Seasonal to interannual variability of vegetation and fires at SAFARI 2000 sites inferred from advanced very high resolution radiometer time series data

Abstract

NOAA advanced very high resolution radiometer data are used to place the SAFARI 2000 and SAFARI 1992 intensive campaigns in the context of the interannual variability of vegetation conditions in southern Africa. Normalized difference vegetation index (NDVI) measurements and sea surface temperature (SST) indices of El Niño/Southern Oscillation (ENSO) are compared and the connections explained. The paper shows the vegetation evolution for the 2000 growing season, with unprecedented high and persistent NDVI anomalies associated with a cold phase of ENSO (La Niña) and above average rainfall between November and May, south of 15°S. In contrast, the 1992 season showed marked negative NDVI anomalies associated with an extreme drought in the southern part of the region, associated with the warm phase of ENSO (El Niño). These differences in NDVI patterns resulted in different patterns of fire distribution. More satellite detections of active fires were observed in 2000 than in 1992, especially for Botswana, Namibia, southern Zimbabwe, and southern Mozambique. Comparisons between in situ airborne measurements collected in 2000 and 1992 require an understanding of the extremely different vegetation and fire conditions associated with those years. Generalizations from results of the two SAFARI campaigns should be made with careful consideration of the extreme differences in conditions and the large interannual variability encountered in southern Africa, as depicted by the long‐term record of satellite vegetation measurements.

The Southern Africa Fire Network (SAFNet) regional burned‐area product‐validation protocol

“…Interannual variability in rainfall in Southern Africa is high and linked to a strong El Niñ o signal. Fuel production thus varies from year to year and, with it, fire timing and spatial distribution (Anyamba et al 2003). Burned areas are characterized by deposits of charcoal and ash, by the removal of vegetation cover and fuel, and by the exposure of underlying soil.…”

Interannual Changes of Fire Activity in the Protected Areas of the SUN Network and Other Parks and Reserves of the West and Central Africa Region Derived from MODIS Observations

“…At a regional level in Africa, systematic fire monitoring by Earth observations has been used in the Southern Africa region to support a range of studies related to the land-atmosphere interactions; more particularly in the context of the Southern African Regional Science Initiative: SAFARI-1992 [19] and SAFARI-2000 [20]. For the West Africa region, one could mention the work done by Langaas [21], more particularly on the diurnal fire cycle, or by Kennedy et al [22] and Grégoire [23] on the seasonal distribution.…”

Comparison of global inventories of CO emissions from biomass burning derived from remotely sensed data

“…Great uncertainty still exists in the assessment of gas and particulate emissions because of the higher temporal dynamic of vegetation fires with respect to other sources such as fossil fuel combustion (Liousse et al, 2004;Langmann et al, 2009); fires vary from place to place and from year to year and are characterized by high seasonality (Anyamba et al, 2003;Hély et al, 2003;Boschetti et al, 2004;Michel et al, 2005). Remotely sensed data potentially have all the characteristics for quantifying seasonal and inter-annual information on the emissions from vegetation fires because of their global and quasi continuous coverage (Cooke et al, 1996;Generoso et al, 2003).…”