Weather Glossary

AVERAGE,MAXIMUM AND MINIMUM TEMPERATURE

Lowest,  highest and average temperature (C°) recorded during the period considered. 

AVERAGE DAILY TEMPERATURE

Average temperature (⁰C) for the period considered calculated on a daily (24 hour) basis. Weather maps in the MARS Explorer display actual values as well differences with the long term average (LTA) since 1979.

CLIMATIC WATER BALANCE

Difference (mm) between total rainfall and potential evapotranspiration over the period considered, as compared to the long term average (LTA) since 1979. Negative values indicate areas which are drier than usual (i.e. with a smaller surplus or greater deficit than usual). Positive values indicate areas which are wetter (or less dry) than usual (i.e. with a greater surplus or smaller deficit than usual).

MAXIMUM DAILY TEMPERATURE

Highest temperature (⁰C) recorded during the period considered.

MINIMUM DAILY TEMPERATURE

Lowest temperature (⁰C) recorded during the period considered.

NUMBER OF COLD DAYS

Number of days with minimum temperature below a threshold value of 0⁰C during the period considered. Weather maps in the MARS Explorer display actual values as well as differences with the long term average (LTA) since 1979.

NUMBER OF DAYS WITH SIGNIFICANT RAINFALL

Number of days with precipitation above a threshold value of 5 mm during the period considered. Weather maps in the MARS Explorer display actual values as well as differences with the long term average (LTA) since 1979.

NUMBER OF HOT DAYS

Number of days with maximum temperature above a threshold value of 30⁰C during the period considered. Weather maps in the MARS Explorer display actual values as well differences with the long term average (LTA) since 1979.

RAINFALL

Total amount of precipitation (expressed as mm rainfall equivalents) during the period considered. Weather maps in the MARS Explorer display actual values as well differences with the long term average (LTA) since 1979.

TEMPERATURE SUM

Sum of active temperatures over the period considered. Active temperature is defined here as the daily average temperature in excess of a base temperature of 0 ⁰C, as often used for temperate cereals. For example, the temperature sum for a three day period with average temperatures of respectively -5, +5 and 10 ⁰C is 0 + 5 + 10 = 15 ⁰Cd. Weather maps in the MARS Explorer display the temperature sums as actual values as well as % differences with the long term average (LTA) since 1979.

Crop Glossary

CROP DEVELOPMENT STAGE

Advancement of crop development, here expressed in descriptive terms (e.g. emergence, tillering, heading, flowering, grain filling, ripening, maturity for cereals).

LONGEST HEAT WAVE AROUND FLOWERING

Duration (d) of the longest period of consecutive days with maximum temperature > 30⁰C during a 31 day period starting 15 days before the calculated date of full flowering (anthesis).

PRECOCITY

Advancement of crop development as compared to the long term average (LTA) since 1979.

RAINFALL AROUND FLOWERING

Total amount of precipitation (mm) during a 31 day period, starting 15 days before the calculated date of full flowering (anthesis). Crop maps in the MARS Explorer display actual values as well % differences with the long term average (LTA) since 1979.

RAINFALL AROUND HARVESTING

Total amount of precipitation (mm) during a 31 day period, starting 15 days before the calculated date of harvest maturity. Crop maps in the MARS Explorer display actual values as well % differences with the long term average (LTA) since 1979.

RAINFALL AROUND SOWING

Total amount of precipitation (mm) during a 31 day period, starting 15 days before the estimated average sowing date.

RELATIVE SOIL MOISTURE

Soil moisture content in relation to plant available water capacity expressed on a scale from 0 (water available to plants) to 100 (soil water content at drained upper limit). Crop maps in the MARS Explorer display actual values as well % differences with the long term average (LTA) since 1979.

Remote Sensing Glossary

Fapar (smoothed) copernicus

fAPAR is the Fraction of Absorbed Photosynthetically Active Radiation of the incoming solar radiation that is absorbed by a crop plant for photosynthetic activity. fAPAR is a unitless variable.FAPAR be used as a indicator of the status and development of crop growth. The statellite-derived FAPAR depends, apart from the crop canopy structure itself, on other factor like the atmospheric conditions of observation and the geometry of observations. and angular configuration. FAPAR is defined by the Global Climate Observing System (GCOS) one of the 50 Essential Climate Variables