SCIENTIFIC REPORT ON COST SHORT TERM SCIENTIFIC MISSION Tania Marinova National Institute of Meteorology and Hydrology at the Bulgarian Academy of Sciences, 66 Tsarigradsko shose, blvd., Sofia 1784, BULGARIA, COST STSM Reference Number: COST-STSM-ES STSM Topic: Homogenization of Monthly Climate Data Period: 04 October 2009 – 17 October 2009 Host: Tamas Szentimrey, Hungarian Meteorological Service, 1024 Budapest, Hungary, COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

1. Introduction The STSM main goal is to study the Hungarian homogenization procedure (MASH v.3.02) and to apply it on the monthly benchmark dataset prepared by the WG1 within the framework of the COST Action ES0601: Advances in homogenization methods of climate series: an integrated approach (HOME). During the STSM at the Hungarian Meteorological Service 7 surrogate networks (air temperature – 5, precipitation – 2) and 1 synthetic network (air temperature) from the monthly benchmark dataset (1900–1999) have been homogenized by the program system MASH. The obtained results will contribute to reach the scientific purposes of the COST Action ES0601. COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

2. MASH procedure for the STSM Special MASH procedure for the purposes of the STSM has been developed by the author of the program system MASH Dr. Tamas Szentimrey. ). Detailed description of that procedure is given in the scientific report (firstly, examination of the shorter period 1925–1999, in view of the great number of missing data in the period 1900–1924, and then examination of the entire period 1900–1999; No metadata; Significant level: 0.05 – air temperature, 0.01 – precipitation ). Scheme of the file directories used in the course of the procedure execution is presented in Fig.1. COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

Figure 1. Scheme of the file directories used in the course of the MASH procedure execution during the STSM COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

3. Data The MASH procedure for the STSM has been applied on 8 data networks from the HOME monthly benchmark dataset, as follows: 5 surogate air temperature networks 5 surogate air temperature networks [000001], [000002], [000003], [ ],[000020] - [000001], 9 stations, monthly minimum air temperature - [000002], 5 stations, monthly minimum air temperature - [000003], 15 stations, mean monthly air temperature - [000019], 9 stations, mean monthly air temperature - [000020], 9 stations, monthly minimum air temperature 2 surrogate precipitation networks 2 surrogate precipitation networks [000005], [000009] - [000005], 9 stations, monthly precipitation sum - [000009], 5 stations, monthly precipitation sum 1 synthetic air temperature network 1 synthetic air temperature network [000003] - [000003], 9 stations, mean monthly air temperature COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

4. Results The final results for each of the stations from the corresponding network include:   homogenized monthly series and corresponding flags   detected break points and outliers   long-term annual variations of the original and homogenized data series, graphically presented. All detected break points and outliers, as well as the long- term annual variations of the original and homogenized minimum air temperature series for the stations from the surrogate network [000001] are presented. COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

Detected break points, outliers Minimum air temperature – surrogate network [000001]: stations (1), (2) COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

Minimum air temperature – surrogate network [000001]: stations (3), (4), (5) Detected break points, outliers COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

Figure 2. Surrogate network [000001] – annual minimum air temperature variations for the period 1900 – 1999, stations: (1) – , (2) – , (3) – , (4) – , (5) – COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

Minimum air temperature – surrogate network [000001]: stations (6), (7) Detected break points, outliers COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

Detected break points, outliers Minimum air temperature – surrogate network [000001]: stations (8), (9) COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

Figure 3. Surrogate network [000001] – annual minimum air temperature variations for the period 1900 – 1999, stations: (6) – , (7) – , (8) – , (9) – COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain

Thank you for your attention! COST ES0601 Working Groups 2-4 meeting, 25 – 27 January 2010, Palma de Mallorca, Spain