Sentences with phrase «vegetation greenness»

While recent findings based on satellite records indicate a positive trend in vegetation greenness over global drylands, the reasons remain elusive.

To clarify the impact of long - term drought on the Congo rainforest, Zhou and colleagues set out to see whether they could detect a trend in a satellite measure of vegetation greenness called the Enhanced Vegetation Index.

In addition to global evapotranspiration trends, they examined vegetation greenness and general climate data including temperature, precipitation and cloudiness.

One of the lead authors of the study, Arindam Samanta, said» The MODIS vegetation greenness data suggest a more widespread, severe and long - lasting impact to Amazonian vegetation than what can be inferred based solely on rainfall data.»

Analysis of satellite - sensed vegetation greenness and meteorological station data suggest an enhanced plant growth and lengthened growing season duration at northern high latitudes since the 1980s (Zhou et al., 2001, 2003c).

Teasing out changes in vegetation greenness over the Amazon is one of the most challenging problems for satellite remote sensors because there's no tougher place on Earth to observe the surface.

The FORMA alerts system then detects pronounced changes in vegetation cover over time, as measured by the Normalized Difference Vegetation Index (NDVI), a measure of vegetation greenness.

The positive trend in vegetation greenness has been observed through satellite images, but the reasons for it had been unclear.

«With our work, we have shown that there is a dry season greening but that under extended drought we get a decline in vegetation greenness.»

Measurements from a handful of field stations across the basin, however, indicated the vegetation greenness due to increased sunlight in the dry season would decline once the water in the soils was used up — especially in drought years.

They found that temperature is likely to be useful to migrants in making adjustments in timing in route, however, they dispute the notion that a commonly used index of vegetation greenness is a useful cue for migration timing in the study region.

For example, in years that had more than average burning during the dry season, measurements of soil moisture, evaporation and vegetation greenness — all of which help to trigger rain — decreased in the following wet season.

To do so, Ichoku and his colleagues used satellite records from 2001 to 2014 — including data from NASA's Moderate Resolution Imaging Spectroradiometer and the Tropical Rainfall Measurement Mission — to analyze the impact of fires on various water cycle indicators, namely soil moisture, precipitation, evapotranspiration and vegetation greenness.

Previous research used satellite - based measurements of vegetation greenness to investigate changes in the Amazon rainforest, notably the effects of severe short - term droughts in 2005 and 2010.

The images were taken at weekly intervals, from 2002 to 2007, of the wheat - growing seasons to measure the «vegetation greenness» − an indicator of crop yield.

The trend in vegetation greenness has been linked to increasing growing season length at high latitudes and enhancemed terrestrial CO2 uptake in northern ecosystems.

three global land cover seasonality products describing the vegetation greenness, the snow and the burned areas occurrence dynamics,

Satellite measures of vegetation greenness, together with animal stocking data and key climatic factors, reveal interannual precipitation variability to be a significant constraint on global pasture productivity.