Lecturer with rank of: Professor
Ph.D. Princeton University
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The goal of my research is to gain a better understanding of such basic aspects of the atmospheric circulation as the pole-to-equator temperature gradient, the climatic distribution of surface easterlies and westerlies, and the location and strength of the jet stream. In this work I use a hierarchy of models ranging from comprehensive and realistic numerical circulation models to very idealized dynamical systems that capture some aspects of the relevant physics.
Examples of topics on which I have focused recently include: the fundamental issue of how best to think of the atmosphere as a whole as a “heat engine” and how best to understand the relatively low efficiency with which the atmosphere generates kinetic energy; how changes in the water vapor distribution in the atmosphere as climate warms produce a positive feedback on this warming; a hypothesis on factors that control how the poleward energy transport is partitioned between the atmosphere and the ocean; and the way in which large-scale mountain ranges and land-sea heating contrasts create the stationary waves, or deviations from longitudinal symmetry, that we see in the planetary-scale tropospheric wind field.
I have also begun a study of turbulent moist convection in the tropics with the aim of improving our understanding of the temperature and relative humidity profiles in the tropics, an issue that turns out to be very relevant to the global warming problem.
Pauluis, O., and I. M. Held, 2002: Entropy budget of an atmosphere in radiative-convective equilibrium. Part I: Maximum work and frictional dissipation. Journal of the Atmospheric Sciences, 59(2), 125-139.
Held, I. M., and B. J. Soden, 2000: Water vapor feedback and global warming. Annual Review of Energy and the Environment, 25, 441-475.
Held, I. M., 2001: The partitioning of the poleward energy transport between the tropical ocean and atmosphere. Journal of the Atmospheric Sciences, 58(8), 943-948.
Held, I. M., M. Ting, and H. Wang, 2002: Northern winter stationary waves: theory and modeling. Journal of Climate, 15(16), 2125-2144.