**3. Drought monitoring using SEMDP products**

In this section, case studies for drought monitoring in Australia using SEMDP products are presented. Australia is the driest continent on the Earth, apart from Antarctica. About 70% of Australia receives less than 500 mm of rain annually, which classifies those parts of the continent as arid or semiarid areas. Drought monitoring is vital for informed decision-making in agriculture, disaster risk management, water management, and other sectors.

In Australia, the Bureau of Meteorology defines drought in the affected region when the rainfall over a 3-month period is being in the lowest decile of what has been recorded for that region in the past [6]. Drought often affects Australia—rainfall observations which the Bureau of Meteorology conducts since the middle of the nineteenth century show that on average drought occurs once every 18 years; severity and duration of drought vary. The worst drought which affected Australia since the European settlement—the Millennium drought—occurred in the 2000s.

The Millennium drought affected southern and eastern regions of the continent (states of Victoria, New South Wales, Queensland, and South Australia), southwest of Western Australia, and Tasmania. The largest Australian agricultural region—the Murray-Darling basin—was severely affected, and water resources which supply cities and towns including capital cities of Melbourne, Sydney, Brisbane, Adelaide, and many other cities and towns were also severely affected.

The Millennium drought commenced with rainfall deficit in 1996–1997 and continued during very dry years in 2001–2002 (**Figure 5**); it was clear that this is the worst drought in Australia on record [7].

During the year 2006 southeastern parts of Australia had the second driest year on record [8]; agricultural region of the Murray-Darling basin was particularly severely affected by drought conditions (**Figure 6**). Drought continued to affect the Murray-Darling basin in 2007; it was already seventh consecutive year of below average rainfall for the basin. Dry and hot conditions continued to affect Australia through to early 2010.

**57**

**Figure 6.**

*rain gauge observations.*

**Figure 5.**

*Meteorology rain gauge observations.*

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

*Rainfall deciles for Australia in January 2001–December 2002 derived from the Australian Bureau of* 

The 2010–2011 La Niña event brought the Millennium drought to the end. This La Niña event was one of the strongest on records, and it resulted in recordbreaking rainfall in the Murray-Darling basin and above average rainfall over the southeast parts of the country (**Figure 7**). Significant increase in surface water storage and soil moisture due to continuing above average rainfall ended drought

*Rainfall deciles for Australia in January–December 2006 derived from the Australian Bureau of Meteorology* 

The Millennium drought was the most severe drought which affected Australia over the past few centuries. It is pertinent to examine the usefulness of space-based observations for drought monitoring over Australia; here

conditions in the southeastern parts of Australia [9].

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

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

#### **Figure 5.**

*Rainfall - Extremes, Distribution and Properties*

**3. Drought monitoring using SEMDP products**

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

management, water management, and other sectors.

and many other cities and towns were also severely affected.

worst drought in Australia on record [7].

In this section, case studies for drought monitoring in Australia using SEMDP products are presented. Australia is the driest continent on the Earth, apart from Antarctica. About 70% of Australia receives less than 500 mm of rain annually, which classifies those parts of the continent as arid or semiarid areas. Drought monitoring is vital for informed decision-making in agriculture, disaster risk

In Australia, the Bureau of Meteorology defines drought in the affected region when the rainfall over a 3-month period is being in the lowest decile of what has been recorded for that region in the past [6]. Drought often affects Australia—rainfall observations which the Bureau of Meteorology conducts since the middle of the nineteenth century show that on average drought occurs once every 18 years; severity and duration of drought vary. The worst drought which affected Australia since the European settlement—the Millennium drought—occurred in the 2000s. The Millennium drought affected southern and eastern regions of the continent (states of Victoria, New South Wales, Queensland, and South Australia), southwest of Western Australia, and Tasmania. The largest Australian agricultural region—the Murray-Darling basin—was severely affected, and water resources which supply cities and towns including capital cities of Melbourne, Sydney, Brisbane, Adelaide,

The Millennium drought commenced with rainfall deficit in 1996–1997 and continued during very dry years in 2001–2002 (**Figure 5**); it was clear that this is the

During the year 2006 southeastern parts of Australia had the second driest year on record [8]; agricultural region of the Murray-Darling basin was particularly severely affected by drought conditions (**Figure 6**). Drought continued to affect the Murray-Darling basin in 2007; it was already seventh consecutive year of below average rainfall for the basin. Dry and hot conditions continued to affect Australia

**56**

**Figure 4.**

through to early 2010.

*Rainfall deciles for Australia in January 2001–December 2002 derived from the Australian Bureau of Meteorology rain gauge observations.*

#### **Figure 6.**

*Rainfall deciles for Australia in January–December 2006 derived from the Australian Bureau of Meteorology rain gauge observations.*

The 2010–2011 La Niña event brought the Millennium drought to the end. This La Niña event was one of the strongest on records, and it resulted in recordbreaking rainfall in the Murray-Darling basin and above average rainfall over the southeast parts of the country (**Figure 7**). Significant increase in surface water storage and soil moisture due to continuing above average rainfall ended drought conditions in the southeastern parts of Australia [9].

The Millennium drought was the most severe drought which affected Australia over the past few centuries. It is pertinent to examine the usefulness of space-based observations for drought monitoring over Australia; here

#### **Figure 7.**

*Rainfall deciles for Australia in July 2010–March 2011 derived from the Australian Bureau of Meteorology rain gauge observations.*

we present a case study for the year 2007 of the Millennium drought utilizing rainfall percentile, 1-month and 3-month SPI values derived from the EORC/ JAXA GSMaP data.

The SPI is an index which is widely used for meteorological drought detection and monitoring. Positive values of the SPI correspond to precipitation above median, and negative values of the SPI correspond to precipitation below median. Drought conditions are classified when the SPI values are equal to or below −1.0. Specifically, for the SPI values −1.0 and below conditions are classified as "moderately dry," for −1.5 and below as "severely dry," and for −2.0 and below as "extremely dry."

As described above, the main agricultural region in southeastern Australia—the Murry-Darling basin—was severely affected by the Millennium drought. Examining 1-month SPI for August 2007 (**Figure 8**) and rainfall percentile (**Figure 9**) derived from EORC/JAXA GSMaP, one can find that drought-affected areas where the SPI values are less than −1.5 (i.e., "severely dry") correspond well to areas of rainfall below the 10th percentile. The detected by space-based observations droughtaffected areas are in good correspondence with areas defined as "very much below average" on rainfall decile map for August 2007 derived from the Australian Bureau of Meteorology rain gauge observations (**Figure 10**). Similarly, areas where values of 3-month SPI for July–September 2007 (**Figure 11**) are below −1.5 are in good correspondence with areas of "very much below average" rainfall on rainfall decile map (**Figure 12**).

It should be noted that space-based and in situ observations are in good agreement over the Murry-Darling basin in southeastern Australia where the density of surface-based observations is high; however, there are noticeable discrepancies between them over the central parts of the continent where the density of surfacebased observations is very low. It clearly demonstrates value of space-based rainfall estimates for drought detection and monitoring, especially for regions where rain gauge observations are limited or unavailable.

SEMDP products became available to NMHSs and RCCs in Asia-Pacific on a quasi-operational basis from December 2018, thanks to the dedicated efforts of

**59**

**Figure 9.**

**Figure 8.**

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

*SPI for Australia in August 2007 derived from the EORC/JAXA GSMaP data.*

scientists and IT experts from the EORC/JAXA and the CPC/NOAA. Here we demonstrate usefulness of available SEMDP products for operational drought monitoring in Australia using the VHI. 2018 for Australia was a year of persistent warmth (the third warmest year on record with mean temperature 1.14°C above the

*Rainfall percentiles for Australia in August 2007 derived from the EORC/JAXA GSMaP data.*

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

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

**Figure 8.** *SPI for Australia in August 2007 derived from the EORC/JAXA GSMaP data.*

**Figure 9.** *Rainfall percentiles for Australia in August 2007 derived from the EORC/JAXA GSMaP data.*

scientists and IT experts from the EORC/JAXA and the CPC/NOAA. Here we demonstrate usefulness of available SEMDP products for operational drought monitoring in Australia using the VHI. 2018 for Australia was a year of persistent warmth (the third warmest year on record with mean temperature 1.14°C above the

*Rainfall - Extremes, Distribution and Properties*

we present a case study for the year 2007 of the Millennium drought utilizing rainfall percentile, 1-month and 3-month SPI values derived from the EORC/

*Rainfall deciles for Australia in July 2010–March 2011 derived from the Australian Bureau of Meteorology rain* 

The SPI is an index which is widely used for meteorological drought detection and monitoring. Positive values of the SPI correspond to precipitation above median, and negative values of the SPI correspond to precipitation below median. Drought conditions are classified when the SPI values are equal to or below −1.0. Specifically, for the SPI values −1.0 and below conditions are classified as "moderately dry," for −1.5 and below as "severely dry," and for −2.0 and below as "extremely dry."

As described above, the main agricultural region in southeastern Australia—the Murry-Darling basin—was severely affected by the Millennium drought. Examining 1-month SPI for August 2007 (**Figure 8**) and rainfall percentile (**Figure 9**) derived from EORC/JAXA GSMaP, one can find that drought-affected areas where the SPI values are less than −1.5 (i.e., "severely dry") correspond well to areas of rainfall below the 10th percentile. The detected by space-based observations droughtaffected areas are in good correspondence with areas defined as "very much below average" on rainfall decile map for August 2007 derived from the Australian Bureau of Meteorology rain gauge observations (**Figure 10**). Similarly, areas where values of 3-month SPI for July–September 2007 (**Figure 11**) are below −1.5 are in good correspondence with areas of "very much below average" rainfall on rainfall decile

It should be noted that space-based and in situ observations are in good agreement over the Murry-Darling basin in southeastern Australia where the density of surface-based observations is high; however, there are noticeable discrepancies between them over the central parts of the continent where the density of surfacebased observations is very low. It clearly demonstrates value of space-based rainfall estimates for drought detection and monitoring, especially for regions where rain

SEMDP products became available to NMHSs and RCCs in Asia-Pacific on a quasi-operational basis from December 2018, thanks to the dedicated efforts of

**58**

JAXA GSMaP data.

**Figure 7.**

*gauge observations.*

map (**Figure 12**).

gauge observations are limited or unavailable.

#### **Figure 10.**

*Rainfall deciles for Australia in August 2007 derived from the Australian Bureau of Meteorology rain gauge observations.*

**Figure 11.** *SPI for Australia for 3 months (July–September 2007) derived from the EORC/JAXA GSMaP data.*

1961–1990 average) and protracted drought (average rainfall was 412.8 mm which is 11% below the 1961–1990 average of 465 mm) [10]. Annual rainfall was very low ("very much below average" and "lowest on record") over the southeastern parts of the country and above average in the area between the northwest and southeast of Western Australia (**Figure 13**). Rainfall was particularly low over the southeast from April; September was record-dry. Dry conditions had an impact on vegetation which could be estimated by the vegetation health index.

**61**

**Figure 13.**

*rain gauge observations.*

**Figure 12.**

*gauge observations.*

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

The VHI is computed using observations from Advanced Very High Resolution Radiometer (AVHRR) instrument onboard the NOAA polar orbiting satellites in the visible, infrared, and near-infrared bands and used to identify stress on vegetation related to drought [11]. Maps of the VHI for the last week of September 2017 (above average rainfall for Australia was observed in that year) and the last week of September 2018 are presented in **Figure 14** demonstrating difference between relatively healthy vegetation over Australia in September 2017 (**Figure 14a**) and stressed

*Rainfall deciles for Australia in January–December 2018 derived from the Australian Bureau of Meteorology* 

*Rainfall deciles for Australia in July–September 2007 derived from the Australian Bureau of Meteorology rain* 

vegetation in September 2018 (**Figure 14b**) due to impact of dry conditions.

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

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

#### **Figure 12.**

*Rainfall - Extremes, Distribution and Properties*

**60**

**Figure 11.**

**Figure 10.**

*observations.*

1961–1990 average) and protracted drought (average rainfall was 412.8 mm which is 11% below the 1961–1990 average of 465 mm) [10]. Annual rainfall was very low ("very much below average" and "lowest on record") over the southeastern parts of the country and above average in the area between the northwest and southeast of Western Australia (**Figure 13**). Rainfall was particularly low over the southeast from April; September was record-dry. Dry conditions had an impact on vegetation

*SPI for Australia for 3 months (July–September 2007) derived from the EORC/JAXA GSMaP data.*

*Rainfall deciles for Australia in August 2007 derived from the Australian Bureau of Meteorology rain gauge* 

which could be estimated by the vegetation health index.

*Rainfall deciles for Australia in July–September 2007 derived from the Australian Bureau of Meteorology rain gauge observations.*

#### **Figure 13.**

*Rainfall deciles for Australia in January–December 2018 derived from the Australian Bureau of Meteorology rain gauge observations.*

The VHI is computed using observations from Advanced Very High Resolution Radiometer (AVHRR) instrument onboard the NOAA polar orbiting satellites in the visible, infrared, and near-infrared bands and used to identify stress on vegetation related to drought [11]. Maps of the VHI for the last week of September 2017 (above average rainfall for Australia was observed in that year) and the last week of September 2018 are presented in **Figure 14** demonstrating difference between relatively healthy vegetation over Australia in September 2017 (**Figure 14a**) and stressed vegetation in September 2018 (**Figure 14b**) due to impact of dry conditions.

**Figure 14.** *CPC/NOAA VHI for (a) 24–30 September 2017 and (b) 24–30 September 2018.*

### **4. Heavy precipitation monitoring using SEMDP products**

In this section, case studies of heavy precipitation over Australia in December 2010 and Thailand and Peninsular Malaysia in November–December 2014 which caused widespread flooding are presented.

An "extreme rainfall" is defined when a mean rainfall for a specified period is higher than a certain percentile threshold, e.g., 90th–99th percentile (**Figure 15**).

Extreme rainfall associated with La Niña event has been observed over Australia in 2010 and 2011. In 2011, Australia experienced its third wettest year since national rainfall records began in 1900 [12]. Averaged across Australia, both years experienced rainfall well above average—690 mm (225 mm above the long-term average of 465 mm) in 2010 [9] and 699 mm (234 mm above the long-term average of 465 mm) in 2011 [12].

**63**

**Figure 15.**

Peninsular Malaysia.

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

The 2010–2011 La Niña event was one of the strongest on record, comparable in strength with the La Niña events of 1917–1918, 1955–1956, and 1975–1976, and it has significant impact on Australian rainfall. La Niña is typically associated with increased rainfall in northern and eastern Australia. During the 2010–2011 La Niña, most of the mainland Australia experienced significantly higher than average rainfall over the 9 months from July 2010 to March 2011 (**Figure 7**). A number of new Australian rainfall records were set: wettest September, December, and March on record and second wettest October and February. Extreme rainfall associated with La Niña event has been observed over parts of western and eastern Australia in December 2010 (**Figure 16**). The record-breaking rainfall during the 2010–2011 La Niña led to widespread flooding in many regions between September 2010 and March 2011 including southeast Queensland, large areas of northern and western Victoria, New South Wales, northwestern Western Australia, and eastern Tasmania

*EORC/JAXA GSMaP rainfall percentile over SEMDP domain for December 2010.*

In **Figure 17**, EORC/JAXA GSMaP rainfall percentile over Australia for December 2010 is presented. An area above 95th percentile derived from GSMaP approximately corresponds to an area of rainfall deciles "very much above average" as derived from rain gauge observations by the Australian Bureau of Meteorology (**Figure 16**); it demonstrates that this extreme rainfall event was well detected using GSMaP.

The second case study examines episodes of heavy precipitation over Thailand and Peninsular Malaysia in November–December 2014 [13]. In November 2014, an episode of heavy rainfall and subsequent flooding in the coastal area of northeastern Peninsular Malaysia occurred from 13 to 20 November 2014. In the second half of December 2014, two episodes of heavy precipitation caused widespread flooding in south of Thailand, Kelantan, Terengganu, and Pahang and on the east coast of

Accumulated rainfall over Peninsular Malaysia in November and December 2014 derived from GSMaP is presented in **Figure 18a** and **b**, respectively. Time series of daily precipitation for November–December 2014 averaged over land in

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

that were subject to significant flooding.

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

**Figure 15.** *EORC/JAXA GSMaP rainfall percentile over SEMDP domain for December 2010.*

The 2010–2011 La Niña event was one of the strongest on record, comparable in strength with the La Niña events of 1917–1918, 1955–1956, and 1975–1976, and it has significant impact on Australian rainfall. La Niña is typically associated with increased rainfall in northern and eastern Australia. During the 2010–2011 La Niña, most of the mainland Australia experienced significantly higher than average rainfall over the 9 months from July 2010 to March 2011 (**Figure 7**). A number of new Australian rainfall records were set: wettest September, December, and March on record and second wettest October and February. Extreme rainfall associated with La Niña event has been observed over parts of western and eastern Australia in December 2010 (**Figure 16**). The record-breaking rainfall during the 2010–2011 La Niña led to widespread flooding in many regions between September 2010 and March 2011 including southeast Queensland, large areas of northern and western Victoria, New South Wales, northwestern Western Australia, and eastern Tasmania that were subject to significant flooding.

In **Figure 17**, EORC/JAXA GSMaP rainfall percentile over Australia for December 2010 is presented. An area above 95th percentile derived from GSMaP approximately corresponds to an area of rainfall deciles "very much above average" as derived from rain gauge observations by the Australian Bureau of Meteorology (**Figure 16**); it demonstrates that this extreme rainfall event was well detected using GSMaP.

The second case study examines episodes of heavy precipitation over Thailand and Peninsular Malaysia in November–December 2014 [13]. In November 2014, an episode of heavy rainfall and subsequent flooding in the coastal area of northeastern Peninsular Malaysia occurred from 13 to 20 November 2014. In the second half of December 2014, two episodes of heavy precipitation caused widespread flooding in south of Thailand, Kelantan, Terengganu, and Pahang and on the east coast of Peninsular Malaysia.

Accumulated rainfall over Peninsular Malaysia in November and December 2014 derived from GSMaP is presented in **Figure 18a** and **b**, respectively. Time series of daily precipitation for November–December 2014 averaged over land in

*Rainfall - Extremes, Distribution and Properties*

**4. Heavy precipitation monitoring using SEMDP products**

*CPC/NOAA VHI for (a) 24–30 September 2017 and (b) 24–30 September 2018.*

caused widespread flooding are presented.

In this section, case studies of heavy precipitation over Australia in December 2010 and Thailand and Peninsular Malaysia in November–December 2014 which

An "extreme rainfall" is defined when a mean rainfall for a specified period is higher than a certain percentile threshold, e.g., 90th–99th percentile (**Figure 15**). Extreme rainfall associated with La Niña event has been observed over Australia in 2010 and 2011. In 2011, Australia experienced its third wettest year since national rainfall records began in 1900 [12]. Averaged across Australia, both years experienced rainfall well above average—690 mm (225 mm above the long-term average of 465 mm) in 2010 [9] and 699 mm (234 mm above the long-term average of 465 mm) in

**62**

2011 [12].

**Figure 14.**

#### **Figure 16.**

*Australian rainfall deciles for December 2010 derived from the Australian Bureau of Meteorology rain gauge observations.*

**Figure 17.** *EORC/JAXA GSMaP rainfall percentile over Australia for December 2010.*

the area from 100°E to 105°E; EQ to 8°N is presented in **Figure 19**. In November 2014, accumulated rainfall exceeded 1000 mm along the east coast of Peninsular Malaysia. The first episode of persistent heavy rainfall occurred from 13 to 20 November. In December 2014, areas of monthly total rainfall above 500 mm expand over the southern part of Thailand and the most of Malaysia. Particularly heavy

**65**

**Figure 18.**

**Figure 19.**

*2014.*

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

precipitation occurred over the eastern parts of the Peninsular with monthly total rainfall estimated at 1500 mm and above. Second episode of long-lasting heavy rainfall occurred from 14 to 30 December. Results obtained from space-based

*EORC/JAXA GSMaP time series of daily precipitation for November–December 2014 averaged over land in* 

*EORC/JAXA GSMaP total precipitation over Peninsular Malaysia in (a) November 2014 and (b) December* 

observations are in correspondence with results presented in [13].

*the area from 100°E to 105°E; EQ to 8°N; solid black line represents 18-year mean.*

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

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

#### **Figure 18.**

*Rainfall - Extremes, Distribution and Properties*

**64**

**Figure 17.**

**Figure 16.**

*observations.*

the area from 100°E to 105°E; EQ to 8°N is presented in **Figure 19**. In November 2014, accumulated rainfall exceeded 1000 mm along the east coast of Peninsular Malaysia. The first episode of persistent heavy rainfall occurred from 13 to 20 November. In December 2014, areas of monthly total rainfall above 500 mm expand over the southern part of Thailand and the most of Malaysia. Particularly heavy

*EORC/JAXA GSMaP rainfall percentile over Australia for December 2010.*

*Australian rainfall deciles for December 2010 derived from the Australian Bureau of Meteorology rain gauge* 

*EORC/JAXA GSMaP total precipitation over Peninsular Malaysia in (a) November 2014 and (b) December 2014.*

#### **Figure 19.**

*EORC/JAXA GSMaP time series of daily precipitation for November–December 2014 averaged over land in the area from 100°E to 105°E; EQ to 8°N; solid black line represents 18-year mean.*

precipitation occurred over the eastern parts of the Peninsular with monthly total rainfall estimated at 1500 mm and above. Second episode of long-lasting heavy rainfall occurred from 14 to 30 December. Results obtained from space-based observations are in correspondence with results presented in [13].

**Figure 20.**

*Time series of daily precipitation for November–December 2014 averaged over land in the area from 100°E to 105°E; EQ to 8°N derived from (a) EORC/JAXA GSMaP (red line) and (b) CPC GAG (blue line).*

**Figure 21.**

*Scatter plot of (a) pentad (5-day) and (b) 10-day precipitation averaged over land in the area from 100°E to 105°E; EQ to 8°N for November–December 2014 derived from the EORC/JAXA GSMaP versus the CPC GAG.*

**67**

**Figure 22.**

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

In **Figure 20**, time series of daily precipitation derived from the EORC/JAXA GSMaP data and in situ observations derived from the CPC rain gauge analysis (CPC GAG) for November–December 2014 averaged over land in the area from 100°E to 105°E; EQ to 8°N are presented. All episodes of heavy precipitation in November and December 2014 are detected well by space-based observations. In general, there is a good correspondence between the EORC/JAXA GSMaP space-

*EORC/JAXA GSMaP (a) daily precipitation over the Peninsular Malaysia on 18 November 2014, (b) ratio of* 

based rainfall estimates and the CPC GAG rain gauge analysis.

*the daily precipitation to 18-year climatology, and (c) daily percentile.*

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

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

#### **Figure 22.**

*Rainfall - Extremes, Distribution and Properties*

**Figure 20.**

**66**

**Figure 21.**

*Scatter plot of (a) pentad (5-day) and (b) 10-day precipitation averaged over land in the area from 100°E to 105°E; EQ to 8°N for November–December 2014 derived from the EORC/JAXA GSMaP versus the CPC GAG.*

*Time series of daily precipitation for November–December 2014 averaged over land in the area from 100°E to 105°E; EQ to 8°N derived from (a) EORC/JAXA GSMaP (red line) and (b) CPC GAG (blue line).*

*EORC/JAXA GSMaP (a) daily precipitation over the Peninsular Malaysia on 18 November 2014, (b) ratio of the daily precipitation to 18-year climatology, and (c) daily percentile.*

In **Figure 20**, time series of daily precipitation derived from the EORC/JAXA GSMaP data and in situ observations derived from the CPC rain gauge analysis (CPC GAG) for November–December 2014 averaged over land in the area from 100°E to 105°E; EQ to 8°N are presented. All episodes of heavy precipitation in November and December 2014 are detected well by space-based observations. In general, there is a good correspondence between the EORC/JAXA GSMaP spacebased rainfall estimates and the CPC GAG rain gauge analysis.

Scatter plot—comparison between CPC GAG and GSMaP satellite precipitation estimates—is presented in **Figure 21**; results for pentad (5-day) and 10-day mean precipitation (mm/day) are plotted on the top and bottom panels, respectively. Only data pairs of precipitation over a 0.25<sup>o</sup> lat/lon grid box with at least one reporting rain gauge are included in the comparison. The correlation coefficients of pentad and 10 days are 0.84 and 0.88, respectively, indicating good agreement between space-based estimates and surface-based rain gauge observations.

An example of detecting daily heavy precipitation using GSMaP data is presented in **Figure 22**. Precipitation was particularly heavy across the eastern coast of the peninsular with daily totals above 200 mm (**Figure 22a**); this exceeded 18-year climatology more than five times (**Figure 22b**). In Narathiwat province of Thailand and Kelantan and Terengganu provinces of Malaysia, the daily precipitation was higher than the 99th percentile (**Figure 22c**) causing widespread flood in the affected areas.

In summary, presented case studies of detecting extreme precipitation in Australia, Thailand, and the Peninsular Malaysia demonstrate that space-based observations provide valuable information for monitoring heavy rainfall.
