WP1000

Met Office: A development version of the global climate model (with improved representation of convection) was integrated for 20 years (1957-76)  and the characteristics of the Asian summer monsoon simulation assessed. Compared with previous versions, the strength of the Somali Jet and intensity of the rainfall distribution are both reduced (and consequently improved). The results were presented at the Trieste conference.

Met Office / UREADMY: The vegetation component of the Hadley Centre climate model is being modifed to further improve the representation the vegetation seasonality in the monsoon regions.  The upgraded scheme will be used in simulations to examine the effect of vegetation seasonality on the simulation of monsoon climates (on track for Year 2 milestone).

WP1200

Met Office: Using data from the idealised SST experiments mentioned in the annual report, the mechanisms linking SST anomalies in the Mediterranean, to summer rainfall over the Sahel have been investigated. It is proposed that when Mediterranean SSTs are warmer than average, then local evaporation is enhanced, and the moisture content of the lower troposphere increases. This additional moisture is advected  southwards across the eastern Sahara by the mean flow, leading to enhanced low-level  moisture convergence over the Sahel, which feeds enhanced rainfall. This is then amplified by  four positive feedback mechanisms: a more rapid influx of moisture from the tropical Atlantic triggered by enhanced convective heating; a reduced outflow of moisture from the mid-level African easterly jet due to a surface wetness and baroclinic feedback; an enhanced local hydrological cycle; and a larger rainfall contribution from African easterly waves. A paper discussing these results, and those reported earlier, has been submitted for publication. This aspect of the work is now complete.

WP2000

Met Office: Our contribution to this work pakage was completed in year 1. The remaining task is to make our regional climate simulations of the Indian summer monsoon available on the PROMISE archive (see WP4000).

WP3100

Met Office: A coupled climate-vegetation simulation was performed with a scenario of a transition from an undisturbed Amazon rainforest to partial deforestation as projected for 2020 considering Brazil's development plans.  Mean Amazonian rainfall shows a small decreasing trend,

but interannual and interdecadal variability is large and further work is needed to establish whether the trend is statisically significant.

WP4000

Met Office: Seasonal predictions using persisted SST anomalies, made with HadAM3, have been completed (under the DEMETER project) using initial conditions from Nov 1986 to Nov 1991 and for 1972. The response to ENSO (as portrayed by the 1988-1987 differences) looks

encoraging. Parallel predictions using the coupled model are about to commence. Data from these predictions and from our regional climate simulations will be made available on the PROMISE archive within the next 6 months.

WP5000

Met Office: The latest version of the Hadley Centre regional climate model (HadRM3H) has been installed at the Indian Institute of Tropical Meteorology in Pune. It will be used to produce high resolution predictions of climate change over India.