Sea-Ice, Clouds and Atmospheric Conditions in the Arctic and Their Interactions as Derived from a Merged C3M Data Product

• Other Authors: Nag, Bappaditya (authoraut), Cai, Ming, 1957- (professor directing dissertation), Tam, Christopher K. W. (university representative), Clarke, Allan J. (committee member), Liu, Guosheng (committee member), Speer, Kevin G. (Kevin George) (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Program in Geophysical Fluid Dynamics (degree granting department)
• Format: Text
• Language: English
• Published: Florida State University
• Subjects: Atmospheric sciences; Meteorology; Arctic; albedo; North Atlantic; Sea ice
• Online Access: http://purl.flvc.org/fsu/fd/FSU_2016SU_Nag_fsu_0071E_13367; http://fsu.digital.flvc.org/islandora/object/fsu%3A366099/datastream/TN/view/Sea-Ice,%20Clouds%20and%20Atmospheric%20Conditions%20in%20the%20Arctic%20and%20Their%20Interactions%20as%20Derived%20from%20a%20Merged%20C3M%20Data%20Product.jpg

The polar regions of the world constitute an important sector in the global energy balance. Among other effects responsible for the change in the sea-ice cover like ocean circulation and ice-albedo feedback, the cloud-radiation feedback also plays a vital role in modulation of the Arctic environment. However the annual cycle of the clouds is very poorly represented in current global circulation models. This study aimed to explore the atmospheric conditions in the Arctic on an unprecedented spatial coverage spanning 70°N to 80°N through the use of a merged data product, C3MData (derived from NASA's A-Train Series). The following three topics provide outline on how this dataset can be used to accomplish a detailed analysis of the Arctic environment and provide the modelling community with first information to update their models aimed at better forecasts. (1)The three properties of the Arctic climate system to be studied using the C3MData are sea-ice, clouds, and the atmospheric conditions. The first topic is to document the present states of the three properties and also their time evolutions or their seasonal cycles. (2)The second topic is aimed at the interactions or the feedbacks processes among the three properties. For example, the immediate alteration in the fluxes and the feedbacks arising from the change in the sea-ice cover is investigated. Seasonal and regional variations are also studied. (3)The third topics is aimed at the processes in native spatial resolution that drive or accompany with sea ice melting and sea ice growth. Using a composite approach based on a classification due to surface type, it is found that limitation of the water vapour influx from the surface due to change in phase at the surface featuring open oceans or marginal sea-ice cover to complete sea-ice cover is a major determinant in the modulation of the atmospheric moisture. The impact of the cloud-radiative effects in the Arctic is found to vary with sea-ice cover and seasonally. The effect of the marginal sea-ice cover becomes more and more pronounced in the winter. The seasonal variation of the dependence of the atmospheric moisture on the surface and the subsequent feedback effects is controlled by the atmospheric stability measured as a difference between the potential temperature at the surface and the 700hPa level. A regional analysis of the same suggests that most of the depiction of the variations observed is contributed from the North Atlantic region. A Dissertation submitted to the Geophysical Fluid Dynamics Institute in partial fulfillment of the requirements for the degree of Doctor of Philosophy. Summer Semester 2016. May 2, 2016. C3MData, Cloud, Feedback, Interaction, Sea-Ice, Stabillity Includes bibliographical references. Ming Cai, Professor Directing Dissertation; Christopher Tam, University Representative; Allan Clarke, Committee Member; Guosheng Liu, Committee Member; Kevin Speer, Committee Member.