On 1 March 1997 a recreational pilot reported flying under and in front of a roll cloud on the northern Tasmanian coastline. This roll cloud, which was accompanied by a marked wind change at the surface, was propagating westward along the northern Tasmanian coastline, rather than in the easterly direction usual for cool change passage in the mid-latitudes. This paper describes the synoptic envi...

Soil moisture can significantly influence atmospheric evolution. However the soil moisture state predicted by land surface models, and subsequently used as the boundary condition in atmospheric models, is often unrealistic. New remote sensing technologies are able to observe surface soil moisture at the scales and coverage required by numerical weather prediction (NWP), and there is potential t...

The development of the adjoint of the forecast model and of the adjoint of the data assimilation system (adjointDAS) make feasible the evaluation of the derivative-based forecast sensitivity to DAS input parameters in numerical weather prediction (NWP). The adjoint estimation of the forecast sensitivity to the observation error covariance in the DAS is considered as a practical approach to prov...

The long term goal of this project is to develop tools for the automated analysis and nowcasting of conventional and remotely-sensed meteorological data, primarily for use at regional forecast centers, and aboard ship in remote littoral regions in which the Navy operates. In contrast to predicting weather out to several days (the purpose of numerical weather prediction), the purpose here is to ...

The presence of nonlinear terms in the governing equations of a dynamical system usually leads to the loss of predictability, e.g. in numerical weather prediction. However, for the El Niño-Southern Oscillation (ENSO) phenomenon, in an intermediate coupled equatorial Pacific model run under the 1961–1975 and the 1981–1995 climatologies, the latter climatology led to longer-period oscillations, t...

The ocean and the atmosphere are dynamically coupled by the transport of momentum which is driven by the wind shear at the sea surface. However, in situ wind measurements are relatively sparse over most of the world’s ocean and are largely limited to the locations of shipping routes. They are insufficient to cover the temporal and spatial scales required to study global environmental changes. T...

We have studied the accuracy of ice thickness (hi) retrieval based on night-time MODIS (Moderate Resolution Imaging Spectroradiometer) ice surface temperature (Ts) images and HIRLAM (High Resolution Limited Area Model) weather forcing data from the Arctic. The study area is the Kara Sea and eastern part of the Barents Sea, and the study period spans November–April 2008–11 with 199 hi charts. Fo...

A major challenge for operational numerical weather prediction over the Antarctic and Southern Ocean is the lack of traditional meteorological observations. This increases uncertainty in the model initial condition and results in inferior forecast skills as compared with numerical weather prediction in mid-latitudes over the Northern Hemisphere. With the lack of traditional observations over th...