Atmospheric circulation anomalies, related to snowfall events on the Tanzanian volcano Kilimanjaro, were analyzed based on hourly snowfall data from an automated weather station (AWS), global precipitation and reanalysis products. Analysis of 5 years of data (2000–2005) shows that snowfall on Kilimanjaro is linked to large-scale circulation anomalies, which can be identified in global reanalysi...

Automated electronic soil moisture sensors, such as time domain reflectometry (TDR) and capacitance probes are being used extensively to monitor and measure soil moisture in a variety of scientific and land management applications. These sensors are often used for a wide range of soil moisture applications such as drought forage prediction or validation of large-scale remote sensing instruments...

A numerical method is developed for fire spread simulation modelling. The two dimensional surface model presented takes into account moisture content, radiation, wind and slope effects, which are by far the most important mechanisms in fire spread. We consider the combustion of a porous solid, where the energy conservation equation is applied. The influence of moisture content and eventually he...

In this paper a formulation for layer averaged sub-surface moisture transport, that models the lateral flow, is developed using the Richard’s equation. This formulation is consistent with the approach currently adopted in contemporary models used in land– atmosphere interaction studies. Explicit expressions are derived for layer averaged lateral transport contribution from diffusion, gravity, d...

[1] We test the hypothesis that the Pacific Ocean contributes moisture to the Intertropical Convergence Zone (ITCZ) over southern Central America, by spatial analysis of surface water dO values from Panama and Costa Rica. The dO values decrease with distance from the Caribbean Sea to the isthmian divide then gradually increase from the divide toward the Pacific slope, which suggests a contribut...

[1] To explore the role of hurricanes in the climate system, a detailed analysis is made of the bulk atmospheric moisture budget of Ivan in September 2004 and Katrina in August 2005 from simulations with the Weather and Research Forecasting (WRF) model at 4 km resolution without parameterized convection. Heavy precipitation exceeding 20 mm h 1 in the storms greatly exceeds the surface flux of m...

The Madden–Julian oscillation (MJO) produced by a mesoscale model is investigated using standardized statistical diagnostics. Results show that upperand lowerlevel zonal winds display the correct MJO structure, phase speed (8 m s) and space–time power spectrum. However, the simulated free atmosphere moisture, outgoing longwave radiation and precipitation do not exhibit any clear MJO signal. Yet...

Summer rainfall in the Sahel region of Africa exhibits one of the largest signals of climatic variability and with a population reliant on agricultural productivity, the Sahel is particularly vulnerable to major droughts such as occurred in the 1970s and 1980s. Rainfall levels have subsequently recovered, but future projections remain uncertain. Here we show that Sahel rainfall is skilfully pre...

Most major features of the interdecadal shift in boreal winter-spring precipitation over the American continents associated with the 1976–1977 transition are reproduced in atmospheric general circulation model (GCM) simulations forced with observed sea surface temperature (SST). The GCM runs forced with global and tropical Pacific SSTs produce similar multidecadal changes in precipitation, indi...