Analysis

* Using 'Excel' for statistics

* The normal year value(평년값), as defined, uses the arithmetical average of the weather data for the past 30 years (1989-2018)

* The analysis method used in the Jeju Climate Change Characteristics Analysis Book by the Jeju Regional Meteorological Administration was referred to

Seasonal and annual average for climate statistics analysis are based on the Meteorological Administration's Climate Statistics Guidelines(기후통계지침) (KMA, 2019)
- Annual statistics were processed as monthly data for the year from January to December of the year
- We calculate an arithmetic mean of each season of data that divided the year into spring (March – May), summer (June – August), fall (September – November), and winter (December – February of the year).

Climate change tendency are analyzed with trend lines using average annual values for each analysis element for 46 years (1973-2018)

To compare the last 10 years (2009-2018) with the first 10 years (1973-1982)

Analyze trend between 15 years to identify tendency in climate change

Climate factors and extreme climate conditions index use thresholds developed by WMO CLIMDEX and KMA
- High Temperature Extreme Phenomenon Index : Heatwave days, tropical night days
- Low Temperature Extreme Phenomenon Index : Number of days of frost, Number of freezing days

*North Korea’s weather data that can be provided are limited to the heatwave and freezing, so only two indexes were used.

Selecting Station

The Northernmost, SEONBONG

Station number : 3

Latitude : 42° 19'N

Altitude above the sea level : 3m

The Southernmost, SEOGWIPO

Station number : 189

Latitude : 33° 24'N

Altitude above the sea level : 52m

We want to find out how the climate differed within the relatively narrow Korean Peninsula. Comparing the climate between North and South Korea, the difference in latitude is expected to be the most significant. However, the most representative North Korean city, Pyongyang, was 37° 34' 60"N latitude, which is only about 2° different from the South Korean capital of Seoul, was 39° 2’ 2”N latitude. For a more accurate comparison, the southern and northernmost sections of the Korean Peninsula were designated as observatories. So the southernmost part was designated as Mara island in Jeju Special Self-Governing Province and the northernmost as Onseong county in North Hamgyong Province. However, the Weather Data Open Portal, where we get weather data, did not provide weather and climate data for all regions and districts. Within the scope of the data provided, the project was carried out by resetting the southernmost to Seogwipo Observatory in Jeju Special Self-Governing Province and the northernmost to Seonbong City in North Hamgyong Province.

Selecting the Data

Collective Agency : Weather Data Open Portal(기상자료개방포털) & KMA

Collection Period : 1973~2018(for 46 years)

Weather Data Open Portal provides observation sources from 27 staions sent by North Korea through the World Meteorological Organization(WMO)'s weather communication network (GTS) starting in 1973. Therefore, we set to analyze the most recent value from 1973 to 2018 in accordance with the period of data in North Korea that can be obtained.