We have successfully implemented an explicit cloud scheme within the Florida State University Global Spectral Model. This includes the liquid water mixing ratio and cloud fractions as two additional dependant variables. The main purpose of this extension is two fold: we wished to improve our global cloud forecasting capability (low, medium and high clouds) and to have a better definition of the...

The authors exploit the remarkable similarity between recent climate trends and the structure of the ‘‘annular modes’’ in the month-to-month variability (as described in a companion paper) to partition the trends into components linearly congruent with and linearly independent of the annular modes. The index of the Northern Hemisphere (NH) annular mode, referred to as the Arctic Oscillation (AO...

We evaluate the new regional quasigeoid model (OTG12) for New Zealand using the method which utilises the discretised integralequation approach for computing the near-zone contribution. The far-zone contribution is computed by modi ed spherical harmonics of the geopotential. Adopting the remove-compute-restore computation scheme, the nearand far-zone contributions are computed for the residual ...

The response of atmospheric blocks and the wave amplitude of midlatitude jets to changes in the midlatitude to pole, near-surface temperature difference (ΔT), is studied using an idealized dry general circulation model (GCM) with Held-Suarez forcing. Decreasing ΔT results in slower zonal winds, a mean state with reduced meridional gradient of the 500 hPa geopotential height (Z500), a smaller va...

Arctic sea surface height (SSH) is poorly observed by radar altimeters due to the poor coverage of the polar oceans provided by conventional altimeter missions and because large areas are perpetually covered by sea ice, requiring specialized data processing. We utilize SSH estimates from both the icecovered and ice-free ocean to present monthly estimates of Arctic Dynamic Ocean Topography (DOT)...

Fire is the dominant disturbance in forest ecosystems across Canada and Alaska, and has important implications for forest ecosystems, terrestrial carbon dioxide emissions and the forestry industry. Large fire activity had increased in Canadian and Alaskan forests during the last four decades of the 20th century. Here we combined the Palmer Drought Severity Index and historical large fire databa...

Recent research has used enstrophy-based diagnostics to identify the development and dissipation stages of blocking events. These previous studies made use of reanalysis data sets in the calculations of the enstrophy-based diagnostics, such as the NCEP-NCAR reanalysis (2.5× 2.5) of geopotential height and horizontal winds. However, none of these studies has explored the use of the enstrophy-bas...

The geopotential height (GPH) product created from global observations by the High Resolution Dynamics Limb Sounder (HIRDLS) instrument on NASA’s Earth Observing System (EOS) Aura spacecraft is discussed. The accuracy, resolution and precision of the HIRDLS version 7 algorithms are assessed and data screening recommendations are made. Comparisons with GPH from observations, reanalyses and model...