-20 and 20-30 cm depths of experimental plots with a crop rotation of winter wheat (Triticum aestivum L.), soybean (Glycine max. L.), grain maize (Zea mays L.). The AWC under CT was higher than the RT and NT. The BD was increased with depth in all treatments, and was higher under RT and NT than the CT. The long-term experiment revealed that BD increase under long-term RT and NT should be monitored to avoid deterioration of soil health, and yield loss due to limiting root penetration and storing available water needed during drought periods.

Precipitable water vapor from GPS tropospheric path delays over the Eastern Mediterranean: trends, diurnal and long-term variability

2021 ◽  
Author(s):  
Shlomi Ziskin Ziv ◽  
Pinhas Alpert ◽  
Yoav Yair ◽  
Yuval Reuveni
Keyword(s):  
Water Vapor ◽  
Mediterranean Region ◽  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Precipitable Water ◽  
Annual Variations ◽  
Diurnal Cycles ◽  
Mean Trend ◽  
Data Period

<p>Global Navigation Satellite System (GNSS) tropospheric path delays provide an important tool for studying Precipitable Water Vapor (PWV) variations. Here, we process and analyze PWV time series extracted from the Survey Of Israel Active Permanent Network (SOI-APN) GNSS ground receivers in the Eastern Mediterranean region. We derive the annual and seasonal PWV diurnal cycles along with the PWV long-term trends, annual and inter-annual variations. The data period spans from 5 to 21 years, ensuring its suitability for studying the PWV variations at different time scales. For the diurnal cycles, we focus on the summer months (JJA), where the Mediterranean Sea Breeze (MSB) plays a dominant role in transporting humidity inland. We find that for most stations, the diurnal amplitude in summer is the highest compared to the seasonal mean. Moreover, using the PWV peak hour in the coastal and highland stations, we detect a frontal MSB propagation from the coastline eastward inland combined with northern winds enhancement due to the Coriolis force. The peak hour is also correlated with the distance from the Mediterranean Sea shore, substantiating the MSB’s role as a key driver of the PWV diurnal variability during summer months. In addition, a strong correlation between the PWV diurnal cycle and the atmospheric Mixing Layer Height (MLH) diurnal variations is found using ceilometer data, suggesting that the MLH modulates the PWV. For the annual cycles, the PWV monthly mean values and variability are high in the summer months (JJA) however, Sep and Oct supersede the JJA values where Oct has the highest variability in all stations. We suggest that the Red-Sea Trough (RST) synoptical system plays a dominant factor in shifting the mean PWV annual peak values from the summer months to Oct. This is  further substantiated by harmonic analysis which reveals a non-negligible semi-annual mode with peaks at Apr and Oct when the RST synoptical system is most frequent. The PWV inter-annual variations as represented by the monthly mean anomalies are consistent between all stations, thus suggesting a common regional driver. Moreover, a comparison between the PWV station average anomalies and the ERA5 (the European Centre for Medium-Range Weather Forecasts' latest global reanalysis) regional mean anomalies show a correlation of 0.95. Furthermore, a correlation of 0.72 was found between the regional mean moisture flux anomalies at 750 hPa taken from ERA5 and the station average PWV anomalies, implying that moisture flow accounts for most of the inter-annual variability, however the significance of the 750 hPa pressure level remains ambiguous. In the long term, we find an increasing regional mean trend of ~ 0.5 mm/decade for the whole data period (1998-2019) whereas for the last decade (2010-2019) we find a mean trend of ~ 1 mm/decade suggesting an accelerated moistening of the Eastern Mediterranean region. </p>

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