Subject: Administrative: Status of GOES-16 Cloud Optical Depth L2 data, --001a11402b0e06474e056634ec4f Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable *Topic: Status of GOES-16 Cloud Optical Depth L2 DataDate/Time Issued: February 27, 2018 1725 UTCProduct(s) or Data Impacted: GOES-16 Cloud Optical Depth L2 DataDate/Time of Initial Impact: February 22, 2018 at 2215 UTCDate/Time of Expected End: N/ALength of Event: N/A Details/Specifics of Change: The GOES-R Peer/Stakeholder Product Validation Review (PS-PVR) for ABI L2+ Cloud Optical and Microphysical Properties (COMP) Provisional Maturity was held on February 22, 2018. As a result of this review, the PS-PVR panel recommended that the ABI Cloud Optical Depth (COD) product be declared Provisional. This was accomplished at approximately 2215 UTC on February 22, 2018. At the same time, the PS-PVR panel recommended that the ABI Cloud Particle Size (CPS) transition to Provisional be delayed. The ABI L2+ Cloud Optical Depth product assigns each earth-navigated cloudy pixel a value. Non-cloudy pixels or those for which the retrieval was not successful receive fill values. For pixels with solar zenith angles less than or equal to 82=C2=BA (daytime), valid COD values can range from 0.5 to= 50.0 while pixels with solar zenith angles greater than 82=C2=BA (nighttime) wil= l have valid COD values ranging from 1.0 to 8.0. COD values outside those ranges are considered less accurate and their usage is not recommended. Similarly, pixels with solar zenith angles between 65=C2=BA and 90=C2=BA sh= ould be considered less accurate and do not meet the product specifications. Daytime COD values are derived using visible and near-infrared channels while the nighttime COD values are derived from near-infrared and infrared channels. The COD product is generated for every ABI Full Disk (FD) of the Earth and Continental United States (CONUS) region. Provisional maturity, by definition, means that: - Validation activities are ongoing and the general research community is now encouraged to participate;- Severe algorithm anomalies are identified and under analysis. Solutions to anomalies are in development and testing.- Incremental product improvements may still be occurring;- Product performance has been demonstrated through analysis of a small number of independent measurements obtained from select locations, periods, and associated ground truth or field campaign efforts;- Product analysis is sufficient to communicate product performance to users relative to expectations (Performance Baseline);- Documentation of product performance exists that includes recommended remediation strategies for all anomalies and weaknesses. Any algorithm changes associated with severe anomalies have been documented, implemented, tested, and shared with the user community;- Testing has been fully documented; and- Product is ready for operational use and for use in comprehensive cal/val activities and product optimization. Provisional users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized. Persons desiring to use the GOES-16 ABI Provisional maturity Cloud Optical Depth products for any reason, including but not limited to scientific and technical investigations, are encouraged to consult the NOAA algorithm working group (AWG) scientists for feasibility of the planned applications. This product is sensitive to upstream processing, such as the quality of the calibration, navigation and the other cloud algorithms (mask, type/phase, height). Known issues at the Provisional validation stage include: 1. Missing values occur randomly due to upstream L1b issues;2. The upstream cloud algorithms can lead to clear regions being assigned a cloud optical depth or cloudy regions being classified as clear sky, hence receiving no COD value;3. Issues in the NWP products can cause upstream cloud algorithms to misidentify cloudy pixels as non-cloudy so COD retrievals are not performed;4. Optically thin cirrus clouds are sometimes misclassified as liquid water, supercooled liquid water or mixed phase, which impacts COD values;5. The risk of misclassifying liquid water clouds as ice is greatest in regions with broken cumulus clouds, hence COD values are impacted in those situations; 6. The ability to correctly identify clouds that have both liquid water and ice within the portion of the cloud influencing the measured ABI radiances is limited.7. Any past or future calibration changes to channels involved in the day or night COD retrievals can impact the COD retrievals.8. Due to several reasons the CPS won=E2=80=99t be transitioned to Provisional at this moment. It is likely t= hat retrieval will be adjusted, which may be also have an impact to COD product. Contact for further information: OSPO User Services at SPSD.UserServices@noaa.gov Contacts for specific information on the ABI L2 COD product:Jaime Daniels jaime.daniels@noaa.gov Wayne MacKenzie wayne.mackenzie@noaa.gov Andrew Heidinger andrew.heidinger@noaa.gov * <301-286-3647> --001a11402b0e06474e056634ec4f Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Topic: = Status of GOES-16 Cloud Optical Depth L2 Data

Date/Time Issued: February 27, 2018 1725 UTC

Product(s) or Data= Impacted: GOES= -16 Cloud Optical Depth L2 Data

Date/Time of Initia= l Impact: Febru= ary 22, 2018 at 2215 UTC

Date/Time of Expected End<= /span>: =C2=A0N/A

Length of Event: =C2=A0N/A

=C2=A0

Details/Specifics of Change: The GOES-R Peer/Stakeholder Product V= alidation Review (PS-PVR) for ABI L2+ Cloud Optical and Microphysical Prope= rties (COMP) Provisional Maturity was held on February 22, 2018. As a resul= t of this review, the PS-PVR panel recommended that the ABI Cloud Optical D= epth (COD) product be declared Provisional. This was accomplished at approx= imately 2215 UTC on February 22, 2018. At the same time, the PS-PVR panel r= ecommended that the ABI Cloud Particle Size (CPS) transition to Provisional= be delayed.

=C2=A0

The ABI L2+ Cloud Optical Depth product assigns each e= arth-navigated cloudy pixel a value. Non-cloudy pixels or those for which t= he retrieval was not successful receive fill values. For pixels with solar = zenith angles less than or equal to 82=C2=BA (daytime), valid COD values ca= n range from 0.5 to 50.0 while pixels with solar zenith angles greater than= 82=C2=BA (nighttime) will have valid COD values ranging from 1.0 to 8.0. C= OD values outside those ranges are considered less accurate and their usage= is not recommended. Similarly, pixels with solar zenith angles between 65= =C2=BA and 90=C2=BA should be considered less accurate and do not meet the = product specifications. Daytime COD values are derived using visible and ne= ar-infrared channels while the nighttime COD values are derived from near-i= nfrared and infrared channels. The COD product is generated for every ABI F= ull Disk (FD) of the Earth and Continental United States (CONUS) region.

=C2=A0

Provisional maturity, by definition, means tha= t:

  • Validation activities are ongoing and the general research community is no= w encouraged to participate;

  • Severe algorith= m anomalies are identified and under analysis. Solutions to anomalies are i= n development and testing.

  • Incremental produ= ct improvements may still be occurring;

  • Prod= uct performance has been demonstrated through analysis of a small number of= independent measurements obtained from select locations, periods, and asso= ciated ground truth or field campaign efforts;

  • Product analysis is sufficient to communicate product performance to use= rs relative to expectations (Performance Baseline);

  • Documentation of product performance exists that includes recommen= ded remediation strategies for all anomalies and weaknesses. Any algorithm = changes associated with severe anomalies have been documented, implemented,= tested, and shared with the user community;

  • Testing has been fully documented; and

  • Prod= uct is ready for operational use and for use in comprehensive cal/val activ= ities and product optimization.

=C2=A0

Provisional users bear a= ll responsibility for inspecting the data prior to use and for the manner i= n which the data are utilized. Persons desiring to use the GOES-16 ABI Prov= isional maturity Cloud Optical Depth products for any reason, including but= not limited to scientific and technical investigations, are encouraged to = consult the NOAA algorithm working group (AWG) scientists for feasibility o= f the planned applications. This product is sensitive to upstream processin= g, such as the quality of the calibration, navigation and the other cloud algorithms (ma= sk, type/phase, height).

=C2=A0

<= span style=3D"font-family:Arial;color:rgb(34,34,34);background-color:transp= arent;font-weight:400;font-style:normal;font-variant:normal;text-decoration= :none;vertical-align:baseline;white-space:pre-wrap">Known issues at the Pro= visional validation stage include:

  1. Missing values occur randomly due to ups= tream L1b issues;

  2. The upstream cloud algor= ithms can lead to clear regions being assigned a cloud optical depth or clo= udy regions being classified as clear sky, hence receiving no COD value;

  3. Issues in the NWP products can cause upstrea= m cloud algorithms to misidentify cloudy pixels as =C2=A0non-cloudy so COD = retrievals are not performed;

  4. Optically th= in cirrus clouds are sometimes misclassified as liquid water, supercooled l= iquid water or mixed phase, which impacts COD values;

  5. The risk of misclassifying liquid water clouds as ice is greate= st in regions with broken cumulus clouds, hence COD values are impacted in = those situations; =C2=A0

  6. The ability to co= rrectly identify clouds that have both liquid water and ice within the port= ion of the cloud influencing the measured ABI radiances is limited.<= /p>

  7. Any past or future calibration changes to channel= s involved in the day or night COD retrievals can impact the COD retrievals= .

  8. Due to several reasons the CPS won=E2=80= =99t be transitioned to Provisional at this moment. It is likely that retri= eval will be adjusted, which may be also have an impact to COD product.

Contact for further = information: OSPO User Services at SPSD.UserServices@noaa.gov

Contacts for specific information on the ABI L2 COD product:

Jaime Daniels jaime.daniels@noaa.gov

Wayne Ma= cKenzie w= ayne.mackenzie@noaa.gov

<= span style=3D"font-family:Arial;color:rgb(34,34,34);background-color:transp= arent;font-weight:400;font-style:normal;font-variant:normal;text-decoration= :none;vertical-align:baseline;white-space:pre-wrap">Andrew Heidinger andrew.heiding= er@noaa.gov



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