Monopulse radarsare one of the most accurate tracking radars used to guide various platforms. Detection and tracking of surface targets with these radars are performed in order to point strike targets. Sea clutter presents challenges for detecting floated targets and in addition to affecting detection height, it can cause errors in monopulse angle finding. In this paper, the airborne monopulse ...

This study investigates how variations in Arctic sea ice and sea surface conditions influence δ18O of presentday Arctic precipitation. This is done using the model isoCAM3, an isotope-equipped version of the National Center for Atmospheric Research Community Atmosphere Model version 3. Four sensitivity experiments and one control simulation are performed with prescribed sea surface temperature ...

[1] The GISS coupled model is used to investigate the sensitivity of sea ice to each of the following parameterizations: (1) two sea ice dynamics (CF: cavitating fluid; VP: viscousplastic), (2) the specification of oceanic isopycnal mixing coefficients in the Gent and McWillams isopyncal mixing (GM), and (3) the wajsowicz viscosity diffusion (WV). The large-scale sea ice properties are highly s...

J.M. Grebmeier and W. Maslowski (eds.), The Pacifi c Arctic Region: Ecosystem Status and Trends in a Rapidly Changing Environment, DOI 10.1007/978-94-017-8863-2_3, © Springer Science+Business Media Dordrecht 2014 Abstract Over the past several decades, there has been a fundamental shift in sea ice cover, age, and thickness across the Pacifi c Arctic Region (PAR). Satellite data reveal that tren...

We present moments and likelihood methods that estimate a DNA substitution rate from a group of closely related sister species pairs separated at an assumed time, and we test these methods with simulations. The methods also estimate ancestral population size and can test whether there is a significant difference among the ancestral population sizes of the sister species pairs. Estimates present...

Communication depends on reliability. Yet, the existence of stable honest signalling presents an evolutionary puzzle. Why should animals signal honestly in the face of a conflict of interest? While students of animal signalling have offered several theoretical answers to this puzzle, the most widely studied model, commonly called the 'handicap principle', postulates that the costs of signals st...

Animals often retreat to refugia when alarmed and the time they spend hiding reflects an economic decision that trades off reducing predation risk with other beneficial activities. Typically, refugia such as burrows are static, but some refugia are dynamic. For species with defensive mutualisms, hiding might be contingent on their mutualist's behaviour. We disturbed and quantified hiding time i...