**1. Introduction to SEMDP**

Meteorological observations clearly demonstrate that the global climate change occurs since the beginning of the industrial revolution, with particular rapid change since about 1950, including changes in weather and climate extreme events [1]. This increase in weather and climate extremes leads to significant increase in impact of natural disasters on society worldwide. One of the world's most disaster-prone regions is Asia-Pacific. In this region, almost 2 million people were killed in disasters between 1970 and 2011, representing 75% of all disaster fatalities globally; the most frequent hazards in the region are hydrometeorological [2]. The increase in frequency and severity of weather and climate extreme events and their impact on society requires the development and implementation of new tools for monitoring these hazardous phenomena globally using modern satellite remote sensing techniques.

Recognizing the importance of this issue, in February 2017 the World Meteorological Organization organized a workshop on operational space-based weather and climate extremes monitoring demonstration project which was attended by representatives of satellite operators, research and development space agencies, Regional Climate Centres (RCCs), and National Meteorological and Hydrological Services (NMHSs) to stimulate a dialog about enhancing utilization of space-based observation data and products for monitoring weather and climate extremes.

The workshop recognized that significant progress has been made in recent years in developing space-based observations in most geophysical fields and that several high-resolution satellite products were available on a quasi-realtime basis, enabling enhanced utilization for monitoring weather and climate extremes from space. It was also recognized that for many developing and least developed countries, strengthening human and technological capacity is required to provide an adequate level of services. As such, transfer of knowledge from countries with greater technological developments is essential, in order to fully utilize advantages of modern space-based data and derived products in developing countries.

Following the workshop's recommendations, WMO initiated SEMDP – the space-based weather and climate extremes monitoring demonstration project. SEMDP is established to run initially for 2 years (2018–2019) and be focused on weather and climate extremes such as drought and heavy precipitation over the Southeast Asia region and the Pacific Ocean. Space-based data and derived products form critical part of operations at NMHSs and RCCs for weather monitoring; however, satellite products are not fully utilized yet for climate applications.

Most NMHSs in countries of Southeast Asia and the Pacific use conventional surface-based rain gauge observations for extreme precipitation monitoring. Rain gauge observations provide accurate measurements of precipitation; however, data are restricted to locations of meteorological observation stations. For example, spatial distribution of rain gauges over Australia is not uniform: while eastern and southern parts of the country, southwest of Western Australia and northern and eastern parts of Tasmania, are densely covered by observation stations, spatial coverage of interior parts of Australia is poor. This issue of nonuniform spatial coverage is typical for countries in the Asia-Pacific region, and the density of rain gauges in many areas is considered as inadequate by users. In contrast with conventional surface-based observations, rainfall estimates derived from global space-based observations better address users' needs for precipitation information providing uniform spatial coverage.

**53**

*WMO Space-Based Weather and Climate Extremes Monitoring Demonstration Project…*

The satellite-based rainfall estimates are based on retrieval algorithms of passive instrumental measurements (radiometry) relating radio signals recorded in infrared and microwave bands of electromagnetic spectrum to the occurrence and intensity of precipitation. Infrared instruments record signals around 11 μm wavelength providing information about cloud top temperature and then applying mathematical retrieval algorithms converting it to estimates of precipitation. Microwave instruments utilize a broad range of electromagnetic spectrum from 10 to 100 GHz. Channels up to 37 GHz primarily provide information about liquid precipitation in the lower parts of clouds; retrieval algorithms are based on assumption that larger amounts of liquid emit higher amount of microwave radiation. Radio signals received through channels above 37 GHz are primarily used for precipitation estimates in the upper parts of clouds due to scattering microwave radiation by solid precipitation. Microwave satellite-borne instruments are employed on the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement

Space-based observations can also address users' needs for information about precipitation extremes on short time scales. Current operational climate products for drought monitoring derived from surface-based observations are typically focused on identifying rainfall deficits over extended periods (months to years) using percentile and/or decile analysis. As for heavy precipitation, they are typically diagnosed on a monthly time scale. Using space-based observations, it would be possible to monitor extreme precipitation events over shorter time periods—pentad (5 days), week (7 days), and longer periods of up to a month—in order to respond to current and future users' requirements. Monitoring weather and climate extremes on shorter time scales is considered by RCCs and NMHSs as a valuable extension of their operational products to enhance climate services for users in Asia-Pacific. In this chapter, WMO SEMDP and its implementation strategy are described, and first outcomes of Asia-Pacific regional cooperation on drought and heavy

SEMDP is designed as a demonstration project to bring benefits of utilizing space-based observations of extreme precipitation to operational services of RCCs and NMHSs. During the project's first implementation stage, SEMDP's geographical domain covers the Southeast Asia region and the Pacific Ocean—area from 40°N to 45°S and 50°E to 160°W. Two agencies—the Earth Observation Research Center/ Japan Aerospace Exploration Agency and the Climate Prediction Center/National Oceanic and Atmospheric Administration—provide satellite data and products for the SEMDP region. It is planned to (i) gradually expand SEMDP's geographical domain during subsequent stages of the project's implementation to accomplish the global coverage for SEMDP products and (ii) involve more space and meteorological agencies from around the world to contribute to providing RCCs and NMHSs

SEMDP is focused on monitoring extreme events. "Extreme weather event" and "extreme climate event" according to the IPCC AR5 WG I report are defined as follows. "An extreme weather event is an event that is rare at a particular place and time of year. Definitions of rare vary, but an extreme weather event would normally be as rare as or rarer than the 10th or 90th percentile of a probability density function estimated from observations. By definition, the characteristics of what is called extreme weather may vary from place to place in an absolute sense. When a pattern

*DOI: http://dx.doi.org/10.5772/intechopen.85824*

precipitation monitoring from space are presented.

**2. SEMDP precipitation products**

with a range of SEMDP products.

(GPM) mission.

#### *WMO Space-Based Weather and Climate Extremes Monitoring Demonstration Project… DOI: http://dx.doi.org/10.5772/intechopen.85824*

The satellite-based rainfall estimates are based on retrieval algorithms of passive instrumental measurements (radiometry) relating radio signals recorded in infrared and microwave bands of electromagnetic spectrum to the occurrence and intensity of precipitation. Infrared instruments record signals around 11 μm wavelength providing information about cloud top temperature and then applying mathematical retrieval algorithms converting it to estimates of precipitation. Microwave instruments utilize a broad range of electromagnetic spectrum from 10 to 100 GHz. Channels up to 37 GHz primarily provide information about liquid precipitation in the lower parts of clouds; retrieval algorithms are based on assumption that larger amounts of liquid emit higher amount of microwave radiation. Radio signals received through channels above 37 GHz are primarily used for precipitation estimates in the upper parts of clouds due to scattering microwave radiation by solid precipitation. Microwave satellite-borne instruments are employed on the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement (GPM) mission.

Space-based observations can also address users' needs for information about precipitation extremes on short time scales. Current operational climate products for drought monitoring derived from surface-based observations are typically focused on identifying rainfall deficits over extended periods (months to years) using percentile and/or decile analysis. As for heavy precipitation, they are typically diagnosed on a monthly time scale. Using space-based observations, it would be possible to monitor extreme precipitation events over shorter time periods—pentad (5 days), week (7 days), and longer periods of up to a month—in order to respond to current and future users' requirements. Monitoring weather and climate extremes on shorter time scales is considered by RCCs and NMHSs as a valuable extension of their operational products to enhance climate services for users in Asia-Pacific.

In this chapter, WMO SEMDP and its implementation strategy are described, and first outcomes of Asia-Pacific regional cooperation on drought and heavy precipitation monitoring from space are presented.

### **2. SEMDP precipitation products**

SEMDP is designed as a demonstration project to bring benefits of utilizing space-based observations of extreme precipitation to operational services of RCCs and NMHSs. During the project's first implementation stage, SEMDP's geographical domain covers the Southeast Asia region and the Pacific Ocean—area from 40°N to 45°S and 50°E to 160°W. Two agencies—the Earth Observation Research Center/ Japan Aerospace Exploration Agency and the Climate Prediction Center/National Oceanic and Atmospheric Administration—provide satellite data and products for the SEMDP region. It is planned to (i) gradually expand SEMDP's geographical domain during subsequent stages of the project's implementation to accomplish the global coverage for SEMDP products and (ii) involve more space and meteorological agencies from around the world to contribute to providing RCCs and NMHSs with a range of SEMDP products.

SEMDP is focused on monitoring extreme events. "Extreme weather event" and "extreme climate event" according to the IPCC AR5 WG I report are defined as follows. "An extreme weather event is an event that is rare at a particular place and time of year. Definitions of rare vary, but an extreme weather event would normally be as rare as or rarer than the 10th or 90th percentile of a probability density function estimated from observations. By definition, the characteristics of what is called extreme weather may vary from place to place in an absolute sense. When a pattern

*Rainfall - Extremes, Distribution and Properties*

Meteorological observations clearly demonstrate that the global climate change occurs since the beginning of the industrial revolution, with particular rapid change since about 1950, including changes in weather and climate extreme events [1]. This increase in weather and climate extremes leads to significant increase in impact of natural disasters on society worldwide. One of the world's most disaster-prone regions is Asia-Pacific. In this region, almost 2 million people were killed in disasters between 1970 and 2011, representing 75% of all disaster fatalities globally; the most frequent hazards in the region are hydrometeorological [2]. The increase in frequency and severity of weather and climate extreme events and their impact on society requires the development and implementation of new tools for monitoring these hazardous phenomena globally using modern satellite remote sensing

Recognizing the importance of this issue, in February 2017 the World Meteorological Organization organized a workshop on operational space-based weather and climate extremes monitoring demonstration project which was attended by representatives of satellite operators, research and development space agencies, Regional Climate Centres (RCCs), and National Meteorological and Hydrological Services (NMHSs) to stimulate a dialog about enhancing utilization of space-based observation data and products for monitoring weather and climate

The workshop recognized that significant progress has been made in recent years in developing space-based observations in most geophysical fields and that several high-resolution satellite products were available on a quasi-realtime basis, enabling enhanced utilization for monitoring weather and climate extremes from space. It was also recognized that for many developing and least developed countries, strengthening human and technological capacity is required to provide an adequate level of services. As such, transfer of knowledge from countries with greater technological developments is essential, in order to fully utilize advantages of modern space-based data and derived products in

Following the workshop's recommendations, WMO initiated SEMDP – the space-based weather and climate extremes monitoring demonstration project. SEMDP is established to run initially for 2 years (2018–2019) and be focused on weather and climate extremes such as drought and heavy precipitation over the Southeast Asia region and the Pacific Ocean. Space-based data and derived products form critical part of operations at NMHSs and RCCs for weather monitoring; however, satellite products are not fully utilized yet for climate applications.

Most NMHSs in countries of Southeast Asia and the Pacific use conventional surface-based rain gauge observations for extreme precipitation monitoring. Rain gauge observations provide accurate measurements of precipitation; however, data are restricted to locations of meteorological observation stations. For example, spatial distribution of rain gauges over Australia is not uniform: while eastern and southern parts of the country, southwest of Western Australia and northern and eastern parts of Tasmania, are densely covered by observation stations, spatial coverage of interior parts of Australia is poor. This issue of nonuniform spatial coverage is typical for countries in the Asia-Pacific region, and the density of rain gauges in many areas is considered as inadequate by users. In contrast with conventional surface-based observations, rainfall estimates derived from global space-based observations better address users' needs for precipitation information providing

**1. Introduction to SEMDP**

techniques.

extremes.

developing countries.

uniform spatial coverage.

**52**

of extreme weather persists for some time, such as a season, it may be classed as an extreme climate event, especially if it yields an average or total that is itself extreme (e.g., drought or heavy rainfall over a season)." [3]. Thus, SEMDP approach to defining drought and heavy rainfall is based on the above definitions.

Based on the workshop's recommendations and consequent consultations with the satellite data providers (EORC/JAXA and CPC/NOAA) and users (RCCs and NMHSs in Southeast Asia and the Pacific), SEMDP aims to satisfy users' requirements for monitoring precipitation extremes on short time scales, i.e., on pentad (5 days) to weekly up to monthly basis utilizing satellite-based products available on near real-time basis for monitoring "heavy precipitation" and "drought" events on a routine basis ("operationally") for climate analysis and monitoring and for the development of improved climate services. Brief introduction of EORC/JAXA and CPC/NOAA satellite-derived data and products available for RCCs and NMHSs in Asia-Pacific is given below.

SEMDP precipitation products produced by EORC/JAXA are based on the Global Satellite Mapping of Precipitation (GSMaP) [4]. GSMaP products are in high demand—more than 4200 users from 114 countries from around the world are registered for the GSMaP data distribution. For SEMDP users in Asia-Pacific, EORC/JAXA provides mean precipitation estimates derived from GSMaP version 6 for hourly, daily (00–23 UTC), pentad (5 days), weekly (Monday–Sunday), 10-day, and monthly precipitation with spatial resolution of 0.1°lat/lon grid box (an example of monthly precipitation for July is given in **Figure 1**). In addition, statistics for daily, pentad, and weekly extreme precipitation (90th–99th percentiles) and percentage of rainy (≥1 mm/day) days in a month is provided (examples are presented in **Figures 2** and **3**). For drought monitoring, the standardized precipitation index (SPI; 1 month, 2 months, and 3 months) for grid boxes over land with spatial resolution of 0.25°lat/lon grid box is provided.

CPC/NOAA provides SEMDP users with a similar set of products using the Climate Prediction Center morphing technique (CMORPH) satellite precipitation

**55**

**Figure 3.**

**Figure 2.**

available for SEMDP region.

*EORC/JAXA GSMaP percentage of rainy days for the month of July.*

*WMO Space-Based Weather and Climate Extremes Monitoring Demonstration Project…*

*EORC/JAXA GSMaP 90th percentile of daily precipitation for the month of July.*

estimates (see [5] for detail). In addition to the SPI, weekly normalized differential vegetation index (NDVI; **Figure 4**) and the vegetation health index (VHI) are also

*DOI: http://dx.doi.org/10.5772/intechopen.85824*

**Figure 1.** *EORC/JAXA GSMaP monthly mean of daily precipitation for the month of July.*

*WMO Space-Based Weather and Climate Extremes Monitoring Demonstration Project… DOI: http://dx.doi.org/10.5772/intechopen.85824*

**Figure 2.** *EORC/JAXA GSMaP 90th percentile of daily precipitation for the month of July.*

**Figure 3.** *EORC/JAXA GSMaP percentage of rainy days for the month of July.*

estimates (see [5] for detail). In addition to the SPI, weekly normalized differential vegetation index (NDVI; **Figure 4**) and the vegetation health index (VHI) are also available for SEMDP region.

*Rainfall - Extremes, Distribution and Properties*

Asia-Pacific is given below.

of extreme weather persists for some time, such as a season, it may be classed as an extreme climate event, especially if it yields an average or total that is itself extreme (e.g., drought or heavy rainfall over a season)." [3]. Thus, SEMDP approach to

Based on the workshop's recommendations and consequent consultations with the satellite data providers (EORC/JAXA and CPC/NOAA) and users (RCCs and NMHSs in Southeast Asia and the Pacific), SEMDP aims to satisfy users' requirements for monitoring precipitation extremes on short time scales, i.e., on pentad (5 days) to weekly up to monthly basis utilizing satellite-based products available on near real-time basis for monitoring "heavy precipitation" and "drought" events on a routine basis ("operationally") for climate analysis and monitoring and for the development of improved climate services. Brief introduction of EORC/JAXA and CPC/NOAA satellite-derived data and products available for RCCs and NMHSs in

SEMDP precipitation products produced by EORC/JAXA are based on the Global Satellite Mapping of Precipitation (GSMaP) [4]. GSMaP products are in high demand—more than 4200 users from 114 countries from around the world are registered for the GSMaP data distribution. For SEMDP users in Asia-Pacific, EORC/JAXA provides mean precipitation estimates derived from GSMaP version 6 for hourly, daily (00–23 UTC), pentad (5 days), weekly (Monday–Sunday), 10-day, and monthly precipitation with spatial resolution of 0.1°lat/lon grid box (an example of monthly precipitation for July is given in **Figure 1**). In addition, statistics for daily, pentad, and weekly extreme precipitation (90th–99th percentiles) and percentage of rainy (≥1 mm/day) days in a month is provided (examples are presented in **Figures 2** and **3**). For drought monitoring, the standardized precipitation index (SPI; 1 month, 2 months, and 3 months) for grid boxes over land with

CPC/NOAA provides SEMDP users with a similar set of products using the Climate Prediction Center morphing technique (CMORPH) satellite precipitation

spatial resolution of 0.25°lat/lon grid box is provided.

*EORC/JAXA GSMaP monthly mean of daily precipitation for the month of July.*

defining drought and heavy rainfall is based on the above definitions.

**54**

**Figure 1.**

**Figure 4.** *CPC/NOAA CMORPH weekly NDVI for 24–30 December 2018.*
