NATIONAL METEOROLOGICAL SERVICE SERVICIO METEOROLÓGICO NACIONAL (SMN) ARGENTINA. Liliana N. NúñN. úñez. .

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1 NATIONAL METEOROLOGICAL SERVICE SERVICIO METEOROLÓGICO NACIONAL (SMN) ARGENTINA Liliana N. NúñN úñez.

2 At the Argentine National Meteorological Service (SMN in Spanish)

3 At the Argentine National Meteorological Service (SMN in Spanish) We use the mean and the statistics that are our normal values.

4 .At the Argentine National Meteorological Service (SMN in Spanish).We use the mean and the statistics that are our normal values..we know that we are immerse in a climatic change, then, I think that we need to change the period of the normal or employ another indicator to qualify the meteorological variables.

5 Related with the precipitation, the SMN produce daily, decadal and monthly bulletins, that include:

6 Related with the precipitation, the SMN produce daily, decadal and monthly bulletins, that include: Hydrological balance Days with and without precipitation Accumulated precipitation at different periods of time Indices to qualify the precipitation NDVI

7 Hydrological balance and related with it

8 Hydrological balance, ETP, precipitation less ETP and balance difference with the previous decade ETP precipitation (Potential less ETP evapotranspiration balance, difference between two consecutive periods

9 Related with the precipitation, the SMN produce daily, decadal and monthly bulletins, that include: Hydrological balance Needs of water in the coming 10 days to be: Not with drought Not at the beginning of drought

10 Related with the precipitation, the SMN produce daily, decadal and monthly bulletins, that include: Hydrological balance Needs of water at the following ten 10 days to be: Not with drought, Not at the beginning of drought in good conditions begin to have excesses

11 Related with the precipitation, the SMN produce daily, decadal and monthly bulletins, that include: Hydrological balance Evolution of the balance along three years

12 Related with the precipitation, the SMN produce daily, decadal and monthly bulletins, that include: Hydrological balance Days with and without precipitation accumulated precipitation indices to qualify the precipitation Difference with the normal mean or anomaly Percent of normal or Percent of anomaly SPI Quintiles Deciles NDVI PROBn

13 For special presentations, for the Agropecuary Emergency National Commission (where the representatives of the agriculturists that want to be declared in an emergency or disaster present their situation to be accepted or not), or for others we prepare special repots. For example, this year, part of the Argentina suffered a severe drought. Part of the report is as follows

14 2008 anual precipitation Decil

15 Enero 2009 NDVI JAN 2007 NDVI JAN 2009

16 JUL AUG 2009 AUG 2009 Precipitation Anomaly

17 SMN Hidric balance One month difference

18 andonsomeoccasionsweuse the Monthly Martone indice

19 In Argentina, rainfall doesn't have a normal behavior. The mean is not a representative statistic. Then the anomaly and the porcentual anomaly are bad indices for the Argentina precipitation For this region the SPI and the Decil are bad indices too, but the Decil is better.

20 We developed a new index: the PROBn It s related with the Decil, then I'll do a comparison between the two

21 Deciles (Gibbs and Maher,1967) PROBn (Núñez, 2009) uses historical data.- Divides the record into tenths of the distribution. uses historical data.- divides the record into fixed intervals, with physic meaning, and obtain their probabbility..- each series has his own limits.- shouldn t be presented on a map.- all the series has the same limits.- can be presented on a map

22 comparison DECILES PROBn each 10% probability determines the value that corresponds, the deciles choose the intervals between those whowanttostudytheseries, and then determines the probability

23 -- DECIL.- The serie is ordered from lowest to highest and the extreme values are established PROBn.- establish the limits of the intervals.- The serie is ordered from lowest to highest and the extreme values are established.- establish the interval of each decile.-establish the percentage of each interval.- Determine the decile to which each data belongs, and the probability of it= 10%.- Determine the interval to which each data belongs and the probability of it= PROBn

24 DECIL PROBn Establish the qualification of the data.- relative qualification.- qualification dependent on the series.- without physical meaning.- percentage of data in the decile= 10%.- percentage independent of the serie. Each interval has the same probability of occurrence= 10% Establish the qualification of the data.- absolute qualification.- qualification independent on the series.- with physical meaning.-percentage of data in the interval= PROBn.-percentage dependent of the serie. Each interval has a probability of occurrence = PROBn

25 DECIL.-Percentage of data that are below: Defined the interval is always the same percentage of data that are exceeded. PROBn.-Percentage of data that are below: Defined the interval is variable the percentage of data that are exceeded. Percentage of data that are above Defined the interval is the always the same percentage of data that are above. The deciles of different time periods are not combinable Percentage of data that are above Defined the interval is variable the percentage of data that are above. The PROBn of different time periods are combinable

26 Example For the intervals I use a modification of the Blair CLASIFICATION BY RAINFALL (Blair,1942) Climatic type Extreme arid 100 Arid 250 Semiarid 500 Dry subhumid 600 Mid subhumid 800 Subhumid 1000 Humid Humid Humid Humid Hiperhumid > 2000 annual rainfall (mm)

27 Annual precipitation at estations Est-1, Est-2 and Est-3:

28 DECIL - PROBn

29 DECIL - PROBn

30 DECIL - PROBn 3 3

31 DECIL - PROBn At this example 200 mm for PROBn is always ARID, while 200 mm for the Deciles is "extremely above average" for Est-1 or "Extremely below average" for Est-3

32 DECIL - PROBn At this example 1800 mm for PROBn is always HUMID-18, while 1800 mm for the Deciles is "extremely above average" for Est-3 or "Extremely below average" for Est-2

33 DECIL - PROBn At this example 1800 mm for PROBn is always HUMID-18, while 1800 mm for the Deciles is "extremely above average" for Est-3 or "Extremely below average" for Est-2 This is the reason for what PROBn can be presented on a map and

34 PROBn With this methology it's possible to obtain 4 indices PROBn: the probability in the interval PROBnb: the probability below the interval PROBna: the probability above the interval And PROBnd: the probability in the interval and below it (the equivalent to the Decil) It provides a complete description of the distribution of the series

35 PROBnd PROB1d = monthly precipitation average and the probability of the interval in which it is located more probability below this range (n = 1 month) the

36 PROBnd PROB1d = monthly precipitation average and the probability of the interval in which it is located more probability below this range (n = 1 month) the

37 PROBnd and MOVn

38 PROBnA and MOVn Probability above the interval

39 Thanks!!! Liliana Núñez Agrometeorology Department National Weather Service - lnunez@smn.gov.ar

40 SERVICIO METEOROLÓGICO NACIONAL

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