Impact of next generation satellites: Himawari-8

Impact of next generation satellites: Himawari-8 JapanMeteorological Agency (JMA) Tomoyuki Inazawa, Toshiyuki Kitajima* Meteorological Research Institute(MRI) Hiroshi Ishimoto, Masahiro Hayashi Tokyo VAAC Toshiyuki Sakurai, Kazuki Ito Japan Meteorological Agency

Contents VAAC • Current status of Himawari-8 product • GEOCAT/VOLCAT performance assessment • Differences of the brightness temperature difference (BTD) between Himawari-8 and MTSAT-2 • Future status of Himawari-8 product • Current activities of the Meteorological Research Institute (MRI) • Aerosol product of Himawari-8 MRI, JMA Japan Meteorological Agency

Evaluation of GEOCAT/VOLCAT product - from the view point of Tokyo VAAC operations • Tokyo VAAC started trial usage of GEOCAT/VOLCAT Volcanic Ash (VA) product as reference. • In order to understand its characteristic and effectiveness, Tokyo VAAC conducted case reviews. SATAID –SATELLITE ANALYSIS TOOL Height of ash cloud Japan Meteorological Agency

Summary of Case reviews by Tokyo VAAC • GEOCAT/VOLCAT VA product, so far, has not shown enough detection capability for operational use. Small eruption events are especially overlooked.Additionally, some volcanic ash clouds are detected only for a short period and becomes non-detectable on the next image. • Estimated volcanic ash cloud heights tend to be higher than real heights. Japan Meteorological Agency

Detection accuracy of the VA product • As for eruption events in June, 2017 (67 events in the right table), we investigated whether VA was detected by the VA products. Eruption events in June, 2017 Detections of VA product Japan Meteorological Agency

Height derived by the VA product • At the eruption of Sheveluch volcano occurred on 8 August, 2017, the volcanic ash was detected by the VA product. • The height was estimated to be 40,000ft by local volcano observatory, but the height of the VA product was 48000 ft. • The height of the VA product disappeared several times. Japan Meteorological Agency

Issues of GEOCAT/VOLCAT for VAAC’s operations Rapid detection of volcanic ash and accurate estimation of ash top height are important tasks in VAAC operations. • We need to know the limit of VA detection by GEOCAT/VOLCAT. • We need to know the characteristics of VA height derived by GEOCAT/VOLCAT. Tokyo VAAC have conducted further investigations since August in 2018 for the VAAC’s operations. The evaluation is performed monthly. Japan Meteorological Agency

Contents VAAC • Current status of Himawari-8 product • GEOCAT/VOLCAT performance assessment • Differences of the brightness temperature difference (BTD) between Himawari-8 and MTSAT-2 • Future status of Himawari-8 product • Current activities of the Meteorological Research Institute (MRI) of JMA • Aerosol product of Himawari-8 MRI, JMA Japan Meteorological Agency

BTD BTD Comparison of BTDZhupanovsky in Kamchatka Clearly! ??? 14 July 2015 2300UTC MTSAT-2 brightness temperature difference (BTD) 10.8 – 12.0μm 14 July 2015 2240UTC Himawari-8 brightness temperature difference (BTD) 10.4 – 12.4μm The period of both satellites are available: from May 2015 to Mar. 2016 Black: BTDvalue > 0 White: BTD value < 0 Grey: BTD value ≒ 0 Japan Meteorological Agency

Black -> -BTD Infrared BTD Characteristic of Himawari-8 BTDSheveluch in Kamchatka Low level Low level FL360 FL360 Direction of volcanic ash movement: Northeastward (FL360) East-west direction halfway (low level altitude from IR image) 10 January 2018 00UTC Himawari-8 infrared image (10.4 μm) 10 January 2018 00UTC Himawari-8 BTD image (10.4 - 12.4 μm) Black: higher TBB value White: lower TBB value Black: BTDvalue > 0 White: BTD value < 0 Grey: BTD value ≒ 0 Positive BTD value appears more often than MTSAT-2? Japan Meteorological Agency

BTD simulation by two satellites reff τ TBD IR1-IR2 [K] TBD B13-B15 [K] TBB B13 [K] TBB IR1 [K] BTD(10.4-12.4μm) simulation Himawari-8 BTD(10.8-12.0μm) simulation MTSAT-2 Assumption -> volcanic ash at 15km by andesite in the tropical Red line: effective particle radius refｆ Black dash line: optical depth τ Japan Meteorological Agency

Summary of comparing the BTDs of the 2 satellites • From the comparison research, we confirmed that Himawari-8 data contribute to further improvement of the monitoring and detection capability of volcanic ash clouds as compared to MTSAT-2. • Himawari-8 has different characteristics from MTSAT-2. For example, BTD value of volcanic ash clouds can be positive more than MTSAT-2. • Although Himawari-8 provides new observation data, such as new types of composite imagery and products, we need further research on their characteristics to utilize such data more effectively and efficiently. Japan Meteorological Agency

Hyperspectral IR sounder (AIRS, IASI, CrIS, ... etc.) GEO Imager Himawari 8/9 AHI estimation of ash material (Refractive Index: RI) Himawari VOLCAT ash cloud height, effective radius, mass loading LUT of ash optical properties for VOLCAT Zhupanovsky (Kamchatka) 2016.2.12 23:50 UTC =0.3 LUT Determine the best fit RI model for the volcano Mass loading (ton/km2) default LUT (andesite model) Japan Meteorological Agency

Himawari-8 Aerosol Product AOD Current product After 2018.12 (The new algorithm was developed by JAXA) • JMA is providing an aerosol product using visible and near infrared bands of AHI. • This product contains Aerosol Optical Depth (AOD) and Angstrom Exponent. • The area covered with the product is only East Asia now(left figure), because this product is mainly developed to monitor the Asian dusts. • We are going to update the algorithm of this product in December 2018. After updating, the product will cover the full-disk image of Himawari-8/9 (right figure). Japan Meteorological Agency

Thank you for your attention! Japan Meteorological Agency

Impact of next generation satellites: Himawari-8