Seminars at COLA

Coastal earthquakes are very common throughout the world. These earthquakes bring out changes in land, ocean and atmospheric parameters. In the present talk, various land, ocean and atmospheric parameters retrieved from satellite data will be presented. The land, ocean and atmospheric parameters around the epicenter of numerous earthquakes show anomalous behavior prior to the coastal earthquakes. The interaction between land-ocean-atmosphere is found to be controlled by land and ocean parameters and location of the epicenter from the ocean. Numerous parameters deduced from satellite data over epicenter of earthquakes away from the ocean show weak interaction.

The long-term process of warfare involving great powers in the global system is well-documented for the past five hundred years of history (Levy 1983; Small and Singer 1983) with complete data and no missing observations. This study demonstrates the existence of a previously undetected process with exponentially increasing record values in war fatalities, or constantly increasing record magnitudes for warfare produced by the great power core of the global system. Thirteen wars since 1495 have set unprecedented battle-fatality records, not counting civilian and postwar fatalities. Based on these findings, the next record-setting war, which is now statistically overdue by several decades, is estimated to be of at least magnitude 7.35 (approximately 22.5 battle fatalities), global in scale, waged with weapons of mass destruction, and with arguably unpredictable consequences for the Earth's biosphere. Civilian and postwar casualties would significantly increase this preliminary estimate.

Monthly-mean precipitation rates from an ensemble of CCM3 simulations are compared tothose computed from observations of the TRMM satellite over a 44-month period. On regional and sub-regional scales, the comparison fares well over much of the Eastern Hemisphere south of 10S and over South America. However, model - satellite differences are large in portions of Central America and the Caribbean, the southern tropical Atlantic, the northern Indian Ocean, and the western equatorial and southern tropical Pacific. Since precipitation in the Tropics is the primary source of latent energy to the general circulation, such large model - satellite differences imply large differences in the amount of latent energy released. Differences tend to be seasonally-dependent north of 10N, where model wet biases occur in realistic wet seasons or model-generated artificial wet seasons. South of 10N, the model wet biases exist throughout the year or have no recognizable pattern.

The sensitivity of the middle atmosphere circulation to ozone depletion and increase in greenhouse gases is assessed by performing multiyear simulations with a chemistryclimate model. Three simulations with fixed boundary conditions have been carried out: one simulation for the near-past (1960) and two simulations for the near-present (1990 and 2000) conditions, including changes in greenhouse gases, in total organic chlorine, and in average sea surface temperatures. Changes in ozone are simulated interactively by the coupled model. It is found that in the stratosphere, ozone decreases, and that in the Antarctic, the ozone hole develops in both the 1990 and the 2000 simulations but not in the 1960 simulation, as observed. In the Arctic lower stratosphere, a cooling in March with respect to the 1960 simulation is found only for the 2000 simulation. Wave activity emerging from the troposphere is found to be comparable in the winters of the 1960 and 2000 simulations, suggesting that ozone depletion and greenhouse gases increase contribute to the 2000 1960 March cooling in the Arctic lower stratosphere. These results therefore provide support to the interpretation that the extreme low temperatures observed in March in the last decade can arise from radiative and chemical processes, although other factors cannot be ruled out. The comparison of the 1960 and 2000 simulations shows an increase in downwelling in the mesosphere at the time of cooling in the lower stratosphere (in March in the Arctic; in October in the Antarctic). The increase in dynamical heating associated with the increased downwelling may limit the cooling and the strengthening of the lower stratospheric polar vortex from above, facilitating ozone recovery and providing a negative dynamical feedback

Several global quantities are computed from the ERA40 re-analysis for the period 1958-2001 and explored for trends. These are discussed in the context of changes to the global observing system. Temperature, integrated water vapour (IWV) and kinetic energy are considered. The ERA40 global mean temperature in the lower troposphere has a trend of + 0.11K per decade over the period of 1979-2001, which is slightly higher than the MSU measurements, but within the estimated error limit. For the period 1958-2001 the warming trend is 0.14 K per decade but is likely to be an artefact of changes in the observing system. When this is corrected for the warming trend is reduced to 0.10K per decade The global trend in IWV for the period 1979-2001 is + 0.36 mm per decade. This is more than what is determined from the Clausius-Clapeyron relation assuming conservation of relative humidity. It is also larger than results from free model integrations driven by the same observed sea surface temperature (SST) as used in ERA40. It is suggested that the large trend in IWV does not represent a genuine climate trend but an artefact caused by changes in the global observing system such as the use of SSM/I and more satellite soundings in later years. Recent results are in good agreement with GPs measurements. The IWV trend for the period from 1958 is still higher but reduced to + 0.16mm per decade when corrected for changes in the observing systems. Total kinetic energy shows an increasing global trend. It is strongly suggested based on assimilation experiments that this trend is also incorrect and mainly caused by the huge changes in the global observing system in 1979. When this is corrected for no significant change in global kinetic energy from 1958 onwards can be found.