Convective organization and tropical cyclone formation are examined in the framework of the marsupial paradigm through high-resolution numerical model simulations and observational analysis. The marsupial paradigm hypothesizes that the cat’s eye within the wave critical layer, or the so-called wave pouch, provides a favorable environment for tropical cyclone formation. It is found that the meso-β area near the pouch center is characterized by high saturation fraction and a short incubation time scale.
Black carbon in the Mountain West, the Arctic and the Himalayas: What do we know and what's missing?
Earth's albedo and surface temperature are determined partially by the areal coverage of snow, sea-ice, and glaciers. I will review recent work that 1) quantifies changes in Earth's net solar flux caused by cryospheric ablation during the remote sensing era, and 2) explores mechanisms of cryospheric change, with particular focus on processes involving black carbon (BC) aerosols. One key finding is that the Northern Hemisphere cryosphere radiative effect has declined by almost 0.5 W/m2 since 1979, driving a stronger albedo feedback than simulated by most climate models.
The interaction between the atmosphere and the ocean plays an important role in climate variability. This talk will discuss the use of high-resolution coupled regional climate modeling to carry out process studies of air-sea interaction in the Atlantic region. Specific phenomena to be discussed include the maintenance of sea surface temperature gradients over the tropical Atlantic, and the impacts of oceanic feedback on Atlantic hurricane activity.
Comprehensive altimetry monitoring of the Greenland and Antarctic ice sheets revealed a complex pattern of elevation changes and mass loss since the 1990s. However, the determination of detailed and accurate surface changes from the various altimetry data sets and DEMs remained a challenging problem.
Deglacial CO2 rise driven by deepwater formation in the North Pacific: constraints from boron isotopes and radiocarbon
The coastal ocean plays a key role in global biogeochemical cycles. In the Pacific Northwest, the coastal waters are strongly influenced by freshwater inputs from the Strait of Juan de Fuca (fed by the Fraser River and the rivers of Puget Sound) and the Columbia River. These rivers act as a conduit for land-derived nutrients and as a facilitator for entraining ocean-derived nutrients into the coastal euphotic zone. Riverine delivery of nutrients to the coastal ocean may play an important role in winter and spring phytoplankton blooms along the Washington and Oregon coasts.
The supply of dissolved organic nitrogen (DON) from gyre margins into the ocean’s oligotrophic subtropical gyres may potentially provide an important source of new N to gyre surface waters, thus sustaining export production. We explore this process by presenting the global surface ocean DON distribution, identify basin-scale patterns, and investigate potential mechanisms for DON removal from the euphotic zone. Processes contributing to marine DON dynamics will be presented from a combination of geochemical, biological, and modeling approaches.
Each quarter is devoted to current topics relating to Ecosystems. May be repeated for credit as topics vary.
Prerequisite: Earth System Science 200 or equivalent, or consent of instructor.