Open Access. Powered by Scholars. Published by Universities.®

Oceanography and Atmospheric Sciences and Meteorology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Mathematics, Physics, and Computer Science Faculty Articles and Research

Discipline
Keyword
Publication Year

Articles 121 - 130 of 130

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Inter-Continental Transport Of Dust And Pollution Aerosols Across Alexandria, Egypt, Hesham El-Askary, R. Farouk, C. Ichoku, Menas Kafatos Jan 2009

Inter-Continental Transport Of Dust And Pollution Aerosols Across Alexandria, Egypt, Hesham El-Askary, R. Farouk, C. Ichoku, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The flow of pollutants from Europe and desert dust to Europe from the Sahara desert both affects the air quality of the coastal regions of Egypt. As such, measurements from both ground and satellite observations assume great importance to ascertain the conditions and flow affecting the Nile Delta and the large city of Alexandria. We note that special weather conditions prevailing in the Mediterranean Sea result in a westerly wind flow pattern during spring and from North to South during the summer. Such flow patterns transport dust-loaded and polluted air masses from the Sahara desert and Europe, respectively, through Alexandria, …

Go to article

A Study Of Land Surface Processes Using Land Surface Models Over The Little River Experimental Watershed, A. K. Sahoo, P. A. Dirmeyer, P. R. Houser, Menas Kafatos Jan 2008

A Study Of Land Surface Processes Using Land Surface Models Over The Little River Experimental Watershed, A. K. Sahoo, P. A. Dirmeyer, P. R. Houser, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Three different land surface models (Hydrological improvements to the Simplified version of the Simple Biosphere model (HySSiB), Noah model, and Community Land Model (CLM)) were simulated on the NASA Goddard Space Flight Center’s Land Information System platform at 1-km resolution over the Little River Experimental Watershed, Georgia, and the simulated results were analyzed to address the local-scale land-atmosphere processes. All the three models simulated the soil moisture in space and time realistically. The Noah model produced higher soil moisture whereas the CLM got lower soil moisture with many dry down phases. CLM and HySSiB models were oversensitive to the atmospheric …

Go to article

Contrasting The 2007 And 2005 Hurricane Seasons: Evidence Of Possible Impacts Of Saharan Dry Air And Dust On Tropical Cyclone Activity In The Atlantic Basin, D. Sun, K. M. Lau, Menas Kafatos Jan 2008

Contrasting The 2007 And 2005 Hurricane Seasons: Evidence Of Possible Impacts Of Saharan Dry Air And Dust On Tropical Cyclone Activity In The Atlantic Basin, D. Sun, K. M. Lau, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this study, we provide preliminary evidence of possible modulation by Saharan dust of hurricane genesis and intensification, by contrasting the 2007 and 2005 hurricane seasons. It is found that dust aerosol loadings over the Atlantic Ocean are much higher in 2007 than in 2005. The temperature difference between 2007 and 2005 shows warming in the low-middle troposphere (900–700 hPa) in the dusty region in the eastern North Atlantic, and cooling in the Main Development Region (MDR). The humidity (wind) differences between 2007 and 2005 indicate significant drying (subsidence) in the Western North Atlantic (WNA) in 2007. The drier air …

Go to article

Note On The Ndvi-Lst Relationship And The Use Of Temperature-Related Drought Indices Over North America, D. Sun, Menas Kafatos Jan 2007

Note On The Ndvi-Lst Relationship And The Use Of Temperature-Related Drought Indices Over North America, D. Sun, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

A comprehensive evaluation of the relationship between vegetation and Land Surface Temperature (LST) over the North America is presented. It is found that the correlations between LST and Normalized Difference Vegetation Index (NDVI) depend on the season-of-year and time-of-day. For winter, the correlation between NDVI and LST is positive. The strong negative correlations between LST and NDVI are only found during the warm seasons. Thus temperature-related drought indices may only be used in the warm seasons from May to October, and should be used with caution during cold seasons in North America. The cooling effect of vegetation on LST is …

Go to article

Improved Associated Conditions In Rapid Intensifications Of Tropical Cyclones, Ruixin Yang, J. Tang, Menas Kafatos Jan 2007

Improved Associated Conditions In Rapid Intensifications Of Tropical Cyclones, Ruixin Yang, J. Tang, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Rapid intensification (RI) of tropical cyclones (TC) is a major error source in TC intensity forecasting. In order to improve the estimates of RI probability, association rules are used to facilitate the process of mining for candidate sets of conditions. Compared to the relation analysis method, the technique of association rules can simply explore associations among multiple conditions. Our mining results identified a reduced predictor set with fewer factors identified in previous studies but improved RI probabilities. That is, the RI probability with three conditions satisfied: low vertical shear, high humidity, and the TC being in an intensification phase is …

Go to article

Influences Of Winter Haze On Fog/Low Cloud Over The Indo-Gangetic Plains, Ritesh Gautam, N. C. Hsu, Menas Kafatos Jan 2007

Influences Of Winter Haze On Fog/Low Cloud Over The Indo-Gangetic Plains, Ritesh Gautam, N. C. Hsu, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The aerosol loading in south Asia has increased considerably because of the growing population, urbanization, and industrialization in recent years. To understand the effects of aerosols on cloud properties in this region, we have analyzed an extensive collection of aerosol and cloud properties, obtained from the Moderate resolution Imaging Spectroradiometer (MODIS) data, over the Indian subcontinent during winter 2000–2006. During these winter months, the Indo-Gangetic (IG) plains, in the northern part of India, are subjected to dense haze and fog on the basis of MODIS climatology of aerosol optical depth and cloud properties (cloud effective radius, cloud top pressure, and …

Go to article

Role Of Anomalous Warm Gulf Waters In The Intensification Of Hurricane Katrina, Menas Kafatos, D. Sun, Ritesh Gautam, Z. Boybeyi, Ruixin Yang, G. Cervone Jan 2006

Role Of Anomalous Warm Gulf Waters In The Intensification Of Hurricane Katrina, Menas Kafatos, D. Sun, Ritesh Gautam, Z. Boybeyi, Ruixin Yang, G. Cervone

Mathematics, Physics, and Computer Science Faculty Articles and Research

The year 2005 experienced several strong hurricanes intensifying in the Gulf of Mexico before making landfall that severely damaged the Gulf States, especially Hurricane Katrina. Remarkable similarities between sea surface temperature anomaly (SSTA) and major hurricane (categories 3 and higher) activity over the Gulf are identified. However, the intensification of individual hurricanes may not necessarily be temporally and spatially coincident with the distribution of warm waters or high sea surface temperature (SST). High SST values are found in advance of significant intensification of Hurricane Katrina. We emphasize that high SSTA which occurred at the right time and right place was …

Go to article

Diurnal Temperature Range Over The United States: A Satellite View, D. Sun, R. T. Pinker, Menas Kafatos Jan 2006

Diurnal Temperature Range Over The United States: A Satellite View, D. Sun, R. T. Pinker, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Diurnal temperature range (DTR) is an important climate change index. Information on this parameter comes primarily from sparse and unevenly distributed observations of shelter air temperature. In this study, five years of GOES- 8 based estimates of land surface temperature (LST) over the United States are used to evaluate DTR at high spatial resolution. The spatial and temporal patterns that emerged show a high degree of consistency with independent satellite estimates of the Normalized Difference Vegetation Index (NDVI). Specifically, the arid regions in the western and central U.S. have larger DTRs than the eastern United States or the northwest coast. …

Go to article

Extreme Rainfall In Texas: Patterns And Predictability, John W. Nielsen-Gammon, Fuqing Zhang, Andrew M. Odins, Boksoon Myoung Jan 2005

Extreme Rainfall In Texas: Patterns And Predictability, John W. Nielsen-Gammon, Fuqing Zhang, Andrew M. Odins, Boksoon Myoung

Mathematics, Physics, and Computer Science Faculty Articles and Research

Extreme rainfall, with storm total precipitation exceeding 500 mm, occurs several times per decade in Texas. According to a compositing analysis, the large-scale weather patterns associated with extreme rainfall events involve a northward deflection of the tropical trade winds into Texas, with deep southerly winds extending into the middle troposphere. One such event, the July 2002 South-Central Texas flood, is examined in detail. This particular event was associated with a stationary upper-level trough over central Texas and northern Mexico that established a steady influx of tropical moisture from the south. While the onset of the event was triggered by destabilization …

Go to article

Correlation Between Atmospheric Co2 Concentration And Vegetation Greenness In North America: Co2 Fertilization Effect, C. Lim, Menas Kafatos, P. Megonigal Jan 2004

Correlation Between Atmospheric Co2 Concentration And Vegetation Greenness In North America: Co2 Fertilization Effect, C. Lim, Menas Kafatos, P. Megonigal

Mathematics, Physics, and Computer Science Faculty Articles and Research

The possibility that rising atmospheric CO2 concentrations are influencing plant growth in contemporary ecosystems has received little attention, and the studies that exist have been done on a small spatial scale. We correlated the monthly rate of relative change in normalized differenced vegetation index (NDVI) from advanced very high resolution radiometer (AVHRR) data to the rate of change in atmospheric CO2 concentration during the natural vegetation growing season for evidence of a possible CO2 fertilization effect on vegetation development. The study addressed seasonal and annual patterns in spatially averaged NDVI for 3 different ecological regions in North America from 1982 …

Go to article

First Prev